Pennsylvanian and Permian Stratigraphy 

of the Northern Argus Range and 

Darwin Canyon Area, California 

U.S. GEOLOGICAL SURVEY BULLETIN 1691 

Pennsylvanian and Permian Stratigraphy 

of the Northern Argus Range and 

Darwin Canyon Area, California 

By PAUL STONE, CALVIN H. STEVENS, and 

ROBERT T. MAGGINETTI 

U.S. GEOLOGICAL SURVEY BULLETIN 1691 
DEPARTMENT OF THE INTERIOR 

DONALD PAUL HODEL, Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1987 

For sale by the 

Books and Open-File Reports Section 

U.S. Geological Survey 

Federal Center, Box 25425 

Denver, CO 80225 

Library of Congress Cataloging-in-Publication Data 

Stone, Paul. 

Pennsylvanian and Permian stratigraphy of the northern 

Argus Range, Darwin Canyon area, California. 

(U.S. Geological Survey Bulletin 1691) 

Bibliography 

Supt. of Docs. No.: 119.3:1691 

1. Geology, stratigraphic-Pennsylvanian. 2. Geology, 

stratigraphic-Permian. 3. Geology-California-Argus 

Range region. I. Stevens, Calvin H. II. Magginetti, Robert 

T. Ill. Title. IV. Series: U.S. Geological Survey Bulletin 

1691. 

QE75.B9 No. 1691 557.3 s 86-600364 

[QE673] [551.7'52'0979487] 
CONTENTS 

Abstract 1 

Introduction 1 

Overview of the stratigraphy and stratigraphic nomenclature 1 

Underlying rocks 1 

Pennsylvanian rocks 1 

Permian rocks 3 

Overlying rocks 4 

Tihvipah Limestone 4 

Osborne Canyon Formation 5 

Darwin Canyon Formation 7 

Millers Spring Member 10 

Panamint Springs Member 11 

Regional extent of the Tihvipah Limestone, Osborne Canyon Formation, and 

Darwin Canyon Formation 12 

Depositional history 12 

References cited 13 

Measured sections 14 

FIGURES 

1. Location map of region between Owens and Death Valleys, California 2 

2. Chart showing comparison of stratigraphic nomenclature in northern Argus 

Range and Darwin Canyon area and southern lnyo Mountains, California 3 

3. Geologic map of northern Argus Range and Darwin Canyon area, California, 

showing locations of measured sections 6 

4. Measured stratigraphic sections 1-5 9 

ID 

Pennsylvanian and Permian Stratigraphy 

of the Northern Argus Range and 

Darwin Canyon Area, California 

By Paul Stone, Calvin H. Stevens, and Robert T. Magginetti 

Abstract 

The 2-km-thick Pennsylvanian and Permian 

stratal sequence in the northern Argus Range and 

adjacent Darwin Canyon area is herein divided into 

three formations: the Lower and Middle Pennsylvanian 

Tihvipah Limestone, originally described in the 

Cottonwood Mountains (northern Panamint Range) 50 

km to the northeast, and the herein-named Lower 

Permian Osborne Canyon and Darwin Canyon 

Formations, both of which are herein included in the 

newly revised Owens Valley Group. The Darwin 

Canyon Formation is divided into the herein-named 

Millers Spring and Panamint Springs Members. The 

Tihvipah Limestone, which disconformably overlies the 

Upper Mississippian Santa Rosa Hills Limestone, is 

composed of cherty micritic limestone that was 

deposited on a deep carbonate ramp. The 

disconformably overlying Osborne Canyon Formation is 

composed of calcareous mudstone, bioclastic 

limestone, limestone conglomerate, and minor 

calcareous siltstone that were deposited in slope and 

basinal environments. The conformably overlying 

Darwin Canyon Formation is composed of very fine 

grained sandstone, bioclastic limestone, limestone 

conglomerate, and mudstone that were deposited in a 

basinal environment. Unnamed marine strata of Early 

Triassic age overlie the Darwin Canyon Formation 

along an angular unconformity that represents an 

episode of uplift and tilting during which at least 1,000 

m of strata was removed in places by subaerial 

erosion. 

INTRODUCTION 

Sedimentary rocks of Pennsylvanian and Permian 

age are widely exposed in the northern Argus Range 

and the adjacent Darwin Canyon area in east-central 

California (fig. 1). In mapping these areas, Hall and 

MacKevett (1962) and Hall (1971) assigned these rocks 

to the Pennsylvanian and Permian Keeler Canyon 

Formation and the Permian Owens Valley Formation, 

which Merriam and Hall (195 7) had defined in the 

nearby southern Inyo Mountains. As part of a regional 

stratigraphic study, we recently examined the 

Pennsylvanian and Permian sequence in the northern 

Argus Range and Darwin Canyon area in greater detail 

than had been done in the past. Our work has shown 

that this sequence consists of three units of 

formational rank instead of two-a basal unit of 

Pennsylvanian age and two units of Permian age--and 

that the Pennsylvanian and Permian rocks are 

separated by a major disconformity not previously 

documented. We here describe these three units and 

introduce new formational names for two of them. We 

also present a geologic map of the northern Argus 

Range and Darwin Canyon area, showing the locations 

of measured sections discussed in the text, and graphic 

columns of the measured sections. Written 

descriptions of the sections follow the main text. 

OVERVIEW OF THE STRATIGRAPHY AND 

STRATIGRAPHIC NOMENCLATURE 

Underlying Rocks 

Pennsylvanian rocks in the northern Argus Range 

and Darwin Canyon area disconformably overlie about 

200 m of massive light-gray limestone that Hall and 

MacKevett (1962) and Hall (1971) mapped as the Lee 

Flat Limestone, which they considered to be 

Mississippian and Pennsylvanian(?) in age. We here 

reassign these rocks to the Upper Mississippian Santa 

Rosa Hills Limestone as defined by Dunne and others 

(1981), with which they are both lithologically and 

stratigraphically equivalent, and geographically 

restrict the Lee Flat Limestone from the area of this 

report (fig. 2). This restriction follows the usage of 

Dunne and others (1981), who considered the Lee Flat 

to be a valid unit only at its type locality (fig. 1), 

where they demonstrated it to be a local member of 

the Perdido Formation (which underlies the Santa Rosa 

Hills Limestone) and thus not equivalent to the unit 

that previous workers have called the Lee Flat 

Limestone in the northern Argus Range and Darwin 

Canyon area. 

PeiUlSylvanian Rocks 

Lying disconformably above the Santa Rosa Hills 

Limestone in the northern Argus Range and Darwin 

Canyon area is a 100- to 125-m-thick sequence of 

dark-gray cherty limestone of Pennsylvanian age. This 

limestone is characterized by the abundance of small 

spherical chert nodules that previous workers have 

called golfball chert. Pennsylvanian cherty limestone 

sequences of similar lithology and thickness are 

present throughout much of the region between Owens 

Overview of tbe Stratigraphy and Stratigraphic Nomenclature 1 
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20 KILOMETERS 

Warm Spring 

Canyon 

Figure 1. Region between Owens and Death Valleys, California, showing area discussed in report (see figure 

3) and other localities mentioned in text. 

and Death Valleys (McAllister, 1952, 1956; Merriam 

and Hall, 1957; Hall and MacKevett, 1962; Ross, 1965; 

Hall, 1971; Moore, 1976; Stone, 1984; Stone and 

Stevens, 1984). 

The first formal name applied to a Pennsylvanian 

cherty limestone sequence in the Owens Valley-Death 

Valley region was the Tihvipah Limestone, which was 

used by McAllister (1952) for a sequence exposed near 

Quartz Spring in the Cottonwood Mountains (fig. 1). 

Later, Merriam and Hall (1957) considered a 

correlative cherty limestone sequence exposed in the 

southern Inyo Mountains as the informal lower member 

2 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 
SOUTHERN INYO NORTHERN ARGUS RANGE-DARWIN CANYON AREA 

MOUNTAINS 

AGE 

MERRIAM AND HALL (1957l; ROSS HALL AND MACK EVETT 

(1965); STONE AND STEVENS (1987) (1962); HALL(I971) 

THIS REPORT 

t.l? 

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< Unnamed marine strata -;:: - Unnamed marine strata c:::: 0 ~ w ~ ........ _., _.,_., ........, ~ 

Q) 0. Conglomerate Mesa - ::::J Owens 0 Formation ...J 0 

~ PUft rr- 1--- (!) Valley ~ 

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a.. w r~ .._,...,__ ........ ....... ?.....r- ........ ~ ........ 

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- 0 Santa Rosa Hi II s Limestone ~ ...J 

I Age given as Permian in reports cited. 

2 Age given as Middle Pennsylvanian to Lower Permian in reports cited. 

3Age given as Mississippian and Pennsylvanian(?) in reports cited. 

Figure 2. Comparison of stratigraphic nomenclature used in this report with that used by previous workers in 

the northern Argus Range and Darwin Canyon area and southern Inyo Mountains, California. 

of the Pennsylvanian and Lower Permian Keeler 

Canyon Formation, rather than assigning this sequence 

to the previously defined Tihvipah Limestone. 

Following Merriam and Hall (195 7), Hall and 

MacKevett (196 2) and Hall (1971) mapped the 

Pennsylvanian cherty limestone sequence exposed in 

the northern Argus Range and Darwin Canyon area as 

the lower part of the Keeler Canyon Formation. Our 

work, however, has shown that the rocks mapped by 

Hall and MacKevett (1962) and Hall (1971) as the upper 

part of the Keeler Canyon Formation in the northern 

Argus Range and Darwin Canyon area are not similar 

in either lithology or age to the upper part of the type 

section of that formation, and that the name Keeler 

Canyon is not applicable in this area. We therefore 

geographically restrict the Keeler Canyon Formation 

from the area of this report and reassign its strata in 

this area to the Tihvipah Limestone (thus encompassing 

the Pennsylvanian cherty limestone sequence exposed 

here within the Tihvipah) (fig. 2). This usage of the 

Tihvipah supersedes the nomenclature proposed by 

Stone (1984) and Stone and Stevens (1984), who 

considered the cherty limestone sequence in the 

northern Argus Range and Darwin Canyon area to be 

part of the Pennsylvanian and Lower Permian Bird 

Spring Formation, the type locality of which is in 

southern Nevada (Hewett, 1931). That assignment was 

based on correlation with cherty limestone of similar 

lithology and age ascribed by Stone (1984) and Stone 

and Stevens (1984) to the lower part of the Bird Spring 

Formation at Panamint Butte in the southern 

Cottonwood Mountains and at Warm Spring Canyon in 

the southern Panamint Range (fig. 1). 

