The Pennsylvanian-early Permian Bird Spring carbonate shelf, Southeastern California: fusulinid biostratigraphy, paleogeographic evolution, and tectonic implications

Special Paper 429

. . THE GEOLOGICAL SOCIETY OF AMERICA® •

The Pennsylvanian-Early Pern1ian Bird Spring Carbonate Shelf, Southeastern California: Fusulinid Biostratigraphy, Paleogeographic Evolution, and Tectonic ln1plications

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf, Southeastern California: Fusulinid Biostratigraphy, Paleogeographic Evolution, and Tectonic Implications

Calvin H. Stevens Department of Geology San Jose State University San Jose, California 95192 USA Paul Stone U.S. Geological Survey 345 Middlefield Road Menlo Park, California 94025 USA

Special Paper 429 3300 Penrose Place, P.O. Box 9140

Boulder, Colorado 80301-9140 USA

2007

Copyright © 2007, The Geological Society of America, Inc. (GSA). All rights reserved. GSA grants permission to individual scientists to make unlimited photocopies of one or more items from this volume for noncommercial purposes advancing science or education, including classroom use. For permission to make photocopies of any item in this volume for other noncommercial, nonprofit purposes, contact the Geological Society of America. Written permission is required from GSA for all other forms of capture or reproduction of any item in the volume including, but not limited to, all types of electronic or digital scanning or other digital or manual transformation of articles or any portion thereof, such as abstracts, into computer-readable and/or transmittable form for personal or corporate use, either noncommercial or commercial, for-profit or otherwise. Send permission requests to GSA Copyright Permissions, 3300 Penrose Place, P.O. Box 9140, Boulder, Colorado 80301-9140, USA. Copyright is not claimed on any material prepared wholly by government employees within the scope of their employment. Published by The Geological Society of America, Inc. 3300 Penrose Place, P.O. Box 9140, Boulder, Colorado 80301-9140, USA www.geosociety.org Printed in U.S.A. GSA Books Science Editor: Abhijit Basu Library of Congress Cataloging-in-Publication Data The Pennsylvanian-early Permian Bird Spring carbonate shelf, Southeastern California : fusulinid biostratigraphy, paleogeographic evolution, and tectonic implications / Calvin H. Stevens, Paul Stone. p. cm. — (Special paper ; 429) Includes bibliographical references. ISBN 978-0-8137-2429-4 (pbk.) 1. Fusulinida—California, Southern. 2. Stratigraphic correlation— California, Southern. 3. Geology, Stratigraphic—Pennsylvanian. 4. Geology, Stratigraphic—Permian. 5. Geology, Structural—California, Southern. I. Stevens, Calvin H. II. Stone, Paul, 1947–. QE772.P42 2007 551.7’5209794—dc22 2007007000 Cover: View north toward Striped Butte in Butte Valley, southern Panamint Range, Death Valley National Park, California, showing steeply dipping to overturned, well-bedded limestone of the Pennsylvanian and Early Permian Bird Spring Formation. The almost complete section exposed here is about 1 km thick and extends from the Lower Pennsylvanian at the stratigraphic base (left) to Lower Permian at the top. Fusulinids and colonial corals indicating a shelf depositional environment are abundant in the Upper Pennsylvanian to Lower Permian part of the section.

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Contents Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Chronostratigraphic Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Paleogeographic Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Stratigraphic Framework. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Previous Studies of Fusulinids in Southeastern California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Fusulinid Sample Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Fusulinid Faunas and Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Fusulinid Zone 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Fusulinid Zone 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Fusulinid Zone 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Fusulinid Zone 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Fusulinid Zone 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Fusulinid Zone 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Correlations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Fusulinid Zone 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Fusulinid Zone 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Fusulinid Zone 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Fusulinid Zone 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Fusulinid Zone 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Fusulinid Zone 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Comparison of Bird Spring Shelf and Keeler Basin Fusulinid Faunas. . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Comparison of Bird Spring Shelf and Darwin Basin Fusulinid Faunas . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Interpretations and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 General Paleoenvironmental Significance of Fusulinids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Fusulinid Distribution and Sedimentation Patterns on the Bird Spring Shelf . . . . . . . . . . . . . . . . . . . 19 Possible Effects of Eustatic Sea-Level Fluctuations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Regional Paleogeographic Evolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Tectonic Interpretations and Timing of the Last Chance Thrust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Tectonic Correlations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Systematic Paleontology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Fusulinid Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 iii

iv

Contents

Appendix 1. List of Fusulinid Samples with General Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Appendix 2. Descriptions of Outcrop Areas and Fusulinid Localities . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Ship Mountains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Providence Mountains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Old Dad Mountain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Cowhole Mountain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Warm Spring Canyon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Striped Butte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Panamint Butte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Appendix 3. Locality Information for Figured Specimens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

The Geological Society of America Special Paper 429 2007

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf, Southeastern California: Fusulinid Biostratigraphy, Paleogeographic Evolution, and Tectonic Implications Calvin H. Stevens* Department of Geology, San Jose State University, San Jose, California 95192, USA Paul Stone† U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA

ABSTRACT The Bird Spring Shelf in southeastern California, along with coeval turbidite basins to the west, records a complex history of late Paleozoic sedimentation, sea-level changes, and deformation along the western North American continental margin. We herein establish detailed correlations between deposits of the shelf and the flanking basins, which we then use to reconstruct the depositional history, paleogeography, and deformational history, including Early Permian emplacement of the regionally significant Last Chance allochthon. These correlations are based on fusulinid faunas, which are numerous both on the shelf and in the adjoining basins. Study of 69 fusulinid species representing all major fusulinid-bearing Pennsylvanian and Lower Permian limestone outcrops of the Bird Spring Shelf in southeastern California, including ten new species of the genera Triticites, Leptotriticites, Stewartina, Pseudochusenella, and Cuniculinella, forms the basis for our correlations. We group these species into six fusulinid zones that we correlate with fusulinid-bearing strata in east-central and southern Nevada, Kansas, and West Texas, and we propose some regional correlations not previously suggested. In addition, we utilize recent conodont data from these areas to correlate our Early Permian fusulinid zones with the standard Global Permian Stages, strengthening their chronostratigraphic value. Our detailed correlations between the fusulinid-bearing rocks of the Bird Spring Shelf and deep-water deposits to the northwest reveal relationships between the history of shelf sedimentation and evolution of basins closer to the continental margin. In Virgilian to early Asselian (early Wolfcampian) time (Fusulinid Zones 1 and 2), the Bird Spring Shelf was flanked on the west by the deep-water Keeler Basin in which calcareous turbidites derived from the shelf were deposited. In early Sakmarian (early middle Wolfcampian) time (Fusulinid Zone 3), the Keeler Basin deposits were uplifted and transported eastward on the Last Chance thrust. By middle Sakmarian

*[email protected] † [email protected] Stevens, C.H., and Stone, P., 2007, The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf, Southeastern California: Fusulinid Biostratigraphy, Paleogeographic Evolution, and Tectonic Implications: Geological Society of America Special Paper 429, 82 p., doi: 10.1130/2007.2429. For permission to copy, contact [email protected]. ©2007 The Geological Society of America. All rights reserved.

1

2

C.H. Stevens and P. Stone (middle middle Wolfcampian) time (within Fusulinid Zone 4), emplacement of the Last Chance allochthon was complete, and subsidence caused by thrust loading had resulted in development of a new turbidite basin (Darwin Basin) along the former western part of the Bird Spring Shelf. At the same time, farther east into the craton, paralic facies began prograding westward, so that the youngest fusulinid-bearing limestones on the shelf in this area become progressively younger to the west. Eventually, in Artinskian to Kungurian (late Wolfcampian to Leonardian) time (Fusulinid Zones 5 and 6), deposition of fusulinid-bearing limestone on the shelf was restricted to a marginal belt between the prograding paralic facies to the east and the Darwin Basin to the west. Development of the Keeler Basin in Pennsylvanian to earliest Permian time was approximately coeval with collision between South America-Africa (Gondwana) and North America (Laurentia) on the Ouachita-Marathon orogenic belt. This basin developed inboard of a northwest-trending, sinistral fault zone that truncated the continental margin. Later, in the Early Permian, the Last Chance allochthon, which was part of a northeast-trending belt of deformation that extended into northeastern Nevada, was emplaced. This orogenic belt probably was driven by convergence at the continental margin to the northwest. This work adds significant detail to existing interpretations of the late Paleozoic as a time of major tectonic instability on the continental margin of southeastern California as it changed from a relatively passive margin that had characterized most of the Paleozoic to an active convergent margin that would characterize the Mesozoic. Keywords: Late Paleozoic, biostratigraphy, paleogeography, southwestern USA, tectonics.

INTRODUCTION The Bird Spring Shelf (Fig. 1) was a broad area of shallowwater marine carbonate sedimentation that extended over much of southern Nevada and southeastern California during late Paleozoic time (e.g., Rich, 1977; Stevens, 1977, 1991b; Ross, 1991). The shelf is delineated by outcrops of the Pennsylvanian to Early Permian Bird Spring Formation and equivalent strata; it was flanked on the west and northwest by deep-water turbidite basins in which the Pennsylvanian to Early Permian Keeler Canyon Formation (Keeler Basin of Stevens et al., 2001) and the Early Permian Osborne Canyon and Darwin Canyon Formations of the Owens Valley Group (herein called the Darwin Basin) accumulated (Stone and Stevens, 1988; Stevens, 1991b; Stevens et al., 2001). Together, the Bird Spring Shelf and the flanking turbidite basins record a complex history of late Paleozoic sedimentation and deformation along this part of the western North American continental margin (Stevens et al., 1997). Fusulinids, which are among the most useful fossils for biostratigraphic correlation and environmental interpretation in upper Paleozoic rocks, are abundant in the carbonate deposits of the Bird Spring Shelf. In southern Nevada these fossils have been the subject of several studies that have established the general biostratigraphic framework for that part of the Bird Spring Shelf (Christy, 1958; Rich, 1961; Cassity and Langenheim, 1966; Lenhart, 1975; Gamache, 1986; Ho, 1990). Fusulinids also are

locally abundant in rocks of the Bird Spring Shelf in southeastern California, but few of these have been systematically studied and described. As a result, a complete biostratigraphic framework of the Bird Spring Shelf in southeastern California has not been developed, and correlation of events occurring during evolution of the shelf and development of the flanking turbidite basins has not been fully established. In this paper we report on fusulinids from seven of the most important outcrop areas of Bird Spring Shelf rocks in southeastern California, including the Providence Mountains where Thompson and Hazzard (1946) previously studied the fusulinid succession, and propose a zonation useful for correlating these rocks with sections elsewhere in the western United States. Use of conodont data, where available, also has permitted us to correlate our Fusulinid Zones with the standard Global Permian Stages, strengthening their chronostratigraphic significance. Finally, our fusulinid zonation permits detailed correlations of the Bird Spring Shelf strata with the coeval basinal deposits to the west and northwest, in which fusulinids also are abundant. These correlations provide new insights into the evolving paleogeography of the region and the relationship between shelf sedimentation and structural deformation of the late Paleozoic continental margin, especially with regard to emplacement of the regionally significant Last Chance allochthon during a major episode of thrust faulting that affected the margin in the Early Permian (Stevens and Stone, 2005).

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf 118o

S OOD MT

15

NA ARIZO DA NEVA

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COTTON W

NG BIRD SPRI SHELF

NG RI SP GE RD AN R

Salt Spring Hills

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G RAN

Striped Butte

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Warm Spring Canyon

West edge of Bird Spring Shelf

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Paleographic features in northwestern part of map area. LP, Lone Pine; PB, Panamint Butte

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Darwin Canyon

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Marble Canyon

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Ubehebe Mine

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NARDINO MOUNTAIN S

San Bernardino

0

50

100

KILOMETERS

o

34

Figure 1. Map showing locations of features in southeastern California referred to in text. Names of the seven areas studied for this report are shown in bold. Western margin of Bird Spring Shelf is shown for Middle Pennsylvanian time. Major westward swing of the margin south of the Cenozoic Garlock fault is due to Mesozoic and Cenozoic structural modification (Stevens et al., 2005).

CHRONOSTRATIGRAPHIC NOMENCLATURE The primary focus of this work is on rocks of Late Pennsylvanian and Early Permian age, in which fusulinids of the Bird Spring Shelf are most abundant. The chronostratigraphic units used in this study for uppermost Pennsylvanian and Lower Permian strata of the Bird Spring Shelf are as follows: Virgilian and Bursumian Stages for uppermost Pennsylvanian strata and Asselian, Sakmarian, Artinskian, and Kungurian Stages for Lower Permian strata (Fig. 2). The standard Global Permian Stages for the Lower

Permian, based on sections in the Ural Mountains of Russia and Kazakhstan (Jin Yugan et al., 1997), have been formally approved by the Permian Subcommission of the International Commission on Stratigraphy (ICS). Recently the International Union of Geological Sciences (IUGS) Subcommission on Carboniferous Stratigraphy (Heckel, 2004) ratified a Carboniferous subdivision. We here follow their definition of the regional North American Stages of the Pennsylvanian except that we recognize an additional informal stage, the Bursumian, because the faunas of the Bursumian are distinctive and important in our study.

Lower

Permian

SERIES

C.H. Stevens and P. Stone

SYSTEM

4

GLOBAL STAGE

NORTH AMERICAN STAGE

Kungurian

Leonardian

Artinskian Sakmarian

Wolfcampian (restricted)

Upper

Bursumian Gzhelian

Middle

Kasimovian Moscovian

Lower

Pennsylvanian

Asselian

Bashkirian

Virgilian Missourian Desmoinesian Atokan Morrowan

Figure 2. Chronostratigraphic units used in this study.

inner part of this fringing margin, here referred to as the cratonal platform, accumulated siliciclastic sediment derived from emergent areas to the east, along with some interbedded carbonate sediment (Miller et al., 1992). To the west, on the outer part of the margin in the areas here referred to as the Bird Spring Shelf and the Ely Shelf (Fig. 3), carbonate sedimentation was predominant. These two areas of carbonate shelf sedimentation, which are typified by locally abundant marine faunas including fusulinids and colonial corals, probably originally formed a single continuous band. Today, however, they are separated by a data gap in which outcrops of late Paleozoic strata are largely absent. These two parts of the shelf also differ in their paleogeographic settings. Whereas the Ely Shelf was bordered on the west by remnant uplifts of the Mississippian Antler orogenic belt, the Bird Spring Shelf was flanked by a tectonically active continental borderland (Fig. 3) characterized by turbidite basins and intervening uplifts. The borderland included the Keeler and Darwin Basins as well as other Pennsylvanian–Permian deep-water basins farther west (e.g., Carr et al., 1997; Stevens and Greene, 1999). On the west, the borderland is interpreted to have been terminated by a major left-lateral fault zone (Fig. 3) along which a fragment of the pre-Pennsylvanian continental margin was truncated and translated several hundred kilometers to the south (e.g., Dickinson, 2000; Stevens et al., 2005). On a global scale, the Bird Spring Shelf was part of an extensive belt of tropical to subtropical deposits characterized by colonial corals and fusulinids that stretched all along the western and northwestern margins of the Pangean supercontinent (Fig. 4). In the Early Permian the Bird Spring Shelf was located just north of the paleoequator according to the reconstruction of Scotese and Langford (1995). STRATIGRAPHIC FRAMEWORK

The Bursumian Stage was proposed by Ross and Ross (1987, 1994) to fill the gap between the Late Pennsylvanian Virgilian Stage and the base of the Permian in North America. Because of problems concerning the type Bursum Formation, Wilde (2002) and Lucas (2004) have put forward the name Newwellian to replace Bursumian, and Wilde (2006) used the name Newwellian in his study of fusulinids in the New Well region in the Big Hatchet Mountains. Here, however, we will continue to use the informal term Bursumian, which, together with the Virgilian in North America, is approximately equivalent to the Gzhelian in the Ural Mountains (Fig. 2). The Asselian, Sakmarian, and much of the Artinskian are considered equivalent to the Wolfcampian (shown as restricted to strata of Permian age in Fig. 2) in North America, and the upper Artinskian through the Kungurian are equivalent to the Leonardian. PALEOGEOGRAPHIC SETTING The Bird Spring Shelf was part of a broad, sloping continental margin that extended at least from southern California to southern Idaho during Pennsylvanian and Early Permian time (Fig. 3). The

The Bird Spring Formation was named by Hewett (1931) for a sequence of limestone and subordinate clastic rocks ~750 m thick in the southern Spring Mountains and Bird Spring Range in southern Nevada, after preliminary use of this formational name by Glock (1929). As originally defined by Hewett (1931), the Bird Spring Formation included all strata above the Mississippian Monte Cristo Limestone and below a thick sequence of clastic rocks of presumed Permian age assigned to the Supai Formation. Hewett (1931) reported only Pennsylvanian fossils in the type area of the Bird Spring Formation, but subsequent work (Longwell and Dunbar, 1936; Rich, 1961; Langenheim et al., 1962) showed that regionally the formation as originally defined spans latest Mississippian to Early Permian time and has a maximum thickness of more than 2000 m. Webster and Lane (1967) later restricted the Bird Spring Formation in southern Nevada to exclude a thin but widespread basal clastic unit of Late Mississippian age, which they named the Indian Springs Formation. Other proposals to modify the stratigraphic boundaries of the Bird Spring Formation (e.g., Bissell, 1960, 1962) and to elevate the formation to group rank (Langenheim et al.,

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf 122o

120o

CALIFO

118o

OREGO

RNIA

116o

114o

SH EL F

S

WYOMING COLORADO

3

IBB

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ANT

PLAT FORM

EL Y

ANTLER

NE RA TE R

42o

38o

EMERG ENT

LF

PARTIA LLY

D BIR 100

122o

34o NEW MEXICO ARIZONA

KILOMETERS 0

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120o

118o

116o

36o

CRAT ONAL

SHE ING SPR

BOR

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lt au kF c rlo Ga

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DATA GAP

Sa

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IDAHO UTAH

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IC AN OC E IBB

o i c io n t eoz Pal unca Late ntal Tr tin e F a u lt Con

38o

110o

N NEVADA

40o

112o

AREAS

124o

5

114o

112o

110o

108o

Figure 3. Map showing paleogeographic setting of the Bird Spring Shelf on the late Paleozoic continental margin of southwestern United States. In California, paleogeographic features are offset by the Mesozoic Intrabatholithic Breaks 2 and 3 (IBB2, IBB3) and by the Cenozoic San Andreas, Garlock, and Death Valley–Furnace Creek (DVFCF) Faults. Modified from Stevens (1982), Miller et al. (1992), and Stevens et al. (1992).

1962) have not gained general acceptance. Shelf carbonate strata equivalent to parts of the Bird Spring Formation are represented by the Callville Limestone (Longwell, 1928) and Pakoon Limestone (McNair, 1951) in southeasternmost Nevada, northwestern Arizona, and southwestern Utah, and by the Tippipah Limestone (Johnson and Hibbard, 1957) in southwestern Nevada. In southeastern California, early geologic mapping and stratigraphic studies (e.g., Hazzard, 1937, 1954; Hewett, 1956) showed that the Bird Spring Formation occurs in several widely separated ranges in the Mojave Desert region. The formation is now recognized as far south as the San Bernardino Mountains (Brown, 1991) and as far north as the Death Valley area (Panamint Range and Cottonwood Mountains) (Stone and Stevens, 1984) (Fig. 1).

The seven outcrop areas represented in this study provide a regional transect across the Bird Spring Shelf in California. From southeast to northwest, these areas are (1) the Ship Mountains, (2) the Providence Mountains, (3) Old Dad Mountain, (4) Cowhole Mountain, (5) Striped Butte and (6) nearby Warm Spring Canyon in the southern Panamint Range, and (7) Panamint Butte in the southern Cottonwood Mountains (Fig. 1). Outcrop areas not considered for this study include Marble Canyon in the central Cottonwood Mountains (Stone, 1984) and the Nopah Range (Hazzard, 1937; Burchfiel et al., 1982), where fusulinids are rare and the Bird Spring Formation does not extend into the Permian; the Clark Mountain Range (Clary, 1967) and the San Bernardino Mountains (Brown, 1991), where only Pennsylvanian fusulinids

6

C.H. Stevens and P. Stone

CORAL BELT

EUROPE

PALEOPACIFIC OCEAN

BIRD SPRING SHELF

NORTH AMERICA

EO PAL

R ATO U EQ

TETHYS

Figure 4. Plate-tectonic reconstruction showing location of Bird Spring Shelf in the Early Permian Thysanophyllum coral belt of Stevens (1982).

OCEAN

N MIA PER

SOUTH AMERICA

have been reported; the New York Mountains (Burchfiel and Davis, 1977) and the Soda Mountains (Grose, 1959; Walker and Wardlaw, 1989), where most of the rocks are recrystallized; and minor outcrops, such as those in the Salt Spring Hills and near the town of Baker (e.g., Grose, 1959), that are too stratigraphically incomplete for our purposes. The relationship of the Bird Spring Formation to units above and below differs from area to area (Fig. 5). Over much of its extent in California, as in southern Nevada, the Bird Spring Formation overlies a thin sequence of Upper Mississippian clastic rocks correlative with the Indian Springs Formation (Stevens, 1991b). Where the Indian Springs Formation is absent, the Bird Spring Formation overlies Mississippian carbonate rocks assigned to the Monte Cristo Limestone or Santa Rosa Hills Limestone (Dunne et al., 1981; Stevens, 1991a). Throughout the region studied, we place the base of the Bird Spring Formation at the base of the lowest thick-bedded, gray limestone above the Mississippian rocks mentioned above. The Bird Spring Formation is unconformably overlain by the Triassic Moenkopi Formation in the Providence Mountains (Hazzard, 1954) and by the Jurassic Aztec Sandstone at Old Dad Mountain (Dunne, 1977). At Warm Spring Canyon and Panamint Butte, we place the top of the Bird Spring Formation above the highest shallow-water limestone in the stratigraphic sequence. There the Bird Spring

Formation is overlain by Lower Permian basinal strata of the Owens Valley Group (Stone and Stevens, 1984). Elsewhere the top is not exposed. In the areas studied, the Bird Spring Formation typically comprises thick sequences of limestone and subordinate silty to sandy rocks that are well exposed on steep slopes, cliffs, and isolated hills (Fig. 6). The lower part of the formation typically is composed of cherty limestone (Fig. 7A) with abundant nodular to lenticular chert and silty interbeds. An exception is in the Ship Mountains, the southeasternmost section studied. There the lower part of the Bird Spring Formation includes abundant dolomite and a prominent zone of dark-brown calcareous sandstone and sandy limestone (Figs. 6A, 7B) just below the main fusulinid-bearing limestone interval (Stone et al., 1983). The Upper Pennsylvanian to Lower Permian strata, where most of the fusulinids occur, generally consist of thick-bedded to massive, micritic to biomicritic limestone in which nodular chert and siltstone are present locally (Figs. 7C, 7D). In these beds, fusulinids (Fig. 7E) commonly are associated with a variety of colonial corals (Figs. 7F, 7G), less common solitary corals (Fig. 7H), and other marine invertebrate fossils. In both the Ship Mountains and the Providence Mountains, the upper few hundred meters of the Bird Spring Formation consist primarily of thin-bedded, light-colored limestone and dolomite in which fusulinids are rare or absent.

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf AREA UNIT

PANAMINT BUTTE

STRIPED BUTTE

WARM SPRING CANYON

COWHOLE MOUNTAIN

OLD DAD MOUNTAIN

Warm Spring Formation

JURASSIC

7 PROVIDENCE MOUNTAINS

SHIP MOUNTAINS

Fountain Peak Rhyolite Aztec Ss. Moenkopi Fm.

TRIASSIC

Owens Valley Group PERMIAN Osborne Canyon Formation1

PENNSYLVANIAN

MISSISSIPPIAN

1Osborne

Bird Spring Formation

Bird Spring Formation

Bird Spring Formation

Bird Spring Formation

Bird Spring Formation

Bird Spring Formation

Monte Cristo Limestone

Monte Cristo Limestone

Bird Spring Formation

Indian Springs Formation Santa Rosa Hills Limestone

Santa Rosa Hills Limestone

Monte Cristo Limestone

Canyon Formation is part of the Owens Valley Group.

Figure 5. Stratigraphic units relevant to the Bird Spring Formation in the seven areas studied.

A stratigraphically complete, structurally uncomplicated section of the Bird Spring Formation is not present in any of the areas studied. Sections in the Ship Mountains and at Striped Butte (Figs. 6A, 6E) are structurally simple, but neither the base nor the top of the formation is exposed at either locality. Numerous fault-bounded, partial sections, including the base of the formation, are exposed in the Providence Mountains (Fig. 6B). The section at the crest of the range is nearly complete but is disrupted by faults of uncertain displacement (Hazzard, 1954). The Bird Spring Formation at Old Dad Mountain is broken into multiple fault blocks that greatly complicate the stratigraphic section (Dunne, 1977). The Cowhole Mountain section appears homoclinal, but the base is faulted (Fig. 6C) and the top is not exposed (Novitsky-Evans, 1978). In addition, the uppermost part of the Cowhole Mountain section is complicated by faulting. At Warm Spring Canyon, the base (Fig. 6D) and top of the Bird Spring Formation are well exposed, but the lower and upper parts of the formation are separated by a major fault that cuts out several hundred meters of strata (Wrucke, 1966; Stone, 1984), and the upper part of the section is locally faulted. At Panamint Butte, the base (Fig. 6F) and top of the section are represented,

but in different fault blocks between which there may be missing section (Hall, 1971; Stone, 1984). These complications hinder regional stratigraphic correlations and detailed interpretations of the depositional history. PREVIOUS STUDIES OF FUSULINIDS IN SOUTHEASTERN CALIFORNIA In addition to the study of fusulinids by Thompson and Hazzard (1946) in the Providence Mountains, Stone (1984) illustrated but did not describe numerous fusulinid species from the Bird Spring Formation from Striped Butte, Warm Spring Canyon, and Panamint Butte. Later, Stevens (1995) illustrated a Middle Pennsylvanian (Desmoinesian) fusulinid from the Bird Spring Formation at Marble Canyon in the central Cottonwood Mountains. Riggs (1962), Magginetti et al. (1988), and Stevens et al. (2001) described and illustrated transported fusulinids in deepwater deposits of the Keeler Canyon Formation and Owens Valley Group in the Inyo Mountains, which are temporally correlative with beds of the Bird Spring Formation. Magginetti et al. (1988) also included fusulinids from sediment-gravity-flow

A

sandy beds

fusulinid limestone

C Fault

SHIP MTS

COWHOLE MTN

B

g Fm prin isto Ls S d r r Bi te C Mon

PROVIDENCE MTS

D

WARM SPRING CANYON

Bird Spring Fm

lower Pz dolomite intruded by Mz diorite g

rin

rd

Bi

Fm

Sp

gs

Fm

rin

an

Sp

di

In

sa

ta

lls Hi

Ls

Ro

n

Sa

E

STRIPED BUTTE

F

PANAMINT BUTTE

Bird Spring Fm

Santa cherty ls

cherty ls Ls Rosa Hills

color-banded ls

base of incomplete section of Bird Spring Fm

Figure 6. General views of the Bird Spring Formation in southeastern California. (A) Ship Mountains. Dark-weathering sandy beds overlain by light-colored fusulinid-bearing limestone in middle part of Bird Spring Formation. (B) Providence Mountains. Dark, well-bedded limestone of Bird Spring Formation overlying cliff-forming, light-colored Monte Cristo Limestone. (C) Cowhole Mountain. Limestone of Bird Spring Formation overlying older Paleozoic dolomite and intrusive Mesozoic diorite on low-angle fault. (D) Warm Spring Canyon. Dark, well-bedded limestone of Bird Spring Formation overlying thin unit of clastic rocks (Indian Springs Formation), which in turn overlies massive, light-colored Santa Rosa Hills Limestone. (E) Striped Butte. Well-bedded, color-banded limestone of Bird Spring Formation, with unit of dark, cherty limestone at base of incomplete section; lowest abundant fusulinids are in beds near summit. (F) Panamint Butte. Well-bedded limestone of Bird Spring Formation, with prominent zone of dark, cherty limestone at base, overlying massive, light-colored Santa Rosa Hills Limestone.

A

B

C

D

E

F

G

H

Figure 7. Photographs showing outcrop characteristics of Bird Spring Formation. (A) cherty limestone in lower part of formation, Warm Spring Canyon. (B) Dark-weathering sandstone in unit below fusulinid-bearing limestone unit, Ship Mountains. (C) Typical thick-bedded limestone in fusulinid-bearing part of formation, Cowhole Mountain. (D) Thick-bedded limestone with sparse chert nodules in fusulinid-bearing part of formation, Ship Mountains. (E) Limestone with abundant fusulinids, Warm Spring Canyon. (F) Limestone with syringoporoid colonial coral, Warm Spring Canyon. (G) Limestone with fasciculate colonial coral (Tschussovskenia), Striped Butte. (H) Limestone with abundant solitary caninoid corals, Warm Spring Canyon.

10

C.H. Stevens and P. Stone

deposits in Darwin Canyon and the Argus Range. Stone (1984) and Stone et al. (2000) illustrated but did not describe representative species from the Keeler Canyon Formation and Owens Valley Group. The only other studies of fusulinids in the region were by Ross and Sabins (1966) and Rich (1971) from rocks of uncertain paleogeographic affinities west of the Bird Spring Shelf.

faunas will be discovered in the region, but they are not obvious in the sections we studied. On the basis of the fusulinid faunas in the younger rocks of the Bird Spring Shelf in the seven areas studied in California, we recognize six fusulinid zones ranging in age from Virgilian to Kungurian (Leonardian). From stratigraphically lowest to highest, these are called Fusulinid Zones 1–6 (Fig. 8).

FUSULINID SAMPLE MATERIAL Fusulinid Zone 1 The present study is based primarily on examination of ~1000 fusulinid thin sections from 95 samples collected by the authors over a period of many years. These include 22 samples originally reported on by Stone (1984) and reexamined during the present study. All but one of the 95 samples are from the Bird Spring Formation; the exception (S-1227) is from the basal part of the Osborne Canyon Formation at Panamint Butte. In addition to these samples collected by us, we studied fusulinids from six samples loaned to us from the National Museum of Natural History (formerly the U.S. National Museum). These samples were collected from the Bird Spring Formation in the Ship Mountains and Providence Mountains by one of the authors (Stone) and K.H. Howard in 1978. Finally, we reexamined the specimens illustrated by Thompson and Hazzard (1946) from the Bird Spring Formation in the Providence Mountains. These specimens were loaned to us by James Ingle from the Micropaleontologic Laboratory collection at Stanford University. The stratigraphic positions of selected fusulinid samples used for this study are shown in Figure 8. All fusulinid samples studied, along with their general locations, are listed in Appendix 1. Detailed locality and stratigraphic information for all samples is presented in Appendix 2, which also includes stratigraphic columns and geologic maps showing sample localities (Figs. A1– A20). Repository information and additional information on figured specimens is given in Appendix 3.

Fusulinids representing this zone have been collected from the Providence Mountains, Old Dad Mountain, and Panamint Butte. The sparse fauna is characterized by relatively primitive species of Triticites including T. muddiensis and T. bensonensis. Other species recognized in this zone are Pseudofusulinella cf. P. harbaughi, Triticites elegantoides, T. hermanni, and T. aff. T. rothi. Fusulinid Zone 2 The base of this zone is placed below the first appearance of large, inflated species of Triticites, including T. californicus and T. cellamagnus. This zone also includes numerous species of Leptotriticites and relatively rare occurrences of Schwagerina. Species present in this zone in addition to those listed above are Triticites buttensis n. sp., T. aff. T. californicus, T. gigantocellus n. sp., Leptotriticites aff. L. americanus, L. glenensis, L. aff. L. hatchetensis, L. cf. L. hughesensis, L. cf. L. varius, L. wetherensis, L. cf. L. koschmanni, L. sp. 1, Schwagerina providens (rare), and S.? sp. 1. In addition, Leptotriticites californicus n. sp. and L. aff. L. gracilitatus, both more characteristic of Fusulinid Zone 3, occur in one sample (S-1963, Warm Spring Canyon) that we provisionally consider to represent the uppermost part of Zone 2. Zone 2 fusulinids are well represented in the Providence Mountains and at Warm Spring Canyon, Striped Butte, and Panamint Butte.

FUSULINID FAUNAS AND ZONES Fusulinid Zone 3 We here report on 69 fusulinid species representing 11 genera (see SYSTEMATIC PALEONTOLOGY and Plates 1–8). These include one species of Pseudofusulinella, 12 species of Triticites, 15 species of Leptotriticites, 15 species of Schwagerina, five species of Pseudoschwagerina, two species of Paraschwagerina, seven species of Stewartina, four species of Pseudochusenella, five species of Parafusulina, and one species each of Advenella, Cuniculinella and Eoparafusulina. Ten new species are described: Triticites buttensis, T. gigantocellus, Leptotriticites californicus, L. warmspringensis, L. panamintensis, Stewartina magnifica, S. ultimata, Pseudochusenella buttensis, P. hazzardi, and Cuniculinella mojavensis. The fusulinids identified in this study range in age from Missourian (~Kasimovian) to Kungurian (Leonardian). Only one species (Triticites cf. T. burgessae), from sample S-1968 at Striped Butte, is interpreted as Missourian in age; the remainder are Virgilian to Kungurian in age. Possibly other pre-Virgilian

The base of this zone is placed above the highest occurrence of robust species of Triticites, above which Pseudochusenella, Paraschwagerina, Pseudoschwagerina, and Stewartina first appear. The distinctive coral Protowentzelella also occurs widely in this zone. Fusulinid Zone 3 is represented in all areas studied and is restricted to the Bird Spring Formation, except at Panamint Butte, where it encompasses both the upper part of the Bird Spring Formation and lower part of the overlying Osborne Canyon Formation. In the Ship Mountains the entire fusulinidbearing part of the section belongs to this zone. Zone 3 marks the acme of Permian fusulinid faunas on the Bird Spring Shelf in California. Species recognized in this zone are Triticites sp. 1, Leptotriticites californicus n. sp., L. aff. L. gracilitatus, L. aff. L. hatchetensis, L. cf. L. hughesensis, L. panamintensis n. sp., L. cf. L. koschmanni, Schwagerina aculeata, S. aculeata plena, S. cf. S. elkoensis, S. longissimoidea, S. modica,

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf S. providens, S. cf. S. pugunculus, S. vervillei, S. cf. S. wellsensis, S. sp. 3, S. sp. 4, Pseudoschwagerina arta, P. cf. P. gerontica, P. roeseleri, P. uddeni, Advenella bifurcata, Paraschwagerina elongata, P. fairbanksi, Stewartina convexa (rare), S. multispira, S. texana, S. uber, S. sp. 1, Pseudochusenella buttensis n. sp., P. hazzardi n. sp., P.? sp. 1, and possibly P. concisa. This zone probably could be divided into a lower part, lacking Stewartina convexa, and an uppermost part containing rare specimens of this species. Fusulinid Zone 4 The base of this zone is placed immediately below the first occurrence of Eoparafusulina linearis, the most characteristic fusulinid within it. Other species include Leptotriticites californicus n. sp., L. warmspringensis n. sp., L. sp. 1, L. sp. 3, L. sp. 4, Schwagerina vervillei, S. sp. 4, Pseudoschwagerina arta, P. cf. P. gerontica, P. uddeni, P. sp. 1, and Stewartina convexa. In the region studied, Fusulinid Zone 4 is best represented at Cowhole Mountain and in Warm Spring Canyon, where our collections include numerous specimens of Eoparafusulina linearis along with the colonial coral Protowentzelella, which extends upward from Zone 3. In addition, at Warm Spring Canyon this zone is locally characterized by large caninoid solitary corals such as those shown in Figure 7H. In the Providence Mountains, Fusulinid Zone 4 is represented by a single occurrence of a species we refer to Eoparafusulina in the upper part of the Bird Spring Formation. This specimen is from collection 627 of Thompson and Hazzard (1946), who identified it as Parafusulina sp. Fusulinid Zone 5 This zone, which is recognized only at Old Dad Mountain, lacks Eoparafusulina and is characterized by Cuniculinella mojavensis n. sp. and two highly advanced species of Stewartina, S. magnifica n. sp. and S. ultimata n. sp. Other species occurring in this zone are Schwagerina aff. S. davisi, S. vervillei, S.? sp. 2, and Stewartina convexa (rare). Fusulinid Zone 6 The base of this zone is placed below the lowest beds containing species of the genus Parafusulina. Species present in this zone include Schwagerina cf. S. menziesi, Parafusulina cf. P. bakeri, P. aff. P. shaksgamensis crassimarginata, P. aff. P. durhami, P. splendens, and Parafusulina sp. 1. Like Zone 5, Fusulinid Zone 6 is recognized only at Old Dad Mountain. CORRELATIONS Recently some of the most important Upper Pennsylvanian and Lower Permian sections in the United States have been correlated with the Global Stages shown in Figure 2, mostly on the basis of their conodont faunas (Wardlaw et al., 1998; Wardlaw and Davydov, 2000). In some areas the conodonts are interspersed

11

with fusulinid faunas, permitting correlation of the fusulinid faunas with the Global Stages. These fusulinid faunas then can be used to correlate sections where fusulinids occur, but where conodonts are sparse or nonexistent, with the Global Stages. Our interpretation of the correlation of the six fusulinid zones recognized in the Bird Spring Shelf strata of southeastern California with several other fusulinid-bearing sections in the United States is shown on Figure 9. Boundaries between stages within some well-known fusulinid-bearing sections are as follows. In north-central Nevada, Wardlaw et al. (1998) placed the Asselian-Sakmarian boundary within the uppermost Riepe Spring Limestone and the ArtinskianKungurian boundary within the Pequop Formation on the basis of conodonts. In the same general area, Ritter (1986) placed the Sakmarian-Artinskian boundary within the Rib Hill Sandstone in a section lacking distinctive fusulinids, also on the basis of conodonts. In Kansas, the Virgilian-Bursumian boundary was placed at the base of the Admire Group on the basis of fusulinids (Ross and Ross, 2002), and on the basis of conodonts, the base of the Permian was placed at the base of the Bennett Shale Member of the Red Eagle Formation (Boardman and Mazzullo, 1998), the Asselian-Sakmarian boundary was placed at the base of the Eiss Limestone, and the Sakmarian-Artinskian boundary was placed at the base of the Florence Limestone (Wardlaw and Davydov, 2000). In the Glass Mountains, West Texas, Wardlaw and Davydov (2000) placed the Gzhelian-Asselian boundary within the upper Gray Limestone Member of the Gaptank Formation and the Asselian-Sakmarian boundary at the base of bed 9 in section 22 of the Neal Ranch Formation of Ross (1963), which is in the lower part of cycle NR-8 of Ross and Ross (2003a, 2003b). Ross and Ross (2003b) indicated that the Gray Limestone Member is separated from the Neal Ranch Formation by an unconformity, as shown in Figure 9. Ross and Ross (1999) also correlated fusulinids near the base of the Lenox Hills Formation with the Florence Limestone, thus implying that the Sakmarian-Artinskian boundary lies at the base of the Lenox Hills Formation. As explained below, we place this boundary within the Lenox Hills Formation (Fig. 9). In the Franklin Mountains in westernmost Texas, conodonts suggest that the Sakmarian-Artinskian boundary is at least as high as within the Cerro Alto Formation (Wardlaw et al., 2004). The above stage boundaries provide a framework within which other, in some cases more detailed, correlations can be made. Several widespread North American fossil species or assemblages can be used as keys to correlation. The oldest are the beds of the Bursumian, which are characterized by large, robust species of Triticites, including T. creekensis in New Mexico (Lucas et al., 2000) and T. californicus and T. cellamagnus in California. This assemblage is very widespread in the western United States. The next particularly distinctive fossil zone is characterized by the coral Protowentzelella. This coral occurs throughout east-central and southern Nevada and adjacent states, and in the Hueco and Franklin Mountains of West Texas (Stevens, 1982). In east-central Nevada, this coral zone occurs within

FUSULINID ZONES

PANAMINT BUTTE

STRIPED BUTTE

WARM SPRING CANYON

6 5 4 Osborne Canyon Fm.

S-1227 Owens Valley Group

? ? S-1232 S-1931 S-1928

S-1966 ? S-1965 ? S-1930 S-0382 S-1960 S-1959

S-1914 S-1927 S-1915 S79-SB-26 S-1933 S-1922

S-1932

3

S-1913

?

? S-1968

Hiatus

S-1911 81-PB-39 81-PB-38

2 81-PB-37

Indian Springs Fm. Santa Rosa Hills Ls.

1 81-PB-35

EXPLANATION

preZone 1

Sandstone

Sandy limestone

Siltstone

Massive limestone

Shale

Thick-bedded limestone

Conglomeratic limestone

Thin-bedded limestone

Thin-bedded siliceous limestone

Dolomite

Cherty limestone

Fault

Silty limestone

S-1911

Fusulinid sample

Santa Rosa Hills Ls.

Figure 8. Generalized stratigraphic columns in the seven areas studied, showing approximate stratigraphic positions of selected fusulinid samples and correlation of fusulinid zones here recognized. Placement of zone boundaries between widely spaced samples is arbitrary.

OLD DAD MOUNTAIN

COWHOLE MOUNTAIN

SHIP MOUNTAINS

PROVIDENCE MOUNTAINS

Moenkopi Fm.

?

Aztec Sandstone S-1946

S-1951 S-1866 S-1864 S-1865

?

?

?

?

S-1949

S-1863

S-1849 S-1850

Coll. 627 of Thompson and Hazzard (1946) ?

S-1862

S-1848

S-1947

S-1463 S-1461

f14073 f14063

S-1875 S-1860

? ?

S-1460 S-1857

?

?

?

?

S-1459

S-1456

Monte Cristo Ls. S-1870 S-1457 S-1458

S-1847

Monte Cristo Ls.

200 METERS

SCALE

100

0

Monte Cristo Ls.

SYSTEM

Permian

Pennsylvanian

Fusulinid Zone 1

Beds 211–224

?

Beds 235–237

Bed 239

Cassity and Langenheim, 1966

Triticites coronadoensis

Triticites californicus

Pseudofusulina attenuata

Schwagerina bellula

Pseudofusulina huecoensis

Eoparafusulina linearis

Schwagerina aculeata? Stewartina convexa Schwagerina cf. S. crebrisepta

Hiatus?

Parafusulina leonardensis

Stevens et al., 1979

North-central Nevada

Wabaunsee Group

Admire Group

Up to base of Bennett Shale

Up to base of Eiss Limestone

Upper part

?

Up to base of Florence Limestone

Upper part

Sumner Group

Thompson, 1954

Kansas

Lower part

Gray Limestone Member

Cycles NR-1–NR-7 Hiatus?

Hiatus?

Cycles NR-8–NR-16

Hiatus?

Cycle LH-1

Cycle LH-2

Cycle LH-3

Cycle H-1

Cycles H-2–H-7

Upper member Magdalena Fm. of Williams (1963)

Hueco Canyon Formation

Cerro Alto Fm.

Alacran Mountain Formation

?

Williams, 1963 Simo et al., 2000

Ross and Ross, 2003a Cathedral Mountain Fm. (Cycle C-1)

Hueco and Franklin Mountains, Texas

Glass Mountains, Texas

Figure 9. Correlation of fusulinid zones of the Bird Spring Shelf with sections in Nevada, Kansas, and Texas.

Beds 289–92A

Beds 90A–68A

Fusulinid Zone 2

Beds 62A–32A

Beds 23A–8A

?

Beds 227B–243B

Beds 270B–341B

Rich, 1961

Hiatus?

Fusulinid Zone 3

Fusulinid Zone 4

Fusulinid Zone 5

Fusulinid Zone 6

This paper

Bird Spring Formation

STANDARD STAGES

Kungurian

Artinskian

Sakmarian

Asselian

Gzhelian

Bird Spring Shelf, southern Nevada

Fusulinid Zones

NORTH AMERICAN STAGES

Leonardian

Wolfcampian

Hiatus?

Bird Spring Formation

Bursumian

Pequop Formation Rib Hill Ss. Riepe Spring Limestone

Bird Spring Shelf, southeastern California

Bird Spring Formation

Virgilian

Chase Group Council Grove Group

Hess Ls. Lenox Hills Formation Neal Ranch Formation Gaptank Formation

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf the Riepe Spring Limestone, which conodonts suggest straddles the Asselian-Sakmarian boundary (Wardlaw et al., 1998). Throughout the Cordilleran region the Protowentzelella beds commonly are overlain by beds bearing Eoparafusulina linearis or closely related species. In east-central Nevada, E. linearis occurs near the base of the Rib Hill Sandstone in close stratigraphic proximity to the Riepe Spring Limestone (Stevens, 1979), which is early Sakmarian at the youngest (Wardlaw et al., 1998). Thus, E. linearis in this area is considered to be Sakmarian in age. In the Hueco and Franklin Mountains, in extreme western Texas, a form similar to E. linearis, occurring near the top of the Hueco Canyon Formation (Williams, 1963, 1966), also must be as old as Sakmarian because, as mentioned above, Sakmarian conodonts occur in the overlying Cerro Alto Formation (Wardlaw et al., 2004) (Fig. 9). We here suggest that the E. linearis-bearing beds in the Lenox Hills Formation in the Glass Mountains, West Texas, where Protowentzelella is lacking, also are Sakmarian in age. Stewartina convexa, which generally occurs above beds containing Eoparafusulina linearis, also is useful for regional correlations. In north-central Nevada this species occurs in the lower part of the Arcturus Formation (Stevens et al., 1979), and in the Hueco and Franklin Mountains it is confined to the Alacran Mountain Formation (Williams, 1963, 1966) well above the Eoparafusulina beds. In the Glass Mountains, S. convexa occurs in the upper Lenox Hills Formation (cycle LH-3 of Ross and Ross, 2003a). We consider this species to be mostly Artinskian in age. Using the chronostratigraphic framework and correlation criteria outlined above, we correlate the six fusulinid zones of the Bird Spring Shelf in southeastern California (Fig. 9) as follows. Fusulinid Zone 1 This zone correlates with faunas in southern Nevada considered upper Virgilian by Cassity and Langenheim (1966). It also contains species that compare well with those in the upper Virgilian part of the Gaptank Formation in West Texas (Ross, 1965), the Virgilian in north-central Texas (Kauffman and Roth, 1966), the Virgilian in the Earp Formation in Arizona (Ross and Tyrrell, 1965), and various other Late Pennsylvanian faunas in the western United States. Fusulinid Zone 2 This zone corresponds to the zone of Triticites californicus in north-central Nevada (Stevens et al., 1979). The fauna of Zone 2 also is similar to that in the Bursum Formation in New Mexico (Lucas et al., 2000), the Admire Group and the lower part of the Council Grove Group in Kansas (Thompson, 1954), post-Virgilian rocks of the Earp Formation in Arizona (Sabins and Ross, 1963), the Gray Limestone Member of the Gaptank Formation in the Glass Mountains, Texas (Ross and Ross, 2003a, 2003b), and rocks in north-central Texas considered early Wolfcampian

15

by Kauffman and Roth (1966). On the basis of these correlations we assign this zone a Bursumian (Late Pennsylvanian) age. Fusulinid Zone 3 This zone is correlative with the faunas above bed 234 of the Bird Spring Formation in the Arrow Canyon Range in southern Nevada (Cassity and Langenheim, 1966), and similar forms are present in the zones of Schwagerina bellula and Pseudofusulina huecoensis in north-central Nevada (Stevens, et al., 1979). This zone also correlates with faunas in the upper Neal Ranch Formation (cycles NR-8 through NR-16) and lower part of the Lenox Hills Formation (cycle LH-1) in the Glass Mountains (Ross and Ross, 2003a, 2003b). The faunas of the Hueco Canyon Formation in the Hueco and Franklin Mountains (Williams, 1963, 1966), with the exception of the highest beds containing Eoparafusulina, also correlate with Fusulinid Zone 3. These correlations suggest a late Asselian to middle Sakmarian (late early to middle middle Wolfcampian) age for Fusulinid Zone 3. The profound faunal change between Fusulinid Zones 2 and 3 on the Bird Spring Shelf suggests the existence of a hiatus representing much of Asselian time. Fusulinid Zone 4 We interpret Fusulinid Zone 4 as correlative with the fusulinid faunas in the Rib Hill Sandstone in north-central Nevada (Stevens et al., 1979), the middle of the Lenox Hills Formation (cycle LH-2) in the Glass Mountains (Ross and Ross, 2003a, 2003b), and the uppermost Hueco Canyon Formation in the Hueco and Franklin Mountains (Williams, 1963, 1966), all of which contain Eoparafusulina linearis or similar species. On the basis of these correlations, we here assign Fusulinid Zone 4 a late Sakmarian (late middle Wolfcampian) age. Fusulinid Zone 5 Stewartina ultimata n. sp., occurring only in Fusulinid Zone 5, is similar to, but apparently somewhat more advanced than, S. elongata (Ross and Ross) from the middle part of the Lenox Hills Formation (cycle LH-2) in the Glass Mountains (Ross and Ross, 2003a). Stewartina magnifica n. sp., also confined to Fusulinid Zone 5, appears to be more advanced than S. convexa, which occurs in cycle LH-3 in the Lenox Hills Formation in the Glass Mountains and the Alacran Formation in the Hueco and Franklin Mountains. Thus, the youngest beds in Fusulinid Zone 5 may be slightly younger than the youngest strata in those areas in Texas. On the basis of these correlations, we assign this zone an Artinskian (late Wolfcampian to early Leonardian) age. Fusulinid Zone 6 This zone probably is equivalent to the zone of Parafusulina leonardensis in north-central Nevada (Stevens et al., 1979) and to

16

C.H. Stevens and P. Stone

the upper Hess Limestone (cycles H-2 through H-7) and Cathedral Mountain Formation (cycle C-1) in the Glass Mountains (Ross and Ross, 2003a, 2003b). We therefore regard this zone as early Kungurian (early Leonardian) in age. COMPARISON OF BIRD SPRING SHELF AND KEELER BASIN FUSULINID FAUNAS West of the Bird Spring Shelf, in the southern Inyo Mountains and adjacent areas, rocks of the Keeler Canyon Formation and lowermost Lone Pine Formation (part of the Owens Valley Group) accumulated in the deep-water Keeler Basin (Stevens et al., 2001). The Keeler Canyon Formation (Fig. 10A) is represented primarily by bioclastic turbidites interbedded with dark hemipelagic limestones; the overlying lower member of the Lone Pine Formation consists primarily of thin-bedded calcareous mudstone, siltstone, and very fine grained sandstone. Deposition of carbonate sediment in the area of the Keeler Basin apparently began in Morrowan (Early Pennsylvanian) time, probably more or less simultaneously with the initial deposition of the Bird Spring Formation on the shelf (Stone, 1984; Stone and Stevens, 1984). As on the shelf, fusulinids in the Keeler Basin did not become abundant until Virgilian time. From the Virgilian into the Sakmarian (middle Wolfcampian), however, fusulinid faunas are abundant and deposition in the Keeler Basin apparently was continuous. Ten fusulinid zones, referred to as F1 to F10 (Stevens et al., 2001), are recognized in the rocks of the Keeler Basin (Fig. 11). All faunas in the Keeler Basin were transported from shallow into deep water in sediment-gravity flows, and although there apparently was some mixing of faunas of different ages, a consistent biostratigraphy was developed (Stevens et al., 2001). Because of the lack of any other likely source, we consider these faunas to have originated on the Bird Spring Shelf to the east. Both fusulinids and conodonts have been recovered from the Keeler Canyon and lowermost Lone Pine formations in the

A

Keeler Canyon Fm

southern Inyo Mountains and adjacent areas. The conodont faunas were correlated with Global Stages by Stevens et al. (2001). In this paper the associated fusulinids are correlated with those of the Bird Spring Shelf (Fig. 11), from which few conodonts have been recovered. The oldest sample in our fusulinid collections from the Bird Spring Shelf is from low in the Striped Butte section. This sample (S-1968) can be correlated with Zone F3 in the Keeler Canyon Formation on the basis of a primitive form of Triticites similar to T. burgessae. This species was considered Missourian by Stevens et al. (2001). We have assigned no fusulinid zone to this occurrence on the shelf because of the paucity of material. Fusulinid Zone 1 of the Bird Spring Shelf is correlated with Zone F4 of the Keeler Basin (Fig. 11) based on the common occurrence of Triticites hermanni. In addition, T. bensonensis, which occurs in the Bird Spring Formation, is similar to T. whetstonensis of the Keeler Basin. Stevens et al. (2001) considered this fauna as early Gzhelian (Virgilian) in age on the basis of conodonts. Fusulinid Zone 2 of the Bird Spring Shelf is characterized by Triticites cellamagnus and T. californicus. Specimens very similar to both of these species are common in turbidites of Zones F5 and F6 and sparse in those of Zone F7 of the Keeler Basin. Zone F5 of late Gzhelian (Bursumian) age (Stevens et al., 2001) is dominated by such species and is interpreted to correlate with Fusulinid Zone 2 on the Bird Spring Shelf. In addition to species of Triticites, however, Zones F6 and F7 of Asselian age (Stevens et al., 2001) also contain fusulinids that occur only higher than Zone 2 on the Bird Spring Shelf. These include relatively advanced species of Schwagerina such as S. aculeata in Zone F6 and Pseudoschwagerina in Zone F7. We therefore interpret Zones F6 and F7 of the Keeler Basin as younger than Fusulinid Zone 2 of the Bird Spring Shelf, and the specimens of Triticites in these zones to have been reworked from older deposits. The lower part of Fusulinid Zone 3 of the Bird Spring Shelf contains several species similar to those in Zones F9 and F10 of

B

Darwin Canyon Fm

Figure 10. General views of turbidite sequences in Keeler and Darwin Basins. (A) Limestone turbidites of Keeler Canyon Formation (Keeler Basin), near Ubehebe Mine. (B) Interbedded siliciclastic and limestone turbidites of Darwin Canyon Formation (Darwin Basin), Darwin Canyon.

Bird Spring Formation

Sakmarian

Panamint Springs Member Unit 7 E

Unit 6

A-D

Unit 5 Unit 4 Unit 3 Unit 2 Unit 1

Osborne Canyon Formation Zone 3

Conglomerate Mesa area Sedimentary rocks of Santa Rosa Flat

Zone 5

Zone 4 Wolfcampian

Darwin Canyon area

Millers Spring Member

Zone 6

17

Darwin Basin Stratigraphic Units (Magginetti et al., 1988; Stone et al., 1989)

Kungurian

Artinskian

Permian

Keeler Basin Fusulinid Zones (Stevens et al., 2001)

Darwin Canyon Formation

Leonaradian

Stage

Bird Spring Shelf Fusulinid Zones (This Paper)

Lone Pine Formation

System

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf

Units 8–10 Hiatus? Unit 7 Unit 6 Unit 5 Unit 4

Unit 3 Unit 2 Unit 1 Osborne Canyon Formation

F10

Asselian

Pennsylvanian

Hiatus?

Bursumian

Zone 2

Virgilian

Zone 1

Missourian

pre-Zone 1

Keeler Canyon Formation

F9 F8 F7 Hiatus

Hiatus

F6 F5 F4 F3

Figure 11. Correlation of fusulinid zones of the Bird Spring Shelf with coeval basinal sections in east-central California. Note that fusulinid zones in the Keeler Canyon Formation have been correlated with stages defined by conodonts (Stevens et al., 2001).

the Keeler Basin, suggesting that these units correlate (Fig. 11). The key species include Stewartina sp. 1, which is similar to a species referred to Reticulosepta? sp. 5 from Zone F9; Pseudoschwagerina arta, which is close to Pseudoschwagerina aff. P. parabeedei in Zone F9; Stewartina uber, which resembles Stewartina spp. 1 and 2 from Zones F10 and F9, respectively; and Pseudochusenella hazzardi n. sp. and P. buttensis n. sp., which are similar to P. cf. P. jewetti from Zone F9. We interpret rocks correlative with Zones F6 through F8 of the Keeler Basin to be missing at the inferred disconformity between Fusulinid Zones 2 and 3 on the Bird Spring Shelf at Warm Spring Canyon, at Striped Butte, and very likely in the Providence Mountains and elsewhere on the shelf. The upper part of Fusulinid Zone 3 and Fusulinid Zones 4–6 of the Bird Spring Shelf are younger than the youngest fusulinid faunas of the Keeler Basin.