Permian Rocks 

The Tihvipah Limestone in the northern Argus 

Range and Darwin Canyon area is disconformably 

overlain by rocks of Early Permian age that have a 

maxim urn thickness of about 1,900 m and comprise two 

units of formational rank. The lower unit, about 350m 

thick, is composed of mudstone, bioclastic limestone, 

and limestone conglomerate; it encompasses most of 

Overview of the Stratigraphy and Stratigraphic Nomenclature 3 
the rocks previously mapped as the upper part of the 

Keeler Canyon Formation by Hall and MacKevett 

(1962) and Hall (1971). The upper unit consists of two 

parts: (1) a lower part about 475 to 600 m thick and 

composed mainly of thick-bedded, very fine grained 

sandstone, bioclastic limestone, and limestone 

conglomerate and (2) an upper part about 1,000 m in 

maximum thickness and composed mainly of thinbedded, very fine grained sandstone. This unit 

encompasses most of the rocks previously mapped as 

the Owens Valley Formation by Hall and MacKevett 

(1962) and Hall (1971). 

Our work has shown that all of the Permian rocks 

in the northern Argus Range and Darwin Canyon area 

are age correlative with parts of the Owens Valley 

Formation as originally defined in the southern lnyo 

Mountains. In contrast to previous interpretations, we 

believe that there are no rocks in this area that 

correlate in either lithology or age with the upper part 

of the Keeler Canyon Formation, a sequence of 

bioclastic limestone more than 800 m thick. It is now 

clear that the geologic time interval represented by 

the upper part of the Keeler Canyon Formation at its 

type locality (late Middle Pennsylvanian to earliest 

Permian) is spanned by the disconformity between the 

Tihvipah Limestone and the overlying Permian rocks in 

the northern Argus Range and Darwin Canyon area. 

The rocks mapped as the upper part of the Keeler 

Canyon Formation by Hall and MacKevett (1962) and 

Hall (1971) are not only distinctly younger than that 

unit, but contain proportionately more mudstone and 

less limestone and have more diverse and variable 

lithology than that unit. 

In a companion study to this one, Stone and 

Stevens (1987) have raised the Owens Valley Formation 

to group rank in the southern Inyo Mountains where it 

consists of two newly named formations--the Lower 

Permian Lone Pine Formation and the Upper Permian 

Conglomerate Mesa Formation--separated by an 

angular unconformity (fig. 2). Our work has shown 

that the Permian rocks exposed in the northern Argus 

Range and Darwin Canyon area are approximately the 

same age as the Lone Pine Formation, but differ 

markedly in lithology from that formation. The Lone 

Pine Formation, which has a maximum thickness of 

about 1,000 m, consists mainly of dark-colored, thinbedded calcareous mudstone, lacks sandstone like that 

present in the northern Argus Range and Darwin 

Canyon area, and contains only a minor amount of 

bioclastic limestone. This difference in lithology 

precludes the use of the name Lone Pine Formation in 

the northern Argus Range and Darwin Canyon area and 

necessitates the introduction of new formational 

names. We herein introduce the new name Osborne 

Canyon Formation for the lower of the two Pa-mian 

units present in this area, and the new name Darwin 

Canyon Formation for the upper unit (fig. 2). We also 

introduce the new name Millers Spring Member for the 

lower part of the Darwin Canyon Formation and the 

new name Panamint Springs Member for the upper 

part. Previously, Stone and Stevens (1984) used the 

informal names Formation B and Formation C for the 

units herein named the Osborne Canyon and Darwin 

Canyon Formations, respectively. 

We include both the Osborne Canyon and Darwin 

Canyon Formations in the Owens Valley Group mainly 

as a means of establishing a formal tie between these 

formations and the age-equivalent Lone Pine 

Formation. In addition, the name Owens Valley has 

been established in the northern Argus Range and 

Darwin Canyon area for more than 20 years, and 

retaining the name at the group level provides 

continuity in stratigraphic nomenclature. 

Over lying Rocks 

The Darwin Canyon Formation is overlain with 

angular unconformity by more than 800 m of marine 

strata from which Lewis and others (1983) reported 

Early Triassic fossils. These unnamed marine strata 

originally were mapped as part of the Owens Valley 

Formation by Hall and MacKevett (1962). The angular 

unconformity separating the Darwin Canyon Formation 

and the Triassic marine strata spans the geologic time 

interval represented by the Conglomerate Mesa 

Formation, which consists of coarse-grained clastic 

rocks, in the southern Inyo rv-Iountains (fig. 2). 

TIHVIP AH LIMESTONE 

The Tihvipah Limestone, which is here 

geographically extended into the northern Argus Range 

and Darwin Canyon area (and additional areas noted 

later), is a cliff-forming unit ranging in thickness from 

approximately 100 to 125 m. It is 121 m thick in 

measured section 1 in upper Osborne Canyon on the 

east side of the northern Argus Range (figs. 3, 4). The 

sharp, disconformable contact between the darkcolored well-bedded Tihvipah Limestone and the 

underlying light-gray massive Santa Rosa Hills 

Limestone is one of the most conspicuous formational 

boundaries in Paleozoic rocks exposed between Owens 

and Death Valleys. 

The Tihvipah Limestone consists primarily of 

medium- to dark-gray micritic limestone that contains 

abundant nodular, lenticular, and thinly bedded darkgray chert. Spherical chert nodules (golfball chert) are 

especially diagnostic of the unit. Garlow (1984) 

showed that much of the chert in the formation 

contains poorly preserved radiolarians. Tremolite 

produced by widespread low-grade metamorphism is 

common in the limestone. The cherty limestone is 

interbedded with light-gray to light-brown silty or 

argillaceous limestone commonly metamorphosed to 

fine-grained calc-hornfels. Typically, cherty 

limestone ledges 1 to 5 m thick alternate with 

relatively thin recessive intervals of silty or 

argillaceous limestone. Bedding within the cherty 

limestone itself is defined mainly by beds, lenses, and 

aligned nodules of chert that divide otherwise uniform 

limestone intervals into even layers 10 to 50 em 

thick. A well-bedded appearance results. Also present 

in the Tihvipah Limestone are rare beds 40 em to 1.5 

m thick of bioclastic limestone and limestone 

conglomerate composed of poorly sorted echinoderm al 

debris, coral and bryozoan fragments, and limestone 

clasts suspended in a micrite matrix. 

The Tihvipah Limestone locally shows evidence 

of large-scale soft-sediment deformation. Slump 

4 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 
features that evidently formed during or shortly after 

deposition are particularly well developed in upper 

Osborne Canyon a short distance north of measured 

section 1 (fig. 3). 

Pennsylvanian cherty limestone sequences in the 

Owens Valley-Death Valley region, including the 

sequence here assigned to the Tihvipah Limestone in 

the northern Argus Range and Darwin Canyon area, 

have long been regarded to be of Atokan (early Middle 

Pennsylvanian) age based on the widespread 

occurrence of the fusulinid Fusulinella in their upper 

parts (McAllister, 1952; Merriam and Hall, 1957 Hall 

and MacKevett, 1962; Hall, 1971; Moore, 1976; Stone, 

1984). However, Morrowan (Early Pennsylvanian) 

conodonts are now known to be present a few meters 

above the base of one such sequence exposed in the 

southern Darwin Hills (H.R. Lane and R.H. Miller, 

written commun., 1976), and also in the lower part of 

another such sequence exposed at Marble Canyon in 

the Cottonwood Mountains (J.E. Repetski, written 

commun. in Stone, 1984). On the basis of lithologic 

correlation with these sequences, we consider the 

·Tihvipah Limestone in the northern Argus Range and 

Darwin Canyon area to range in age from Early into 

Middle Pennsylvanian. In addition, correlative cherty 

limestone sequences that are regarded as the lower 

part of the Keeler Canyon Formation in the southern 

Inyo MoW1tains (Merriam and Hall, 1957; Ross, 1965) 

are here considered to range into the Early 

Pennsylvanian, rather than being restricted to the 

Middle Pennsylvanian as has been previously thought 

(fig. 2). 

We interpret the Tihvipah Limestone as having 

accumulated in moderately deep water on a gently 

sloping carbonate ramp. This interpretation is based 

on the fine grain size and dark color of the limestone, 

the abundance of chert containing radiolarians, the 

apparent absence of in-place benthic fossils, and the 

presence of slump features. The rare matrixsupported limestone conglomerates in the formation 

probably were deposited as debris flows. 

OSBORNE CANYON FORMATION 

The Osborne Canyon Formation is here named 

after Osborne Canyon, the northernmost major canyon 

on the east side of the Argus Range (fig. 1). This 

formation disconformably overlies the Tihvipah 

Limestone and is conformably overlain by the Darwin 

Canyon Formation. The type section of the formation 

is located in measured section 1 (figs. 3, 4), high on the 

east side of the Argus Range above Osborne Canyon (in 

SW 1/4 sec. 13, T. 19 S., R. 41 E., Panamint Butte 15-

minute quadrangle) about 7 km south of Panamint 

Springs. 

The Osborne Canyon Formation is composed of 

calcareous mudstone, bioclastic limestone, limestone 

conglomerate, and minor calcareous siltstone. The 

most characteristic features of the formation are the 

abundance of mudstone and the presence of coarsegrained limestone. The generally slope-forming 

Osborne Canyon Formation is easily distinguished at a 

distance from the underlying cliff-f cr ming Tihvipah 

Limestone. 

The type section of the Osborne Canyon 

Formation has a measured thickness of 346 m and 

consists of three locally mappable, informally 

designated members (in ascending order, members A, 

B, and C). Member A, 52 m thick, is composed 

primarily of light-gray to light-brown, plane-laminated 

calcareous siltstone; member B, 137 m thick, is 

composed mainly of light-gray to light-brown, massive 

to vaguely bedded calcareous mudstone; member C, 

157 m thick, is composed mainly of light-gray to lightbrown, evenly bedded and laminated calcareous 

mudstone. In addition to these slope-forming finegrained rocks, all three members contain randomly 

spaced resistant beds of medium- to dark-gray 

coarsely bioclastic limestone and limestone 

conglomerate. The base of the formation is placed at 

the base of a limestone conglomerate bed that sharply 

overlies the highest cherty limestone bed in the 

Tihvipah Limestone. The low-angle trW1cation of beds 

at the top of the Tihvipah Limestone reflects erosion 

along this contact. The top of the formation, which 

also is sharp, is placed at the base of the lowest thick 

sequence of brown-weathering, very fine grained 

sandstone in the overlying Darwin Canyon Formation. 

The predominantly clast-supported bioclastic 

limestone and limestone conglomerate beds in the 

Osborne Canyon Formation have sharp bases and tops 

and range in thickness from 10 em to 7.5 m. Many 

graded beds show the Ta and Tb divisions of the Bouma 

sequence. Clasts as large as 10 em in diameter consist 

of echinodermal debris, fusulinids, other bioclasts, and 

micritic limestone fragments. Coral fragments are 

present in a few beds near the top of the formation. 