COMPARISON OF BIRD SPRING SHELF AND DARWIN BASIN FUSULINID FAUNAS The Darwin Basin, represented by outcrops of the Owens Valley Group in the Argus Range, Darwin Canyon area, and southeastern Inyo Mountains (Fig. 1), immediately east of the older Keeler Basin, developed after deposition in the Keeler Basin ended. In the Argus Range and Darwin Canyon area, the basin section consists of the Osborne Canyon Formation and the overlying Darwin Canyon Formation (Fig. 10B), which consists of a lower Millers Spring Member and an upper Panamint Springs Member (Stone et al., 1987; Magginetti et al., 1988). In the southeastern Inyo Mountains near Conglomerate Mesa, the section was divided into the Osborne Canyon Formation and the overlying sedimentary rocks of Santa Rosa Flat by Magginetti

18

C.H. Stevens and P. Stone

et al. (1988) and Stone et al. (1989). Strata of the Darwin Basin comprise a variety of silty, sandy, calcareous, and conglomeratic rocks that originated as marine turbidites and debris-flow deposits (Stevens et al., 1989). Both fusulinids and corals provide ties between the Bird Spring Shelf and the Osborne Canyon Formation (Fig. 11). A species that Magginetti et al. (1988) assigned to Pseudoschwagerina uddeni, but which we now would place in P. roeseleri, occurs in the basal part of the Osborne Canyon Formation in Darwin Canyon; P. roeseleri is typical of the middle part of Fusulinid Zone 3 of the Bird Spring Shelf. A species that Magginetti et al. (1988) referred to as Stewartina? sp. A from the upper part of the Osborne Canyon Formation is similar to S. convexa, which first appears in the upper part of Fusulinid Zone 3 of the Bird Spring Shelf. Finally, the colonial coral Protowentzelella, which is typical of Fusulinid Zone 3, also occurs in the Osborne Canyon Formation in Darwin Canyon. The Osborne Canyon Formation in Darwin Canyon is approximately correlative with rocks assigned to the Osborne Canyon Formation in our section at Panamint Butte (Fig. 8), which contains the typical Zone 3 fusulinids Schwagerina cf. S. elkoensis and S. vervillei. Rocks assigned to the Osborne Canyon Formation near Conglomerate Mesa are considered correlative with Fusulinid Zone 3 of the Bird Spring Shelf even though they contain species characteristic of Fusulinid Zone 2, including forms we now place in Triticites cellamagnus, T. aff. T. californicus, and Leptotriticites sp. 2. These fusulinids are here considered to have been reworked from older deposits because they occur in turbidites and the Osborne Canyon Formation elsewhere represents Fusulinid Zone 3. Alternatively, the rocks at Conglomerate Mesa could be older than the type Osborne Canyon Formation. The Darwin Canyon Formation also can be correlated with rocks of the Bird Spring Shelf. The most convincing correlation is between Fusulinid Zone 4 of the shelf and unit 2 of the Millers Spring Member in Darwin Canyon (Fig. 11). Eoparafusulina linearis is common to both units, and the composition of the coral fauna, including species of Protowentzelella and a large caninoid coral unknown anywhere else, is similar. The overlying unit 5 of the Millers Spring Member contains Pseudoschwagerina uddeni, a species occurring in Fusulinid Zones 3 and 4. Unit 6A contains Schwagerina vervillei, a species typical of Fusulinid Zones 3 and 4, although occurring rarely in Zone 5. These two units therefore are also correlated with Fusulinid Zone 4. The first appearance of Chalaroschwagerina, a typical upper Wolfcampian genus, and forms similar to Stewartina convexa and S. magnifica n. sp. in unit 6E of the Millers Spring Member suggest correlation with Fusulinid Zone 5. The sedimentary rocks of Santa Rosa Flat near Conglomerate Mesa also can be correlated with rocks of the Bird Spring Shelf (Fig. 11). Unit 1 of this sequence contains Pseudoschwagerina sp. B of Magginetti et al. (1988), which is similar to our Pseudoschwagerina sp. 1 from Fusulinid Zone 4 of the shelf. The coral Protowentzelella is represented in units 3 and 4 as well as in unit 1 of the sedimentary rocks of Santa Rosa Flat. Thus,

units 1–4, and unit 5, which lacks fusulinids, are provisionally correlated with Fusulinid Zone 4 of the Bird Spring Shelf. Unit 6 of the sedimentary rocks of Santa Rosa Flat, which contains Chalaroschwagerina, Stewartina convexa and S. magnifica n. sp., probably correlates with Fusulinid Zone 5 of the shelf. The overlying unit 7 contains Cuniculinella inyoensis, which is very similar to C. mojavensis n. sp. from Fusulinid Zone 5 of the Bird Spring Shelf, suggesting a close correlation. Finally, units 8–10 of the sedimentary rocks of Santa Rosa Flat contain species of the genus Parafusulina and probably correlate in part with Fusulinid Zone 6 of the Bird Spring Shelf. The above correlations between rocks of the Darwin Basin and the Bird Spring Shelf have resulted in a slightly different correlation between the sections in Darwin Canyon and Conglomerate Mesa than that shown by Magginetti et al. (1988). INTERPRETATIONS AND DISCUSSION General Paleoenvironmental Significance of Fusulinids Fusulinids were widespread during the late Paleozoic, but they show clear signs that the paleoenvironment controlled their distribution. Temperature, salinity, water depth, and substrate were the most important controlling factors, as is true for most modern benthic marine invertebrates. Temperature control is very clear. During the Permian, fusulinids were restricted to warm, tropical to subtropical waters, with a latitude range similar to that of the commonly associated colonial corals, which was shown by Stevens (1985), Stevens et al. (1990), and Fedorowski et al. (2007, Fig. 1A) to extend from ~40° N to 40° S. Rocks representative of coastal margins farther north and south lack fusulinids and corals but commonly contain other shallow-shelf fossils. Another important controlling factor was salinity. Thompson (1964) postulated that fusulinids were stenohaline, tolerating a salinity range similar to that of modern corals and echinoderms, because they never are associated with fossils whose modern counterparts live in brackish-water environments. In the Lower Permian of eastern Nevada, fusulinids occupied a position on the open shelf, far seaward from euryhaline bay and lagoon environments (Yancey and Stevens, 1981). The third major controlling factor was water depth. Yancey and Stevens (1981) showed that although there was considerable overlap of their fusulinid and coral communities, the fusulinids commonly occupied a position farther seaward than many of the corals, especially fasciculate forms, indicating some difference in the ecologic requirements of these two groups. Some colonial corals probably lived in water so shallow that they might have been exposed at extremely low tides. The fusulinids, however, apparently required deeper water. For example, in the Middle Pennsylvanian of Colorado, Stevens (1969) demonstrated that the minimum water depth for fusulinids there was ~13 m. The maximum depth to which fusulinids lived has never been directly established, but a modern analogue of the fusulinids

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf (Alveolinella) is reported to live at depths of 3–5 m in protected areas in a lagoon, but elsewhere at depths of 20–30 m (Severin and Lipps, 1989). Cushman (1921, 1933) reported tests from a maximum depth of 70 m. Ross (1974, 1982) suggested that the fusulinids with keriothecal walls may have been hermatypic (i.e., contained photosynthetic dinoflagellates in the tissues), which would have limited them to depths of less than ~50 m. A fourth environmental factor, substrate composition, was of relatively minor importance for fusulinids as a whole inasmuch as specimens occur in a variety of rock types that range from siliciclastic shales, siltstones, and sandstones to pure carbonate rocks. Different types of fusulinids, however, apparently were adapted to different types of substrates and environments (Ross, 1965). For example, Ross (1982) has shown that large, highly elongate forms preferred rippled calcarenite substrates, whereas inflated forms were more often associated with “patch reef accumulations” or “bioherms” (Ross, 1964). In summary, upper Paleozoic rocks that contain abundant fusulinids reflect deposition in warm, tropical to subtropical, normal marine waters, mostly at depths of ~10–50 m, with different forms occupying slightly different ecologic niches. Therefore, thick sections of upper Paleozoic marine strata that lack fusulinids generally can be interpreted to have been deposited in water either too shallow or too deep for these organisms. In most cases, the difference in the lithologic features of sediment deposited in these two different depth zones makes interpretation relatively straightforward. Nearshore paralic environments, for example, are indicated by unfossiliferous dolomite, silty carbonate rocks that lack stenohaline fossils such as corals and crinoids, and sandstone; deeper-water shelf environments are often represented by dark, micritic limestone characterized by a very limited marine fauna, and black chert nodules; and slope to basinal environments typically are composed of very fine grained rocks with interbedded debris-flow deposits and turbidites. Fusulinid Distribution and Sedimentation Patterns on the Bird Spring Shelf The distribution of fusulinids across the Bird Spring Shelf in southeastern California during Late Pennsylvanian to Early Permian time varies both geographically and stratigraphically, which indicates shifting of environments on the shelf through space and time. These environmental shifts can be used for reconstructing the depositional history of the shelf. The Bird Spring Shelf was established by Early Pennsylvanian time with the initial deposition of the Bird Spring Formation. In southern Nevada, almost the entire Pennsylvanian System of the Bird Spring Shelf is represented by fusulinid-bearing limestone (e.g., Rich, 1961; Cassity and Langenheim, 1966). By contrast, in most of California, the pre–upper Virgilian shelf accumulated micritic limestone largely devoid of calcareous fossils including fusulinids, and containing abundant black chert in rocks of Morrowan to Atokan age (Stone, 1984). These sediments probably were deposited in water too deep to support fusulinids.

19

Fusulinids first became abundant across most of the shelf in California, from the Providence Mountains on the southeast to Panamint Butte on the northwest, during Virgilian to Bursumian time (Fusulinid Zones 1 and 2). Judging from the similarity in faunal content and lithofacies at this time, depositional conditions were relatively uniform across much of the shelf. An exception is in the Ship Mountains, where neither Fusulinid Zone 1 nor 2 is represented. Here correlative strata, some of which are very sandy, were deposited in very shallow water environments inhospitable to fusulinids. Fusulinids became most widespread and abundant on the Bird Spring Shelf during the time of Fusulinid Zone 3 (late Asselian to middle Sakmarian [late early to middle middle Wolfcampian]), spreading as far southeast as the Ship Mountains, where this zone is represented by a section of thick-bedded, fusulinidrich limestone. Conditions in the Ship and Providence Mountains later changed, however, and the fusulinid-bearing section in each range is overlain by hundreds of meters of thin-bedded, chalky to dolomitic limestone and fine-grained sandstone lacking fusulinids. That facies, which extends to the exposed top of the Bird Spring section, represents very shallow water, nearshore conditions unfavorable for fusulinids. At Warm Spring Canyon the sequence is quite different. There, Fusulinid Zone 3 is very thin, and a sharp contact separates thick-bedded limestones of Zone 3 from underlying thinbedded, shaly limestones at the top of Zone 2. At nearby Striped Butte, in contrast, there is no major lithologic change between rocks containing Fusulinid Zone 2 and Zone 3 fusulinids. However, because of the major faunal change between these zones, we infer a disconformity at this level representing nondeposition on the shelf through much of Asselian time (Fig. 9). At Panamint Butte, Fusulinid Zone 3, which includes the upper part of the Bird Spring Formation (Stone, 1984), is represented by a thick sequence of thick-bedded limestone and minor limestone conglomerate composed of transported large, rounded concretions. The limestone conglomerate beds are interpreted as debris-flow deposits (Stone, 1984), suggesting a position on the upper part of a distally steepened ramp at the northwestern margin of the shelf. Zone 3 extends into the overlying Osborne Canyon Formation, which is composed primarily of bioclastic limestone turbidites but also contains limestone conglomerate beds similar to those in the underlying Bird Spring Formation (Stone, 1984). The late Sakmarian (late middle Wolfcampian) Fusulinid Zone 4 is represented by shelf limestones primarily at Cowhole Mountain and Warm Spring Canyon. At Warm Spring Canyon, Zone 4 is abruptly overlain by deeper-water strata of the Owens Valley Group, apparently reflecting sudden subsidence of the shelf. At Cowhole Mountain, the top of Fusulinid Zone 4 is not exposed, and at nearby Old Dad Mountain, this zone has not been recognized. In the Providence Mountains, Zone 4 occurs in thin-bedded, generally unfossiliferous limestone that we interpret to represent the shallowest water environments that fusulinids could tolerate.

20

C.H. Stevens and P. Stone

Fusulinid Zones 5 and 6, which occur in thick-bedded limestones at Old Dad Mountain, indicate the continuation of openshelf sedimentation through Artinskian (late Wolfcampian) into Kungurian (Leonardian) time. To the southeast, in the Ship and Providence Mountains, any sediment accumulating at this time was in paralic and nearshore environments devoid of fusulinids. Evidently, as these shallow-water environments were prograding westward, subsidence was occurring simultaneously on the northwestern part of the shelf at Warm Spring Canyon and Panamint Butte where the coeval sections consist of rocks deposited in slope and basinal environments. Possible Effects of Eustatic Sea-Level Fluctuations Some aspects of fusulinid distribution and depositional patterns on the Bird Spring Shelf in California are here interpreted to have been in response to changes in eustatic sea level. These interpretations are based primarily on a detailed sea-level curve for the late Paleozoic presented by Ross and Ross (1987). The first notable event on the Bird Spring Shelf was the sudden appearance of fusulinids in Zone 1 (Virgilian) and especially their greatly increased abundance in Zone 2 (Bursumian) across much of the study area. Prior to Zone 1 time, most of the shelf, particularly in the northwestern part of the study area (Fig. 1), was characterized by deposition of dark, micritic limestone lacking fusulinids, and is interpreted as representing deep-water deposition. Ross and Ross (1987) showed a major episode of falling sea level in the latest Pennsylvanian, so the abundance of fusulinids in Zones 1 and 2 can be interpreted as due to a lowering of sea level so that depths across much of the shelf fell within the ecologic zone favorable for fusulinids. Continued lowering of sea level at the end of the Pennsylvanian (Ross and Ross, 1987) may have ultimately resulted in a regression of marine environments across much of the shelf, leading to development of the apparent disconformity between Fusulinid Zones 2 and 3. Wilde (2006), in fact, suggested that there may be a worldwide unconformity at this level. This drop in sea level also probably caused the shelf margin to migrate westward to a position where it provided shallow-water carbonate sediment for the voluminous turbidites in fusulinid zones F6 through F8 in the Keeler Basin (Fig. 8). These zones span the apparent depositional gap on the Bird Spring Shelf. A gradual rise in eustatic sea level during Asselian into Sakmarian time (Ross and Ross, 1987) offers an explanation for the maximum development of fusulinids and colonial corals on the Bird Spring Shelf in Fusulinid Zone 3 and the spread of fusulinids and colonial corals as far cratonward as the Ship Mountains. The same transgression also is evident in northwesternmost Arizona, where McNair (1951) reported Pseudoschwagerina and other fusulinids that probably represent Zone 3 as far east as the Grand Wash Cliffs ~120 km northeast of Las Vegas (beyond the area of Figure 1). The regional extent of this transgression is consistent with the interpretation that its cause was a eustatic rise in sea level. The onset of very shallow water sedimentation and the corresponding disappearance of fusulinids in the Ship and Providence

Mountains after Zone 3 time can be correlated with a major drop in sea level in the latter part of the Sakmarian (Ross and Ross, 1987). This event marked the beginning of progradation of shallow-water environments across the shelf. Regional Paleogeographic Evolution The late Paleozoic depositional and tectonic framework of the northwestern part of the region under consideration is relatively well known (e.g., Stone, 1984; Stone and Stevens, 1984; Stevens and Stone, 1988, 2005; Stevens et al., 1997, 2001). This part of the region was characterized primarily by the development of Pennsylvanian to Lower Permian deep-water basins. Here, on the basis of the correlation of fusulinid zones, we link the paleogeographic development of these basins with that of the Bird Spring Shelf to the southeast. For the purpose of this discussion, we recognize the following paleogeomorphic units of Pennsylvanian and Early Permian age: the Bird Spring Shelf, upon which the Bird Spring Formation was deposited; the Tihvipah Ramp, characterized by the Tihvipah Limestone of Stone et al. (1987) and the Tihvipah Member of the Keeler Canyon Formation of Stevens et al. (2001); the Keeler Basin, in which units of the Keeler Canyon Formation above the Tihvipah Member were deposited; the Darwin Basin, in which the Osborne Canyon Formation, Darwin Canyon Formation, and sedimentary rocks of Santa Rosa Flat accumulated; and a submarine ridge, here called the Conglomerate Mesa Uplift, which marked the western margin of the Darwin Basin. The Bird Spring Shelf, which extended over a broad area in southern Nevada and southeastern California (Fig. 1), persisted from the Early Pennsylvanian to at least early Kungurian (Leonardian) time. The Morrowan (Early Pennsylvanian) through Atokan (early Middle Pennsylvanian) Tihvipah Ramp extended from the Argus Range westward throughout the Inyo Mountains. The Keeler Basin, which developed above most of the Tihvipah Ramp in Desmoinesian (late Middle Pennsylvanian) time, lasted into the early Sakmarian (early middle Wolfcampian). The Darwin Basin began to develop east of the older Keeler Basin shortly thereafter, in late early Sakmarian time. It expanded to incorporate part of the shelf in the middle Sakmarian (middle middle Wolfcampian), slightly earlier at Panamint Butte, and persisted into the Kungurian (Leonardian). Here, we illustrate the evolving relationships between these paleogeomorphic units by constructing paleogeographic maps based on four time slices: Atokan (early Middle Pennsylvanian), Bursumian (Late Pennsylvanian), late Sakmarian (late middle Wolfcampian), and middle Artinskian (late Wolfcampian) (Fig. 12). During the Atokan, the Bird Spring Shelf extended westward into the Panamint Range and Cottonwood Mountains. From there the shelf merged westward into the Tihvipah Ramp (Fig. 12A). The shelf deposits of this age consist primarily of cherty micritic limestone. The ramp deposits, represented in the Santa Rosa Hills, Argus Range, and Inyo Mountains (Stone and Stevens, 1988), are similar except they also include intercalated

UM

Slope

PB PBL

PBL CM

CM SRH

SRH

WSC

WSC

DC

Spring

Basin

DC

ATOKAN

SB

BURSUMIAN

CH OD PR

OD PR

SH

CM

SRH

WSC

t ?

?

?

?

?

?

CH

Spring

Uplif

t

MIDDLE ARTINSKIAN

SB

DC

Basin

esa

Spring

Uplif

Basin

esa

DC

PB

SRH

Cgl M

Basin

Cgl M

Basin

SB

Bird

MC

PBL WSC

?

PB

D

LCT UM

Darwin

CM

Lone Pine

PBL

LATE SAKMARIAN

Bird

Darwin

Lone Pine

MC

SH

25 KM

C

LCT UM

0

?

?

25 KM

Shelf

N

Shelf

N

?

?

? CH

0

PB

Spring

Ramp

SB

B

MC

Bird

Bird

MC

r Keele

A

h Tihvipa

UM

OD PR

OD PR CH

Shelf

25 KM

?

0

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SH

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25 KM

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0

N

Shelf

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SH

Figure 12. Paleogeographic maps illustrating evolution of the Bird Spring Shelf and adjacent basins during Pennsylvanian and Early Permian time. (A) Atokan. (B) Bursumian. (C) Late Sakmarian. (D) Middle Artinskian. Localities shown: CH—Cowhole Mountain; CM—Conglomerate Mesa; DC—Darwin Canyon; MC—Marble Canyon; OD—Old Dad Mountain; PB—Panamint Butte; PBL—Permian Bluff; PR—Providence Mountains; SB—Striped Butte; SH—Ship Mountains; SRH—Santa Rosa Hills; UM—Ubehebe Mine; WSC—Warm Spring Canyon. Palinspastic restorations are modified from Snow and Wernicke (2000). In addition, note that localities CM, PBL, and UM in (A) and (B) are in their inferred positions prior to eastward displacement in the upper plate of the Last Chance thrust (LCT) during Sakmarian time (Stevens and Stone, 2005).

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C.H. Stevens and P. Stone

rare turbidites and debris-flow deposits. The section in the northern Argus Range (Fig. 1), east of Darwin Canyon, also contains well-developed slump features (Stone et al., 1987). The easternmost ramp deposits, in the Argus Range and Santa Rosa Hills, are unconformably overlain by considerably younger strata of the Owens Valley Group. In the Inyo Mountains, the ramp deposits are overlain by turbidites of the Keeler Basin. Bursumian rocks contain a fusulinid fauna (Fusulinid Zone 2) dominated by large inflated species of Triticites. These fossils show that the Bird Spring Shelf extended at least as far west as Striped Butte and Panamint Butte during this time interval (Fig. 12B). To the west, the Keeler turbidite basin occupied the area of the Inyo Mountains, where much of the Tihvipah Ramp had been depressed and incorporated into the basin. An intervening area that includes the northern Argus Range, Santa Rosa Hills, and central Cottonwood Mountains (Marble Canyon area) contains few rocks of this age (Stone and Stevens, 1984; Stone et al., 1987) and is interpreted to represent a slope where sparse sediment accumulated. During middle to late Sakmarian (middle Wolfcampian) time, strata bearing rich fusulinid and coral faunas (Fusulinid Zone 3) accumulated on the Bird Spring Shelf. Shelf deposits of this age are especially well developed in the southern Panamint Range, at Cowhole Mountain, and in the Providence Mountains (Fig. 12C). To the west, the former slope in the Argus Range and Santa Rosa Hills was incorporated into the deep-water Darwin Basin, in which a thick sequence of turbidites and debris-flow deposits accumulated. At Panamint Butte, the basal sediments of the Darwin Basin (Osborne Canyon Formation) were deposited directly on the shelf deposits of the Bird Spring Formation, suggesting very rapid subsidence. Farther west, the Conglomerate Mesa Uplift separated the Darwin Basin from the Lone Pine Basin (a successor to the older Keeler Basin) to the west. Prior to middle Artinskian (late Wolfcampian) time (Fusulinid Zone 4), the western margin of the Bird Spring Shelf had receded farther eastward (Fig. 12D) so that the Warm Spring Canyon area was incorporated into the deep-water Darwin Basin, as shown by Stone and Stevens (1988). Elsewhere on the shelf to the south, nearshore and paralic facies had prograded westward across the shelf to include the Ship and Providence Mountains, leaving only a relatively narrow part of the shelf in the Old Dad Mountain area where fusulinid-bearing limestones (Fusulinid Zones 5 and 6) were still accumulating. To the west, the Conglomerate Mesa Uplift remained essentially unchanged. The paleogeography developed during the middle Artinskian (late Wolfcampian) apparently persisted with little change into the Kungurian (Leonardian). Tectonic Interpretations and Timing of the Last Chance Thrust The paleogeographic evolution of the region as outlined above can be related to a protracted period of late Paleozoic tectonism along the western margin of North America. First,

transtension related to truncation of the continental margin resulted in subsidence of the Keeler Basin in Early to Middle Pennsylvanian time (Stone and Stevens, 1988; Stevens et al., 2005). Later, in the Early Permian, contraction resulted in uplift and eastward displacement of the deep-water rocks of the Keeler Basin on the Last Chance thrust, as seen in the southeastern Inyo Mountains near Conglomerate Mesa (Stevens and Stone, 1988, 2005). In the later stages of emplacement of the Last Chance allochthon, thrust loading caused depression of the western part of the Bird Spring Shelf and development of the Darwin Basin (Snow, 1992; Stevens and Stone, 2005). The Conglomerate Mesa Uplift is interpreted as an antiformal stack that developed at the leading edge of the Last Chance allochthon (Stevens and Stone, 2005). Previous work, based on analysis of fusulinids and conodonts from the Keeler Basin (Stevens et al., 2001) and analysis of fusulinids from the Darwin Basin (Magginetti et al., 1988), suggested that emplacement of the Last Chance allochthon began in the early Sakmarian and that the final emplacement and development of the Darwin Basin took place prior to Artinskian (late Wolfcampian) time (Stevens and Stone, 2005). The fusulinid faunas identified in the present report allow us to refine our interpretations of the development of the Last Chance thrust and to correlate events occurring on the Bird Spring Shelf with the development of the Keeler and Darwin Basins. The first indication of deformation in the rocks of the Keeler Basin was a change in the sedimentary character of the basinal deposits at the beginning of Zone F10 time. At that time, hemipelagic strata with sparse bioclastic sediment-gravity-flow deposits, assigned to the lower member of the Lone Pine Formation, replaced the richly bioclastic strata of the Keeler Canyon Formation. We interpret this marked reduction in the influx of bioclastic sediment-gravity-flow deposits to reflect initial uplift and eastward transport of the Keeler Basin rocks on the Last Chance thrust, which apparently separated this basin from most of its former sediment source. Deformation at this time also may have steepened the slope that connected the Keeler Basin with the Bird Spring Shelf (Fig. 12B), leading to submarine erosion and development of the unconformity that separates the initial deposits of the Lower Permian Darwin Basin (Osborne Canyon Formation) from Middle Pennsylvanian deposits of the Tihvipah Ramp (Stone et al., 1987; Stevens et al., 2001). Continued development of the Last Chance allochthon resulted in formation of a topographic high, the Conglomerate Mesa Uplift, and major subsidence of the western part of the Bird Spring Shelf, creating the Darwin Basin (Fig. 12C). Evidence of the latter phases of deformation is recorded in the Bird Spring Shelf deposits of Fusulinid Zone 4 in the southern Panamint Range and in deposits of the Darwin Basin. At this time the shelf evidently became unstable, resulting in collapse and emplacement of massive sediment-gravity-flow deposits in Unit 2 of the Millers Spring Member (Stevens et al., 1989) in Darwin Canyon. In the southern Panamint Range (Warm Spring Canyon), this event was closely followed by further subsidence of the shelf,

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf

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The two most important tectonic events that occurred during evolution of the Bird Spring Shelf in east-central California were development of the Keeler Basin west of the shelf beginning in the Early to Middle Pennsylvanian (Stevens et al., 2001)

duc Hav tion ? alla h B Def asin ? orma tion ? Dry Mtn Belt Trou SHE gh LF

TECTONIC CORRELATIONS

and emplacement of the Last Chance allochthon along the western margin of the shelf in the Early Permian (Stevens and Stone, 2005). Both events can be related to other tectonic events known elsewhere in western North America (Fig. 13). Development of the Keeler Basin was approximately simultaneous with the collision of South America–Africa (Gondwana) with North America (Laurentia) along the Ouachita-Marathon orogenic belt and with the origin of cratonal uplifts and basins of the ancestral Rocky Mountain region (Kluth and Coney, 1981). At the time of this major orogenic episode, a northwest-trending zone of sinistral faulting (late Paleozoic continental truncation fault on Figure 3, more or less equivalent to the CaliforniaCoahuila transform of Dickinson, 2000) is thought to have been initiated along the western margin of North America (Fig. 13A). The tectonic relationship of this sinistral fault zone to continental collision and development of the Ouachita-Marathon belt is uncertain, although Stevens et al. (1993) and Dickinson (2000) have suggested that it accommodated southeastward subduction of oceanic crust beneath Gondwana (Fig. 13A). Whatever the origin of the fault zone, the Keeler Basin developed a short distance to the east as part of the “borderland” shown in Figure 3, probably as a result of transtension as originally suggested by Stone and Stevens (1988). The second event, emplacement of the Last Chance allochthon, was approximately coeval with continental-margin deformation in northeastern Nevada (Fig. 13B). There, Trexler et al. (2004) have described a series of contractional deformations that affected rocks in the foreland of the remnant Antler Belt from Middle Pennsylvanian to Early Permian time. One event, the P1 deformation of Trexler et al. (2004), expressed by open, northeast-trending folds, occurred in the late Asselian, just prior to emplacement of the Last Chance thrust. Slightly later, in the same general region, the north-northeast-trending Dry Mountain

Hyp o Isla thetica nd Arc l sub

as indicated by the transition from the shelf deposits of the Bird Spring Formation to the overlying basinal deposits of the Owens Valley Group (Fig. 12D) (Stone, 1984; Stone and Stevens, 1984). Drowning of the Bird Spring Shelf in this area coincided with the cessation of fossil-bearing sediment-gravity flows into the Darwin Basin, as shown by the lack of such deposits in the relatively fine grained, thin-bedded Panamint Springs Member of the Darwin Canyon Formation (Stone et al., 1987). Near Conglomerate Mesa at the western margin of the Darwin Basin, unit 2 of the sedimentary rocks of Santa Rosa Flat, which may be correlative with the lower part of Fusulinid Zone 4 of the Bird Spring Shelf, apparently abuts the antiformal stack at the front of the Last Chance thrust, and unit 3 overlaps it (Stone et al., 1989). Thus, emplacement of the Last Chance thrust evidently had been completed when the shelf in the southern Panamint Range subsided. In summary, our data indicate that emplacement of the Last Chance allochthon began early in Bird Spring Shelf Fusulinid Zone 3 time and was completed early in Fusulinid Zone 4 time. Emplacement of the allochthon, therefore, represents much of Sakmarian (middle Wolfcampian) time, which lasted ~10 m.y. according to Gradstein et al. (2004). Displacement on the thrust was ~30 km (Stevens and Stone, 2005) indicating a rate of 3+ mm/yr. As the allochthon shifted eastward, so did the locus of subsidence due to loading, as recorded by the sequence of sedimentological events discussed above.

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Figure 13. Maps showing major paleotectonic features related to the Bird Spring Shelf. (A) Middle Pennsylvanian. (B) Early Permian. Modified from Stevens et al. (1993), Dickinson (2000) and Trexler et al. (2004). Shaded areas are uplifts of the ancestral Rocky Mountains.

24

C.H. Stevens and P. Stone

trough of Stevens (1979) developed after deposition of the Riepe Spring Limestone, the youngest beds of which were dated early Sakmarian by Wardlaw et al. (1998). This feature, therefore, formed simultaneously with emplacement of the Last Chance thrust. The Dry Mountain trough migrated eastward through time (Stevens, 1979), suggesting that it developed as a result of thrust loading farther west. Thus, this trough is analogous to the Darwin Basin of east-central California, which developed in the foreland of the Last Chance allochthon. It therefore seems likely that the Early Permian structural features in east-central California and northeastern Nevada were part of a single, broadly defined belt of deformation (Fig. 13B), even though precise connections between the individual features cannot be made. Dickinson (2000) suggested that the driving force behind this deformation was convergence and northwest-directed subduction of the continental margin beneath a hypothetical island arc (Fig. 13B). The sinistral transform fault that was initiated near the western margin of North America in the Pennsylvanian continued to be active into the Early Permian, eventually slicing off a continental fragment that now constitutes the Caborca block (Fig. 13B) and transporting it southeastward to its present location in Mexico (Stone and Stevens, 1988; Stevens et al., 2005). Removal of the Caborca block placed the Bird Spring Shelf close to the northwest-trending, truncated continental margin.

Basin were thrust above the western margin of the Bird Spring Shelf as part of the Last Chance allochthon. At this time, a new turbidite basin (the Darwin Basin) subsided in the foreland of the Last Chance allochthon and the western margin of the Bird Spring Shelf receded to the east. This event probably was driven by convergence at the western edge of the continental margin and was a precursor to subduction and arc magmatism, which became widespread by the Triassic. SYSTEMATIC PALEONTOLOGY Family FUSULINELLIDAE Staff and Wedekind, 1910 Genus PSEUDOFUSULINELLA Thompson, 1951 Members of this genus are sparse in the samples studied; we recognize only one species. PSEUDOFUSULINELLA cf. P. HARBAUGHI Skinner and Wilde, 1965 Plate 1, Figure 4 Discussion.—The available specimens are slightly smaller, but otherwise rather closely resemble the types from the McCloud Limestone in eastern Klamath Mountains. Figured specimen.—SJS 144f, sample 81-PB-35, Panamint Butte. Occurrence.—81-PB-35; Fusulinid Zone 1.

SUMMARY The Bird Spring Shelf, represented by the Pennsylvanian– Early Permian Bird Spring Formation, was a broad area of shallow-water carbonate sedimentation that covered a large part of southeastern California and southern Nevada. This shelf was part of the western continental margin of North America that lay close to the Permian paleoequator. In this study of the fusulinid faunas from seven outcrop areas of the Bird Spring Shelf in southeastern California, ten new species and 59 additional species are described. These fossils define six fusulinid zones that are correlated with Global Stages, with several other fusulinid-bearing sections in the United States, and with local, coeval basinal deposits to the northwest. These correlations indicate that sea-level fluctuations had an important effect on deposition on the shelf and allow a refined analysis of the Late Pennsylvanian to Early Permian paleogeographic evolution of the western North American continental margin in California, which was characterized by a protracted period of tectonic activity. Two tectonic events were of particular significance in the paleogeographic evolution of the region. First, in Early to Middle Pennsylvanian time, the continental margin was truncated along a northwest-trending, sinistral fault zone that probably was tectonically linked to the late Paleozoic collision between Laurentia and Gondwana. This event led to development of an unstable borderland west of the Bird Spring Shelf. The easternmost element in this borderland was the Keeler Basin, which was filled with a thick sequence of calcareous turbidites derived largely from the shelf to the east. Later, in the Early Permian, rocks of the Keeler

Family TRITICITIDAE Davydov, 1986 Genus TRITICITES Girty, 1904 In collections we obtained from the Bird Spring Formation, we recognize 12 species of this genus, of which two, T. buttensis and T. gigantocellus, are considered new and are described here. Other species are T. bensonensis, T. cf. T. burgessae, T. californicus, T. aff. T. californicus, T. cellamagnus, T. elegantoides, T. hermanni, T. muddiensis, T. aff. T. rothi, and T. sp. 1. TRITICITES BENSONENSIS Ross and Tyrrell, 1965 Plate 1, Figure 6 Discussion.—The specimens from California have delicate structures with septa strongly folded near the poles, and with a form ratio of ~2.2 at six and one-half volutions. These specimens closely resemble the types from Arizona except that they are slightly more elongate. Figured specimen.—SJS 148f, sample S-1458, Providence Mountains. Occurrence.—S-1458, S-1847, S-1873?, 81-PB-35; Fusulinid Zone 1. TRITICITES cf. T. BURGESSAE Burma, 1942 (not illustrated) Discussion.—The California specimens are poorly preserved, but their size and shape, size of the proloculus, and nature of the chomata are similar to the types, which are characteristic of early Missourian strata in the Midcontinent United States. Occurrence.—S-1968; pre–Fusulinid Zone 1.