Limestone beds in members A and B of the type 

section are highly lenticular, commonly have erosive 

bases, and appear to be confined to channels. In 

contrast, limestone beds in member C are planar, 

laterally extensive sheets. 

Most of the calcareous mudstone in member B of 

the type section is massive and contains inclusions of 

micritic limestone that have irregular, gradational 

contacts with the enclosing matrix. These inclusions 

appear to have been incorporated into the matrix 

before lithification. Some of the inclusions are 

randomly distributed and appear to be redeposited 

clasts; others are aligned in wavy or convolute 

patterns that probably developed by soft-sediment 

deformation of bedding. In contrast, most of the 

calcareous mudstone in member C is thinly and evenly 

bedded. Some of the mudstone in member C contains 

abundant dark-gray spherical to subspherical limestone 

nodules or concretions that are aligned parallel to 

bedding. 

Less than 1 km south of the type section, a 

lenticular body of massive limestone conglomerate 

about 75 m thick occurs at the base of the Osborne 

Canyon Formation. This conglomerate appears to 

replace member A of the type section along strike and 

evidently occupies a channel bounded laterally by beds 

of member A. Southward along strike, the 

conglomerate rapidly decreases in thickness to only a 

few meters. 

The Osborne Canyon Formation is characterized 

by pronounced lateral variations in thickness and 

Osborne Canyon Formation 5 
lithology. For example, a section of the formation 

near the eastern base of the Argus Range just outside 

the area of figure 3 is only about 120 m thick; it 

comprises about 60 m of pink to maroon calcareous 

mudstone overlain by about 60 m of thick-bedded 

limestone conglomerate. Despite such variations, the 

formation is easily recognized throughout and beyond 

the report area on the basis of its general lithology and 

consistent stratigraphic relations. 

We have identified the following fusulinids from 

limestone beds at several horizons in the type section 

of the Osborne Canyon Formation: 

36° 

17' 

Leptotri tici tes? sp. 

Schwagerina aff. §_. wellsensis Thompson 

and Hansen 

Schwagerina spp. 

Pseudofusulina? aff. 

P. loringi Thompson 

Pseudoschwagerina uddeni Beede and Kniker 

Stewartina? sp. 

Eoparafusulina cf • .§_. linearis (Dunbar 

and Skinner) 

Eoparafusulina sp. 

Cuniculinella sp. 

30" ~~~v .. ~~~~~~~ ~~· ?~+~-~~t ~~H~~+H•~-~~~~~ 

2 KILOMETERS 

Figure 3. Geologic map of northern Argus Range and Darwin Canyon area, California, showing locations of 

measured sections discussed in text. See figure 1 for location of map. Base from U.S. Geological Survey, 

1:62,500, Darwin, 1950; Panamint Butte, 1951 (contour interval 40 feet). Geology mapped in 1980-1981. 

Dikes mapped by G.C. Dunne. 

6 Pennsylvanian and Permian Stratigraphy, Nortbern Argus Range and Darwin Canyon Area, California 
This fusulinid assemblage indicates a middle 

Wolf cam pian age (Maggin etti, 19 83; Stone, 19 84). The 

presence of Pseudoschwagerina and Eoparafusulina in 

collection RTM-2 about 9.5 m above the base of the 

formation (fig. 4) 'indicates that no part of the 

formation in the type section is older than middle 

Wolfcampian in age. Therefore, the disconformity 

between the Osborne Canyon Formation and the 

underlying Tihvipah Limestone represents most or all 

of Late Pennsylvanian and earliest Permian time. 

We interpret the Osborne Canyon Formation to 

have accumulated in deep-water marine slope and 

basinal environments. We consider the limestone beds 

in the formation to be sediment-gravity-flow deposits 

derived from carbonate shelves or banks upslope from 

the site of deposition. The abundance of soft-sediment 

deformation features in mudstones of the lower part of 

the formation (member B) strongly suggests a slope 

environment. The lenticular limestone beds in 

members A and B, including the massive lens of 

limestone conglomerate at the base of the formation 

just south of the type section, probably are slopechannel deposits. The lateral continuity of limestone 

beds in the upper part of the formation (member C) 

and the general lack of soft-sediment deformation 

features in the associated mudstones probably reflect 

Qa 

Tv 

KJg 

Jd-/ 

Jgb 

RS 

Pdp 

Pdm 

Po 

EXPLANATION 

Alluvium and talus (Quaternary) 

Volcanic rocks (Tertiary) 

Leucocratic granitoid rocks (Cretaceous? and 

Jurassic)--Quartz monzonite and granite 

Mafic to intermediate dikes (Jurassic)--

Correlated with Independence dike swarm 

Gabbro, granodiorite, and minor quartz 

monzonite (Jurassic?) 

Marine sedimentary rocks (Lower Triassic)--

Light-brown calc-hornfels and gray 

marble; minor siltstone and shale; sandy 

limestone and calcareous sandstone in 

lowermost part 

Owens Valley Group (Lower Permian)--In this 

area, consists of: 

Darwin Canyon Formation--Divided into: 

Panamint Springs Member--Brown, thin-bedded 

siltstone and very fine grained 

sandstone; medium- to dark-gray limestone 

in lowermost part 

Millers Spring Member--Brown, thick-bedded, 

very fine grained sandstone and mediumto dark-gray, thin- to thick-bedded 

bioclastic to conglomeratic limestone 

Osborne Canyon Formation--Light-gray to 

light-brown, thin-bedded to massive 

calcareous mudstone and medium- to darkgray, thin- to thick-bedded bioclastic to 

conglomeratic limestone; minor calcareous 

siltstone 

Figure 3. Continued. 

a change from a channeled slope environment to an 

unchanneled basin-floor environment. 

In light of the relatively deep-water marine 

origin of both the Osborne Canyon Formation and the 

underlying Tihvipah Limestone, we interpret the 

disconformity between them to have resulted from 

submarine erosion or nondeposition on the slope rather 

than from subaerial erosion. This interpretation is 

st.pported by the lack of pronounced angular 

discordance between the two formations and by the 

nearly constant thickness of the Tihvipah Limestone 

throughout the study area. 

DARWIN CANYON FORMATION 

The Darwin Canyon Formation is here named 

after Darwin Canyon, the major canyon between the 

northern Argus Range and the Darwin Hills (fig. 1). 

This formation conformably overlies the Osborne 

Canyon Formation and is unconformably overlain by 

unnamed marine strata of Early Triassic age. 

We here divide the Darwin Canyon Formation 

into two formally named members, the Millers Spring 

IPt 

Ms 

Mp 

MOm 

-t-

-t60 _j_ 

Tihvipah Limestone (Middle and Lower 

Pennsylvanian)--Medium- to dark-gray, 

thin- to thick-bedded micritic limestone 

with abundant nodular, lenticular, and 

bedded chert; subordinate light-gray to 

light-brown silty or argillaceous 

limestone 

Santa Rosa Hills Limestone (Upper 

Mississippian)--Light-gray massive 

limestone 

Perdido Formation (Mississippian)--Dark-gray 

limestone and thin-bedded chert 

Marble (Mississippian and (or) Devonian)--

Presumably correlative with the Devonian 

Lost Burro Formation and (or) the 

Mississippian Tin Mountain Limestone, 

Perdido Formation, and Santa Rosa Hills 

Limestone 

Contact 

Fault--Dashed where approximately located, 

dotted where concealed. Arrows show 

relative movement direction 

Anticline 

Syncline--dashed where approximately located 

Strike and dip of beds 

Inclined 

Horizontal 

Line of measured section 

Darwin Canyon Formation 7 
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EXPLANATION 

Limestone 

Cherty limestone 

Silty and sandy 

limestone 

Bioclastic limestone and 

limestone conglomerate 

Limestone conglomerateMud supported 

So n d s to n e - T h i c k b e d d e d , 

very fine grained 

Sandstone- Thin bedded, 

very fine grained 

Siltstone 

Mudstone- Plane bedded 

Mudstone- Massive to 

irregularly bedded 

Correlation line 

Unconformity 

II 175 Fusulinid locality 

Figure 4. Generalized graphic columns of measured sections 1-5. Type sections of Osborne Canyon Formation and Darwin Canyon 

Formation in measured sections 1, 2A, 2B, 2C, and 2D denoted by heavy outline. Stratigraphic positions of fusulinid collections 

shown to right of columns. Locations of measured sections shown on figure 3. 
Member and the overlying Panamint Springs Member 

(figs. 2, 4). These units are named after Millers 

Spring, which is located near the head of Darwin 

Canyon, and Panamint Springs, which is situated on 

California State Highway 190 at the northeast base of 

the Argus Range. The type section of the Millers 

Spring Member is a composite section measured in five 

segments correlated by marker beds (fig. 4). The 

lowest segment overlies the type section of the 

Osborne Canyon Formation in measured section 1, high 

on the east slope of the Argus Range (in SW 1/4 sec. 13 

and SE 1/4 sec. 14, T. 19 S., R. 41 E., Panamint Butte 

15-minute quadrangle); the other segments (measured 

sections 2A, 2B, 2C and 2D) are in Darwin Canyon 

north of the Darwin fault (in NW 1/4 sec. 10, SW 1/4 

sec. 3, and SE 1/4 sec. 4, T. 19 S., R. 41 E., Darwin 15-

minute quadrangle) (figs. 3, 4). The type section of the 

Panamint Springs Member overlies that of the Millers 

Spring Member in measured section 2D (in E 1/2 sec. 4, 

T. 19 S., R. 41 E., Darwin 15-minute quadrangle). The 

type section of the Darwin Canyon Formation is 

defined as the composite of the type sections of its 

two members. We have also measured reference 

sections through parts of the Millers Spring Member 

and Panamint Springs Member in the hills south of the 

Darwin fault: Millers Spring Member--in S 1/2 sec. 10 

(measured sections 3 and 4, figs. 3, 4) and N 1/2 sec. 

15 (measured section 5, figs. 3, 4), T. 19 S., R. 41 E., 

Darwin 15-minute quadrangle; Panamint Springs 

Member--in S 1/2 sec. 10, T. 19 S., R. 41 E., Darwin 

15-minute quadrangle (measured section 3, figs. 3, 4). 

The Darwin Canyon Formation is composed 

mainly of well-bedded, brown-weathering, very fine 

grained sandstone and calcarenitic sandstone; the 

Millers Spring Member additionally contains abundant 

medium- to dark-gray, calcarenitic, coarsely bioclastic 

limestone and limestone conglomerate and subordinate 

gray to pink calcareous mudstone and silty mudstone. 

The formation is distinguished from the underlying 

Osborne Canyon Formation primarily by the dominance 

of sandstone over mudstone. The brown leagy slopes 

typically formed by the Darwin Canyon Formation 

contrast strongly with the generally smooth, gray 

slopes formed by the Osborne Canyon Formation. 

Near intrusive bodies, parts of the Darwin Canyon 

Formation have been metamorphosed to quartzite, 

calc-hornfels, and marble. 

Millers Spring Member 

The Millers Spring Member ranges in thickness 

from about 475 to 600 m in the area of this report and 

averages about 550 m thick. In its composite type 

section, the member has a measured thickness of 487 

m. 

The Millers Spring Member has a distinctive 

internal stratigraphy. Four units composed chiefly of 

medium- to thick-bedded, very fine grained sandstone 

and calcarenitic sandstone (units 1, 3, 5, and 7) are 

separated by three units composed largely of limestone 

(units 2, 4, and 6) (fig. 4). All seven units can be 

mapped throughout the northern Argus Range and 

Darwin Canyon area with only minor changes in 

thickness and lithology. 

Sandstone of the Millers Spring Member is 

quartzitic to subarkosic (and variably calcareous) in 

composition and arenitic in texture. Thin sections 

show that the sandstone typically is composed of 70 to 

80 percent framework grains and 20 to 30 percent 

calcite cement. The detrital fraction generally 

consists of about 60 to 80 percent quartz, 5 to 25 

percent feldspar, 10 to 15 percent calcite 

(echinodermal debris and peloids), and trace amounts 

of muscovite and heavy minerals. Some beds contain 

as much as 50 percent detrital calcite. Grains are 

subangular to subrounded and are very well sorted in 

the coarse silt to very fine sand range. Grains smaller 

than 0.05 mm and larger than 0.1 mm are rare. 

Neither terrigenous nor calcareous mud is present in 

the sandstone. 

Sandstone beds in the Millers Spring Member are 

planar and laterally extensive; they range in thickness 

from 10 em to 3.5 m and have an average thickness of 

about 50 em. These beds alternate with recessive, 

generally poorly exposed intervals of mudstone that 

range in thickness from less than 1 em to about 2 m. 

The average ratio of sandstone to mudstone is between 

1.5:1 and 2:1. Sandstone beds have sharp lower and 

upper contacts and range from apparently massive to 

pervasively plane laminated, crosslaminated, and 

convolute laminated. Calcarenitic beds are more 

conspicuously laminated than the more purely 

siliciclastic beds. With rare exceptions, the sandstone 

beds are not visibly graded, although thin sections 

show that many beds are weakly graded. Flute and 

groove casts are rare. 

The three limestone units of the Millers Spring 

Member consist mainly of clast-supported, coarsely 

bioclastic limestone and limestone conglomerate beds 

ranging in thickness from 1 to 5 m. These beds are 

composed of tightly packed echinodermal debris, 

fusulinids, massive and fasciculate coral fra5ments, 

other bioclasts, and micritic limestone clasts in a 

micritic limestone matrix. Maximum clast size in 

most beds is about 5 em. Many graded beds display the 

Ta and Tb divisions of the Bouma sequence. A few 

thick beds of mud-supported limestone conglomerate 

(con glom era tic mudstone) are present in addition to 

the clast-supported beds. 

Each of the limestone units of the Millers Spring 

Member has a characteristic stratigraphy. Unit 2 

typically consists of two thick c1ast-supported 

limestone beds overlain by a thick rna trix-supported 

bed. Leo (1983) studied unit 2 in detail and 

demonstrated the substantial 1a teral continuity of the 

individual beds within it. Unit 4 consists of a basal 

zone of several thick, clast-supported, coarse-grained 

limestone beds overlain by a zone of thinner, finer 

grained limestone beds. Unit 6 consists of three 

discrete zones of thick, coarse-grained limestone beds 

(units 6A, 6C, and 6E) separated by intervals of thickbedded sandstone (units 6B and 6D). Unit 6E is capped 

by a distinctive pink, mud-supported con glom era te bed 

10 m thick. All three limestone units maintain their 

lithologic identity throughout and beyond the study 

area and make excellent stratigraphic markers. 

We have identified fusulinids from units 2, 4, 5, 

and 6 of the Millers Spring Member in the type section 

and in the reference sections south of the Darwin 

fault. Collections from units 2 and 4 yielded the 

10 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 
following taxa: 

Schwagerina aculeata Thompson and 

Hazzard 

Schwagerina elkoensis? Thompson 

and Hansen 

Schwagerina aff. §_.~lata Thompson 

Schw~~rina aff. §_. thomp~~ll!. Needham 

Schwag~~~na spp. 

Pseudofusulina? aff. 

~? lori.!!fj_ Thompson 

Chusenella compacta (White) 

Paraschyv-agerina sp. 

Pseu_2osch~agerina sp. 

Stewartina. moranensis (Thompson) Stewa.rtiriasp:----

Stewartina? spp. 

Eoparafusl!lina cf • .§_. linearis (Dunbar and 

Skinner) 

Cuniculinella spp. 

Collections from units 5 and 6 yielded the following 

taxa: 

Schwagerina ~uleata Thompson and 

Hazzard 

~chwa~ina cf. §_. crebrisepta Ross 

~hwagerina diversifor!fiiS Dunbar and 

Skinner 

Schwagerina elkoensis Thompson and Hansen 

Schwag_erina cf. §_.~!~Thompson 

Schwagerina aff. §_. thompsoni Needham 

Schwagerina cf. §_. weJ:.!~~nsi~ Thompson and 

Hansen 

~hwagerina spp. 

Chusenella sp. 

Pseudoschwagerina uddeni (Beede and 

Kniker) 

Pseudoschwagerina ~~Thompson 

Pseudoschw!!_gerina sp. 

Stewartina sp. 

Chalarosc1iwagerina sp. 

Parafusulina sp. 

These fusulinid assemblages indicate a middle to 

late Wolfcampian age. Fusulinid assemblages from 

units 2 and 4 lack typical late Wolfcampian taxa and 

are considered middle Wolfcampian in age. The 

assemblages from units 5 and 6 contain the typical late 

Wolfcampian fusulinids Schwagerina cf. §_. crebriseeta, 

Schwa erina diversiformis, and C~aroschwagerina sp. 

Magginetti, 1983; Stone, 1984}. We interpret the 

presence of Parafusulina, a typical Leonardian genus, 

in one collection (1410, unit 5, measured section 4) as 

an unusually early occurrence of this genus; the 

fusulinids in this collection, although redeposited, do 

not appear to have been significantly reworked. 

We interpret the Millers Spring Member to 

represent deposition in a deep-water marine basinal 

environment, primarily because of the presence of 

Bouma sequences in the clast-supported limestone 

beds. These beds evidently are turbidites that were 

derived from carbonate banks or shelves upslope from 

the site of deposition. We interpret the thick, matrixsupported beds such as those in units 2 and 6E as 

submarine debris-flow deposits that resulted from 

collapse of large segments of the shelf and slope 

adjacent to the basin. The lateral continuity of the 

limestone units, and of many individual beds, strongly 

suggests that deposition took place on a generally 

featureless basin floor. 

Sandstone beds in the Millers Spring Member 

probably are sediment-gravity-flow deposits akin to 

turbidites, as indicated by their lateral continuity and 

their association with limestone turbidites and debrisflow deposits. However, these beds differ from typical 

turbidites in at least three important respects: they 

lack a muddy matrix and Bouma sequences, they 

generally lack flute and groove casts, and they are 

much more strongly and pervasively crosslaminated 

than typical turbidites of comparable thickness. Their 

exact mechanism of deposition is unclear. 

Panamint Springs Member 

The Panamint Springs Member of the Darwin 

Canyon Formation is a lithologically homogeneous unit 

composed mainly of light-brown, thin-bedded, very 

fine grained sandstone and siltstone. It is distinguished 

from the unaerlying Millers Spring Member by its 

consistently thin bedding and by its general lack of 

coarse-grained limestone. 

The Panamint Springs Member, where not 

covered at the top by alluvium or Tertiary volcanic 

rocks, is overlain with angular unconformity by 

unnamed Triassic marine strata (fig. 3). The best 

exposure of this unconformity is on a cliff face in 

Darwin Canyon immediately south of the Darwin fault, 

where thick-bedded sandy limestone and calcareous 

sandstone of Early Triassic age overlie the Panamint 

Springs Member with an angular discordance of about 

15°. Owing to this angular relationship with the 

overlying rocks, the Panamint Springs Member ranges 

in thickness from zero in the western part of the 

report area to about 1,000 m a short distance east of 

the area. The type section of the member in Darwin 

Canyon (measured section 2D) is 372 m thick. 

Although the stratigraphic relations of the 

Panamint Springs Member are clearly revealed in the 

type section, the lithologic features of the member are 

somewhat obscure there as a result of 

metamorphism. The original lithology of the member 

is better displayed in the vicinity of measured section 

3 south of the Darwin fault (fig. 3). There, the 

member is composed mainly of very fine grained 

sandstone and siltstone in laterally extensive, graded, 

laminated and crosslaminated beds 2 to 15 em thick. 

Many of these beds show the Ta, Tb, and Tc divisions 

of the Bouma sequence. Beds are either amalgamated 

or are separated by mudstone partings that are 

generally less than 1 em thick. Bedding is very even 

and planar, although the basal surfaces of some beds 

show evidence of scour. Most beds are composed of 

about 50 percent detrital quartz and feldspar and 

about 50 percent detrital and recrystallized calcite. 

Locally interbedded with the thin-bedded sandstone 

and siltstone are relatively thick (20 em to 1 m) beds 

of coarse-grained sandstone containing chert pebbles 

and silicified reworked fusulinids. Such beds, most of 

which are graded, are particularly common in the 

lower part of the member. 

Darwin Canyon Formation 11 
The lowermost part of the Panamint Springs 

Member is a distinctive unit of medium- to dark-gray, 

generally fine-grained calcarenitic limestone and 

light-gray, brown, and pink mudstone. This unit, which 

has a measured thickness of 65 m in the type section 

of the Panamint Springs Member, sharply overlies the 

highest thick-bedded sandstone unit in the Millers 

Spring Member. Locally, as in Darwin Canyon south of 

the Darwin fault, the basal limestone unit is deformed 

by conspicuous folds that do not extend into the 

enclosing sandstone beds. Although the lithology of 

this limestone unit is atypical of the Panamint Springs 

Member, its base is the most objective horizon on 

which to define the base of the member. The basal 

limestone unit grades upsection into the thin-bedded 

siltstone and sandstone that composes the rest of the 

member. 