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14 15 Plate 1. Fusulinids from the Bird Spring Formation. All about ×8 except as noted. 1: Triticites muddiensis Cassity and Langenheim, 1966 (SJS 216f, sample S-1458, Providence Mountains). 2: Triticites sp. 1 (sample USGS f14074, Providence Mountains). 3: Triticites hermanni Skinner and Wilde, 1965 (SJS 143f, sample S-1874, Providence Mountains). 4. Pseudofusulinella cf. P. harbaughi Skinner and Wilde, 1965 (SJS 144f, sample 81-PB-35, Panamint Butte). (about ×16). 5, 10, 12: Triticites gigantocellus n. sp. (5, USNM 531295, and 10, USNM 531296, paratypes, both from sample S-0382, Warm Spring Canyon; 12, USNM 531294, holotype, sample S-1915, Striped Butte). 6: Triticites bensonensis Ross and Tyrrell, 1965 (SJS 148f, sample S-1458, Providence Mountains). 7: Triticites cellamagnus Thompson and Bissell, 1954 (SJS 149f, sample S-1456, Providence Mountains). 8: Triticites aff. T. californicus Thompson and Hazzard, 1946 (SJS 150f, sample 81-PB-27, Panamint Butte). 9: Triticites californicus Thompson and Hazzard, 1946 (SJS 151f, sample S79-SB-26, Striped Butte). 11: Leptotriticites sp. 3 (SJS 152f, sample S-1965, Warm Spring Canyon). 13: Leptotriticites sp. 4 (SJS 153f, sample S79-WS-20, Warm Spring Canyon). 14, 15: Triticites buttensis n. sp. (14, USNM 531292, paratype; 15, USNM 531293, holotype; both from sample S-1915, Striped Butte).

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13 Plate 2. Fusulinids from the Bird Spring Formation. All about ×8. 1: Leptotriticites aff. L. hatchetensis Skinner and Wilde, 1965 (sample USGS f14074, Providence Mountains). 2, 3: Leptotriticites panamintensis n. sp. (2, USNM 531297, holotype; 3, USNM 531298, paratype; both from sample S-1912, Panamint Butte). 4: Leptotriticites cf. L. varius Wilde, 2006 (SJS 158f, sample S-1869, Providence Mountains). 5: Leptotriticites wetherensis (Thompson, 1954) (SJS 159f; sample S-1869, Providence Mountains). 6: Leptotriticites cf. L. hughesensis (Thompson, 1954) (SJS 160f, sample S-1460, Providence Mountains). 7: Leptotriticites aff. L. americanus (Thompson, 1954) (SJS 161f, sample S-1926, Striped Butte). 8, 9: Leptotriticites glenensis (Thompson, 1954) (8, SJS 162f; 9, SJS 163f; both from sample S-1869, Providence Mountains). 10, 12: Leptotriticites californicus n. sp. (10, USNM 531312, holotype; 12, USNM 531313, paratype; both from sample 82-WS-14, Warm Spring Canyon). 11, 13: Leptotriticites warmspringensis n. sp. (11, USNM 531299, holotype, sample S-1966; 13, USNM 531300, paratype, sample 82-WS-14; both from Warm Spring Canyon).

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13 Plate 3. Fusulinids from the Bird Spring Formation. All about ×8. 1: Schwagerina aculeata Thompson and Hazzard, 1946 (SJS 168f, sample S-1945, Ship Mountains). 2: Schwagerina sp. 3 (SJS 169f, sample S-1947, Ship Mountains). 3, 7: Schwagerina vervillei Thompson, 1954 (3, SJS 170f, sample S-1862; 7, SJS 171f, sample S-1866; both from Cowhole Mountain). 4, 6: Schwagerina cf. S. wellsensis Thompson and Hansen, 1954 (4, sample USGS f14067; 6, sample USGS f14070; both from Ship Mountains). 5: Schwagerina? sp. 2 (SJS 172f, sample S-1949, Old Dad Mountain). 8: Schwagerina cf. S. elkoensis Thompson and Hansen, 1954 (SJS 173f, sample S-1911, Panamint Butte). 9: Schwagerina aculeata plena Thompson and Hazzard, 1946 (SJS 174f, sample S-1877, Providence Mountains). 10: Leptotriticites aff. L. gracilitatus Skinner and Wilde, 1965 (SJS 175f, sample S-1859, Cowhole Mountain). 11: Leptotriticites cf. L. koschmanni (Skinner, 1931) (SJS 176f, sample S-1914, Striped Butte). 12: Leptotriticites sp. 2 (SJS 177f, sample S-1869, Providence Mountains). 13: Leptotriticites sp. 1 (SJS 178f, sample S79-WS-20, Warm Spring Canyon).

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11 12 Plate 4. Fusulinids from the Bird Spring Formation. All about ×8. 1: Schwagerina modica Thompson and Hazzard, 1946 (SJS 179f, sample S-1875, Providence Mountains.) 2: Schwagerina cf. S. pugunculus Ross, 1959 (SJS 180f, sample S-1945, Ship Mountains). 3: Schwagerina providens Thompson and Hazzard, 1946 (sample USGS f14067, Ship Mountains). 4: Schwagerina? sp. 1 (SJS 181f, sample S-1915, Striped Butte). 5, 8: Paraschwagerina fairbanksi Skinner and Wilde, 1965 (5, SJS 182f; 8, SJS 183f; both from sample S-1913, Panamint Butte). 6: Pseudoschwagerina sp. 1 (SJS 184f, sample S-1965, Warm Spring Canyon). 7: Advenella bifurcata Wilde, 2006 (SJS 185f, sample S-1911, Panamint Butte). 9: Paraschwagerina elongata Skinner and Wilde, 1965 (SJS 186f, sample S-1945, Ship Mountains). 10: Pseudoschwagerina roeseleri Thompson and Hazzard, 1946 (SJS 187f, sample S-1958, Warm Spring Canyon). 11: Pseudoschwagerina arta Thompson and Hazzard, 1946 (SJS 189f, sample S-1232, Panamint Butte). 12: Schwagerina sp. 4 (SJS 188f, sample 82-WS-2, Warm Spring Canyon).

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11 9 12 Plate 5. Fusulinids from the Bird Spring Formation. All about ×8 1: Schwagerina longissimoidea (Beede, 1916), emend. Thompson, 1954 (sample USGS f14063, Ship Mountains). 2: Stewartina sp. 1 (sample USGS f14073, Ship Mountains). 3, 4: Stewartina uber (Thompson and Hazzard, 1946) (3, SJS 190f, sample S-1461; 4, SJS 191f, sample S-1463; both from Providence Mountains). 5: Stewartina multispira (Thompson and Hazzard, 1946) (sample USGS f14067, Ship Mountains). 6–8: Pseudochusenella buttensis n. sp. (6, USNM 531307, paratype; 7, USNM 531306, holotype; 8, USNM 531308, paratype; all from sample S-1928, Striped Butte). Note: USNM 531308 also contains illustrated specimen of Pseudochusenella? sp. 1 (Plate 6, Fig. 4). 9: Pseudoschwagerina cf. P. gerontica Dunbar and Skinner, 1937 (SJS 195f, sample S-1465, Providence Mountains). 10–12: Pseudochusenella hazzardi n. sp. (10, USNM 531315, paratype; 11, USNM 531316, paratype; 12, USNM 531314, holotype; all from sample USGS f14074, Providence Mountains).

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9 Plate 6. Fusulinids from the Bird Spring Formation. All about ×8. 1, 4: Pseudochusenella? sp. 1 (1, SJS 196f; 4, USNM 531308; both from sample S-1928, Striped Butte). Note: USNM 531308 also contains paratype of Pseudochusenella buttensis n. sp. (Plate 5, Fig. 8). 2: Stewartina uber (Thompson and Hazzard, 1946) (SJS 198f, sample S-1463, Providence Mountains). 3, 5: Pseudochusenella concisa (Thompson and Hazzard, 1946) (3, Stanford University Paleo. Type Coll., #7692, holotype, sample III-9 of Thompson and Hazzard [1946], Providence Mountains; 5, reversed, negative print of same specimen showing more detail). Originally illustrated by Thompson and Hazzard (1946, Plate 11, Fig. 9). 6: Stewartina texana (Dunbar and Skinner, 1937) (SJS 199f, sample S-1462, Providence Mountains). 7: Pseudoschwagerina uddeni (Beede and Kniker, 1924) (SJS 200f, sample S-1465, Providence Mountains). 8, 9: Stewartina ultimata n. sp. (8, USNM 531304, holotype; 9, USNM 531305, paratype; both from sample S-1949, Old Dad Mountain).

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7 Plate 7. Fusulinids from the Bird Spring Formation. All about ×8. 1. Triticites elegantoides Ross, 1965 (SJS 203f, sample S-1874, Providence Mountains). 2. Stewartina convexa (Thompson, 1954) (SJS 204f, sample S-1851, Old Dad Mountain). 3. Parafusulina sp. 1 (SJS 205f, sample S-1946, Old Dad Mountain). 4. Parafusulina aff. P. durhami Thompson and Miller, 1949 (SJS 206f, sample S-1946, Old Dad Mountain). 5–7. Cuniculinella mojavensis n. sp. (5, USNM 531310, paratype; 6, USNM 531311, paratype; 7, USNM 531309, holotype; all from sample S-1852, Old Dad Mountain).

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6 Plate 8. Fusulinids from the Bird Spring Formation. All about ×8. 1: Parafusulina cf. P. shaksgamensis crassimarginata Knight, 1956 (SJS 210f, sample S-1853, Old Dad Mountain). 2, 3: Eoparafusulina linearis (Dunbar and Skinner, 1937) (2, SJS 211f; 3, SJS 212f; both from sample 82-WS-2, Warm Spring Canyon). 4–6: Stewartina magnifica n. sp. (4, USNM 531302, paratype; 5, USNM 531301, holotype; 6, USNM 531303, paratype; all from sample S-1843, Old Dad Mountain).

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf TRITICITES BUTTENSIS n. sp. Plate 1, Figures 14, 15 Diagnosis.—This fusulinid is a large, elongate species with gently convex lateral slopes. Mature shells of six volutions range from 8.6 mm long and 3.5 mm wide to 10.8 mm long and 4.5 mm wide, giving a form ratio of 2.2–2.3. The proloculus is 0.52– 0.54 mm in diameter and growth is uniform throughout. The spirotheca is moderately thick to thick, and septa are highly fluted in the polar regions, decreasing rapidly toward the proloculus. In the sixth volution the tunnel angle is 40–50°. Chomata are well developed in the first two volutions where they appear to be relatively symmetrical; they also occur sporadically in later chambers. Etymology.—Named for Striped Butte, where the types were collected. Types.—Holotype-USNM 531293 (Plate 1, Fig. 15); paratype-USNM 531292 (Plate 1, Fig. 14). Both from sample S-1915, Striped Butte. Discussion.—This species differs from T. cellamagnus Thompson and Bissell in having a larger form ratio and a larger proloculus. It is somewhat similar to T. mutabilis Wilde, but the former has thicker walls and a much larger proloculus. Occurrence.—S-0382, S-1915, S-1927, S79-SB-28; Fusulinid Zone 2. TRITICITES CALIFORNICUS Thompson and Hazzard, 1946 Plate 1, Figure 9 Discussion.—Specimens studied have a form ratio of ~1.4, well-developed chomata throughout the shell, and a proloculus with an outside diameter of ~0.27 mm. As this species was named for specimens from the Providence Mountains in the Mojave Desert, it is no surprise that the present specimens closely resemble the types. Figured specimen.—SJS 151f, sample S79-SB-26, Striped Butte. Occurrence.—S-0539, S-0617, S-1226, S-1456, S-1910?, S-1915, S-1916, S-1927, S-1932?, S-1933, S-1953, S79-SB-26, 81-PB-27, 81-PB-37, 81-PB-38; Fusulinid Zone 2.

TRITICITES aff. T. CALIFORNICUS Thompson and Hazzard, 1946 Plate 1, Figure 8 Discussion.—These specimens closely resemble T. californicus in most respects, differing primarily in possession of a much smaller proloculus (~0.16 mm) and higher, less massive chomata. Figured specimen.—SJS 150f, sample 81-PB-27, Panamint Butte. Occurrence.—S-0382, S-1456, S-1960, 81-PB-27; Fusulinid Zone 2. TRITICITES CELLAMAGNUS Thompson and Bissell, 1954 Plate 1, Figure 7

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Discussion.—The types of this species are characterized by a large proloculus with an outside diameter of 0.31–0.43 mm, averaging 0.37 mm. It resembles T. californicus Thompson and Hazzard, but differs in being a little more elongate and having less rounded poles and a larger proloculus. The specimen figured here is slightly more inflated than the types with a form ratio of ~1.9, but the outside diameter of the proloculus is 0.39 mm, well within the range of sizes in the type specimens. Thompson and Hazzard (1946) noted that one specimen assigned to T. californicus had a proloculus with a diameter of 0.41 mm. We assign this specimen to T. cellamagnus. Figured specimen.—SJS 149f, sample S-1456, Providence Mountains. Occurrence.—S-0382, S-0616, S-1456, S-1915, S-1927, S-1953, S-1959, S-1960, S79-SB-26, S79-SB-28, 81-PB-38, 81PB-39; Fusulinid Zone 2. TRITICITES ELEGANTOIDES Ross, 1965 Plate 7, Figure 1 Discussion.—The single specimen present has seven volutions and a form ratio of ~2.5. Gentle lateral slopes terminate in rounded poles. Low, rounded chomata bordering a straight tunnel occur in all of the earlier chambers. Figured specimen.—SJS 203f, sample S-1874, Providence Mountains. Occurrence.—S-1874; Fusulinid Zone 1.

TRITICITES GIGANTOCELLUS n. sp. Plate 1, Figures 5, 10, 12 Diagnosis.—The test of T. gigantocellus n. sp. is large and rounded with convex lateral slopes. Mature shells of six and onehalf volutions are ~7.7 mm long and 5.2 mm wide. Form ratios range from 1.4 to ~1.8. The proloculus ranges from ~0.52 mm to 0.74 mm in diameter. Growth is uniform throughout. The spirotheca is thick, especially in the outer volutions. The septa are highly fluted near the polar ends, but fluting decreases rapidly toward the proloculus. The tunnel is quite narrow, ~30° in the last volution, and chomata are well developed in the first three volutions where they are quite asymmetrical. Etymology.—Name reflects the very large size of the proloculus. Types.—Holotype-USNM 531294, sample S-1915, Striped Butte (Plate 1, Fig. 12); paratypes-USNM 531295 and USNM 531296, sample S-0382, Warm Spring Canyon (Plate 1, Figs. 5 and 10). Discussion.—This species resembles T. cellamagnus Thompson and Bissell, T. buttensis n. sp., and T. pinguis Dunbar and Skinner. However, the proloculus is consistently larger than in T. cellamagnus and T. pinguis, although Wilde (2006, Pl. 67, Fig. 5) illustrated one specimen referred to the latter species with a proloculus approaching that of T. gigantocellus in size. The present species has a smaller form ratio and a narrower tunnel angle than T. buttensis n. sp.

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Occurrence.—S-0382, S-1456, S-1915, S-1967; Fusulinid Zone 2.

TRITICITES HERMANNI Skinner and Wilde, 1965 Plate 1, Figure 3 Discussion.—The specimens from eastern California have a form ratio of 3.1–3.2 and a proloculus with an outside diameter of 0.20 mm. Chomata in the inner three to four volutions are narrow, becoming broad in the outer volutions. Other than the shape of the chomata in the inner chambers, the present specimens closely resemble the holotype from the Klamath Mountains, northern California. Figured specimen.—SJS 143f, sample S-1874, Providence Mountains. Occurrence.—S-1870, S-1874; Fusulinid Zone 1.

TRITICITES MUDDIENSIS Cassity and Langenheim, 1966 Plate 1, Figure 1 Discussion.—A typical specimen is 3.6 mm long and 1.8 mm in diameter. The proloculus is ~0.10 mm in outside diameter. This specimen has slightly higher chomata and is less elongate than the holotype of this simple species described originally from the Bird Spring Formation in southern Nevada. It is, however, quite similar to two of the paratypes. Figured specimen.—SJS 216f, sample S-1458, Providence Mountains. Occurrence.—S-1457, S-1458, S-1870; Fusulinid Zone 1. TRITICITES aff. T. ROTHI Skinner, 1931 (not illustrated) Discussion.—Specimens assigned to this species resemble T. rothi but differ in being smaller with less septal fluting. Occurrence.—S-1874, Providence Mountains, Fusulinid Zone 1.

TRITICITES SP. 1 Plate 1, Figure 2 Diagnosis.—The single specimen recovered is elongate with gently convex lateral slopes. The test of eight volutions is 8 mm long and 2.5 mm wide, giving a form ratio of 3.2. The proloculus is small and growth is uniform throughout. The spirotheca is thin. Septal folding is restricted to the polar regions. Chomata are low, but persist throughout most of the test. The tunnel angle in the sixth volution is ~58°. Discussion.—This species resembles a form included in T. rockensis by Thompson (1954, Pl. 9, Fig. 18), described by him as an abnormally elongate specimen. That specimen differs somewhat from the present one, however, in having less prominent chomata. Figured specimen.—USGS f14074, Providence Mountains. Occurrence.—USGS f14074; Fusulinid Zone 3.

Genus LEPTOTRITICITES Skinner and Wilde, 1965 Our collections include many specimens of Leptotriticites. Here we recognize 15 species. Three new species, L. warmspringensis, L. californicus, and L. panamintensis, are described and named. Other species include L. aff. L. americanus, L. glenensis, L. aff. L. gracilitatus, L. aff. L. hatchetensis, L. cf. L. hughesensis, L. cf. L. koschmanni, L. wetherensis, L. cf. L. varius, and four unassigned species. LEPTOTRITICITES aff. L. AMERICANUS (Thompson, 1954) Plate 2, Figure 7 Discussion.—This is a species with very delicate structures, a small proloculus (outside diameter of ~0.12 mm), and a form ratio of ~3.2. The present specimens appear slightly more delicate, are slightly more elongate, and have less axial filling than the holotype, but they fall within the range of specimens shown by Thompson (1954). Figured specimen.—SJS 161f, sample S-1926, Striped Butte. Occurrence.—S-1922, S-1926; Fusulinid Zone 2. LEPTOTRITICITES CALIFORNICUS n. sp. Plate 2, Figures 10, 12 Diagnosis.—This species is characterized by its elongate slender form and its rounded poles. The holotype, consisting of six and one-half volutions, is 10 mm long and 2.4 mm in diameter, giving a form ratio of ~4.2. The proloculus ranges from ~0.1 to 0.2 mm in diameter. The spirotheca is thin and septa are folded throughout much of the test. The chomata are more or less symmetrical and border a tunnel spanning ~30°. Etymology.—The species is named for the State of California. Types.—Holotype-USNM 531312 (Plate 2, Fig. 10); paratype-USNM 531313 (Plate 2, Fig. 12). Both from sample 82WS-14, Warm Spring Canyon. Discussion.—The proportions of this species are similar to that of L. gracilitatus Skinner and Wilde, but the test of L. californicus n. sp. is less cylindrical, septal folding generally is more restricted to the polar regions, the poles are more bluntly rounded, and the test is more loosely constructed. Occurrence.—S-1462, S-1849, S-1912, S-1963, S-1966, S79-WS-20, 82-WS-14; Fusulinid Zones 2(?), 3, and 4. LEPTOTRITICITES GLENENSIS (Thompson, 1954) Plate 2, Figures 8, 9 Discussion.—The California specimens are similar to the types in being rather highly inflated with massive chomata and in having moderate amounts of axial filling. Figured specimens.—SJS 162f (Plate 2, Fig. 8) and SJS 163f (Plate 2, Fig. 9), sample S-1869, Providence Mountains. Occurrence.—S-1460, S-1869; Fusulinid Zone 2. LEPTOTRITICITES aff. L. GRACILITATUS Skinner and Wilde, 1965 Plate 3, Figure 10

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf Discussion.—The California specimens of eight volutions have a form ratio of ~3.9, the proloculus is ~0.13 in outside diameter, and the tunnel angle is ~27° in the last volution. Our specimens resemble the holotype and paratype of this species except that the shell is more cylindrical. Figured specimen.—SJS 175f, sample S-1859, Cowhole Mountain. Occurrence.—S-1462, S-1859, S-1863?, S-1963; Fusulinid Zones 2(?) and 3. LEPTOTRITICITES aff. L. HATCHETENSIS Skinner and Wilde, 1965 Plate 2, Figure 1 Discussion.—The California specimens of seven volutions are 4.3 mm long and 2.1 mm in diameter for a form ratio of ~2.0. The proloculus is minute, ~0.07 mm, and the chomata are very heavy. These specimens resemble the holotype in many respects but differ especially in having very heavy chomata and a somewhat larger form ratio. Figured specimen.—Unnumbered specimen, sample USGS f14074, Providence Mountains. Occurrence.—S-1869, S79-SB-26, USGS f14074; Fusulinid Zones 2 and 3. LEPTOTRITICITES cf. L. HUGHESENSIS (Thompson, 1954) Plate 2, Figure 6 Discussion.—Specimens provisionally assigned to L. hughesensis occur in several of our samples. The California specimens, however, are less elongate than the type specimens, lack the heavy axial filling in the early chambers of the type specimens, and are initially more loosely coiled. This species is less inflated, has less massive chomata, and generally has a smaller proloculus than L. glenensis (Thompson). Figured specimen.—SJS 160f, sample S-1460, Providence Mountains. Occurrence.—S-1460, S-1900, S-1912, S-1914, S-1922, S-1923, S-1929; Fusulinid Zones 2 and 3.

LEPTOTRITICITES cf. L. KOSCHMANNI (Skinner, 1931) Plate 3, Figure 11 Discussion.—Our specimens are almost identical to a form referred to as Dunbarinella koschmanni (Skinner) by Thompson (1954, Pl. 22, Fig. 9). However, Thompson’s specimen is not a topotype and differs from Skinner’s types in its much larger proloculus. For this reason the present specimens are only provisionally assigned to this species. L. pseudokoschmanni Wilde is very similar, but it has a slightly greater form ratio. The present specimens also resemble L. hughesensis (Thompson) to some extent, but the former consistently have larger proloculi and generally more highly fluted septa. Specimens of this species are similar to L. californicus n. sp. but are less elongate. Figured specimen.—SJS 176f, sample S-1914, Striped Butte.

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Occurrence.—S-1900, S-1914, S-1933; Fusulinid Zones 2 and 3. LEPTOTRITICITES PANAMINTENSIS n. sp. Plate 2, Figures 2, 3 Diagnosis.—This species is characterized by its robust form and delicate structures. It has convex lateral slopes and sharply rounded poles. The holotype is 6.4 mm long and has a diameter of 3.0 mm, giving a form ratio of slightly greater than 2.1. The proloculus is ~0.1 mm in diameter. The spirotheca is thin and septa are folded throughout most of the test. The tunnel angle averages ~30° and is bounded by chomata that tend to be irregular in size and shape. Etymology.—The name is derived from Panamint Butte, the type locality. Types.—Holotype-USNM 531297 (Plate 2, Fig. 2); paratype-USNM 531298 (Plate 2, Fig. 3). Both from sample S-1912, Panamint Butte. Discussion.—This species has an overall similarity to L. wetherensis (Thompson). It differs from that species in having much more septal fluting. Occurrence.—S-1912, S-1914; Fusulinid Zone 3.

LEPTOTRITICITES cf. L. VARIUS Wilde, 2006 Plate 2, Figure 4 Discussion.—The California specimens resemble the type specimens from New Mexico except that the former have much less septal folding. Figured specimen.—SJS 158f, sample S-1869, Providence Mountains. Occurrence.—S-1869; Fusulinid Zone 2.

LEPTOTRITICITES WARMSPRINGENSIS n. sp. Plate 2, Figures 11, 13 Diagnosis.—The test of L. warmspringensis n. sp. is very large, achieving a length of at least 14 mm. The holotype has seven volutions and is ~12 mm long and 3.4 mm wide giving a form ratio of ~3.5. The shell has gently sloping convex lateral slopes with rounded poles. Proloculi range in diameter from ~0.1 mm to 0.2 mm. Chamber height increases uniformly throughout growth. The spirotheca is relatively thin and the septa are rather highly folded throughout most of the test. The chomata are massive and are present in all except the last chamber, forming a tunnel angle that averages ~30°. Etymology.—Named for the type locality in Warm Spring Canyon. Types.—Holotype-USNM 531299, sample S-1966 (Plate 2, Fig. 11); paratype-USNM 531300, sample 82-WS-14 (Plate 2, Fig. 13). Both from Warm Spring Canyon. Discussion.—This species bears some resemblance to L. koschmanni (Skinner), but the latter species has a much smaller form ratio and a less cylindrical shape.

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Occurrence.—S-1966, S79-WS-20, 82-WS-14; Fusulinid Zone 4. LEPTOTRITICITES WETHERENSIS (Thompson, 1954). Plate 2, Figure 5 Discussion.—The California specimens very closely resemble the type specimens from Texas except that the septa are more highly folded. Figured specimen.—SJS 159f (Plate 2, Fig. 5), sample S-1869, Providence Mountains. Occurrence.—S-1869, S-1963; Fusulinid Zones 2 and 3(?).

LEPTOTRITICITES sp. 1 Plate 3, Figure 13 Diagnosis.—This species is characterized by its large size and minute proloculus. It attains a length of up to 14 mm and a diameter of 3 mm. The form ratio ranges from ~4.3 to 4.6. The shell commonly is almost cylindrical. The tunnel angle is quite wide, almost 60°. The septa are moderately fluted, but few folds occur in the middle third of the shell. Discussion.—The size, shape, and occurrence of these specimens described here suggest that this “species” may be a microspheric form of L. warmspringensis n. sp., with which it occurs. However, there are more specimens of this form than would be expected if it were a microspheric form, so here it is considered a separate species. Figured specimen.—SJS 178f, sample S79-WS-20, Warm Spring Canyon. Occurrence.—S79-WS-20; Fusulinid Zone 4. LEPTOTRITICITES sp. 2 Plate 3, Figure 12 Diagnosis.—This species is very elongate, achieving a length of at least 10.5 mm and a diameter of 3 mm, giving a form ratio of ~3.5. The proloculus has an outside diameter of 0.17 mm. The lateral slopes are gently convex. The tunnel angle is ~55° and the tunnel is bordered by chomata in the first four or five volutions. Septal fluting is confined to the polar regions. Discussion.—The size of the shell is similar to that of L. californicus n. sp. and L. warmspringensis n. sp. Both of those species, however, have different shapes and septal fluting occurs throughout much more of the test. Figured specimen.—SJS 177f, sample S-1869, Providence Mountains. Occurrence.—S-1459, S-1869; Fusulinid Zone 2. LEPTOTRITICITES sp. 3 Plate 1, Figure 11 Diagnosis.—One specimen attains a length of at least 8.5 mm and a diameter of 2.9, giving a form ratio of 2.9. Some other specimens have slightly lower form ratios. The proloculus is small, the outside diameter being ~0.1 mm. The chomata are high and well developed, and septal folding is moderately well developed.

Discussion.—This species is similar to L. californicus n. sp., but it is less elongate. Figured specimens.—SJS 152f, sample S-1965 from Warm Spring Canyon. Occurrence.—S-1965; Fusulinid Zone 4.

LEPTOTRITICITES sp. 4 Plate 1, Figure 13 Diagnosis.—Test is large, elongate with gentle lateral slopes. Length is ~8.5 mm and width 2.8 mm, giving a form ratio of ~3. The proloculus is ~0.08 mm in diameter; afterwards the shell expands uniformly. Chomata are asymmetric and border a straight tunnel with an angle of ~40°. Septal fluting is mostly restricted to the polar regions. Discussion.—This species resembles L. californicus n. sp. but has a smaller form ratio and less septal fluting. Figured specimen.—SJS 153f, sample S79-WS-20, from Warm Spring Canyon. Occurrence.—S79-WS-20; Fusulinid Zone 4. Family SCHWAGERINIDAE Dunbar and Henbest, 1930 Genus SCHWAGERINA Moeller, 1877 Our collections include numerous specimens of Schwagerina. Here we recognize 15 species, of which 11 are identified or compared to previously described species. These are S. aculeata, S. aculeata plena, S. aff. S. davisi, S. cf. S. elkoensis, S. longissimoidea, S. cf. S. menziesi, S. modica, S. providens, S. cf. S. pugunculus, S. vervillei, and S. cf. S. wellsensis. Four additional species are figured (Plate 3, Figs. 2 and 5; Pl. 4, Figs. 4 and 12), but data are inadequate for formal designations as new species. SCHWAGERINA ACULEATA Thompson and Hazzard, 1946 Plate 3, Figure 1 Discussion.—The specimens in our collections closely resemble the types from the Providence Mountains. Figured specimen.—SJS 168f, sample S-1945, Ship Mountains. Occurrence.—S-1232, S-1850, S-1862, S-1863, S-1875, S-1945, S79-WS-3?, USGS f14063, USGS f14073; Fusulinid Zone 3. SCHWAGERINA ACULEATA PLENA Thompson and Hazzard, 1946 Plate 3, Figure 9 Discussion.—The specimens in our collections closely resemble the types from the Providence Mountains. Figured specimen.—SJS 174f, sample S-1877, Providence Mountains. Occurrence.—S-1236, S-1461, S-1857, S-1860, S-1862, S-1867, S-1876, S-1877, USGS f14071; Fusulinid Zone 3. SCHWAGERINA cf. S. DAVISI Williams, 1963 (not illustrated)

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf

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Discussion.—The present specimen is large; at the seventh volution it is ~12 mm long and 4 mm wide. Axial filling is dense in the early volutions. This species is similar to S. davisi, differing in having coarser structural elements including slightly thicker walls. Occurrence.—S-1845; Fusulinid Zone 5.

Discussion.—The specimens studied closely resemble the holotype from the Providence Mountains. Figured specimen.—Unnumbered specimen, sample USGS f14067, Ship Mountains. Occurrence.—S-1232, S-1850?, S-1876, S-1877, S-1915, S-1931, 81-PB-27, USGS f14067; Fusulinid Zone 3, rarely Zone 2.

SCHWAGERINA cf. S. ELKOENSIS Thompson and Hansen, 1954 Plate 3, Figure 8 Discussion.—The California specimens are large for this species, ranging up to 8.5 mm in length and 3.7 mm in diameter. They are more elongate but otherwise quite similar to S. elkoensis. Figured specimen.—SJS 173f, sample S-1911, Panamint Butte. Occurrence.—S-1227, S-1463, S-1862, S-1911; Fusulinid Zone 3.

SCHWAGERINA cf. S. PUGUNCULUS Ross, 1959 Plate 4, Figure 2 Discussion.—This species has a maximum length of at least 10.5 mm with a diameter of ~3 mm. The first volutions are fairly tight and elongate, and there commonly is a small amount of axial filling in the early volutions. The California specimens tend to be more elongate than the type specimens, but otherwise they are quite similar. Figured specimen.—SJS 180f, sample S-1945, Ship Mountains. Occurrence.—S-1862, S-1867, S-1945; Fusulinid Zone 3.

SCHWAGERINA LONGISSIMOIDEA (Beede, 1916), emend. Thompson, 1954 Plate 5, Figure 1 Discussion.—A single specimen of this species from California has a length of 11.3 mm and a diameter of 2.8 mm, giving a form ratio of 4. The septa are moderately and irregularly folded. Thus, this specimen is similar in all respects to the specimens illustrated by Thompson (1954), including a reillustration of the holotype. Wilde (2006) presented a photograph said to be the holotype that clearly belongs to a different species. This evidently was a mistake. Figured specimen.—Unnumbered specimen, sample USGS f14063, Ship Mountains. Occurrence.—USGS f14063; Fusulinid Zone 3. SCHWAGERINA cf. S. MENZIESI Williams, 1963 (not illustrated) Discussion.—This species attains a length of nearly 10 mm and a diameter of ~2.3 mm. Heavy axial filling is restricted to the first several volutions and the septa are highly folded throughout. Thus, the present species closely resembles the holotype of S. menziesi. Occurrence.—S-1946; Fusulinid Zone 6. SCHWAGERINA MODICA Thompson and Hazzard, 1946 Plate 4, Figure 1 Discussion.—The specimens in our collections are very similar to those described by Thompson and Hazzard (1946) from the Providence Mountains. Figured specimen.—SJS 179f, sample S-1875, Providence Mountains. Occurrence.—S-1875; Fusulinid Zone 3. SCHWAGERINA PROVIDENS Thompson and Hazzard, 1946 Plate 4, Figure 3

SCHWAGERINA VERVILLEI Thompson, 1954 Plate 3, Figures 3, 7 Discussion.—This species attains a length of 7.5 mm and a diameter of 2.5 mm. The septa are highly and quite regularly folded, and axial filling is light. These specimens are very similar to the types of S. vervillei except that they generally have less massive axial filling. Figured specimens.—SJS 170f, sample S-1862 (Plate 3, Fig. 3); SJS 171f, sample S-1866 (Plate 3, Fig. 7). Both from Cowhole Mountain. Occurrence.—S-1227, S-1232, S-1463?, S-1862, S-1864, S-1865, S-1866, S-1949; Fusulinid Zones 3 and 4, rarely Zone 5. SCHWAGERINA cf. S. WELLSENSIS Thompson and Hansen, 1954 Plate 3, Figures 4, 6 Discussion.—This species has a shell up to 10.2 mm long and 3.2 mm in diameter. The septa are highly and evenly folded pole to pole, and a moderate amount of axial filling is present in the earlier volutions. This species bears some resemblance to the holotype of S. wellsensis and appears to overlap the variation recognized by Thompson and Hansen (in Thompson, 1954) in their species. Figured specimens.—Unnumbered specimens, samples USGS f14067 (Plate 3, Fig. 4) and USGS f14070 (Plate 3, Fig. 6), Ship Mountains. Occurrence.—S-1875, S-1876, S-1877, S-1947, USGS f14067, USGS f14070; Fusulinid Zone 3. SCHWAGERINA? sp. 1 Plate 4, Figure 4 Diagnosis.—This species is moderately fusiform with a length of ~7.3 mm and a diameter of 3.0 mm, giving a form ratio of ~2.4 in specimens with seven volutions. The proloculus is minute. After the first three volutions, which increase in

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height gradually, the next chamber is abruptly higher; succeeding chambers then again increase in height gradually throughout the remainder of the shell. Moderate axial filling continues throughout all volutions. Septal folding is rather low and irregular. The tunnel is bordered by chomata in the initial volutions. Discussion.—This species is unlike any described species of Schwagerina, and as it also contains chomata, it is here questionably assigned to the genus. Figured specimen.—SJS 181f, sample S-1915, Striped Butte. Occurrence.—S-1848, S-1915; Fusulinid Zone 2. SCHWAGERINA? sp. 2 Plate 3, Figure 5 Diagnosis.—Shell elongate and lateral slopes taper to sharply rounded poles. The single specimen recovered is 9.2 mm long and 2.3 mm in diameter, giving a form ratio of ~4. The proloculus is small. This is followed by several tightly coiled volutions after which the shell expands more rapidly and uniformly. Axial filling is dense in the inner chambers. The septa are highly and evenly folded throughout the shell. The tunnel is obscure. Discussion.—Cuniculi were not seen in the specimen but are present in the sample. We questionably assign this species to the genus Schwagerina because it is unlike any previously described species of Parafusulina. Figured specimen.—SJS 172f, sample S-1949, Old Dad Mountain. Occurrence.—S-1949; Fusulinid Zone 5. SCHWAGERINA sp. 3 Plate 3, Figure 2 Diagnosis.—Shell robust, specimens of six to seven volutions ~5.5 mm long and 3.0 mm in diameter, giving a form ratio of ~1.8. Proloculus is moderately large, ~0.2 mm in outside diameter. Chomata may be present in the first several volutions, but this was not confirmed because of poor preservation. The tunnel is quite narrow, ~20°. Figured specimen.—SJS 169f, sample S-1947, Ship Mountains. Discussion.—This species does not bear a close resemblance to any described species of Schwagerina. Occurrence.—S-1464, S-1931, S-1947; Fusulinid Zone 3.

SCHWAGERINA sp. 4 Plate 4, Figure 12 Diagnosis.—Shell large and elongate. Specimens with six volutions are 12 mm long and 3.2–3.6 mm in diameter, giving a form ratio of 3.3–3.7. Proloculus 0.1–0.2 mm in diameter. In some specimens the inner two volutions are tightly coiled, but later chambers are higher. The tunnel is rather narrow and commonly obscure. Discussion.—Some specimens resemble S. complexa Thompson but differ from that species in generally being more

elongate, possessing larger proloculi, and commonly lacking tightly coiled inner volutions. Figured specimen.—SJS 188f, sample 82-WS-2, Warm Spring Canyon. Occurrence.—S-1945, S-1965, 82-WS-2, Fusulinid Zones 3 and 4. Genus PSEUDOSCHWAGERINA Dunbar and Skinner, 1936 Specimens belonging to the genus Pseudoschwagerina are numerous in our collections and exhibit a wide variety of form. Four previously described species include P. arta, P. cf. P. gerontica, P. roeseleri, and P. uddeni. One additional, unassigned species also is present. PSEUDOSCHWAGERINA ARTA Thompson and Hazzard, 1946 Plate 4, Figure 11 Discussion.—The specimens in our collections closely resemble the types, which were collected from the Providence Mountains. Figured specimen.—SJS 189f, sample S-1232, Panamint Butte. Occurrence.—S-1232, S-1465, S-1849?, S-1948, S-1965, USGS f14074; Fusulinid Zone 3, rarely Zone 4. PSEUDOSCHWAGERINA cf. P. GERONTICA Dunbar and Skinner, 1937 Plate 5, Figure 9 Discussion.—The California specimens at five volutions are 10.5 mm long and 7.5 mm in diameter, giving a form ratio of 1.4. The juvenarium consists of approximately three volutions, after which there is a large expansion followed by decreasing expansion. The specimens studied are similar to P. gerontica in many respects but differ in being less elongate. Perhaps because they are immature they also lack the polar elongation characteristic of mature specimens of P. gerontica. Figured specimen.—SJS 195f, sample S-1465, Providence Mountains. Occurrence.—S-1465, S79-WS-20; Fusulinid Zones 3 and 4. PSEUDOSCHWAGERINA ROESELERI Thompson and Hazzard, 1946 Plate 4, Figure 10 Discussion.—The specimens studied closely resemble the type specimens of P. roeseleri, which were collected from the Providence Mountains. Figured specimen.—SJS 187f, sample S-1958, Warm Spring Canyon. Occurrence.—S-1875, S-1930, S-1958; Fusulinid Zone 3. PSEUDOSCHWAGERINA UDDENI (Beede and Kniker, 1924) Plate 6, Figure 7

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf Discussion.—Our specimens from California are very similar to specimens illustrated by Ross (1963), which we accept as representative of the species. As observed by Ross (1963) the type specimens of Beede and Kniker probably include several forms of different ages, so it is uncertain which one should be considered the holotype. Figured specimen.—SJS 200f, sample S-1465, Providence Mountains. Occurrence.—S-1461?, S-1463, S-1465, S-1849, S-1850, S-1863, S-1864, S-1867, S-1875, S-1964, S-1969, S79-WS-20, USGS f14073?; Fusulinid Zones 3 and 4.

PSEUDOSCHWAGERINA sp. 1 Plate 4, Figure 6 Diagnosis.—This elongate species of five and one-half volutions attains a length of 8.5 mm and a diameter of 2.7 mm, giving a form ratio of ~3.15. The proloculus is small, ~0.22 mm. The juvenarium consists of two to three tightly coiled volutions in which chomata are prominent. Afterwards expansion is rapid for two volutions and then there is an abrupt decrease in chamber height. Septa are fluted only near the poles. Discussion.—This species resembles P. portalensis Sabins and Ross, except that the California specimens are more elongate and have less septal folding. Figured specimen.—SJS 184f, sample S-1965, Warm Spring Canyon. Occurrence.—S-1864, S-1965; Fusulinid Zone 4. Genus ADVENELLA Wilde, 2006 A single specimen of the monotypic genus, which we accept with some trepidation, is present in our collections. ADVENELLA BIFURCATA Wilde, 2006 Plate 4, Figure 7 Discussion.—In many respects the California specimen resembles A. bifurcata with septal folding appearing intermediate between the specimens shown by Wilde (2006) in his Figures 1 and 2 on Plate 102. The present specimen and those on Plate 102 of Wilde are considerably different from the specimen shown by that author on Plate 101, which we would consider a species of Pseudoschwagerina. Figured specimen.—SJS 185f, sample S-1911, Panamint Butte. Occurrence.—S-1911; Fusulinid Zone 3. Genus PARASCHWAGERINA Dunbar and Skinner, 1936 Two species of Paraschwagerina occurring in southeastern California are here assigned to species previously described from the Klamath Mountains, unlike most other species here described. PARASCHWAGERINA ELONGATA Skinner and Wilde, 1965 Plate 4, Figure 9

39

Discussion.—This species has a proloculus with an outside diameter of ~0.12 mm. The juvenarium consists of two to three volutions. Septa are highly fluted with septal folds commonly reaching the roof of the chamber. The specimen from eastern California is similar to P. elongata except that in the former the expansion from the juvenarium to the remainder of shell is less abrupt. Figured specimen.—SJS 186f, sample S-1945, Ship Mountains. Occurrence.—S-1463, S-1945; Fusulinid Zone 3. PARASCHWAGERINA FAIRBANKSI Skinner and Wilde, 1965 Plate 4, Figures 5, 8 Discussion.—This is a delicate-appearing species with a proloculus of ~0.12 mm and a juvenarium of two to four volutions. The septa are highly and uniformly fluted pole to pole. The studied specimens differ slightly from the types of P. fairbanksi in that the former have smaller and less elongate juvenaria and more rounded poles. This species also resembles P. phrenesa Wilde, but it has a less elongate juvenarium and is generally shorter. Figured specimens.—SJS 182f (Plate 4, Fig. 5) and SJS 183f (Plate 4, Fig. 8), both from sample S-1913, Panamint Butte. Occurrence.—S-1857, S-1913; Fusulinid Zone 3. Family PSEUDOFUSULINIDAE Dutkevich, 1934, emend. A. Miklukho-Maclay, 1959 Genus STEWARTINA Wilde, 1971 Seven species of Stewartina are recognized in our samples. Four of these were previously named: S. convexa, S. multispira, S. texana, and S. uber. Two other species, S. magnifica and S. ultimata, are described as new, and one other species is unassigned. STEWARTINA CONVEXA (Thompson, 1954) Plate 7, Figure 2 Discussion.—The specimens from California conform closely to the characters of the holotype. Figured specimen.—SJS 204f, sample S-1851, Old Dad Mountain. Occurrence.—S-1845, S-1850, S-1851, S-1865, S-1866, S-1867, S-1877, S-1955; Fusulinid Zone 4, rarely Zones 3 and 5. STEWARTINA MAGNIFICA n. sp. Plate 8, Figures 4–6 Diagnosis.—This is a very large species attaining a length of greater than 15 mm and a diameter of 5 mm. The proloculus is ~0.55 mm in diameter. The juvenarium is large but consists of only two to three volutions. Expansion after the juvenarium is moderately abrupt. The septa are highly but rather irregularly fluted throughout most of the shell. The tunnel angle is narrow in the juvenarium, broadening to ~25° in later volutions. Etymology.—Named for the grandeur of the shell. Types.—Holotype-USNM 531301 (Plate 8, Fig. 5); paratypes-USNM 531302 and USNM 531303 (Plate 8, Figs. 4 and 6). All from sample S-1843, Old Dad Mountain.

40

C.H. Stevens and P. Stone

Discussion.—This species resembles S. elongata (Ross and Ross) in some details, but S. magnifica n. sp. tends to have a better defined juvenarium, a generally better defined tunnel, and a much larger proloculus. Occurrence.—S-1843, S-1851, S-1852, S-1919, S-1949; Fusulinid Zone 5. STEWARTINA MULTISPIRA (Thompson and Hazzard, 1946) Plate 5, Figure 5 Discussion.—The specimens in the collections studied closely resemble the holotype, which was collected from the Providence Mountains. Figured specimen.—Unnumbered specimen, sample USGS f14067, Ship Mountains. Occurrence.—S-1461, USGS f14067; Fusulinid Zone 3. STEWARTINA TEXANA (Dunbar and Skinner, 1937) Plate 6, Figure 6 Discussion.—The California specimens closely resemble the cotypes from Texas, appearing to be intermediate between the specimens Dunbar and Skinner (1937) showed in their Figures 4 and 6. Figured specimen.—SJS 199f, sample S-1462, Providence Mountains. Occurrence.—S-1461, S-1462, S-1849; Fusulinid Zone 3. STEWARTINA UBER (Thompson and Hazzard, 1946) Plate 5, Figures 3, 4; Plate 6, Figure 2 Discussion.—The specimens studied were collected in the Providence Mountains, as were the type specimens, which are very similar. Figured specimens.—SJS 190f, sample S-1461 (Plate 5, Fig. 3); SJS 191f (Plate 5, Fig. 4); and SJS 198f (Plate 6, Fig. 2), sample S-1463. All from the Providence Mountains. Occurrence.—S-1461, S-1463, S-1849?, S-1857, S-1860; Fusulinid Zone 3. STEWARTINA ULTIMATA n. sp. Plate 6, Figures 8, 9 Diagnosis.—This is the largest known species of the genus. It attains a length of more than 16 mm and a diameter of 5.5 mm. The form ratio ranges from 2.9 to 3.4. The proloculus ranges from ~0.35 to 0.45 mm in diameter. The juvenarium, which consists of approximately three volutions, is not distinct in most specimens; there is only a very small expansion after development of these first volutions. The septa are highly fluted and in the earlier volutions extend from pole to pole. The folds may be somewhat irregular, but they tend to be regularly spaced. The tunnel is narrow in the juvenarium and is obscure in later volutions. Etymology.—The name reflects the most advanced stage in evolution of the genus. Types.—Holotype-USNM 531304 (Plate 6, Fig. 8); paratype-USNM 531305 (Plate 6, Fig. 9). Both from sample S-1949, Old Dad Mountain.

Discussion.—This species bears some resemblance to S. magnifica n. sp. but differs in having considerably more septal fluting with much more regular folds, a more cylindrical shape, and a smaller proloculus. This species is close to S. elongata (Ross and Ross) from Texas, but the California specimens tend to be a little more cylindrical and elongate, have less regular septal folding, and commonly have a slightly larger proloculus. Occurrence.—S-1949; Fusulinid Zone 5. STEWARTINA sp. 1 Plate 5, Figure 2 Diagnosis.—This is a moderate size species with a rounded outline. It attains a length of 7.7 mm and a diameter of 2.9 mm, giving a form ratio of ~2.7. The proloculus is minute, very small for the genus. The juvenarium is small and consists of two to three volutions. Expansion after the juvenarium is not abrupt. The septa are rather highly, but irregularly, folded throughout the test. The tunnel is narrow and in the juvenarium bordered by prominent, rounded chomata. Discussion.—The present specimens do not closely resemble any described species of the genus. They broadly resemble some specimens placed in S. needhami (Thompson) by Thompson (1954) but differ in tending to have much greater septal folding, being slightly more cylindrical and elongate, and generally possessing a smaller proloculus. Figured specimen.—Unnumbered specimen, sample USGS f14073, Ship Mountains. Occurrence.—S-1860, USGS f14073, USGS f14074; Fusulinid Zone 3. Genus PSEUDOCHUSENELLA Bensh, 1987 Four species of Pseudochusenella have been recognized in the samples from California. One, P. concisa, was described previously. Two others, P. buttensis and P. hazzardi, are here described as new; a fourth, questionably assigned to this genus, is figured, but not formally named. PSEUDOCHUSENELLA BUTTENSIS n. sp. Plate 5, Figures 6–8 Diagnosis.—This small species attains a maximum length of 5.5 mm and a diameter of 2.2 at seven and one-half volutions. The form ratio ranges from 2.4 to 2.5. The proloculus ranges from 0.06 to 0.12 mm in diameter. The first two or three volutions are rather tightly coiled and are followed by a regular increase in height of the chambers; no distinct juvenarium, however, is developed. The middle of the shell is cylindrical. Septal folds are tight and regularly spaced. Axial filling is very dense in all chambers except the earliest volutions and the last one or two volutions. Etymology.—Named for Striped Butte, where the types were collected. Types.—Holotype-USNM 531306 (Plate 5, Fig. 7); paratypes-USNM 531307 and 531308 (Plate 5, Figs. 6 and 8). All from sample S-1928, Striped Butte.

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf Discussion.—The present species superficially resembles Chusenella referta Skinner and Wilde. Our new species is placed in a different genus because it lacks the juvenarium present in true Chusenella. Occurrence.—S-1236, S-1842, S-1928; Fusulinid Zone 3. PSEUDOCHUSENELLA CONCISA (Thompson and Hazzard, 1946). Plate 6, Figures 3, 5 Discussion.—Stewart (1963) considered this species from the Providence Mountains to belong to the genus Chusenella. In specimens he considered topotypes, he observed that they lacked extensive development of chomata as described by Thompson and Hazzard (1946). Our study shows this to be true of the holotype also. Stewart (1963) apparently accepted the description that the initial two volutions are tightly coiled and that the shell expands rapidly from the second to fifth volutions. The holotype, reprinted here, however, actually shows a gradual increase in chamber height throughout growth. For this reason this species is here assigned to the genus Pseudochusenella. Figured specimen.—Stanford University Paleo. Type Coll., #7692, in sample III-9 of Thompson and Hazzard (1946) from the Providence Mountains. Note: Both figures (Plate 6, Figs. 3 and 5) are of the holotype, which was originally illustrated by Thompson and Hazzard (1946, Pl. 11, Fig. 9). Figure 5 is a reversed, negative print showing more detail than the positive print shown in Figure 3. Occurrence.—Sample III-9 of Thompson and Hazzard (1946), Providence Mountains. Fusulinid zone uncertain. Thompson and Hazzard (1946) list this species with two other species. One, Triticites californicus Thompson and Hazzard, is characteristic of Fusulinid Zone 2; the other, Pseudoschwagerina roeseleri Thompson and Hazzard, is restricted to Zone 3. The matrix of the specimen of Pseudoschwagerina does not match that of Triticites californicus and Pseudochusenella concisa, and apparently came from a different sample. P. concisa may have come from the same sample as T. californicus and could thus represent Fusulinid Zone 2, or it may represent an entirely different sample. Because the other species of Pseudochusenella in the region occur near the base of Fusulinid Zone 3, we here provisionally assign this species to Fusulinid Zone 3.

PSEUDOCHUSENELLA HAZZARDI n. sp. Plate 5, Figures 10–12 Diagnosis.—This moderate size species is elongate with rounded poles. The test attains a length of at least 7 mm and a diameter of 2.4 mm, giving a form ratio of ~2.9. The small proloculus is followed by approximately two tightly coiled volutions and then by a regular increase in chamber height. As in P. buttensis, no distinct juvenarium is developed. Axial filling generally is dense except in the first volution or two and in the two or three final volutions. Septa are highly fluted, forming regular loops with parallel sides.

41

Etymology.—Named for John C. Hazzard, pioneer geologist who worked in the Providence Mountains where the specimens were collected. Types.—Holotype-USNM 531314 (Plate 5, Fig. 12); paratypes-USNM 531315 and USNM 531316 (Plate 5, Figs. 10 and 11). All from sample USGS f14074, Providence Mountains. Discussion.—The present species superficially resembles Chusenella cheni Skinner and Wilde but lacks the juvenarium present in that genus. Occurrence.—S-1928, USGS f14074; Fusulinid Zone 3.

PSEUDOCHUSENELLA? sp. 1 Plate 6, Figures 1, 4 Diagnosis.—This small, elongate species reaches a length of 6.0 mm and a diameter of 2.0 mm, giving a form ratio of 3.0. The proloculus is small, 0.06 mm in diameter. The first two to three volutions are tightly coiled, after which the shell expands uniformly. Axial filling is lacking in the first several volutions but then abruptly fills almost all of the polar regions in all but the last volution. Septa are uniformly folded pole to pole. Discussion.—Our specimens somewhat resemble the type of Chusenella chihsiaensis Lee. The first two to three volutions are tightly coiled, suggestive of a juvenarium of the type present in the genus Chusenella. However, because of poor preservation and some uncertainty as to the nature of the juvenarium, this species is questionably assigned to the genus Pseudochusenella. Figured specimens.—SJS 196f (Plate 6, Fig. 1) and USNM 531308 (Plate 6, Fig. 4), both from sample S-1928, Striped Butte. Note: USNM 531308 also contains a paratype of Pseudochusenella buttensis n. sp. (Plate 5, Fig. 8). Occurrence.—S-1928; Fusulinid Zone 3. Genus CUNICULINELLA Skinner and Wilde, 1965 Only one species of this genus has been identified in our collections, a new species for which we propose the name C. mojavensis.

CUNICULINELLA MOJAVENSIS n. sp. Plate 7, Figures 5–7 Diagnosis.—Specimens of six to seven volutions attain a length of 15 mm and a diameter of 4.2 mm, with form ratios ranging from 3.6 to 3.9. The proloculus is ~0.40 mm in diameter. Chambers increase in height rather uniformly throughout growth. All structural elements are coarse, giving the shell a rugged appearance. The lateral slopes are gently convex and descend to rounded poles. The septa are highly folded with the folds mostly irregularly formed. Cuniculi are present. Etymology.—Named for the Mojave Desert. Types.—Holotype-USNM 531309 (Plate 7, Fig. 7); paratypes-USNM 531310 and USNM 531311 (Plate 7, Figs. 5 and 6). All from sample S-1852, Old Dad Mountain. Discussion.—This species resembles C. inyoensis Magginetti, Stevens, and Stone in many details, but the studied speci-

42

C.H. Stevens and P. Stone

mens have less regular septal folding and the earlier volutions tend to be less elongate. Occurrence.—S-1843, S-1852, S-1949; Fusulinid Zone 5. Genus EOPARAFUSULINA Coogan, 1960 Although there is some variation in the specimens studied, all are assigned to a single species, E. linearis. EOPARAFUSULINA LINEARIS (Dunbar and Skinner, 1937) Plate 8, Figures 2, 3 Discussion.—The specimens from California are moderately variable in their form ratios and amount of axial filling. Many specimens, however, are nearly identical to Dunbar and Skinner’s cotype figured on their Plate 6, Figure 15. Figured specimens.—SJS 211f (Plate 8, Fig. 2) and SJS 212f (Plate 8, Fig. 3), sample 82-WS-2, Warm Spring Canyon. Occurrence.—S-1951, S-1952, S-1954, S-1965, S-1966, 82WS-2; Fusulinid Zone 4. Family POLYDIEXODINIDAE Miklukho-Maclay, 1953 Genus PARAFUSULINA Dunbar and Skinner, 1931 Parafusulina is represented in only one stratigraphic section in the area of this study (Old Dad Mountain). It is represented by five species: P. cf. P. bakeri, P. aff. P. durhami, P. cf. P. shaksgamensis crassimarginata, P. splendens, and an unnamed species.

Occurrence.—S-1853, S-1946; Fusulinid Zone 6. PARAFUSULINA SPLENDENS Dunbar and Skinner, 1937 (not illustrated) Discussion.—The California specimens have a form ratio of ~3.2 at approximately five and one-half volutions, axial filling is dense, and the septa are tightly folded, forming squared-off loops. Thus, these specimens, although poorly preserved, resemble the holotype in most respects. Occurrence.—S-1946, Old Dad Mountain, Fusulinid Zone 6. PARAFUSULINA sp. 1 Plate 7, Figure 3 Diagnosis.—This unique species attains a length of 14 mm and a diameter of 2.4 mm in a specimen of eight volutions, giving a form ratio of ~5.8. The proloculus is small, ~0.16 mm. At maturity the test is cylindrical and the chambers are low, gradually increasing in height with growth. The septa are moderately and evenly folded. Figured specimen.—SJS 205f, sample S-1946, Old Dad Mountain. Discussion.—This unusual species is unlike any other species described. Occurrence.—S-1946; Fusulinid Zone 6. ACKNOWLEDGMENTS

PARAFUSULINA cf. P. BAKERI Dunbar and Skinner, 1937 (not illustrated) Discussion.—The only specimen assigned to this species is too poorly preserved to be illustrated. However, its form, nature of the fluting of the septa, and proloculus size all closely match the cotypes from Texas. Occurrence.—S-1946, Old Dad Mountain, Fusulinid Zone 6. PARAFUSULINA aff. P. DURHAMI Thompson and Miller, 1949 Plate 7, Figure 4 Discussion.—The specimens from California are similar in many details to the type specimens from Texas. They differ in generally having less axial filling and a smaller proloculus of ~0.26 mm. They most closely resemble specimens assigned to this species by Ross and Ross (2003a). Figured specimen.—SJS 206f, sample S-1946, Old Dad Mountain. Occurrence.—S-1853, S-1946; Fusulinid Zone 6. PARAFUSULINA cf. P. SHAKSGAMENSIS CRASSIMARGINATA Knight, 1956 Plate 8, Figure 1 Discussion.—The specimens from Old Dad Mountain resemble this rather ordinary species in size and shape. The present specimens generally have a larger form ratio than the types. Figured specimen.—SJS 210f, sample S-1853, Old Dad Mountain.

We are indebted to Charles Ross, Forrest Poole, Greg Wahlman, and Doug Walker for their careful reading of and insightful critical comments on the manuscript, and to Pat Bickford and the staff at the GSA for their encouragement and aid in preparing the manuscript for publication. Permission from the National Park Service to collect fossils in Death Valley National Park and Mojave National Preserve, and from California State Parks to collect fossils in Providence Mountains State Recreation Area, is gratefully acknowledged. APPENDIX 1. LIST OF FUSULINID SAMPLES WITH GENERAL LOCATIONS [See Appendix 2 for detailed locality information.] S-0382 – Warm Spring Canyon S-0539 – Striped Butte S-0616 – Striped Butte S-0617 – Striped Butte S-1226 – Panamint Butte S-1227 – Panamint Butte S-1232 – Panamint Butte S-1236 – Striped Butte S-1456 – Providence Mountains S-1457 – Providence Mountains S-1458 – Providence Mountains S-1459 – Providence Mountains S-1460 – Providence Mountains

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf S-1461 – Providence Mountains S-1462 – Providence Mountains S-1463 – Providence Mountains S-1464 – Providence Mountains S-1465 – Providence Mountains S-1842 – Striped Butte S-1843 – Old Dad Mountain S-1845 – Old Dad Mountain S-1847 – Old Dad Mountain S-1848 – Old Dad Mountain S-1849 – Old Dad Mountain S-1850 – Old Dad Mountain S-1851 – Old Dad Mountain S-1852 – Old Dad Mountain S-1853 – Old Dad Mountain S-1857 – Cowhole Mountain S-1859 – Cowhole Mountain S-1860 – Cowhole Mountain S-1862 – Cowhole Mountain S-1863 – Cowhole Mountain S-1864 – Cowhole Mountain S-1865 – Cowhole Mountain S-1866 – Cowhole Mountain S-1867 – Cowhole Mountain S-1869 – Providence Mountains S-1870 – Providence Mountains S-1873 – Providence Mountains S-1874 – Providence Mountains S-1875 – Providence Mountains S-1876 – Providence Mountains S-1877 – Providence Mountains S-1900 – Striped Butte S-1910 – Warm Spring Canyon S-1911 – Panamint Butte S-1912 – Panamint Butte S-1913 – Panamint Butte S-1914 – Striped Butte S-1915 – Striped Butte S-1916 – Panamint Butte S-1919 – Old Dad Mountain S-1922 – Striped Butte S-1923 – Striped Butte S-1926 – Striped Butte S-1927 – Striped Butte S-1928 – Striped Butte S-1929 – Striped Butte S-1930 – Warm Spring Canyon S-1931 – Striped Butte S-1932 – Striped Butte S-1933 – Striped Butte S-1945 – Ship Mountains S-1946 – Old Dad Mountain S-1947 – Ship Mountains S-1948 – Ship Mountains

43

S-1949 – Old Dad Mountain S-1951 – Cowhole Mountain S-1952 – Cowhole Mountain S-1953 – Providence Mountains S-1954 – Cowhole Mountain S-1955 – Cowhole Mountain S-1958 – Warm Spring Canyon S-1959 – Warm Spring Canyon S-1960 – Warm Spring Canyon S-1963 – Warm Spring Canyon S-1964 – Warm Spring Canyon S-1965 – Warm Spring Canyon S-1966 – Warm Spring Canyon S-1967 – Warm Spring Canyon S-1968 – Striped Butte S-1969 – Warm Spring Canyon S79-SB-26 – Striped Butte S79-SB-28 – Striped Butte S79-WS-3 – Warm Spring Canyon S79-WS-4 – Warm Spring Canyon S79-WS-20 – Warm Spring Canyon 81-PB-27 – Panamint Butte 81-PB-35 – Panamint Butte 81-PB-37 – Panamint Butte 81-PB-38 – Panamint Butte 81-PB-39 – Panamint Butte 82-WS-2 – Warm Spring Canyon 82-WS-14 – Warm Spring Canyon USGS f14063 – Ship Mountains USGS f14067 – Ship Mountains USGS f14070 – Ship Mountains USGS f14071 – Ship Mountains USGS f14073 – Ship Mountains USGS f14074 – Providence Mountains III-9 of Thompson and Hazzard (1946) – Providence Mountains 627 of Thompson and Hazzard (1946) – Providence Mountains APPENDIX 2. DESCRIPTIONS OF OUTCROP AREAS AND FUSULINID LOCALITIES1

Ship Mountains Rocks of the Bird Spring Formation are exposed in a small group of hills on the western flank of the Ship Mountains in the southeastern part of Cadiz Summit 7.5′ quadrangle (W1/2 sec. 21, T5N, R15E) (Fig. A1). A nearly homoclinal, partially covered section of the Bird 1

Unless otherwise indicated, latitude and longitude values given below were measured to the nearest second from localities plotted on topographic maps based on the original field sheets or aerial photographs. Latitude and longitude values followed by (GPS) were determined in the field with a Garmin eTrex 12-channel GPS unit. All latitudes and longitudes are referenced to the 1927 North American Datum (NAD27). Stratigraphic positions of samples are estimated except where noted. “Field locality” refers to the original field locality number used by the collector to identify the sample location. This number is indicated in cases where the final sample number differs from the original field locality number.