Within the immediate report area (fig. 3), the 

only fossils we have obtained from the Panamint 

Springs Member are reworked fusulinids from a pebbly 

sandstone bed 336 m above the base of the member in 

measured section 3 (collection 11300). This collection 

contains a typical late Wolfcampian fusulinid 

assemblage that includes Schwa.g_~ri~ diversiformis 

Dunbar and Skinner, Sch~agerina cf. §_. crebrise~ 

Ross, ~~oschwageri~~ sp., and Ps~udoschwager!!!!!. 

convexa Thompson. A short distance west of the 

report area, in the northern Darwin Hills, a similar 

pebbly sandstone bed somewhat lower in the member 

contains Para~~lina in addition to late Wolfcampian 

species of Schwagerina and Pseudoschwagerina. This 

bed evidently is late Wolfcampian in age with an 

unusually early occurrence of Parafusulina. At least 

part of the thick sequence of unfosshiferous siltstone 

and sandstone in the Panamint Springs Member above 

our fusulinid collections probably is Leonardian in age. 

The Panamint Springs Member represents 

deposition in a deep-water marine basinal 

environment, as indicated by the dominance of thin 

graded sandstone and siltstone beds of apparent 

turbidite origin. The absence of coarse-grained 

limestone like that in the Millers Spring Member 

indicates that the basin was no longer flanked by 

carbonate shelves and banks. This change in the shelf 

margin probably also resulted in the pronounced 

decrease in average sandstone-bed thickness in the 

Panamint Springs Member relative to that in the 

Millers Spring Member. During deposition of the 

Millers Spring Member, basin-rimming carbonate 

buildups may have ponded sand prior to its discharge 

into the basin, resulting in high-volume sand flows and 

thick beds. The lack of such buildups during deposition 

of the Panamint Springs Member would have prevented 

the ponding of sand, resulting in smaller sand flows and 

thinner beds. 

REGIONAL EXTENT OF THE TIHVIP AH LIMESTONE, 

OSBORNE CANYON FORMATION, AND DARWIN 

CANYON FORMATION 

The Tihvipah Limestone and numerous 

correlative cherty limestone sequences can be 

recognized throughout the region between Owens and 

Death Valleys (Stone, 1984; Stone and Stevens, 1984). 

Sections that we here regard as belonging to the 

Tihvipah and which are nearly identical in lithology 

and thickness to that occurring in the area of this 

report are present at Knight and Bendire Canyons in 

the central Argus Range, the southern Darwin Hills, 

and the Santa Rosa Hills (fig. 1). Hall and MacKevett 

(1962) and Moore (1976) assigned these sections to the 

Keeler Canyon Formation, while Stone and Stevens 

(1984) alternatively assigned them to the Bird Spring 

Formation. At Knight and Bendire Canyons, as in the 

report area, the Tihvipah Limestone rests directly on 

the Santa Rosa Hills Limestone; in the southern 

Darwin Hills and the Santa Rosa Hills, a thin sequence 

of Upper Mississippian sandstone and shale lies 

between the Tihvipah and Santa Rosa Hills 

Limestones. At Marble Canyon in the southern 

Cottonwood Mountains, cherty limestone similar in 

lithology to that of the Tihvipah Limestone forms the 

major part of a Pennsylvanian section more than 600 m 

thick. This section, which Stone and Stevens (1984) 

assigned to the Bird Spring Formation, overlies a thin 

sequence of Upper Mississippian sandstone and shale 

like that in the Santa Rosa Hills and southern Darwin 

Hills. As previously noted, cherty limestone 

lithologically similar to the Tihvipah Limestone forms 

the lower part of the Bird Spring Formation in the 

southern Cottonwood Mountains and the southern 

Panamint Range, and the lower part of the Keeler 

Canyon Formation in the southern Inyo Mountains. 

The Osborne Canyon and Darwin Canyon 

Formations can be recognized at Knight and Bendire 

Canyons in the central Argus Range, in the Darwin 

Hills, and at Marble Canyon in the central Cottonwood 

Mountains (fig. 1), where they encompass some of the 

rocks heretofore mapped as the Keeler Canyon and 

Owens Valley Formations by Hall and IVIacKevett 

(1962), Stadler (1968), Johnson (1971), and Moore 

(1976). Rocks similar in general lithology and age to 

the Osborne Canyon and Darwin Canyon Formations 

are present in the northern Santa Rosa Hills and the 

Conglomerate Mesa area in the southeastern Inyo 

Mountains (Stone and Stevens, 1984). However, the 

stratigraphy of the rocks in the northern Santa Rosa 

Hills and Conglomerate Mesa area differs sufficiently 

from that of the Permian section in the northern Argus 

Range and Darwin Canyon area that, in our opinion, 

the names Osborne Canyon and Darwin Canyon should 

not be extended there. Rocks similar in lithology and 

age to the Osborne Canyon Formation overlie the Bird 

Spring Formation at Panamint Butte in the southern 

Cottonwood Mountains, and rocks that may correlate 

with the Osborne Canyon Formation overlie the Bird 

Spring Formation at Warm Spring Canyon in the 

southern Panamint Range (Stone and Stevens, 1984). 

DEPOSfi'IONAL HISTORY 

During the Late Mississippian, the report area 

was part of a broad, shallow carbonate shelf upon 

which the Santa Rosa Hills Limestone accumulated 

(Dunne and others, 1981). In Early and Middle 

Pennsylvanian time, a substantial rise in relative sea 

level resulted in the deposition of the Tihvipah 

Limestone in moderately deep, quiet water. This sealevel rise probably was caused, at least in part, by 

12 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 
tectonic subsidence of the shelf. Increased subsidence 

in Late Pennsylvanian and earliest Permian time led to 

the development of an unstable slope upon which no 

net sedimentation took place. Sediment accumulation 

resumed in middle Wolfcampian time with deposition 

of the Osborne Canyon Formation disconformably on 

the Tihvipah Limestone and continued through late 

Wolfcampian and probably into Leonardian time with 

deposition of the Darwin Canyon Formation. 

Channeled slope environments prevalent in the report 

area during the early phases of Permian sedimentation 

were replaced by unchanneled basin-floor 

environments as the depositional system matured. The 

area subsequently was uplifted, tilted, and subjected to 

an episode of subaerial erosion during which at least 

1,000 m of strata (the maximum thickness of the 

Panamint Springs Member) was strippea away in 

places. Regional studies (Stone, 1984; Stone and 

Stevens, 1984) sugg-est that uplift occurred primarily in 

late Early or early Late Permian time, prior to the 

deposition of the Upper Permian Conglomerate Mesa 

Formation outside the boundaries of the report area. 

In response to renewed subsidence beginning in the 

Early Triassic, marine sediments were deposited 

unconformably on the tilted and erosionally truncated 

Lower Permian rocks. 

REFERENCES CITED 

Dunne, G.C., Gulliver, R.M., and Stevens, C.H., 1981, 

Correlation of Mississippian shelf-to-basin strata, 

eastern California: Geological Society of America 

Bulletin, Part II, v. 92, p. 1-38. 

Garlow, R.A., 1984, Stratigraphy, petrology, and 

paleogeographic setting of the Middle Pennsylvanian 

Tihvipah Limestone of southeastern California: San 

Jose, Calif., San Jose State University, M.S. thesis, 

134 p. 

Hall, W.E., 1971, Geology of the Panamint Butte 

quadrangle, Inyo County, California: U.S. 

Geological Survey Bulletin 1299, 67 p. 

Hall, W .E., and MacKevett, E.M., Jr., 1962, Geology 

and ore deposits of the Darwin quadrangle, Inyo 

County, California: U.S. Geological Survey 

Professional Paper 368, 87 p. 

Hewett, D.F., 1931, Geology and ore deposits of the 

Goodsprings quadrangle, Nevada: U.S. Geological 

Survey Professional Paper 162, 172 p. 

Johnson, E. A., 1971, Geology of a part of the 

southeastern side of the Cottonwood Mountains, 

Death Valley, California: Houston, Tex., Rice 

University, Ph.D. dissertation, 81 p. 

Lewis, Michael, Wittman, Charles, and Stevens, C.H., 

1983, Lower Triassic marine sedimentary rocks in 

east-central California, in Marzolf, J.E., and Dunne, 

G.C., eds., Evolutio~ of early Mesozoic 

tectonostratigraphic environments--southwestern 

Colorado Plateau to southern Inyo Mountains: Utah 

Geological and Mineral Survey Special Studies 60, p. 

50-54. 

Lico, M.S., 1983, Lower Permian submarine sediment 

gravity flows in the Owens Valley Formation, 

southeastern California: San Jose, Calif., San Jose 

State University, M.S. thesis, 80 p. 

McAllister, J .F., 1952, Rocks and structure of the 

Quartz Spring area, northern Panamint Range, 

California: California Division of Mines Special 

Report 25, 38 p. 

1956, Geology of the Ubehebe Peak quadrangle, 

-ciiifornia: U.S. Geological Survey Geological 

Quadrangle Map GQ-95, scale 1:62,500. 

Magginetti, R. T., 1983, Fusulinid biostratigraphy of 

the Darwin Canyon and Conglomerate Mesa areas, 

Inyo County, California: San Jose, Calif., San Jose 

State University, M.S. thesis, 417 p. 

Merriam, C.W., and Hall, W.E., 1957, Pennsylvanian 

and Permian rocks of the southern Inyo Mountains, 

California: U.S. Geological Survey Bulletin 1061-A, 

13 p. 

Moore, S.C., 1976, Geology and thrust fault tectonics 

of parts of the Argus and Slate Ranges, Inyo County, 

California: Seattle, Wash., University of 

Washington, Ph.D. dissertation, 128 p. 

Ross, D.C., 1965, Geology of the Independence 

quadrangle, Inyo County, California: U.S. 

Geological Survey Bulletin 1181-0, 64 p. 

Stadler, C.A., 1968, The geology of the Goldbelt Spring 

area, northern Panamint Range, Inyo County, 

California: Eugene, Ore., University of Oregon, 

M.S. thesis, 7 8 p. 

Stone, Paul, 1984, Stratigraphy, depositional history, 

and paleogeographic significance of Pennsylvanian 

and Permian rocks in the Owens Valley-Death Valley 

region, California: Stanford, Calif., Stanford 

University, Ph.D. thesis, 399 p. 

Stone, Paul, and Stevens, C.H., 1984, Stratigraphy and 

depositional history of Pennsylvanian and Permian 

rocks in the Owens Valley-Death Valley region, 

eastern California, in Lintz, Joseph, Jr., ed., 

Western geological e"ieursions, v. 4: Geological 

Society of America, Field Trip Guidebook, 1984 

annual meeting, p. 94-119. 

Stone, Paul, and Stevens, C.H., 1987, Stratigraphy 

of the Owens Valley Group (Permian), southern Inyo 

Mountains, California: U.S. Geological Survey 

Bulletin 1692. 