115o25'36" 34o30'43"

GEOLOGIC MAP—SHIP MOUNTAINS

115o24'45"

44

64

f14063 60 f14071 72

f14067

60 60

S-1947 f14070

S-1945 S-1948 f14073

45 60 65

34o00'

0

0.5 KILOMETER CONTOUR INTERVAL 10 METERS

MAP AREA

CADIZ SUMMIT QUADRANGLE

Figure A1. Geologic map showing locations of fusulinid samples in the Bird Spring Formation on the western flank of the Ship Mountains in the southeastern part of Cadiz Summit 7.5′ quadrangle, California. Geology mapped by the authors in 2003.

MAP EXPLANATION—SHIP MOUNTAINS Alluvium (Quaternary) Volcanic rocks (Tertiary) Bird Spring Formation (Permian and Pennsylvanian) Unit 7 (Permian)—Quartzite Unit 6 (Permian)—Thin- to thick-bedded limestone, dolomitic limestone, dolomite, and minor quartzite (80 m) Unit 5 (Permian)—Upper and lower subunits of massive, fossiliferous limestone; middle subunit of sandy limestone, limestone, and quartzite (45 m) Unit 4 (Permian)—Thin- to thick-bedded dolomite, limestone, silty to sandy limestone, and quartzite (260 m). Large parts of unit are covered by alluvium. Fusulinids locally present in lower part of unit Unit 3 (Permian)—Thick-bedded to massive, fossiliferous gray limestone with nodular chert (55 m). Fusulinids abundant Unit 2 (Permian and/or Pennsylvanian)—Upper and lower subunits of brown-weathering sandy limestone, calcareous sandstone, and quartzite; middle subunit of massive, white to light-gray limestone (80 m) Unit 1 (Pennsylvanian)—Thick-bedded to massive limestone and dolomite (140 m)

Contact Fault 60

Strike and dip of beds S-1945 Fusulinid sample locality Line of measured section (Fig. A2)

Figure A1. (Continued).

LITHOLOGIC DESCRIPTION

OLOGY

(METERS)

LITH-

THICKNESS

SAMPLE

CUMULATIVE

UNIT

THICKNESS (METERS)

STRATIGRAPHIC SECTION—SHIP MOUNTAINS

662

Thin- to thick-bedded limestone, dolomitic limestone, and dolomite. Includes two conspicuous intervals of calcareous quartzite. Top of section covered

Unit 6

77 600

Unit 5

Thick-bedded fossiliferous limestone, in part dolomitic

18

Sandy limestone, limestone, and minor quartzite

23 6

Thick-bedded fossiliferous limestone Thin- to thick-bedded calcarenitic limestone. Minor quartzite in upper part

56

Thin- to thick-bedded dolomite, commonly with nodular chert. Less abundant chalky limestone. Minor calcareous sandstone. Partly covered

147

Quartzite, in part calcareous, and minor fossiliferous limestone

22

Chalky, in part silty, thin- to thick-bedded limestone. Minor quartzite in upper part

34

Thick-bedded fossiliferous limestone. Nodular chert common. Fusulinids locally abundant

57

Brown-weathering quartzite, calcareous sandstone, and calcareous sandstone; calc-silicate alteration common

28

Thick-bedded, white to light-gray limestone and marble

29

Brown-weathering quartzite, calcareous sandstone, and calcareous sandstone; calc-silicate alteration common

24

Thick-bedded, white to light-gray limestone and marble. Contains some chert banding and calc-silicate alteration, especially in upper part

97

Thick-bedded, gray dolomite and minor interbedded white limestone and marble. Chert banding common. Base of section covered

44

500

covered

Formation

Unit 4

400

Spring

f14070 S-1947

Bird

covered

f14067 f14073 S-1945 S-1948

Unit 3

300

f14063 f14071

Unit 2

Unit 1

200

100

0

Figure A2. Stratigraphic column of the Bird Spring Formation in the Ship Mountains, showing positions of fusulinid samples. Lithology and thickness based on a measured section by P. Stone in 1978 and on field observations by the authors.

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf Spring Formation in this area is 662 m thick with neither the base nor the top exposed (Fig. A2). This section, which was measured by P. Stone in 1978, is divided into six stratigraphic units, of which only units 3 and 4 contain fusulinids. An overlying, seventh unit was mapped (Fig. A1) but not included in the measured section. Our samples are from one horizon near the base of unit 3, another horizon near the top of unit 3, and an isolated limestone bed in the lower part of unit 4, all on the largest hill in the outcrop area. Fusulinids from several additional beds in unit 3 are not included in this study because of poor preservation. USGS f14063 – Bird Spring Formation, 233 m stratigraphically above base of exposed section, 11 m stratigraphically above base of unit 3. Just northwest of ridge crest, elev ~450 m. Lat 34°30′27″N, long 115°25′13″W. Collected by P. Stone, 26 October 1978, field locality SM-18. Schwagerina aculeata, S. longissimoidea. Fusulinid Zone 3. USGS f14067 – Bird Spring Formation, 273 m stratigraphically above base of exposed section, 50 m stratigraphically above base of unit 3. Southeast side of hill, elev ~410 m. Lat 34°30′26″N, long 115°25′09″W. Collected by P. Stone, 26 October 1978, field locality SM-27. Schwagerina providens, S. cf. S. wellsensis, Stewartina multispira. Fusulinid Zone 3. USGS f14070 – Bird Spring Formation, 329 m stratigraphically above base of exposed section, 49 m stratigraphically above base of unit 4. Southeast side of hill, elev ~380 m. Lat 34°30′25″N, long 115°25′07″W. Collected by P. Stone, 27 October 1978, field locality SM-35. Schwagerina cf. S. wellsensis. Fusulinid Zone 3. USGS f14071 – Bird Spring Formation, lower part of unit 3, approximately same location as USGS f14063. Collected by K.A. Howard, 16 April 1978, field locality KH-78-87. Schwagerina aculeata plena. Fusulinid Zone 3. USGS f14073 – Bird Spring Formation, upper part of unit 3, approximately same location as S-1948. Collected by K.A. Howard, 16 April 1978, field locality KH-78-89. Schwagerina aculeata, Stewartina sp. 1, Pseudoschwagerina uddeni?. Fusulinid Zone 3. S-1945 – Bird Spring Formation, upper part of unit 3, sample from float stratigraphically just below S-1948 (see below). Collected by C.H. Stevens and P. Stone, 4 December 2003. Schwagerina aculeata, S. cf. S. pugunculus, S. sp. 4, Paraschwagerina elongata. Fusulinid Zone 3.

47

mation in this area has an estimated thickness of 1550 m (Fig. A6). It overlies the Mississippian Monte Cristo Limestone, and it is unconformably overlain by the Triassic Moenkopi Formation in some places and by the Jurassic(?) Fountain Peak Rhyolite in others. The lower 1100 m of the Bird Spring Formation consists primarily of thickbedded limestone that locally contains marine megafossils including brachiopods, gastropods, and corals; the upper 450 m consists of thin-bedded, sparsely fossiliferous limestone. Fusulinids are abundant between about 400 and 1000 m above the base of the formation. Most of our fusulinid samples are from a section exposed along the crest of the range, but we also include samples from several other partial sections (Figs. A3–A6). USGS f14074 – Bird Spring Formation, ~250 m stratigraphically above base. High on northwest slope of ridge extending west from crest of range, elev ~1530 m, SW1/4 sec. 24, T10N, R13E. Lat 34°56′16″N, long 115°34′10″W. Collected by K.H. Howard, 2 December 1978, field locality N2B-6. Triticites sp. 1, Leptotriticites aff. L. hatchetensis, Pseudoschwagerina arta, Stewartina sp. 1, Pseudochusenella hazzardi n. sp. Fusulinid Zone 3. [Note: This sample is anomalously low in the stratigraphic section given its faunal content, suggesting that the base or lower part of the Bird Spring Formation here is faulted.] S-1456 – Bird Spring Formation, ~360 m stratigraphically above base, approximately same location as S-1869 but 1 or 2 m lower. Crest of western spur, in saddle east-southeast of peak 1327T, elev ~1280 m, NW1/4 sec. 14, T10N, R13E. Lat 34°57′46″N, long 115°35′12″W. Collected by P. Stone, 1 April 1985, field locality 85-PR-2. Triticites californicus, T. aff. T. californicus, T. cellamagnus, T. gigantocellus n. sp. Fusulinid Zone 2. S-1457 – Bird Spring Formation, ~410 m stratigraphically above base. Crest of range just southeast of “Mitchell” peak (2148.2 m), elev ~2140 m, N1/2 sec. 8, T10N, R14E. Lat 34°58′41″N, long 115°32′12″W. Collected by P. Stone, 2 April 1985, field locality 85-PR-4. Triticites muddiensis. Fusulinid Zone 1. S-1458 – Bird Spring Formation, ~385 m stratigraphically above base. Crest of range just southeast of “Mitchell” peak (2148.2 m), elev ~2140 m, N1/2 sec. 8, T10N, R14E. Lat 34°58′42″N, long 115°32′13″W. Collected by P. Stone, 2 April 1985, field locality 85-PR-6. Triticites bensonensis, T. muddiensis. Fusulinid Zone 1.

S-1947 – Bird Spring Formation, unit 3, same location as USGS f14070. Collected by C.H. Stevens and P. Stone, 4 December 2003, field locality 6. Schwagerina cf. S. wellsensis, S. sp. 3. Fusulinid Zone 3.

S-1459 – Bird Spring Formation, ~720 m stratigraphically above base. Crest of range near summit of low peak, elev ~2020 m, near center of sec. 8, T10N, R14E. Lat 34°58′27″N, long 115°32′13″W. Collected by P. Stone, 2 April 1985, field locality 85-PR-9. Leptotriticites sp. 2. Fusulinid Zone 2.

S-1948 – Bird Spring Formation, approximately same stratigraphic position as USGS f14067. Southeast side of hill, elev ~380 m. Lat 34°30′23″N; long 115°25′16″W. Collected by C.H. Stevens and P. Stone, 4 December 2003, field locality 4. Pseudoschwagerina arta. Fusulinid Zone 3.

S-1460 – Bird Spring Formation, ~765 m stratigraphically above base. Crest of range, elev ~1960 m, near center of sec. 8, T10N, R14E. Lat 34°58′22″N, long 115°32′14″W. Collected by P. Stone, 2 April 1985, field locality 85-PR-10. Leptotriticites glenensis, L. cf. L. hughesensis. Fusulinid Zone 2.

Providence Mountains Rocks of the Bird Spring Formation are extensively exposed in the Providence Mountains (Hazzard, 1954) in the northern part of the Fountain Peak 7.5′ quadrangle (Figs. A3–A5). The Bird Spring For-

S-1461 – Bird Spring Formation, ~1000 m stratigraphically above base. Crest of range, elev ~1960 m, S1/2 sec. 8, T10N, R14E. Lat 34°58′13″N, long 115°32′17″W. Collected by P. Stone, 2 April 1985, field locality 85-PR-12. Schwagerina aculeata plena, Pseudoschwagerina uddeni?, Stewartina multispira, S. texana, S. uber. Fusulinid Zone 3.

GEOLOGIC MAP—PROVIDENCE MOUNTAINS (CREST AND EAST SIDE)

115o33' 34o59'

115o30'30"

Range Crest Section 30 S-1458 S-1874

35 35

50

S-1457 S-1873

35

S-1870 50

15 627

S-1459 30

S-1460

25

S-1463

S-1875 S-1461 S-1462

45 40 15 35

25

20 30

20

25 S-1953 S-1464 S-1876 S-1877 25

55

30

III-9

25

C&K Mine Section

45

35

34o57'30" Fault Block near Range Crest Section 0

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FOUNTAIN PEAK QUADRANGLE

Figure A3. Geologic map showing locations of fusulinid samples in the Bird Spring Formation on the crest and east side of the Providence Mountains in the northeastern part of the Fountain Peak 7.5′ quadrangle, California (C&K Mine, Range Crest, and Fault Block near Range Crest columns, Fig. A6). Geology from Hazzard (1954) and unpublished mapping by P. Stone in 1985.

MAP EXPLANATION—PROVIDENCE MOUNTAINS Alluvium (Quaternary) Talus (Quaternary) Landslide deposits (Quaternary) Terrace gravels (Quaternary) Volcanic and sedimentary rocks (Jurassic?)—Includes Fountain Peak Rhyolite of Hazzard (1954) Moenkopi Formation (Triassic)—Shale, sandstone, limestone, and minor conglomerate Bird Spring Formation (Permian and Pennsylvanian)—Limestone, cherty limestone, silty limestone, and minor siltstone and sandstone. Fusulinids locally abundant between about 400 and 1000 m above base Sedimentary rocks, undivided (Mississippian to Cambrian)—Limestone, dolomite, and siliciclastic sedimentary rocks Granite, gneiss, and schist (Precambrian)

Contact Fault—Dotted where concealed 60

Strike and dip of beds

S-1869

Fusulinid sample locality (this study)

627

Fusulinid sample locality (Thompson and Hazzard, 1946) Line of generalized stratigraphic section (Fig. A6) Figure A3. (Continued).

GEOLOGIC MAP—PROVIDENCE MOUNTAINS ("WEST RIDGE")

115o35'30" 34o58'

115o34'30"

55 45 West Ridge Section

S-1456 S-1869

35

35

20

35 34o57'30"

0

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MAP AREA

FOUNTAIN PEAK QUADRANGLE

Figure A4. Geologic map showing locations of fusulinid samples in the Bird Spring Formation on the west side of the Providence Mountains in the northwestern part of the Fountain Peak 7.5′ quadrangle, California (West Ridge column, Fig. A6). Geology from Hazzard (1954) and unpublished mapping by P. Stone in 1985. See Figure A3 key for explanation.

GEOLOGIC MAP—PROVIDENCE MOUNTAINS ("SOUTHWEST RIDGE")

115o34'30" 35o56'45"

115o33'30"

30

45

35 Southwest Ridge Section

40 f14074

30

S-1465 35

30

35o56' 0

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FOUNTAIN PEAK QUADRANGLE MAP AREA

Figure A5. Geologic map showing locations of fusulinid samples in the Bird Spring Formation on west side of the Providence Mountains in the central part of the Fountain Peak 7.5′ quadrangle, California (Southwest Ridge column, Fig. A6). Geology from Hazzard (1954) and unpublished mapping by P. Stone in 1985. See Figure A3 key for explanation.

STRATIGRAPHIC SECTIONS—PROVIDENCE MOUNTAINS

Range Crest

EXPLANATION Silicic volcanic rocks

Moenkopi Formation Fault

Sandstone Thin-bedded limestone Thick-bedded limestone Massive limestone S-1465

Sample (this study)

672?

Sample (Thompson and Hazzard, 1946); precise location uncertain

C&K Mine

Southwest Ridge

Fountain Peak Rhyolite

Fault Block Near Range Crest

Fault S-1465

West Ridge

672?

S-1464 S-1876 S-1877

S-1463 S-1461 S-1462

f14074 Bird Spring Formation

S-1875

Fault

S-1456 S-1869

III-9?

S-1460

S-1953

S-1459

Monte Cristo Limestone Fault S-1870

Fault

S-1457 S-1873 S-1458 S-1874

200 METERS

SCALE

100

0

Figure A6. Stratigraphic columns of Bird Spring Formation in the Providence Mountains, showing positions of fusulinid samples. Generalized lithology and thickness based on Hazzard (1954), unpublished mapping by P. Stone in 1985, and field observations by the authors.

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf S-1462 – Bird Spring Formation, approximately same locality as S-1461 but a few meters higher stratigraphically. Collected by P. Stone, 2 April 1985, field locality 85-PR-13. Leptotriticites californicus n. sp., L. aff. L. gracilitatus, Stewartina texana. Fusulinid Zone 3. S-1463 – Bird Spring Formation, ~1030 m stratigraphically above base. Crest of range, elev ~1960 m, S1/2 sec. 8, T10N, R14E. Lat 34°58′09″N, long 115°32′20″W. Collected by P. Stone, 2 April 1985, field locality 85-PR-14. Schwagerina cf. S. elkoensis, S. vervillei?, Paraschwagerina elongata, Pseudoschwagerina uddeni, Stewartina uber. Fusulinid Zone 3. S-1464 – Bird Spring Formation, stratigraphic position uncertain because of faulting. Ridge extending west from crest of range, elev ~1880 m, N1/2 sec. 18, T10N, R14E. lat 34°57′33″N, long 115°32′55″W. Collected by P. Stone, 3 April 1985, field locality 85-PR-17. Schwagerina sp. 3. Fusulinid Zone 3. S-1465 – Bird Spring Formation, float sample ~300 m stratigraphically above base. High on northwest slope of ridge extending west from crest of range, elev ~1580 m, SW1/4 sec. 24, T10N, R13E. Lat 34°56′14″N, long 115°34′08″W. Collected by P. Stone, 5 April 1985, field locality 85-PR-24. Pseudoschwagerina arta, P. cf. P. gerontica, P. uddeni. Fusulinid Zone 3. [Note: This sample is anomalously low in the stratigraphic section given its faunal content, suggesting that the base or lower part of the Bird Spring Formation here is faulted.] S-1869 – Bird Spring Formation, approximately same location as S-1456 but 1 or 2 m higher. Collected by P. Stone, 1 April 1985, field locality 85-PR-1. Leptotriticites glenensis, L. aff. L. hatchetensis, L. cf. L. varius, L. wetherensis, L. sp. 2. Fusulinid Zone 2. S-1870 – Bird Spring Formation, ~450 m stratigraphically above base. Crest of range, high on southeast slope of “Mitchell” (peak 2148.2 m), elev ~2120 m, N1/2 sec. 8, T10N, R14E. Lat 34°58′39″N, long 115°32′11″W. Collected by P. Stone, 2 April 1985, field locality 85-PR-3. Triticites hermanni, T. muddiensis. Fusulinid Zone 1. S-1873 – Bird Spring Formation, same location as S-1457. Collected by P. Stone, 2 April 1985, field locality 85-PR-5. Triticites bensonensis? Fusulinid Zone 1. S-1874 – Bird Spring Formation, approximately same location as S-1458 but about 1 m higher stratigraphically. Collected by P. Stone, 2 April 1985, field locality 85-PR-7. Triticites hermanni, T. elegantoides, T. aff. T. rothi. Fusulinid Zone 1. S-1875 – Bird Spring Formation, ~935 m stratigraphically above base. Crest of range, elev ~1960 m, S1/2 sec. 8, T10N, R14E. Lat 34°58′15″N, long 115°32′16″W. Collected by P. Stone, 2 April 1985, field locality 85-PR-11. Schwagerina aculeata, S. modica, S. cf. S. wellsensis, Pseudoschwagerina roeseleri, P. uddeni. Fusulinid Zone 3. S-1876 – Bird Spring Formation, same location as S-1464. Collected by P. Stone, 3 April 1985, field locality 85-PR-15. Schwagerina aculeata plena, S. providens, S. aff. S. wellsensis. Fusulinid Zone 3.

53

S-1877 – Bird Spring Formation, same location as S-1464. Collected by P. Stone, 3 April 1985, field locality 85-PR-16. Schwagerina aculeata plena, S. providens, S. cf. S. wellsensis, Stewartina convexa. Fusulinid Zone 3. S-1953 – Bird Spring Formation, ~275 m stratigraphically above faulted base. East side of range on slope above C&K Mine, elev ~1470 m, N1/2 sec. 16, T10N, R14E. Lat 34°57′42.4″N, long 115°31′08.2″W (GPS). Collected by C.H. Stevens and P. Stone, 22 October 2004, field locality 04-PR-108. Triticites californicus, T. cellamagnus. Fusulinid Zone 2. III-9 – Sample of Thompson and Hazzard (1946). Bird Spring Formation, probably stratigraphically above sample S-1953. East side of range on slope above C&K Mine. Estimated location based on information given by Thompson and Hazzard (1946): elev ~1500 m, N1/2 sec. 16, T10N, R14E; lat 34°57′41″N, long 115°31′08″W. Pseudochusenella concisa. Fusulinid Zone 3? 627 – Sample of Thompson and Hazzard (1946). Bird Spring Formation, upper part, exact stratigraphic position unknown but stratigraphically higher than sample III-9. East side of range, on ridge north of Gilroy Canyon. Estimated location based on information given by Thompson and Hazzard (1946) and Hazzard (1954): elev ~1540 m, central part of sec. 9, T10N, R14E; lat 34°58′28″N, long 115°31′10″W. Eoparafusulina sp. Fusulinid Zone 4.

Old Dad Mountain Rocks of the Bird Spring Formation form most of the southern part of Old Dad Mountain (Hewett, 1956; Dunne, 1977). This outcrop area is mostly in the northwestern part of the Old Dad Mountain 7.5′ quadrangle, but extends westward into the adjacent Cowhole Mountain 7.5′ quadrangle (Fig. A7). The Bird Spring Formation in this area is exposed in several different fault blocks, none of which exhibits a complete stratigraphic section (Fig. A8). The Bird Spring Formation at Old Dad Mountain depositionally overlies the Mississippian Monte Cristo Limestone and is unconformably overlain by the Jurassic Aztec Sandstone. The total exposed thickness of the Bird Spring Formation is about 700 m, but some strata in the middle part of the formation probably are faulted out. The lower 100–200 m of the formation is composed of cherty and silty limestone; the remainder is primarily thick-bedded limestone in which fusulinids and other marine fossils are locally abundant. Our fusulinid collections include samples from the relatively continuous section on the main ridge of Old Dad Mountain and from several downdropped fault blocks on the west side of the range, where the youngest rocks of the Bird Spring Formation are exposed (Figs. A7–A8). Much of the middle part of the formation on the main ridge (between samples S-1848 and S-1850) is inaccessible because of very steep topography. S-1843 – Bird Spring Formation, near upper contact with Jurassic Aztec Sandstone. West side of range, elev ~725 m, T12N, R10E (unsurveyed), Old Dad Mountain 7.5′ quadrangle. Lat 35°05′54″N, long 115°52′24″W. Collected by P. Stone, 10 May 1990, field locality 90-OD-227. Stewartina magnifica n. sp., Cuniculinella mojavensis n. sp. Fusulinid Zone 5. S-1845 – Bird Spring Formation, approximately same location as S-1843 and less than 1 m stratigraphically above that sample. Collected by P. Stone, 10 May 1990, field locality 90-OD-228. Schwagerina aff. S. davisi, Stewartina convexa. Fusulinid Zone 5.

GEOLOGIC MAP—OLD DAD MOUNTAIN

115o52'52" 35o06'12"

30

S-1843 S-1845 S-1851

N AI M

S-1847

115o51'

25

S-1850 35

S-1848

45

15

S-1849

20

20

S-1852

ST WE N ER

30

E DG RI

15 40

25

FA U

LT

25

S-1853

25

BL OC KS

15

S-1946

S-1949 S-1919 35

35o04'38" 0

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MAP AREA

OLD DAD MOUNTAIN QUADRANGLE

Figure A7. Geologic map showing locations of fusulinid samples in Bird Spring Formation at Old Dad Mountain in the northwestern part of the Old Dad Mountain 7.5′ quadrangle and the northeastern part of the Cowhole Mountain 7.5′ quadrangle, California. Geology from Dunne (1977) and unpublished mapping by P. Stone in 1990.

MAP EXPLANATION—OLD DAD MOUNTAIN Alluvium and talus (Quaternary) Sedimentary deposits, undivided (Quaternary and Tertiary) Volcanic and hypabyssal intrusive rocks (Jurassic?) Aztec Sandstone (Jurassic)—Reddish-brown eolian quartz sandstone Bird Spring Formation (Permian and Pennsylvanian)—Primarily medium- to dark-gray, thick-bedded limestone, typically forming rugged slopes and cliffs. Lower 100-200 m of formation is medium-gray to tan, cherty and silty limestone. Fusulinids scattered throughout formation. Detailed stratigraphy and thickness of formation uncertain because of faulting; estimated exposed thickness 700 m Monte Cristo Limestone (Mississippian)—Massive light-gray limestone (Bullion Member)

Contact Fault—Dotted where concealed 60

S-1850

Strike and dip of beds Fusulinid sample locality Line of generalized stratigraphic section (Fig. A8) Figure A7. (Continued).

Partial sections in western fault blocks

Fault

Top eroded S-1946

S-1853

Main Ridge

Aztec Sandstone

Top covered

S-1843 S-1845 S-1851

S-1949

S-1852

S-1849 S-1850

EXPLANATION Eolian quartz sandstone Siltstone Thick-bedded limestone

Bird Spring Formation

STRATIGRAPHIC SECTIONS—OLD DAD MOUNTAIN

Massive limestone S-1848 Fault

Cherty limestone Silty limestone

Fault S-1847

Sample

S-1847

100 METERS

SCALE

0 Monte Cristo Limestone

Figure A8. Stratigraphic columns of Bird Spring Formation at Old Dad Mountain, showing positions of fusulinid samples. Generalized lithology and thickness based on Dunne (1977), unpublished mapping by P. Stone in 1990, and field observations by the authors.

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf S-1847 – Bird Spring Formation, ~140 m stratigraphically above lower contact with Mississippian Monte Cristo Limestone. West side of range, elev ~670 m, T12N, R10E (unsurveyed), Cowhole Mountain 7.5′ quadrangle. Lat 35°06′03″N, long 115°52′35″W. Collected by P. Stone, 11 May 1990, field locality 90-OD-232. Triticites bensonensis. Fusulinid Zone 1. S-1848 – Bird Spring Formation, just above low-angle fault at base of thick section comprising summit ridge. West side of summit ridge, elev ~815 m, T12N, R10E (unsurveyed), Old Dad Mountain 7.5′ quadrangle. Lat 35°05′47″N, long 115°52′00″W. Collected by P. Stone, 10 May 1990, field locality 90-OD-226. Schwagerina? sp. 1. Fusulinid Zone 2. S-1849 – Bird Spring Formation, ~250 m stratigraphically above lowangle fault at base of thick section comprising summit ridge. Sampled beds are stratigraphically just above a prominent zone of tan silty limestone. East side of summit ridge, elev ~1140 m, T12N, R10E (unsurveyed), Old Dad Mountain 7.5′ quadrangle. Lat 35°05′54″N, long 115°51′26″W. Collected by P. Stone, 12 May 1990, field locality 90-OD-234. Leptotriticites californicus n. sp., Pseudoschwagerina arta?, P. uddeni, Stewartina texana, S. uber?. Fusulinid Zone 3. S-1850 – Bird Spring Formation, ~230 m stratigraphically above lowangle fault at base of thick section comprising summit ridge. Sampled beds are stratigraphically just below a prominent zone of tan silty limestone. East side of summit ridge, elev ~1100 m, T12N, R10E (unsurveyed), Old Dad Mountain 7.5′ quadrangle. Lat 35°05′57″N, long 115°51′26″W. Collected by P. Stone, 12 May 1990, field locality 90-OD-235. Schwagerina aculeata, S. providens?, Pseudoschwagerina uddeni, Stewartina convexa?. Fusulinid Zone 3. S-1851 – Bird Spring Formation, same location as S-1845. Collected by P. Stone, 10 May 1990, field locality 90-OD-228. Stewartina convexa, S. magnifica n. sp. Fusulinid Zone 5. S-1852 – Bird Spring Formation, ~350 m stratigraphically above lowangle fault at base of thick section comprising summit ridge; near top of exposed section. Near base of slope on east side of summit ridge, elev ~925 m, T12N, R10E (unsurveyed), Old Dad Mountain 7.5′ quadrangle. Lat 35°05′46″N, long 115°51′06″W. Collected by P. Stone, 12 May 1990, field locality 90-OD-236. Stewartina magnifica n. sp., Cuniculinella mojavensis n. sp. Fusulinid Zone 5. S-1853 – Bird Spring Formation, near top of exposed section in fault block forming secondary ridge southwest of summit ridge. Crest of ridge, elev ~810 m, T12N, R10E (unsurveyed), Old Dad Mountain 7.5′ quadrangle. Lat 35°05′09″N, long 115°51′31″W. Collected by P. Stone, 9 May 1990, field locality 90-OD-224. Parafusulina cf. P. shaksgamensis crassimarginata, P. aff. P. durhami. Fusulinid Zone 6. S-1919 – Bird Spring Formation, sample from float near S-1949. Collected by C.H. Stevens and P. Stone, 5 December 2003, field locality 2F. Stewartina magnifica n. sp. Fusulinid Zone 5. S-1946 – Bird Spring Formation, ~175 m stratigraphically above base of exposed section in fault block forming secondary ridge southwest of summit ridge. Crest of spur branching southwest from ridge, elev ~725 m, T12N, R10E (unsurveyed), Old Dad

57

Mountain 7.5′ quadrangle. Lat 35°04′56″N, long 115°51′35″W. Collected by C.H. Stevens and P. Stone, 5 December 2003, field locality 4. Schwagerina cf. S. menziesi, Parafusulina cf. P. bakeri, P. aff. P. durhami, P. cf. P. shaksgamensis crassimarginata, P. splendens, P. sp. 1. Fusulinid Zone 6. S-1949 – Bird Spring Formation, ~65 m stratigraphically above base of exposed section in fault block forming secondary ridge southwest of summit ridge. On northwest-facing slope of spur branching southwest from ridge, elev ~670 m, T12N, R10E (unsurveyed), Old Dad Mountain 7.5′ quadrangle. Lat 35°04′54″N, long 115°51′43″W. Collected by C.H. Stevens and P. Stone, 5 December 2003, field locality 2. Schwagerina vervillei, Schwagerina? sp. 2, Stewartina magnifica n. sp., S. ultimata n. sp., Cuniculinella mojavensis n. sp. Fusulinid Zone 5.

Cowhole Mountain Rocks of the Bird Spring Formation form the highest ridge of Cowhole Mountain (Novitsky-Evans, 1978) in the southwestern part of the Seventeen Mile Point 7.5′ quadrangle. This ridge includes the summit informally labeled “Soda Lake” peak on the topographic map (Fig. A9). The Bird Spring Formation in this area forms an apparently homoclinal section about 965 m thick (Fig. A10) in the upper plate of a major low-angle fault (Cowhole thrust of Novitsky-Evans, 1978) that structurally overlies older Paleozoic rocks and Mesozoic intrusive rocks. Neither the depositional base nor the top of the Bird Spring Formation is exposed; rocks assigned to the Mississippian Monte Cristo Limestone locally underlie the Bird Spring Formation on a contact mapped as a fault by Novitsky-Evans (1978). Approximately the lower 200 m of the Bird Spring Formation is composed of interbedded limestone and siltstone; the remainder is primarily thick-bedded, locally fossiliferous limestone and silty limestone (Fig. A10). Fusulinids and colonial corals are locally abundant in these rocks. Our fusulinid collections include six widely spaced samples between about 260 and 840 m above the faulted base of the Bird Spring Formation and five closely spaced samples from a 33-m-thick measured section through the uppermost part of the formation (Figs. A10, A11). The top of this measured section is at an unmapped, low-angle fault (not shown in Figure A9) that may have significant intraformational offset as shown in Figure A11. S-1857 – Bird Spring Formation, probably about the same stratigraphic position as S-1859. Crest of spur branching southeast from summit of “Soda Lake” peak, elev ~590 m, SE1/4 sec. 11, T12N, R9E. Lat 35°08′00″N, long 115°59′31″W. Collected by P. Stone, 7 May 1990, field locality 90-CH-206. Schwagerina aculeata plena, Paraschwagerina fairbanksi, Stewartina uber. Fusulinid Zone 3. S-1859 – Bird Spring Formation, ~260 m stratigraphically above faulted base of section. Crest of summit ridge just northeast of “Soda Lake” peak, elev ~680 m, SE1/4 sec. 11, T12N, R9E. Lat 35°08′08″N, long 115°59′34″W. Collected by P. Stone, 7 May 1990, field locality 90-CH-208. Leptotriticites aff. L. gracilitatus. Fusulinid Zone 3. S-1860 – Bird Spring Formation, ~430 m stratigraphically above faulted base of section. Crest of summit ridge at top of peak, elev ~640 m, SE1/4 sec. 11, T12N, R9E. Lat 35°08′11″N, long 115°59′24″W. Collected by P. Stone, 7 May 1990, field locality 90-CH-210. Schwagerina aculeata plena, Stewartina sp. 1, S. uber. Fusulinid Zone 3.

GEOLOGIC MAP—COWHOLE MOUNTAIN

116o00' 35o08'30"

S-1954 S-1864

115o58'48"

S-1951 S-1867 S-1955 S-1865 S-1863

S-1862

S-1952 S-1866

55

S-1860 50 S-1859

60

60

60

45

S-1857

70

60

35o07'30"

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MAP AREA

SEVENTEEN MILE POINT QUADRANGLE

Figure A9. Geologic map showing locations of fusulinid samples in Bird Spring Formation at Cowhole Mountain in the southwestern part of the Seventeen Mile Point 7.5′ quadrangle, California. Geology from Novitsky-Evans (1978) and unpublished mapping by P. Stone in 1990.

MAP EXPLANATION—COWHOLE MOUNTAIN Alluvium (Quaternary) Diorite (Mesozoic) Quartz monzonite (Mesozoic) Bird Spring Formation (Permian and Pennsylvanian)—Light- to medium-gray, thick-bedded to massive limestone, sporadically interbedded with tan siltstone and brown chert. Estimated exposed thickness is 965 m, with the base faulted and the top eroded. Fusulinids locally abundant beginning ~300 m above base of formation, commonly in association with corals Monte Cristo Limestone (Mississippian)—Limestone, in part silty and cherty Goodsprings Dolomite (Cambrian)—Dolomite and minor limestone, chert, siltstone, and silty limestone Carrara Formation (Cambrian)—Thin-bedded shale, marl, siltstone, limestone, and dolomite

Contact Fault—Dotted where concealed 60 S-1864

Strike and dip of beds Fusulinid sample locality Line of generalized stratigraphic section (Fig. A10) Figure A9. (Continued).

SAMPLE

Top covered

S-1867 S-1955 S-1951 S-1866, S-1952 S-1864, S-1954

THICKNESS (METERS) 965 Low-angle fault 900

S-1865 S-1863

800

700 S-1862

Bird Spring

Formation

600

STRATIGRAPHIC SECTION— COWHOLE MOUNTAIN 500

EXPLANATION

S-1860 400

Thick-bedded limestone Massive limestone Silty limestone

300 Siltstone S-1857 S-1859

200

100

Fault

0

Monte Cristo Limestone

Figure A10. Stratigraphic column of Bird Spring Formation at Cowhole Mountain, showing positions of fusulinid samples. Generalized lithology and thickness based on Novitsky-Evans (1978), unpublished mapping by P. Stone in 1990, and field observations by the authors.

CROSS SECTION AND STRATIGRAPHIC COLUMN, UPPER PART OF COWHOLE MOUNTAIN SECTION

W

E

METERS 400

METERS 400 S-1954, ~S-1864

2 3

390

390 S-1952, ~S-1866 S-1951

4

380

380

S-1955

1

~S-1867

5 LT FAU

370

370

Thickness (meters) 33

Samples ~S-1867 low-angle fault

5. Gray limestone with colonial corals (not measured). Possibly offset equivalent of unit 1

S-1955 30

4. Light-gray to tan silty limestone

S-1951 S-1952, ~S-1866 20 3. Light-gray to brown limestone S-1954, ~S-1864 10

2. Light-gray to tan silty limestone

0 1. Gray limestone with colonial corals (not measured)

Figure A11. Geologic cross section and stratigraphic column of the upper exposed part of Bird Spring Formation at Cowhole Mountain, showing positions of fusulinid samples. Sample numbers preceded by a (~) symbol are approximately located. Low-angle fault separating units 4 and 5 may represent significant offset. Lithology, thickness, and structural interpretation based on a measured section and field observations by the authors.

62

C.H. Stevens and P. Stone

S-1862 – Bird Spring Formation, ~660 m stratigraphically above faulted base of section. Crest of ridge, elev ~485 m, SW1/4 sec. 12, T12N, R9E. Lat 35°08′13″N, long 115°59′07″W. Collected by P. Stone, 8 May 1990, field locality 90-CH-213. Schwagerina aculeata, S. aculeata plena, S. cf. S. elkoensis, S. cf. S. pugunculus, S. vervillei. Fusulinid Zone 3. S-1863 – Bird Spring Formation, ~800 m stratigraphically above faulted base of section. Crest of ridge, northeast slope of peak 501T, elev ~475 m, SW1/4 sec. 12, T12N, R9E. Lat 35°08′17″N, long 115°59′03″W. Collected by P. Stone, 8 May 1990, field locality 90-CH-214. Leptotriticites aff. L. gracilitatus?, Schwagerina aculeata, Pseudoschwagerina uddeni. Fusulinid Zone 3. S-1864 – Bird Spring Formation, ~900 m stratigraphically above faulted base of section. Crest of ridge, northeastern peak, elev ~390 m, SW1/4 sec. 12, T12N, R9E. Lat 35°08′22″N, long 115°58′59″W. Collected by P. Stone, 8 May 1990, field locality 90-CH-216. Schwagerina vervillei, Pseudoschwagerina uddeni, P. sp. 1. Fusulinid Zone 4. S-1865 – Bird Spring Formation, ~840 m stratigraphically above faulted base of section. Crest of ridge, northeast base of peak 501T, elev ~440 m, SW1/4 sec. 12, T12N, R9E. Lat 35°08′18″N, long 115°59′00″W. Collected by P. Stone, 8 May 1990, field locality 90-CH-215. Schwagerina vervillei, Stewartina convexa. Fusulinid Zone 4. S-1866 – Bird Spring Formation, approximately same location as S-1864 but a few meters higher stratigraphically. Collected by P. Stone, 8 May 1990, field locality 90-CH-217. Schwagerina vervillei, Stewartina convexa. Fusulinid Zone 4. S-1867 – Bird Spring Formation, structurally beneath low-angle fault that separates this locality from sequence containing S-1866 and stratigraphically lower samples (see Fig. A11). Stratigraphic position of S-1867 is uncertain; it may be structurally offset from an original position below S-1864. Crest of ridge, northeastern peak, elev ~375 m, SW1/4 sec. 12, T12N, R9E. Lat 35°08′23″N, long 115°58′58″W. Collected by P. Stone, 8 May 1990, field locality 90-CH-218. Schwagerina aculeata plena, S. cf. S. pugunculus, Pseudoschwagerina uddeni, Stewartina convexa. Fusulinid Zone 3. The following four samples were collected from a measured section through 33 m of beds in the upper part of the Bird Spring Formation on the northeastern peak of the ridge that includes “Soda Lake” peak (Fig. A11). Base of section is at lat 35°08′21.4″N, long 115°58′59.2″W (GPS), elev ~390 m; top of section is at lat 35°08′22.5″N, long 115°58′58.4″W (GPS), elev ~375 m. The section crosses sample localities S-1864 and S-1866; its top is at the low-angle fault below which is sample locality S-1867 (Fig. A11). Section measured and samples collected by C.H. Stevens and P. Stone, 21 October 2004.

S-1951 – 25 m above base of section; field locality 04-CH-106. Eoparafusulina linearis. Fusulinid Zone 4. S-1952 – 23 m above base of section; field locality 04-CH-105. Probably about the same location as S-1866. Eoparafusulina linearis. Fusulinid Zone 4.

S-1954 – 13.5 m above base of section; field locality 04-CH-104. Probably about the same location as S-1864. Eoparafusulina linearis. Fusulinid Zone 4. S-1955 – Float, ~31 m above base of section; field locality 04-CH-107. Stewartina convexa. Fusulinid Zone 4.

Warm Spring Canyon Rocks of the Bird Spring Formation are exposed for a distance of about 5 km along strike in Warm Spring Canyon in the southern Panamint Range (Wrucke, 1966; Stone, 1984). These outcrops extend from the northwestern part of the Anvil Spring Canyon West 7.5′ quadrangle to the northeastern part of the adjacent Manly Peak 7.5′ quadrangle (Figs. A12–A13). In this area, the Bird Spring Formation depositionally overlies a very thin unit of shale assigned to the Late Mississippian Indian Springs Formation, which in turn depositionally overlies the Mississippian Santa Rosa Hills Limestone. The Bird Spring Formation is depositionally overlain by siliceous limestone assigned to the lower part of the Permian Owens Valley Group (Fig. A14). A major fault at a low angle to bedding divides the Bird Spring Formation into lower and upper parts, each with a maximum exposed thickness of about 250 m. The lower part is composed primarily of cherty and silty limestone; the upper part consists primarily of thick-bedded limestone and silty limestone in which fusulinids and colonial corals are locally abundant. Comparison with an unfaulted section of Bird Spring Formation at Striped Butte 5 km to the southwest suggests that several hundred meters of Bird Spring strata are missing across the fault in Warm Spring Canyon (Stone, 1984). Our fusulinid samples are all from the upper part of the Bird Spring Formation in two different parts of the area: (1) central Warm Spring Canyon in the northwestern part of the Anvil Spring Canyon West 7.5′ quadrangle; and (2) hill 1259T in the northeastern part of the Manly Peak 7.5′ quadrangle (Figs. A12–A14). The upper 41 m of the Bird Spring Formation in central Warm Spring Canyon is represented by a detailed measured section shown in Figure A15.

1.

Samples from localities in the Anvil Spring Canyon West 7.5′ quadrangle:

S-1910 – Bird Spring Formation, upper part, ~120 m stratigraphically below top. Side canyon branching north from main wash of Warm Spring Canyon ~2.5 km east of quadrangle boundary, elev ~990 m. Lat 35°58′48″N, long 116°58′17″W. Collected by P. Stone and C.T. Wrucke, 9 November 2003, field locality 03-WS-1 (= fossil locality 7 of Wrucke, 1966). Triticites californicus? Fusulinid Zone 2. S-1967 – Bird Spring Formation, upper part, ~120 m stratigraphically below top. Ridge above side canyon branching north from main wash of Warm Spring Canyon ~2.5 km east of quadrangle boundary, elev ~1045 m. Lat 35°58′53″N, long 116°58′23″W. Collected by C.H. Stevens and P. Stone, 7 December 2003 (= fossil locality 5 of Wrucke, 1966). Triticites gigantocellus n. sp. Fusulinid Zone 2. The following samples are located in a measured section through the upper 41 m of the Bird Spring Formation (Fig. A15) in a large side canyon branching north from the main wash of Warm Spring Canyon, ~2 km east of the western boundary of the Anvil Spring Canyon West 7.5′ quadrangle. The middle of the measured section is at

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf lat 35°58′58.4″N, long 116°58′40.8″W (GPS), elev ~1000 m. Base of section is at the major fault contact with the lower part of the Bird Spring Formation; top is at the contact with the Owens Valley Group, which is placed at the base of a prominent brown siltstone marker bed. Section measured by P. Stone and C.H. Stevens, 7 December 2003; modified 30 November 2004. [Note: Although most samples were collected prior to measurement of the section, their positions are from known stratigraphic horizons traversed by the measured section.] S-0382 – 6 m above base of section, 35 m below top of Bird Spring Formation. Collected by C.H. Stevens, 1973. Triticites buttensis n. sp., T. aff. T. californicus, T. cellamagnus, T. gigantocellus n. sp. Fusulinid Zone 2. S-1930 – 17 m above base of section, 24 m below top of Bird Spring Formation. Collected by C.H. Stevens and P. Stone, 7 December 2003. Pseudoschwagerina roeseleri. Fusulinid Zone 3. S-1958 – 10 m above base of section, 31 m below top of Bird Spring Formation. Collected by C.H. Stevens and P. Stone, 30 November 2004, field locality 04-WS-2. Pseudoschwagerina roeseleri. Fusulinid Zone 3. S-1969 – 17 m above base of section, 24 m below top of Bird Spring Formation; same horizon as S-1930. Collected by C.H. Stevens, 2003. Pseudoschwagerina uddeni. Fusulinid Zone 3. S79-WS-3 – 9 m above base of section, 32 m below top of Bird Spring Formation. Collected by P. Stone, 13 March 1979. Schwagerina aculeata? Fusulinid Zone 3. S79-WS-4 – 10 m above base of section, 31 m below top of Bird Spring Formation; same horizon as S-1958. Collected by P. Stone, 13 March 1979. Pseudoschwagerina? sp. Fusulinid Zone 3. 2.

Samples from Hill 1259T:

S-1959 – Bird Spring Formation, upper part, ~110 m stratigraphically below top. Near base of western slope of hill, elev ~1200 m. Lat 35°59′01.1″N, long 117°00′53.3″W (GPS). Collected by C.H. Stevens and P. Stone, 30 November 2004, field locality 04-WS-5. Triticites cellamagnus. Fusulinid Zone 2. S-1960 – Bird Spring Formation, upper part, ~85 m stratigraphically below top. Lower part of western slope of hill, elev ~1210 m. Lat 35°59′00.1″N, long 117°00′53.3″W (GPS). Collected by C.H. Stevens and P. Stone, 30 November 2004, field locality 04-WS-6. Triticites aff. T. californicus, T. cellamagnus. Fusulinid Zone 2. S-1963 – Bird Spring Formation, upper part, ~85 m stratigraphically below top. Just north of hilltop, elev ~1250 m. Lat 35°58′59.5″N, long 117°00′49.4″W (GPS). Collected by C.H. Stevens and P. Stone, 16 March 2005, field locality 05-WS-4. Leptotriticites californicus n. sp., L. aff. L. gracilitatus, L. wetherensis. Fusulinid Zone 2 or 3. S-1964 – Bird Spring Formation, upper part, in fault block separated from main part of stratigraphic section. Southwest end of sum-

63

mit ridge, elev ~1250 m. Lat 35°58′55.8″N, long 117°00′54.4″W (GPS). Collected by P. Stone and C.T. Wrucke, 4 May 2005, field locality 05-WS-96. Pseudoschwagerina uddeni. Fusulinid Zone 4. S-1965 – Bird Spring Formation, upper part, approximately same location as S79-WS-20. Collected by C.H. Stevens, 2003. Leptotriticites sp. 3, Schwagerina sp. 4, Pseudoschwagerina arta, P. sp. 1, Eoparafusulina linearis. Fusulinid Zone 4. S-1966 – Bird Spring Formation, upper part, approximately same location as 82-WS-14. Collected by C.H. Stevens, 2003. Leptotriticites californicus n. sp., Leptotriticites warmspringensis n. sp., Eoparafusulina linearis. Fusulinid Zone 4. S79-WS-20 – Bird Spring Formation, upper part, ~12 m stratigraphically below top. Summit ridge southwest of hilltop, elev ~1250 m. Lat 35°58′57″N, long 117°00′52″W. Collected by P. Stone, 14 March 1979; locality reexamined and stratigraphic position determined by P. Stone and C.H. Stevens, 16 March 2005. Leptotriticites californicus n. sp., L. warmspringensis n. sp?, L. sp. 1, L. sp. 4, Pseudoschwagerina cf. P. gerontica, P. uddeni. Fusulinid Zone 4. 82-WS-2 – Bird Spring Formation, upper part, in anomalous fault sliver between lower and upper units of Owens Valley Group. Southwest slope of hill, elev ~1230 m. Lat 35°58′55″N, long 117°00′58″W. Collected by P. Stone, 15 March 1982. Schwagerina sp. 4, Eoparafusulina linearis. Fusulinid Zone 4. 82-WS-14 – Bird Spring Formation, upper part, in anomalous fault sliver between lower and upper units of Owens Valley Group. South slope of hill, elev ~1230 m. Lat 35°58′53.4″N, long 117°00′54.6″W (GPS). Collected by P. Stone, 22 March 1982; locality reexamined and located with GPS by P. Stone and C.H. Stevens, 16 March 2005. Leptotriticites californicus n. sp., L. warmspringensis n. sp. Fusulinid Zone 4.

Striped Butte Rocks of the Bird Spring Formation form almost all of Striped Butte, a prominent peak in Butte Valley surrounded by alluvium (Fig. A16). This locality is about 5 km southwest of Warm Spring Canyon in the southern Panamint Range in the central part of the Manly Peak 7.5′ quadrangle. The steeply dipping rocks of the Bird Spring Formation here form a continuous, nearly homoclinal section about 1000 m thick (Stone, 1984) with neither the base nor the top exposed (Fig. A17). The lower 200 m of the partial section at Striped Butte (unit 1, Figs. A16–A17) consists of cherty and silty limestone. This unit is overlain by about 450 m of thick-bedded limestone, silty limestone, and minor dolomite (unit 2) in which fusulinids and other fossils are rare. The overlying unit 3, about 230 m thick, consists of thick-bedded, highly fossiliferous limestone in which fusulinids and colonial corals are abundant. The uppermost 120 m of the section (unit 4) is composed of thin- to thick-bedded, recessive limestone and minor dolomite that grade upward into thick-bedded limestone similar to that in unit 3. Fusulinids and colonial corals are locally abundant in unit 4. Our fusulinid samples represent most of the significant occurrences in units 3 and 4 (Figs. A16–A17). In addition, our collections include one approximately located sample (S-1968) from unit 2.

35o

GEOLOGIC MAP—CENTRAL WARM SPRING CANYON

116o59' 59'15"

116o58'

70 S-0382 S79-WS-3 S79-WS-4, S-1958 S-1930, S-1969

63 S-1967

S-1910

68

70

35o58'30" 0

0.5 KILOMETER CONTOUR INTERVAL 10 METERS

MANLY PEAK QUADRANGLE

MAP AREA

ANVIL SPRING CANYON WEST QUADRANGLE

Figure A12. Geologic map showing locations of fusulinid samples in Bird Spring Formation in central Warm Spring Canyon in the northwestern part of the Anvil Spring Canyon West 7.5′ quadrangle, California. Geology from Wrucke (1966), Stone (1984), and unpublished mapping by C.T. Wrucke Jr., P. Stone, and C.H. Stevens in 2003–2005.

MAP EXPLANATION—WARM SPRING CANYON Alluvium (Quaternary) Older alluvium (Quaternary) Volcanic rocks (Tertiary) Monzogranite (Cretaceous or Jurassic) Tonalite (Cretaceous or Jurassic) Warm Spring Formation (Jurassic)—Volcanic rocks and minor sandstone; base faulted Owens Valley Group (Permian) Upper unit—Buff- to brown-weathering calcareous siltstone to fine-grained sandstone; medium-gray, fine-grained limestone and silty limestone; and brown-weathering argillite (565 m). Interpreted as deep-water unit composed primarily of turbidites. Base faulted Lower unit—Medium- to dark-gray, medium-bedded, fine-grained limestone containing irregular, discontinuous beds and lenses of buff- to brown-weathering siltstone, argillite, and chert (90 m) Bird Spring Formation (Permian and Pennsylvanian)—Limestone, silty to argillaceous limestone, cherty limestone, and minor siltstone. Upper and lower parts of formation separated by a major fault Upper part (Permian and Pennsylvanian)—Light- to dark-gray, thick-bedded to massive limestone, silty to argillaceous limestone, minor cherty limestone, and rare siltstone (200 m). Fusulinids and corals locally abundant Lower part (Pennsylvanian)—Medium- to dark-gray, thin- to thick-bedded limestone and silty limestone containing abundant nodules, lenses, and thin beds of dark-brown-weathering chert (200 m) Indian Springs Formation (Mississippian)—Calcareous siltstone and shale Santa Rosa Hills Limestone and Stone Canyon Limestone, undivided (Mississippian)—Limestone and cherty limestone Kingston Peak Formation (Neoproterozoic)—Thin-bedded limestone, argillite, and silty limestone (South Park Member) and diamictite (Surprise Member)

Contact Fault 60

Strike and dip of beds

S-0382

Fusulinid sample locality Line of generalized stratigraphic section (Fig. A14)

A

A'

Line of cross section (Fig. A13) Figure A12. (Continued).

GEOLOGIC MAP—WEST END OF WARM SPRING CANYON (HILL 1259-T)

117o01'30" 35o59'15"

117o00'30"

S-1965 S79-WS-20 S-1963

A'

S-1959 S-1960

55

S-1964

A

82-WS-2

82-WS-14 S-1966

60

35o58'30" 0.5 KILOMETER

0

MANLY PEAK QUADRANGLE

CONTOUR INTERVAL 10 METERS

A

ANVIL SPRING CANYON WEST QUADRANGLE

A'

METERS

METERS 1300

1250

1250

1200

1200

1150

1150

?

1300

1100

MAP AREA

1100

Figure A13. Geologic map and cross section showing locations of fusulinid samples in Bird Spring Formation on Hill 1259-T at west end of Warm Spring Canyon in the northeastern part of the Manly Peak 7.5′ quadrangle, California. Geology from Stone (1984) and unpublished mapping by C.T. Wrucke Jr., P. Stone, and C.H. Stevens in 2003–2005. See Figure A12 key for explanation.

STRATIGRAPHIC SECTIONS—WARM SPRING CANYON Hill 1259-T (main section)

Central Warm Spring Canyon Owens Valley Group (lower unit)

Hill 1259-T (anomalous fault blocks) S-1964 S-1966 82-WS-2 82-WS-14

S-1965 S79-WS-20

S-1930 S-1969 S-1958, S79-WS-4 S79-WS-3 S-0382

Upper part

S-1960 S-1963 S-1959 S-1910 S-1967 50 METERS

Bird Spring Formation

Fault SCALE

0

Base covered Lower part

EXPLANATION Thick-bedded limestone Massive limestone Cherty limestone Silty limestone Thin-bedded limestone with siliceous interbeds

Indian Springs Formation

Siltstone Shale S-1959

Santa Rosa Hills Limestone

Sample

Figure A14. Stratigraphic columns of Bird Spring Formation at Warm Spring Canyon, showing positions of fusulinid samples. Generalized lithology and thickness based on Wrucke (1966), Stone (1984), and recent unpublished mapping and field observations by C.T. Wrucke Jr. and the authors.

DETAILED STRATIGRAPHIC SECTION—CENTRAL WARM SPRING CANYON SAMPLE

LITHOLOGY

THICKNESS (METERS)

40 Medium- to dark-gray limestone. Colonial corals (Protowentzelella) in upper 1 m. Stratigraphically overlain by 5 m of brown siltstone that forms basal part of the Owens Valley Group

Brown-weathering calcareous siltstone and light-gray silty limestone

30

Light-gray silty limestone. Fusulinids locally abundant. Colonial corals (Protowentzelella) 6 m above base

20

S-1930 S-1969

S-1958, S79-WS-4

Medium- to dark-gray limestone, in part echinodermal. Colonial corals, including Protowentzelella, abundant 1 m above base; fusulinids especially abundant near top

Light-gray silty limestone. Fusulinids locally abundant

10

S79-WS-3

S-0382 Brown calcareous siltstone. Uppermost part composed of black argillaceous limestone containing fusulinids Dark-gray laminated limestone. Fault at base

0

Figure A15. Detailed stratigraphic column of uppermost Bird Spring Formation on north side of Warm Spring Canyon, showing positions of fusulinid samples. Lithology and thickness based on a measured section by the authors.

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf S-0539 – Bird Spring Formation, unit 3, probably about the same location as S79-SB-26. Collected by C.H. Stevens, 1973. Triticites californicus. Fusulinid Zone 2. S-0616 – Bird Spring Formation, unit 3, probably about the same location as S-1900. Collected by C.H. Stevens, 1973. Triticites cellamagnus. Fusulinid Zone 2. S-0617 – Bird Spring Formation, unit 3, probably about the same location as S79-SB-26. Collected by C.H. Stevens, 1973. Triticites californicus. Fusulinid Zone 2. S-1236 – Bird Spring Formation, unit 3, same location as S-1928. Collected by C.H. Stevens, 1980. Schwagerina aculeata plena, Pseudochusenella buttensis n. sp. Fusulinid Zone 3. S-1842 – Bird Spring Formation, unit 4, same location as S-1928. Collected by C.H. Stevens, 2002. Pseudochusenella buttensis n. sp. Fusulinid Zone 3. S-1900 – Bird Spring Formation, ~790 m stratigraphically above base of exposed section, ~140 m stratigraphically above base of unit 3. Just west of crest of main ridge near northeast end of Striped Butte, elev ~1330 m. Lat 35°57′07″N, long 117°04′02″W. Collected by P. Stone, 15 March 1979, field locality S79-SB-25. Leptotriticites cf. L. hughesensis, L. cf. L. koschmanni. Fusulinid Zone 2. S-1914 – Bird Spring Formation, unit 4, approximately same location as S-1929. Collected by P. Stone, 15 March 1979, field locality S79-SB-32. Leptotriticites cf. L. hughesensis, L. panamintensis n. sp., L. cf. L. koschmanni. Fusulinid Zone 3.

69

December 2003, field locality 1-225. Leptotriticites aff. L. americanus. Fusulinid Zone 2. S-1927 – Bird Spring Formation, ~894 m stratigraphically above base of exposed section, 14 m stratigraphically above base of unit 4. East side of Striped Butte, ~0.5 km south of northeast end, elev ~1290 m. Lat 35°56′59″N, long 117°04′01″W. Collected by C.H. Stevens and P. Stone, 7 December 2003, field locality 2-14. Triticites buttensis n. sp., T. californicus, T. cellamagnus. Fusulinid Zone 2. S-1928 – Bird Spring Formation, ~992 m stratigraphically above base of exposed section, 112 m stratigraphically above base of unit 4. East side of Striped Butte, ~0.6 km south of northeast end, elev ~1210 m. Lat 35°56′55″N, long 117°03′58″W. Collected by C.H. Stevens and P. Stone, 7 December 2003, field locality 2-112. Pseudochusenella buttensis n. sp., P. sp. 1, P. hazzardi n. sp. Fusulinid Zone 3. S-1929 – Bird Spring Formation, ~924 m stratigraphically above base of exposed section, 44 m stratigraphically above base of unit 4; probably same bed as S-1923. East side of Striped Butte, ~0.5 km south of northeast end, elev ~1270 m. Lat 35°56′58″N, long 117°03′59″W. Collected by C.H. Stevens and P. Stone, 7 December 2003, field locality 2-44. Leptotriticites cf. L. hughesensis. Fusulinid Zone 3. S-1931 – Bird Spring Formation, ~1000 m stratigraphically above base of exposed section, ~120 m stratigraphically above base of unit 4; uppermost exposed beds in section. East side of Striped Butte, ~0.5 km south of northeast end, elev ~1200 m. Lat 35°56′57″N, long 117°03′56″W. Collected by C.H. Stevens and P. Stone, 7 December 2003, field locality SB-22. Schwagerina providens, S. sp. 3. Fusulinid Zone 3.

S-1915 – Bird Spring Formation, ~860 m stratigraphically above base of exposed section, ~210 m stratigraphically above base of unit 3. East side of main ridge near northeast end of Striped Butte, elev ~1280 m. Lat 35°57′09″N, long 117°03′58″W. Collected by P. Stone, 15 March 1979, field locality S79-SB-27. Triticites buttensis n. sp., T. californicus, T. cellamagnus, T. gigantocellus n. sp., Schwagerina providens, S.? sp. 1. Fusulinid Zone 2.

S-1932 – Bird Spring Formation, ~ 655 m stratigraphically above base of exposed section, ~5 m stratigraphically above base of unit 3. Base of northern slope of Striped Butte, elev ~1260 m. Lat 35°57′15″N, long 117°04′03″W. Collected by C.H. Stevens and P. Stone, 6 December 2003, field locality SB-4. Triticites californicus? Fusulinid Zone 2.