References Cited 13 
MEASURED SECTIONS {LOCATIONS SHOWN ON FIG. 3) 

Section 1. Tihvipah Limestone; type sections of the Osborne 

Canyon Formation and unit 1 of the Millers Spring Member of 

the Darwin Canyon Formation. Measured on the east side of 

the Argus Range above Osborne Canyon in July 1981. 

Darwin Canyon Formation (Lower Permian) 

(incomplete): 

Millers Spring Member (incomplete): 

Unit 2 (basal bed; not measured): 

Limestone conglomerate, 

bioclastic, medium gray ••••••••••••• 

Unit 1: 

9. Sandstone (25 percent) and cover 

(75 percent). Sandstone, 

quartzose, variably calcareous 

and calcarenitic, gray to brown 

on weathered surface, very fine 

grained; in beds 15 to 80 em thick; 

commonly plane laminated, less 

commonly crosslaminated and 

convolute laminated. Covered 

intervals 60 em to 1.8 m thick ••••• 

8. Limestone; one bed (Bouma Tab); 

grades from coarse-grained echinodermal calcarenite at base to silty 

calcisiltite at top •••••••••••••••••• 

7. Sandstone (50 percent) and cover 

(50 percent), as in 9. Sandstone, 

in beds 30 em to 1.7m thick; mean 

bed thickness about 1.0 m. Covered 

intervals 10 em to 2.0 m thick •••••• 

6. Interval occupied by cross-cutting 

dike ••••••••••••••••••••••••••••••••• 

5. Sandstone (45 percent) and cover 

(55 percent), as in 9. Sandstone, 

generally highly calcareous and 

calcarenitic; in beds 10 em to 

1.0 m thick; mean bed thickness 

about 50 em. Covered intervals 

20 em to 1m thick ••••••••••••••••••• 

4. Interval occupied by cross-cutting 

dike ••••••••••••••••••••••••••••••••• 

3. Sandstone (60 percent), mudstone 

(5 percent), and cover (35 percent), 

as in 9 except for mudstone. Sandstone in beds 15 em to 1.5 m thick; 

mean bed thickness about 60 em. Mudstone, gray, pink, and brown; in beds 

1 to 70 em thick between sandstone 

beds. Covered intervals 20 em to 

1.0 m thick•••••••••••••••••••••••••• 

2. Interval occupied by cross-cutting 

dike ••••••••••••••••••••••••••••••••• 

1. Sandstone (65 percent), mudstone (20 

percent), and cover (15 percent), as 

in 3. Sandstone in beds 20 to 70 em 

thick; mean bed thickness about 

40 em. Mudstone in beds 5 to 

50 em thick. Covered intervals 10 

to 40 em thick ••••••••••••••••••••••• 

Thickness 

meters 

5.6 

1.8 

20.2 

3.5 

14.3 

3.0 

60.9 

3.5 

9.1 

Total thickness unit 1..................... 121.9 

Incomplete thickness Millers Spring 

Member ••••••••••••••••••••••••••••••••••• 121.9 

Section 1: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Incomplete thickness Darwin Canyon 

Thickness 

meters 

Formation •••••••••••••••••••••••••••••••• 121.9 

Conformable contact. 

Osborne Canyon Formation (Lower Permian): 

Member C: 

62. Mudstone, calcareous, light gray; 

poorly exposed ••••••••••••••••••••••• 

61. Limestone, dark gray; one bed 

(Bouma Ta); grades from bioclastic 

limestone conglomerate at base to 

light-gray calcisiltite at top; 

contains limestone clasts to 3 em 

in diameter, broken fasciculate 

rugose corals to 5 em in diameter, 

and fusulinids ••••••••••••••••••••••• 

60. Mudstone, calcareous, light gray; 

limestone beds (fine-grained 

calcarenite; Bouma Tb) 14 and 

40 em thick present 4.0 and 5.4 m 

above base of interval ••••••••••••••• 

59. Limestone; one bed (Bouma Ta); 

grades from dark-gray bioclastic 

limestone conglomerate at base to 

light-gray calcareous mudstone at 

top; contains limestone clasts to 

4 em in diameter, coarse echinodermal debris, and fusulinids; upper 

part of bed contains micritic limestone clasts. Fusulinid collection 

0Cl6: Stewart ina? sp., 

Cuniculinella sp ••••••••••••••••••••• 

58. Covered interval; light-gray 

calcareous mudstone scree •••••••••••• 

57. Limestone; one bed (Bouma Tab); 

grades from coarse-grained bioclastic calcarenite at base to 

laminated fine-grained calcarenite at top; contains fusulinids •••• 

56. Covered interval ••••••••••••••••••••• 

55. Hudstone, calcareous, light gray, 

massive; small dark-gray limestone 

clasts present in basal 80 em •••••••• 

54. Limestone, dark gray; one bed 

(Bouma Tab); grades from coarsegrained bioclastic calcarenite at 

base to fine-grained calcarenite 

at top; contains fusulinids •••••••••• 

53. Mudstone, calcareous, light gray; 

poorly exposed ••••••••••••••••••••••• 

52. Limestone (calcarenite), dark gray, 

fine grained; one bed (Bouma Tbc) •••• 

51. Covered interval ••••••••••••••••••••• 

50. Limestone (calcarenite), dark gray, 

fine grained; one bed (Bouma Tb) ••••• 

49. Mudstone, calcareous ••••••••••••••••• 

48. Limestone (calcarenite), dark gray; 

one bed (Bouma Tab); grades from 

medium grained at base to fine 

grained at top ••••••••••••••••••••••• 

5.0 

4.2 

6.6 

1.7 

2.5 

0.6 

3.5 

4.5 

0.3 

3.0 

0.6 

0.2 

(J.l 

0.1 

0.1 

14 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 
Section 1: Lower Permian--Continued 

Osborne Canyon Formation--Continued 

Member C--Continued 

47. Covered interval ••••••••••••••••••••• 

46. Limestone, dark gray; one bed 

(Bouma Ta); grades from coarsegrained bioclastic (largely 

echinodermal) calcarenite at base 

to medium-grained calcarenite at 

top; contains broken fasciculate 

rugose corals •••••••••••••••••••••••• 

45. Mudstone, calcareous, light gray to 

light brown; poorly exposed •••••••••• 

44. Limestone, dark gray; one bed 

(Bouma Tab); grades from bioclastic 

limestone conglomerate at base to 

laminated fine-grained calcarenite 

at top; contains limestone clasts 

to 12 em in diameter, coarse echinodermal debris, and broken fasciculate 

rugose corals; spherical limestone 

cobbles in lower part of bed may be 

reworked concretions ••••••••••••••••• 

43. Mudstone, calcareous, light brown; 

contains limestone concretions; 

poorly exposed; one bed of laminated calcisiltite 8 em thick 

present 11.5 m above base of 

interval ••••••••••••••••••••••••••••• 

42. Limestone; one bed (Bouma Tab); 

grades from coarse-grained bioclastic (largely echinodermal) 

calcarenite at base to laminated 

calcisiltite at top; contains 

broken fasciculate rugose corals 

and fusulinids••••••••••••••••••••••• 

41. Mudstone, siliceous, brown; 

contains gray limestone concretions; 

subordinate light-gray calcareous 

muds tone • •••••••••••••••••••••••••••• 

40. Mudstone, calcareous, light gray; 

contains rare limestone concretions 

in lower 6.5 m; poorly exposed; 

one bed of laminated calcisiltite 

40 em thick 6.5 m above base of 

inte~al ••••••.•••••••••••••••••••••• 

39. Limestone, dark gray; one bed 

(Bouma Tab); grades from bioclastic 

limestone conglomerate at base to 

laminated calcisiltite at top; 

contains limestone clasts to 2 em 

in diameter and fusulinids. 

Fusulinid collection OC15: 

Schwagerina spp., Stewartina? sp., 

Leptotriticites? sp., Eoparafusulina 

cf. E. linearis •••••••••••••••••••••• 

38. Mudstone, calcareous; poorly 

exposed •••••••••••••••••••••••••••••• 

37. Limestone (calcarenite), medium 

gray, medium grained; one bed •••••••• 

36. Mudstone, calcareous, light gray ••••• 

35. Limestone, dark gray; one bed 

(Bouma Tab); grades from bioclastic 

limestone conglomerate at base to 

laminated calcisiltite at top; 

Thickness 

meters 

1.7 

2.0 

3.0 

2.0 

23.6 

2.5 

1.2 

10.2 

3.5 

2.0 

0.4 

0.8 

Section 1: Lower Permian--Continued 

Osborne Canyon Formation--Continued 

Member C--Continued 

contains limestone clasts to 5 em 

in diameter, coarse echinodermal 

debris, and fusulinids ••••••••••••••• 

34. Mudstone, calcareous, light gray; 

poorly exposed ••••••••••••••••••••••• 

33. Limestone, dark gray; one bed 

(Bouma Tabc); grades from coarsegrained echinodermal calcarenite 

at base to fine-grained calcarenite 

at top; upper part of bed convolute 

laminated ••••••••••••••••••••••• • • • • • 

32. Mudstone, calcareous, light gray; 

poorly exposed ••••••••••••••••••••••• 

31. Limestone, dark gray; one bed 

(Bouma Tb); grades from fine-grained 

calcarenite at base to calcisiltite 

at top ••••••••••••••••••••••••••••••• 

30. Mudstone, calcareous, light gray; 

poorly exposed ••••••••••••••••••••••• 

29. Limestone (calcisiltite), 

light gray; one bed •••••••••••••••••• 

28. Mudstone, calcareous, light gray; 

interbedded with brown siliceous 

mudstone; poorly exposed ••••••••••••• 

27. Limestone, dark gray; one bed 

(Bouma Tab); grades from coarsegrained bioclastic (largely 

echinodermal) calcarenite at base 

to calcisiltite at top; contains 

fusulinids ••••••••••••••••••••••••••• 

26. Limestone (calcarenite), bioclastic 

(largely echinodermal), coarsegrained; one ungraded bed (Bouma 

Ta); contains fusulinids; capped 

by 2 em of mudstone •••••••••••••••••• 

25. Covered interval ••••••••••••••••••••• 

24. Limestone; one bed (Bouma Tab); 

grades from dark-gray, coarsegrained echinodermal calcarenite 

at base to light-gray calcisiltite at toP•••••••••••••••••••••••••• 

23. Covered interval ••••••••••••••••••••• 

22. Limestone; one bed (Bouma Tab); 

grades from dark-gray coarsegrained bioclastic calcarenite 

at base to light-gray laminated 

calcisiltite at top; capped by 

5 em of siliceous mudstone ••••••••••• 

21. Mudstone ••••••••••••••••••••••••• •. • • 

20. Limestone, dark gray; one bed 

(Bouma Tab); grades from coarsegrained bioclastic calcarenite 

at base to laminated mediumgrained calcarenite at top; 

contains fusulinids •••••••••••••••••• 

19. Covered interval ••••••••••••••••••••• 

18. Mudstone, calcareous, plane laminated; 

contains dark-gray limestone 

concretions •••••••••••••••••••••••••• 

Thickness 

meters 

2.4 

2.3 

0.9 

2.0 

0.2 

2.5 

0.6 

1.4 

0.9 

0.8 

3.0 

0.8 

1.3 

0.6 

0.1 

0.4 

1.0 

0.6 

Measured Sections 15 
Section 1: Lower Permian--Continued 

Osborne Canyon Formation--Continued 

Member C--Continued 

17. Mudstone, siliceous, brown, thin 

bedded; contains dark-gray limestone 

concretions to 5 em in diameter; 

poorly exposed ••••••••••••••••••••••• 

16. Limestone, medium gray; one bed 

(Bouma Tab); grades from coarsegrained bioclastic (largely 

echinodermal) calcarenite at base 

to laminated calcisiltite at top; 

contains fusulinids •••••••••••••••••• 

15. Mudstone, siliceous, as in 17; 

poorly exposed ••••••••••••••••••••••• 

14. Limestone (calcarenite), dark gray, 

fine grained; one bed •••••••••••••••• 

13. Covered interval; loose limestone 

concretions in scree ••••••••••••••••• 

12. Mudstone, calcareous, light gray, 

massive; may grade up from 

underlying limestone ••••••••••••••••• 

11. Limestone, dark gray; one bed (Bouma 

Tab); grades from coarse-grained 

bioclastic calcarenite at base to 

light-gray, laminated calcisiltite 

at top; contains fusulinids •••••••••• 

10. Mudstone, calcareous, light brown; 

poorly exposed ••••••••••••••••••••••• 

9. Limestone, medium gray; one bed 

(Bouma Tab); grades from coarsegrained bioclastic calcarenite at 

base to fine-grained calcarenite 

at top; contains fusulinids •••••••••• 

8. Interval largely covered; few 

outcrops of dark-gray micritic 

limestone in beds 10 to 25 em thick 

and light-gray calcareous mudstone; 

one bed of coarse-grained bioclastic 

limestone 13 em thick present 1.0 m 

above base of interval ••••••••••••••• 

7. Mudstone, calcareous, light gray, 

massive; may grade up from 

underlying limestone ••••••••••••••••• 

6. Limestone, medium gray; one bed 

(Bouma Tab); grades from mediumgrained echinodermal calcarenite 

at base to laminated calcisiltite 

at top ••••••••••••••••••••••••••••••• 

5. Mudstone, calcareous, light brown, 

massive; about 50 percent covered •••• 

4. Limestone, medium gray; one bed 

(Bouma Tab); grades from coarsegrained echinodermal calcarenite 

at base to laminated calcisiltite 

at top ••••••••••••••••••••••••••••••• 

3. Covered interval ••••••••••••••••••••• 

2. Mudstone, calcareous, light brown; 

poorly exposed ••••••••••••••••••••••• 

1. Limestone, medium gray; one bed 

(Bouma Tab); grades from coarsegrained bioclastic calcarenite 

Thickness 

meters 

1.7 

0.2 

2.3 

0.1 

2.5 

3.0 

2.1 

2.3 

0.4 

10.6 

1.5 

1.0 

7.2 

1.8 

8.5 

2.0 

Section 1: Lower Permian--Continued 

Osborne Canyon Formation--Continued 

Member C--Continued 

at base to laminated fine-grained 

calcarenite at top; contains 

fusulinids. Fusulinid collection 

OC14: Schwagerina aff. S. 

Thickness 

meters 

wellsensis, Schwagerina sp........... 2.0 

Total thickness member C ••••••••••••••••••• 156.9 

Member B: 

33. Covered interval; light-gray 

calcareous mudstone scree •••••••••••••• 7.5 

32. Mudstone, calcareous, light gray 

to light brown; faintly laminated 

in irregular, convolute patterns; 

laminations defined by aligned 

small clasts of medium- to darkgray micritic limestone; lenticular beds of dark-gray 

limestone (fine-grained calcarenite; Bouma Tb) 15 to 35 em 

thick present at base of interval 

and 3.2, 8.8, 10.9, 16.3, 30.9, 

32.9, 33.3, and 39.7 m above 

base of interval. A 1.5-m-thick 

dike present 1.3 m below top of 

interval. Upper 20 m of 

interval poorly exposed.............. 43.6 

31. Covered interval..................... 2.0 

30. Mudstone, calcareous, light gray to 

light brown, massive; contains 

scattered large irregularly shaped 

clasts of medium- to dark-gray 

micritic limestone; in part covered; 

one lenticular bed of dark-gray, 

fusulinid-bearing bioclastic 

limestone 15 em thick present 

2.4 m above base of interval......... 9.1 

29. Limestone, dark gray; one bed 

Bouma Tab); grades from limestone-pebble conglomerate at 

base to laminated calcisiltite 

at top............................... 0.5 

28. Mudstone, calcareous, as in 30; 

upper part poorly exposed............ 8.3 

27. Limestone, dark gray; one bed (Bouma 

Tab); grades from limestone 

conglomerate at base to finegrained calcarenite at top; 

contains limestone clasts to 2 em 

in diameter.......................... 0.5 

26. Covered interval..................... 0.9 

25. Limestone, dark gray; one bed (Bouma 

Tab); grades from coarse-grained 

bioclastic calcarenite at base to 

laminated calcisiltite at top........ 0.5 

24. Mudstone, calcareous, as in 30; thin 

lenticular beds of bioclastic 

limestone conglomerate present 0.8 

and 2.5 m above base of interval..... 4.8 

23. Siltstone, calcareous, light gray 

to light brown, laminated............ 0.6 

16 Pennsylvanian and Permian Stmtigraphy, Northern Argus Range and Darwin Canyon Area, California 
Section 1: Lower Permian--Continued 

Osborne Canyon Formation--Continued 

Member B--Continued 

22. Limestone, (calcarenite), bioclastic, 

dark gray, coarse grained; one 

ungraded bed (Ta) •••••••••••••••••••• 

21. Mudstone, calcareous, as in 30; 

poorly exposed ••••••••••••••••••••••• 

20. Limestone, dark gray; one bed 

(Bouma Tab); grades from limestone conglomerate at base to 

laminated calcisiltite at top; 

contains limestone clasts to 

6 em in diameter ••••••••••••••••••••• 

19. Covered interval ••••••••••••••••••••• 

18. Limestone, dark gray; one bed 

(Bouma Tab); grades from limestone conglomerate at base to 

laminated calcisiltite at top; 

contains limestone clasts to 

3 em in diameter ••••••••••••••••••••• 

17. Covered interval ••••••••••••••••••••• 

16. Limestone, dark gray; one bed (Bouma 

Tab); grades from limestone 

conglomerate at base to laminated 

calcisiltite at top; contains limestone clasts to 15 em in diameter; 

clasts tightly packed •••••••••••••••• 

15. Mudstone, calcareous, as in 30, 

poorly exposed; one lenticular 

bed of bioclastic limestone 15 em 

thick 3.5 m above base of 

interval ••••••••••••••••••••••••••••• 

14. Limestone, dark gray; one bed (Bouma 

Tab); grades from bioclastic limestone conglomerate at base to laminated calcisiltite in upper 5 em; 

contains limestone clasts to 5 em 

in diameter •••••••••••••••••••••••••• 

13. Siltstone, calcareous, as in 23 •••••• 

12. Limestone, dark gray; one bed 

(Bouma Tab); grades from bioclastic limestone conglomerate 

at base to fine-grained calcarenite at top; poorly sorted; 

contains limestone clasts to 

30 em in diameter; clasts 

tightly packed ••••••••••••••••••••••• 

11. Siltstone, calcareous, as in 23 •••••• 

10. Covered interval ••••••••••••••••••••• 

9. Mudstone, calcareous, as in 30 ••••••• 

8. Covered interval ••••••••••••••••••••• 

7. Mudstone, calcareous, light 

gray, laminated; interbedded 

with black-weathering calcareous 

chert •••••••••••••••••••••••••••••••• 

6. Limestone-pebble conglomerate; 

lenticular ••••••••••••••••••••••••••• 

5. Mudstone, calcareous, as in 30 ••••••• 

4. Limestone conglomerate, bioclastic, dark gray, poorly 

sorted; one bed (Bouma Tab); 

Thickness 

meters 

0.3 

2.0 

1.0 

0.8 

0.5 

0.7 

1.0 

4.5 

1.5 

1.3 

1.8 

2.0 

2.0 

5.0 

5.0 

3.0 

0.2 

1.5 

Section 1: Lower Permian--Continued 

Osborne Canyon Formation--Continued 

Member B--Continued 

contains limestone clasts to 

10 em in diameter and abundant 

coarse echinodermal debris; 

clasts tightly packed; upper 

20 em is laminated 

Thickness 

meters 

calcisiltite......................... 7.5 

3. Covered interval; calcareous 

mudstone scree....................... 4.0 

2. Mudstone, calcareous, light gray, 

massive •••••••••••••••••••••••••••••• 6.0 

1. Limestone, medium gray; one bed 

(Bouma Tab); grades from bioclastic 

limestone conglomerate at base to 

laminated, fine-grained calcarenite 

at top; contains limestone clasts 

to 2 em in diameter and fusulinids. 

Fusulinid collection OC11: 

Leptotriticites? sp., 

Schwagerina sp. ••••••••••••••••••••• 7.0 

Total thickness member B ••••••••••••••••••• 136.9 

Hember A: 

30. Covered interval ••••••••••••••••••••••• 1.0 

29. Limestone, dark gray; one bed 

(Bouma Tab); grades from very 

coarse grained bioclastic 

(largely echinodermal) calcarenite at base to laminated 

calcisiltite at top; contains 

fusulinids. Fusulinid 

collection OC10: 

Schwagerina SP••••••••••••••••••••••• 0.3 

28. Covered interval..................... 2.0 

27. Siltstone, calcareous, light gray 

to light brown, laminated; a 

2-m-thick dike cuts interval 

4.0 m above base..................... 8.0 

26. Limestone conglomerate, bioclastic, dark gray; one 

ungraded bed (Bouma Ta); poorly 

sorted; contains limestone 

clasts, echinodermal debris, 

and fragmented bryozoa to 5 em 

in diameter; clasts tightly 

packed.. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1. 0 

25. Covered interval; calcareous 

siltstone and mudstone scree......... 12.0 

24. Limestone (calcarenite), bioclastic (largely echinodermal), 

dark gray, coarse grained; one 

ungraded bed (Bouma Ta); 

contains fusulinids. Fusulinid 

collection OC9: Schwagerina sp., 

Pseudofusulina? aff. P.? 

loringi •••••••••••••••••••••••••••••• 

23. Covered interval; calcareous 

siltstone scree •••••••••••••••••••••• 

22. Limestone conglomerate, dark 

gray; one ungraded bed (Bouma 

Ta); contains limestone clasts 

0.5 

3.5 

Measured Sections 17 
Section 1: Lower Permian--Continued 

Osborne Canyon Formation--Continued 

Member A--Continued 

to 2 em in diameter; clasts 

tightly packed ••••••••••••••••••••••• 

21. Limestone (calcarenite), bioclastic; 

thinly interbedded with calcareous 

siltstone; poorly exposed •••••••••••• 

20. Limestone (calcarenite), bioclastic, 

medium gray; in lenticular beds 5 

to 10 em thick; contains 

fusulinids; interbedded with calcareous siltstone. Fusulinid 

collection OC8: Pseudofusulina? a££. 