S-1922 – Bird Spring Formation, ~ 790 m stratigraphically above base of exposed section, ~140 m stratigraphically above base of unit 3. Base of northern slope of Striped Butte, elev ~1260 m. Lat 35°57′15″N, long 117°03′59″W. Collected by C.H. Stevens and P. Stone, 6 December 2003, field locality SB-3. Leptotriticites aff. L. americanus, L. cf. L. hughesensis. Fusulinid Zone 2.

S-1933 – Bird Spring Formation, ~ 800 m stratigraphically above base of exposed section, ~150 m stratigraphically above base of unit 3. Base of northern slope of Striped Butte, elev ~1260 m. Lat 35°57′16″N, long 117°03′58″W. Collected by C.H. Stevens and P. Stone, 6 December 2003, field locality SB-2. Triticites californicus, Leptotriticites cf. L. koschmanni. Fusulinid Zone 2.

S-1923 – Bird Spring Formation, ~925 m stratigraphically above base of exposed section, ~45 m stratigraphically above base of unit 3; probably same bed as S-1929. East side of main ridge near northeast end of Striped Butte, elev ~1240 m. Lat 35°57′09″N, long 117°03′54″W. Collected by C.H. Stevens and P. Stone, 6 December 2003, field locality SB-18. Leptotriticites cf. L. hughesensis. Fusulinid Zone 3.

S-1968 – Bird Spring Formation, southwestern ridge, exact location and stratigraphic position uncertain. Probably ~300 m stratigraphically above base of exposed section, ~100 m stratigraphically above base of unit 2. Lat ~35°56′50″N, long ~117°04′35″W. Collected by C.H. Stevens, 1980. Triticites cf. T. burgessae. Below Fusulinid Zone 1.

S-1926 – Bird Spring Formation, ~ 790 m stratigraphically above base of exposed section, ~140 m stratigraphically above base of unit 3; probably same horizon as S-1900. Just west of main ridge near northeast end of Striped Butte, elev ~1330 m. Lat 35°57′09″N, long 117°04′02″W. Collected by C.H. Stevens and P. Stone, 6

S79-SB-26 – Bird Spring Formation, ~830 m stratigraphically above base of exposed section, ~180 m stratigraphically above base of unit 3. East side of main ridge near northeast end of Striped Butte, elev ~1320 m. Lat 35°57′08″N, long 117°04′00″W. Collected by P. Stone, 15 March 1979. Triticites californicus, T. cellamagnus, Leptotriticites aff. L. hatchetensis. Fusulinid Zone 2.

GEOLOGIC MAP—STRIPED BUTTE

117o05' 35o57'30"

117o03'30"

S-1922 S-1932

S-1933 S79-SB-26 (S-0617) (S-0539)

S-1926 S-1900 (S-0616)

S-1923 S79-SB-28 S-1915

50

S-1927 70

(S-1968)

S-1914, S-1929

85 80

66

S-1931 S-1928 S-1842 S-1236

86

dolomite marker bed

35o56'30" 0

1 KILOMETER CONTOUR INTERVAL 10 METERS

MANLY PEAK QUADRANGLE

MAP AREA

ANVIL SPRING CANYON WEST QUADRANGLE

Figure A16. Geologic map showing locations of fusulinid samples in Bird Spring Formation at Striped Butte in the central part of the Manly Peak 7.5′ quadrangle, California. Geology mapped by the authors in 2003.

MAP EXPLANATION—STRIPED BUTTE Alluvium (Quaternary) Owens Valley Group (Permian)—Medium- to thin-bedded gray limestone, grayish-orange silty limestone, pinkish-brown siltstone, and black cherty argillite; in fault contact with Bird Spring Formation. Probably equivalent to lower unit of Owens Valley Group to the east in Warm Spring Canyon Bird Spring Formation (Permian and Pennsylvanian) Unit 4 (Permian and Pennsylvanian)—Light- to dark-gray limestone and minor siltstone (120 m; top covered). Medium- to dark-gray, resistant limestone in upper part of unit grades downward into light- to medium-gray, recessive limestone. Silty beds are scattered throughout unit. Fusulinids locally abundant Unit 3 (Pennsylvanian)—Medium- to dark-gray, thick-bedded fossiliferous limestone containing abundant fusulinids and corals (230 m) Unit 2 (Pennsylvanian)—Light- to medium-gray, thick-bedded limestone, white calcitic marble, and minor brown silty limestone (450 m). Lenticular chert common in upper part of unit. Locally fossiliferous; fusulinids rare. Conspicuous marker bed of tan dolomite 250 m above base of unit Unit 1 (Pennsylvanian)—Medium- to dark-gray limestone and brown silty limestone, locally containing abundant brown chert nodules, lenses, and beds (200 m; base covered)

Contact Fault 60 S-1236

Strike and dip of beds Fusulinid sample locality

(S-0616) Fusulinid sample locality (approximately located) Line of generalized stratigraphic section (Fig. A17) Figure A16. (Continued).

SAMPLE S-1931 S-1236, S-1842, S-1928

Top covered

THICKNESS (METERS) 1000

Unit 4 S-1914, S-1923, S-1929 900

S79-SB-28, S-1927 S-1915 (S-0539, S-0617), S79-SB-26 S-1933 (S-0616), S-1900, S-1922, S-1926

800 Unit 3

700

STRATIGRAPHIC COLUMN— STRIPED BUTTE

S-1932

600

Dolomite marker bed

Unit 2

Bird Spring Formation

500

EXPLANATION Thick-bedded limestone Thin-to thick-bedded recessive limestone Cherty limestone Silty limestone

400

Dolomite

(S-1968)

300

200

100

Base covered

Unit 1

0

Figure A17. Stratigraphic column of Bird Spring Formation at Striped Butte, showing positions of fusulinid samples. Locations of samples in parentheses are approximate. Generalized lithology and thickness based on Stone (1984) and on recent mapping, field observations, and partial measured sections by the authors.

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf S79-SB-28 – Bird Spring Formation, ~895 m stratigraphically above base of exposed section, ~15 m stratigraphically above base of unit 4. Approximately same horizon as S-1927. East side of main ridge near northeast end of Striped Butte, elev ~1260 m. Lat 35°57′08″N, long 117°03′56″W. Collected by P. Stone, 15 March 1979. Triticites buttensis n. sp., T. cellamagnus. Fusulinid Zone 2.

Panamint Butte Rocks of the Bird Spring Formation, originally assigned to the Keeler Canyon and Owens Valley formations by Hall (1971), are extensively exposed in the vicinity of Panamint Butte in the southern Cottonwood Mountains (Stone, 1984). These outcrops are in the central part of the Panamint Butte 7.5′ quadrangle (Figs. A18–A19), where the Bird Spring Formation depositionally overlies the Mississippian Santa Rosa Hills Limestone and is depositionally overlain by rocks assigned to the Lower Permian Osborne Canyon Formation. Because of faulting, however, a continuous stratigraphic section is not present. The Bird Spring Formation in the Panamint Butte area is more than 2000 m thick and is divided into six stratigraphic units (Fig. A20). The lower part of the formation (units 1–5) is exposed in the western and central parts of the outcrop area. The lower 350 m (units 1 and 2 combined) consists of cherty limestone, silty limestone, and siltstone. Unit 3 is a marker unit of white to light-gray recrystallized limestone and marble about 75 m thick. Unit 4 consists of thick-bedded limestone about 525 m thick, with abundant fusulinids in the upper half. Unit 5, faulted at the top, is composed of thick-bedded limestone with an exposed thickness of about 350 m; it contains fusulinids only near the base. The upper 750 m of the Bird Spring Formation (unit 6) is exposed only in the eastern part of the outcrop area and is separated from units 1–5 by faults. It consists primarily of thick-bedded limestone in which fusulinids are present only locally. Unit 6 also contains a few thick beds of conglomeratic limestone similar to that in the overlying Osborne Canyon Formation (Fig. A20). Our fusulinid collections include samples from selected horizons in the upper part of unit 4 and the basal part of unit 5, samples from near the base and near the top of unit 6, and one sample from the Osborne Canyon Formation. [Note that elevations of the samples listed below are given in feet, as well as in meters, to correspond to contours shown on the maps of the Panamint Butte quadrangle (Figs. A18, A19).] S-1226 – Bird Spring Formation, ~725 m stratigraphically above base of formation, ~300 m above base of unit 4. Crest of Cottonwood Mountains at head of Panamint Canyon, elev ~7120 ft (2170 m). Lat 36°25′39″N, long 117°18′58″W. Collected by P. Stone and C.H. Stevens, 9 June 1981, field locality 81-PB-23. Triticites californicus. Fusulinid Zone 2.

73

gerina aculeata, S. providens, S. vervillei, Pseudoschwagerina arta. Fusulinid Zone 3. S-1911 – Bird Spring Formation, ~950 m stratigraphically above base of formation, just above base of unit 5. Northwest side of Panamint Canyon, elev ~6200 ft (1890 m). Lat 36°25′26″N, long 117°20′29″W. Collected by P. Stone, 13 June 1981, field locality 81-PB-40. Schwagerina cf. S. elkoensis, Advenella bifurcata. Fusulinid Zone 3. S-1912 – Bird Spring Formation, float sample, ~875 m stratigraphically above base of formation, ~450 m above base of unit 4. Downslope to east from crest of Cottonwood Mountains, elev ~6450 ft (1970 m). Lat 36°25′47″N, long 117°18′43″W. Collected by P. Stone and C.H. Stevens, 9 June 1981, field locality 81-PB-28. Leptotriticites californicus n. sp., L. cf. L. hughesensis, L. panamintensis n. sp. Fusulinid Zone 3. S-1913 – Bird Spring Formation, unit 6, ~700 m stratigraphically below upper contact with Osborne Canyon Formation. Unnamed canyon in east-central part of Panamint Butte 7.5′ quadrangle, elev ~5320 ft (1620 m). Lat 36°26′24″N, long 117°17′44″W. Collected by P. Stone, 12 June 1981, field locality 81-PB-31. Paraschwagerina fairbanksi. Fusulinid Zone 3. S-1916 – Bird Spring Formation, unit 4, approximately same locality as S-1226. Collected by P. Stone and C.H. Stevens, 9 June 1981, field locality 81-PB-24. Triticites californicus. Fusulinid Zone 2. 81-PB-27 – Bird Spring Formation, ~750 m stratigraphically above base of formation, ~325 m stratigraphically above base of unit 4. Downslope to east from crest of Cottonwood Mountains, elev ~6800 ft (2070 m). Lat 36°25′41″N, long 117°18′52″W. Collected by P. Stone and C.H. Stevens, 9 June 1981. Triticites californicus, T. aff. T. californicus, Schwagerina providens. Fusulinid Zone 2. 81-PB-35 – Bird Spring Formation, ~720 m stratigraphically above base of formation, ~230 m below top of unit 4. Northwest side of Panamint Canyon, elev ~5600 ft (1710 m). Lat 36°25′16″N, long 117°20′23″W. Collected by P. Stone, 13 June 1981. Pseudofusulinella cf. P. harbaughi, Triticites bensonensis. Fusulinid Zone 1. 81-PB-37 – Bird Spring Formation, ~840 m stratigraphically above base of formation, ~110 m below top of unit 4. Northwest side of Panamint Canyon, elev ~5960 ft (1820 m). Lat 36°25′21″N, long 117°20′26″W. Collected by P. Stone, 13 June 1981. Triticites californicus. Fusulinid Zone 2.

S-1227 – Osborne Canyon Formation, ~30 m stratigraphically above lower contact with Bird Spring Formation. North side of unnamed canyon in east-central part of Panamint Butte 7.5′ quadrangle, elev ~4920 ft (1500 m). Lat 36°27′00″N, long 117°17′03″W. Collected by P. Stone, 12 June 1981, field locality 81-PB-34. Schwagerina cf. S. elkoensis, S. vervillei. Fusulinid Zone 3.

81-PB-38 – Bird Spring Formation, ~920 m stratigraphically above base of formation, ~30 m below top of unit 4. Northwest side of Panamint Canyon, elev ~6060 ft (1850 m). Lat 36°25′23″N, long 117°20′26″W. Collected by P. Stone, 13 June 1981. Triticites californicus, T. cellamagnus. Fusulinid Zone 2.

S-1232 – Bird Spring Formation, unit 6, ~100 m stratigraphically below upper contact with Osborne Canyon Formation. Unnamed canyon in east-central part of Panamint Butte 7.5′ quadrangle, elev ~4800 ft (1460 m). Lat 36°26′53″N, long 117°17′08″W. Collected by P. Stone, 12 June 1981, field locality 81-PB-32. Schwa-

81-PB-39 – Bird Spring Formation, ~940 m stratigraphically above base of formation, ~10 m below top of unit 4. Northwest side of Panamint Canyon, elev ~6120 ft (1870 m). Lat 36°25′24″N, long 117°20′27″W. Collected by P. Stone, 13 June 1981. Triticites cellamagnus. Fusulinid Zone 2.

GEOLOGIC MAP—PANAMINT BUTTE (WESTERN PART OF AREA)

117o20'44" 36o26'

117o18'30"

25 Central Section

50 S-1226 S-1916

60 S-1911

S-1912 81-PB-27

50

35

81-PB-39 81-PB-38 81-PB-37

30

81-PB-35

Western Section 36o25' 0

1 KILOMETER CONTOUR INTERVAL 40 FEET

MAP AREA

PANAMINT BUTTE QUADRANGLE

Figure A18. Geologic map showing locations of fusulinid samples in Bird Spring Formation in western part of the Panamint Butte 7.5′ quadrangle, California (Western and Central sections, Fig. A20). Geology from Stone (1984).

MAP EXPLANATION—PANAMINT BUTTE Alluvium (Quaternary) Talus (Quaternary) Volcanic rocks (Tertiary) Osborne Canyon Formation (Permian)—Medium- to dark-gray, bioclastic and conglomeratic limestone containing fusulinids, coral fragments, and spherical to rod-shaped limestone clasts (~75 m exposed). Beds are interpreted as turbidites and debris-flow deposits Bird Spring Formation (Permian and Pennsylvanian) Unit 6 (Permian)—Primarily medium- to light-gray limestone and silty limestone that locally contains fusulinids and other fossils (~750 m exposed in an isolated fault block). Also includes a few thick beds of conglomerate (probably debris-flow deposits) characterized by rounded limestone clasts in crinoidal limestone matrix Unit 5 (Permian? and Pennsylvanian)—Primarily medium-gray, thick-bedded to massive limestone (~750 m exposed) Unit 4 (Pennsylvanian)—Light- to dark-gray limestone (525 m). Consists of upper subunit of light- to medium-gray limestone, silty limestone, and white marble (125 m); middle subunit of light- to dark-gray, locally cherty limestone and rare silty limestone (125 m); and lower subunit of thick-bedded to massive, light- to medium-gray limestone (275 m). Fusulinids are abundant in upper subunit and rare in middle subunit Unit 3 (Pennsylvanian)—White to light-gray calcitic marble; minor dark-gray, cherty and silty limestone (75 m) Unit 2 (Pennsylvanian)—Medium- to dark-gray cherty limestone and tan-weathering silty limestone (200 m). Spherical chert nodules common. Upper part of unit contains prominent beds of white to light-gray calcitic marble Unit 1 (Pennsylvanian)—Medium- to dark-gray silty limestone and tan-weathering calcareous siltstone (150 m). Spherical chert nodules and lenticular chert abundant Sedimentary rocks, undivided (Mississippian)—Limestone and cherty limestone Sedimentary rocks, undivided (Devonian to Cambrian)—Limestone, dolomite, and minor quartzite

Contact Fault—Dotted where concealed 60 S-1912

Strike and dip of beds Fusulinid sample locality Line of generalized stratigraphic section (Fig. A20) Figure A18. (Continued).

GEOLOGIC MAP—PANAMINT BUTTE (EASTERN PART OF AREA)

117o18' 36o27'18'

117o16'48"

25

S-1227 S-1232

10

40

Figure A19. Geologic map showing locations of fusulinid samples in Bird Spring and Osborne Canyon Formations in the eastern part of the Panamint Butte 7.5′ quadrangle, California (Eastern section, Fig. A20). Geology from Stone (1984). See Figure A18 key for explanation.

40

S-1913 Eastern Section

36o26' 0

1 KILOMETER CONTOUR INTERVAL 40 FEET

PANAMINT BUTTE QUADRANGLE

MAP AREA

Eastern section

STRATIGRAPHIC COLUMNS—PANAMINT BUTTE

Osborne Canyon Formation

S-1227 EXPLANATION Conglomeratic limestone

S-1232

Thick-bedded limestone Massive limestone Cherty limestone Silty limestone

Unit 6

Siltstone S-1911

Sample

S-1913

Western section

Fault

Fault

Bird Spring Formation

Unit 5

Central section

S-1911 81-PB-39 81-PB-38

Covered S-1912

81-PB-37 81-PB-27 S-1916 S-1226

81-PB-35

Unit 4

Fault

Unit 3

200 METERS Unit 2 SCALE

100

0

Unit 1

Santa Rosa Hills Limestone

Figure A20. Stratigraphic columns of Bird Spring Formation at Panamint Butte, showing positions of fusulinid samples. Note that one sample is from the overlying Osborne Canyon Formation. Generalized lithology and thickness based on Stone (1984).

APPENDIX 3. LOCALITY INFORMATION FOR FIGURED SPECIMENS All holotypes and paratypes are housed in the National Museum of Natural History (formerly the U.S. National Museum) and bear a USNM number. Figured specimens labeled SJS are housed in the San Jose State University Museum of Paleontology, San Jose, California.

Specimen (Thin section) USNM 531292 USNM 531293 USNM 531294 USNM 531295 USNM 531296 USNM 531297 USNM 531298 USNM 531299 USNM 531300 USNM 531301 USNM 531302 USNM 531303 USNM 531304 USNM 531305 USNM 531306 USNM 531307 1 USNM 531308 1 USNM 531308 USNM 531309 USNM 531310 USNM 531311 USNM 531312 USNM 531313 USNM 531314 USNM 531315 USNM 531316 SJS 143f SJS 144f SJS 148f SJS 149f SJS 150f SJS 151f SJS 152f SJS 153f SJS 158f SJS 159f SJS 160f SJS 161f SJS 162f SJS 163f SJS 168f SJS 169f SJS 170f SJS 171f SJS 172f SJS 173f SJS 174f SJS 175f SJS 176f SJS 177f SJS 178f

Figure Pl. 1, Figure 14 Pl. 1, Figure 15 Pl. 1, Figure 12 Pl. 1, Figure 5 Pl. 1, Figure 10 Pl. 2, Figure 2 Pl. 2, Figure 3 Pl. 2, Figure 11 Pl. 2, Figure 13 Pl. 8, Figure 5 Pl. 8, Figure 4 Pl. 8, Figure 6 Pl. 6, Figure 8 Pl. 6, Figure 9 Pl. 5, Figure 7 Pl. 5, Figure 6 Pl. 5, Figure 8 Pl. 6, Figure 4 Pl. 7, Figure 7 Pl. 7, Figure 5 Pl. 7, Figure 6 Pl. 2, Figure 10 Pl. 2, Figure 12 Pl. 5, Figure 12 Pl. 5, Figure 10 Pl. 5, Figure 11 Pl. 1, Figure 3 Pl. 1, Figure 4 Pl. 1, Figure 6 Pl. 1, Figure 7 Pl. 1, Figure 8 Pl. 1, Figure 9 Pl. 1, Figure 11 Pl. 1, Figure 13 Pl. 2, Figure 4 Pl. 2, Figure 5 Pl. 2, Figure 6 Pl. 2, Figure 7 Pl. 2, Figure 8 Pl. 2, Figure 9 Pl. 3, Figure 1 Pl. 3, Figure 2 Pl. 3, Figure 3 Pl. 3, Figure 7 Pl. 3, Figure 5 Pl. 3, Figure 8 Pl. 3, Figure 9 Pl. 3, Figure 10 Pl. 3, Figure 11 Pl. 3, Figure 12 Pl. 3, Figure 13

Species Triticites buttensis n. sp. Triticites buttensis n. sp Triticites gigantocellus n. sp. Triticites gigantocellus n. sp. Triticites gigantocellus n. sp. Leptotriticites panamintensis n. sp. Leptotriticites panamintensis n. sp. Leptotriticites warmspringensis n. sp. Leptotriticites warmspringensis n. sp. Stewartina magnifica n. sp. Stewartina magnifica n. sp. Stewartina magnifica n. sp. Stewartina ultimata n. sp. Stewartina ultimata n. sp. Pseudochusenella buttensis n. sp. Pseudochusenella buttensis n. sp. Pseudochusenella buttensis n. sp. Pseudochusenella? sp. 1 Cuniculinella mojavensis n. sp. Cuniculinella mojavensis n. sp. Cuniculinella mojavensis n. sp. Leptotriticites californicus n. sp. Leptotriticites californicus n. sp. Pseudochusenella hazzardi n. sp. Pseudochusenella hazzardi n. sp. Pseudochusenella hazzardi n. sp. Triticites hermanni Pseudofusulinella cf. P. harbaughi Triticites bensonensis Triticites cellamagnus Triticites aff. T. californicus Triticites californicus Leptotriticites sp. 3 Leptotriticites sp. 4 Leptotriticites cf. L. varius Leptotriticites wetherensis Leptotriticites cf. L. hughesensis Leptotriticites. aff. L. americanus Leptotriticites glenensis Leptotriticites glenensis Schwagerina aculeata Schwagerina sp. 3 Schwagerina vervillei Schwagerina vervillei Schwagerina? sp. 2 Schwagerina cf. S. elkoensis Schwagerina aculeata plena Leptotriticites aff. L. gracilitatus Leptotriticites cf. L. koschmanni Leptotriticites sp. 2 Leptotriticites sp. 1

Locality S-1915 S-1915 S-1915 S-0382 S-0382 S-1912 S-1912 S-1966 82-WS-14 S-1843 S-1843 S-1843 S-1949 S-1949 S-1928 S-1928 S-1928 S-1928 S-1852 S-1852 S-1852 82-WS-14 82-WS-14 USGS f14074 USGS f14074 USGS f14074 S-1874 81-PB-35 S-1458 S-1456 81-PB-27 S79-SB-26 S-1965 S79-WS-20 S-1869 S-1869 S-1460 S-1926 S-1869 S-1869 S-1945 S-1947 S-1862 S-1866 S-1949 S-1911 S-1877 S-1859 S-1914 S-1869 S79-WS-20 (Continued)

The Pennsylvanian–Early Permian Bird Spring Carbonate Shelf

Specimen (Thin section) SJS 179f SJS 180f SJS 181f SJS 182f SJS 183f SJS 184f SJS 185f SJS 186f SJS 187f SJS 188f SJS 189f SJS 190f SJS 191f SJS 195f SJS 196f SJS 198f SJS 199f SJS 200f SJS 203f SJS 204f SJS 205f SJS 206f SJS 210f

Figure Pl. 4, Figure 1 Pl. 4, Figure 2 Pl. 4, Figure 4 Pl. 4, Figure 5 Pl. 4, Figure 8 Pl. 4, Figure 6 Pl. 4, Figure 7 Pl. 4, Figure 9 Pl. 4, Figure 10 Pl. 4, Figure 12 Pl. 4, Figure 11 Pl. 5, Figure 3 Pl. 5, Figure 4 Pl. 5, Figure 9 Pl. 6, Figure 1 Pl. 6, Figure 2 Pl. 6, Figure 6 Pl. 6, Figure 7 Pl. 7, Figure 1 Pl. 7, Figure 2 Pl. 7, Figure 3 Pl. 7, Figure 4 Pl. 8, Figure 1

Species

Schwagerina modica Schwagerina cf. S. pugunculus Schwagerina? sp. 1 Paraschwagerina fairbanksi Paraschwagerina fairbanksi Pseudoschwagerina sp. 1 Advenella bifurcata Paraschwagerina elongata Pseudoschwagerina roeseleri Schwagerina sp. 4 Pseudoschwagerina arta Stewartina uber Stewartina uber Pseudoschwagerina cf. P. gerontica Pseudochusenella? sp. 1 Stewartina uber Stewartina texana Pseudoschwagerina uddeni Triticites elegantoides Stewartina convexa Parafusulina sp. 1 Parafusulina aff. P. durhami Parafusulina cf. P. shaksgamensis crassimarginata SJS 211f Pl. 8, Figure 2 Eoparafusulina linearis SJS 212f Pl. 8, Figure 3 Eoparafusulina linearis SJS 216f Pl. 1, Figure 1 Triticites muddiensis 2 Pl. 6, Figure 3 Pseudochusenella concisa 7692 2 Pl. 6, Figure 5 Pseudochusenella concisa 7692 Unnumbered Pl. 1, Figure 2 Triticites sp. 1 Unnumbered Pl. 2, Figure 1 Leptotriticites aff. L. hatchetensis Unnumbered Pl. 5, Figure 1 Schwagerina longissimoidea Unnumbered Pl. 4, Figure 3 Schwagerina providens Unnumbered Pl. 3, Figure 4 Schwagerina cf. S. wellsensis Unnumbered Pl. 3, Figure 6 Schwagerina cf. S. wellsensis Unnumbered Pl. 5, Figure 5 Stewartina multispira Unnumbered Pl. 5, Figure 2 Stewartina sp. 1 1 Same thin section (USNM 531308) contains two illustrated fusulinid specimens. 2 Both figures (pl. 6, Figs. 3 and 5) are of the same specimen.

REFERENCES CITED Beede, J.W., 1916, New species of fossils from the Pennsylvanian and Permian rocks of Kansas and Oklahoma: Indiana University Studies, v. 3, p. 5–15. Beede, J.W., and Kniker, H.T., 1924, Species of the genus Schwagerina and their stratigraphic significance: Texas University Bulletin 2433, p. 1–100. Bissell, H.J., 1960, Eastern Great Basin Permo-Pennsylvanian strata—Preliminary statement: American Association of Petroleum Geologists Bulletin, v. 44, p. 1424–1435. Bissell, H.J., 1962, Pennsylvanian and Permian rocks of Cordilleran area, in Branson, C.C., ed., Pennsylvanian System in the United States—A symposium: American Association of Petroleum Geologists, p. 188–263. Boardman, D.R., and Mazzullo, S.J., 1998, Biostratigraphy and sequence stratigraphy of the Pennsylvanian-Permian boundary in Kansas and Oklahoma; Road log and locality guide: Geological Society of America, southcentral meetings, Norman, Oklahoma, 79 p. Brown, H.J., 1991, Stratigraphy and paleogeographic setting of Paleozoic rocks in the San Bernardino Mountains, California, in Cooper, J.D., and Ste-

79 (Continued) Locality S-1875 S-1945 S-1915 S-1913 S-1913 S-1965 S-1911 S-1945 S-1958 82-WS-2 S-1232 S-1461 S-1463 S-1465 S-1928 S-1463 S-1462 S-1465 S-1874 S-1851 S-1946 S-1946 S-1853 82-WS-2 82-WS-2 S-1458 III-9 III-9 USGS f14074 USGS f14074 USGS f14063 USGS f14067 USGS f14067 USGS f14070 USGS f14067 USGS f14073

vens, C.H., eds., Paleozoic Paleogeography of the Western United States II: Los Angeles, Pacific Section SEPM, Book 67, p. 193–207. Burchfiel, B.C., and Davis, G.A., 1977, Geology of the Sagamore Canyon– Slaughterhouse Spring area, New York Mountains, California: Geological Society of America Bulletin, v. 88, p. 1623–1640, doi: 10.1130/00167606(1977)88<1623:GOTSCS>2.0.CO;2. Burchfiel, B.C., Hamill, G.S., IV, and Wilhelms, D.E., 1982, Stratigraphy of the Montgomery Mountains and the northern half of the Nopah and Resting Spring Ranges, Nevada and California: Geological Society of America Map and Chart Series MC-44, scale 1:62 500, 9 p. Carr, M.D., Christiansen, R.L., Poole, F.G., and Goodge, J.W., 1997, Bedrock geologic map of the El Paso Mountains in the Garlock and El Paso Peaks 7½′ quadrangles, Kern County, California: U.S. Geological Survey Miscellaneous Investigations Series Map I-2389, scale 1:24 000. Cassity, P.E., and Langenheim, R.L., Jr., 1966, Pennsylvanian and Permian fusulinids of the Bird Spring Group from Arrow Canyon, Clark County, Nevada: Journal of Paleontology, v. 40, p. 931–968. Christy, R.B., 1958, Some Permian fusulinid faunas near Lee Canyon, Clark County, Nevada [M.S. thesis]: Urbana, University of Illinois, 76 p.

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C.H. Stevens and P. Stone

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MANUSCRIPT ACCEPTED BY THE SOCIETY 23 JANUARY 2007

Printed in the USA

Abstract

Tectonic Correlations

Introduction

Summary

Chronostratigraphic Nomenclature

Systematic Paleontology

Paleogeographic Setting

Fusulinid Plates

Stratigraphic Framework

Acknowledgments

Previous Studies of Fusulinids in Southeastern California

Appendix 1. List of Fusulinid Samples with General Locations

Fusulinid Sample Material

Appendix 2. Descriptions of Outcrop Areas and Fusulinid Localities

Fusulinid Faunas and Zones

Ship Mountains

Fusulinid Zone 1

Providence Mountains

Fusulinid Zone 2

Old Dad Mountain Fusulinid Zone 3 Cowhole Mountain

Fusulinid Zone 4

Warm Spring Canyon

Fusulinid Zone 5

Striped Butte

Fusulinid Zone 6

Panamint Butte

Correlations Fusulinid Zone 1 Fusulinid Zone 2

Appendix 3. Locality Information for Figured Specimens References Cited

Fusulinid Zone 3 Fusulinid Zone 4 Fusulinid Zone 5 Fusulinid Zone 6 Comparison of Bird Spring Shelf and Keeler Basin Fusulinid Faunas Comparison of Bird Spring Shelf and Darwin Basin Fusulinid Faunas Interpretations and Discussion General Paleoenvironmental Significance of Fusulinids Fusulinid Distribution and Sedimentation Patterns on the Bird Spring Shelf Possible Effects of Eustatic Sea-Level Fluctuations Regional Paleogeographic Evolution Tectonic Interpretations and Timing of the Last Chance Thrust

Image: View north toward Striped Butte in Butte Valley, southern Panamint Range, Death Valley ational Park, California, showing steeply dipping to overturned, well-bedded limestone of the Pennsylvanian and Early Permian Bird Spring Formation. The almost complete section exposed here is about 1 km thick and extends from the Lower Pennsylvanian at the stratigraphic base (left) to Lower Permian at the top. Fusulinids and colonial corals indicating a shelf depositional environment are abundant in the Upper Pennsylvanian to Lower Permian part of the section.

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