..!:.·? loringi ••••••••••••••••••••••••••• 

19. Siltstone, calcareous, as in 27; 

poorly exposed ••••••••••••••••••••••• 

18. Limestone conglomerate, medium gray; 

one ungraded bed (Bouma Ta); contains 

limestone clasts to 4 em in diameter; 

clasts tightly packed •••••••••••••••• 

17. Siltstone, calcareous, as in 27; 

poorly exposed ••••••••••••••••••••••• 

16. Limestone (calcarenite), echinodermal, 

medium gray, coarse grained; 

one bed •••••••••••••••••••••••••••••• 

15. Covered interval ••••••••••••••••••••• 

14. Limestone (calcarenite), medium gray, 

fine grained; one bed (Bouma Tb) ••••• 

13. Covered interval ••••••••••••••••••••• 

12. Siltstone, calcareous, as in 27 •••••• 

11. Covered interval ••••••••••••••••••••• 

10. Limestone conglomerate, bioclastic, 

medium gray; one ungraded bed (Bouma 

Ta); contains limestone clasts and 

echinodermal debris to 3 em in 

diameter and fusulinids. Fusulinid 

collection RTM2: Schwagerina sp., 

Pseudofusulina? a££ • .!:_. loringi, 

Pseudoschwagerina uddeni, 

Eoparafusulina sp •••••••••••• 

9. Covered interval ••••••••••••••••••••• 

8. Siltstone, calcareous, as in 27 •••••• 

7. Limestone (calcarenite), echinodermal, 

medium gray, coarse grained; in two 

lenticular graded beds (Bouma Ta) 25 

and 30 em thick; both beds wedge out 

within 10m along strike ••••••••••••• 

6. Siltstone, calcareous, as in 27; 

poorly exposed ••••••••••••••••••••••• 

5. Limestone (calcarenite), echinodermal, 

medium gray; one bed (Bouma Ta); 

grades from coarse grained at base 

to fine grained at top ••••••••••••••• 

4. Siltstone, calcareous, as in 27 •••••• 

3. Limestone (calcarenite), echinodermal, 

medium gray; one bed containing 

internal size-sorted layers 2 to 

10 em thick •••••••••••••••••••••••••• 

2. Covered interval ••••••••••••••••••••• 

Thickness 

meters 

0.3 

1.0 

0.3 

3.0 

0.5 

3.0 

0.1 

0.2 

0.3 

0.4 

1.0 

4.0 

0.4 

0.2 

2.2 

0.5 

3.3 

0.3 

1.1 

0.6 

0.2 

Section 1: Lower Permian--Continued 

Osborne Canyon Formation--Continued 

Member A--Continued 

1. Limestone (calcarenite), echinodermal, 

medium gray; one bed (Bouma Ta); 

grades from coarse grained at base to 

Thickness 

meters 

fine grained at top.................. 0.9 

Total thickness member A................... 52.1 

Total thickness Osborne Canyon Formation ••• 345.9 

Disconformable contact. 

Tihvipah Limestone (Lower and Middle 

Pennsylvanian): 

23. Limestone (micrite), medium gray; 

contains abundant nodular, 

lenticular, and bedded chert; 

tremolite abundant................... 20.0 

22. Covered interval..................... 1.0 

21. Limestone (micrite), medium gray; 

contains abundant nodular chert in 

basal 4 m and mostly lenticular 

and bedded chert above that; chert 

layers in upper part of interval 

are 1 to 5 em thick and spaced 5 to 

to 20 em apart; bedding well 

defined •••••••••••••••••••••••••••••• 

20. Limestone (micrite), cherty, as in 

23; forms ledges ••••••••••••••••••••• 

19. Limestone, bioclastic and 

conglomeratic, light gray; contains 

echinodermal debris, fragmented 

bryozoans, and limestone clasts 

suspended in a micrite matrix •••••••• 

18. Limestone (micrite), cherty, as 

in 23; forms ledges •••••••••••••••••• 

17. Limestone (micrite), variably 

silty or argillaceous, light to 

medium gray; contains abundant 

nodular, lenticular, and bedded 

chert; beds 10 to 20 em thick 

defined by variations in silt or 

clay content and by chert 

layering ••••••••••••••••••••••••••••• 

16. Covered interval ••••••••••••••••••••• 

15. Limestone (micrite), medium to 

dark gray, massive; contains sparse 

nodular chert; forms ledges •••••••••• 

14. Limestone (micrite), medium gray; 

contains abundant nodular, lenticular, and bedded chert; spherical 

chert nodules common; bedding 

defined by chert layers spaced 

20 to 50 em apart; tremolite 

abundant ••••••••••••••••••••••••••••• 

13. Limestone (micrite), variably silty 

or argillaceous, as in 17; beds 10 

to 30 em thick ••••••••••••••••••••••• 

12. Limestone (micrite), dark gray, with 

rare chert; tremolite abundant ••••••• 

11. Covered interval ••••••••••••••••••••• 

19.5 

ll.O 

0.4 

15.5 

8.7 

1.0 

7.5 

7.5 

1.8 

2.0 

3.0 

18 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 
Section 1: Lower and Middle Pennsylvanian--Continued 

Tihvipah Limestone--Continued 

10. Limestone (micrite), variably silty 

Thickness 

meters 

or argillaceous, as in 17............ 3.5 

9. Covered interval..................... 2.0 

8. Limestone (micrite), silty or 

argillaceous, light gray; tremolite 

abundant••••••••••••••••••••••••••••• 1.0 

7. Limestone, bioclastic and 

conglomeratic; contains coarsegrained echinodermal debris, rare 

rugose coral fragments, and 

limestone clasts to 6 em in diameter 

suspended in a micrite matrix; 

tremolite abundant................... 1.5 

6. Covered interval..................... 1.0 

5. Limestone (micrite), medium gray; 

nodular chert uncommon; minor 

light-gray silty or argillaceous 

limestone; coarse echinodermal 

debris present locally............... 5.0 

4. Covered interval..................... 1.5 

3. Limestone (micrite), silty or 

argillaceous, light gray; contains 

rare spherical chert nodules......... 2.0 

2. Covered interval..................... 1.5 

1. Limestone (micrite), medium gray; 

contains nodular, lenticular, and 

bedded chert; small spherical chert 

nodules common; tremolite abundant... 2.8 

Total thickness Tihvipah Limestone....... 120.7 

Disconformable contact. 

Santa Rosa Hills Limestone (Mississippian) 

(not measured): 

Marble, white to light gray, massive, 

coarse grained; forms cliffs ••••••••• 

Section 2. Type sections of the Millers Spring Member (units 2 

through 7) and of the Panamint Springs Member of the Darwin 

Canyon Formation. Measured in four segments (2A, 2B, 2C, 

2D,) in Darwin Canyon north of the Darwin fault in July 1981 

and September 1985. Section 2A includes units 2, 3, and 4 of 

the Millers Spring Member; section 2B includes units 5, 6A, and 

6B of the Millers Spring Member; section 2C includes units 6C, 

6D, and 6E of the Millers Spring Member and the Panamint 

Springs Member; section 2D includes unit 7 of the Millers 

Spring Member and the Panamint Spring Member. 

Section 2D. Type sections of the Panamint Springs Member and 

unit 7 of the Millers Spring Member. 

Unnamed marine strata (Lower Triassic) 

(not measured): 

Limestone and marble, sandy, 

light gray to brown; contains 

planar to gently undulating, 

silty and sandy laminations; 

forms resistant ledges 

averaging about 1m thick •••••••••••• 

Thickness 

meters 

Section 2--Continued 

Unconformable contact (poorly exposed). 

Darwin Canyon Formation (Lower Permian) 

(incomplete): 

Panamint Springs Member: 

75. Covered interval; scree of siltstone 

and very fine grained sandstone •••••• 

74. Limestone (calcisiltite), silty, 

light gray, laminated •••••••••••••••• 

73. Siltstone and very fine grained 

sandstone, quartzose, calcareous, 

brown to reddish brown on weathered 

surface; in planar beds 2 to 10 em 

thick; most beds plane laminated to 

gently crosslaminated •••••••••••••••• 

72. Limestone, silty, as in 74 ••••••••••• 

71. Siltstone and very fine grained 

sandstone, as in 73 •••••••••••••••••• 

70. Limestone, silty, as in 74 ••••••••••• 

69. Siltstone and very fine grained 

sandstone, as in 73 •••••••••••••••••• 

68. Limestone, silty, as in 74 ••••••••••• 

67. Siltstone and very fine grained 

sandstone, as in 73 •••••••••••••••••• 

66. Limestone (calcisiltite), silty, 

light gray; contains irregular brown 

silty layers 5 to 10 em thick •••••••• 

65. Siltstone and very fine grained 

sandstone, as in 73 •••••••••••••••••• 

64. Limestone (calcarenite), medium gray, 

fine grained; one graded bed ••••••••• 

63. Siltstone and very fine grained 

sandstone, as in 73 •••••••••••••••••• 

Thickness 

meters 

4.0 

2.0 

70.0 

2.0 

10.5 

1.0 

4.5 

0.5 

22.5 

3.0 

2.0 

0.5 

2.0 

62. Limestone, silty, as in 74........... 1.5 

61. Siltstone and very fine grained 

sandstone, as in 73 •••••••••••••••••• 

60. Limestone (calcisiltite), medium 

gray; one bed •••••••••••••••••••••••• 

59. Siltstone and very fine grained 

sandstone, as in 73 •••••••••••••••••• 

58. Limestone (calcarenite), pebbly; 

contains fusulinids; poorly exposed. 

57. Limestone (calcisiltite), 

medium gray; poorly exposed •••••••••• 

56. Siltstone and very fine grained 

sandstone, as in 73 •••••••••••••••••• 

55. Sandstone, calcareous, coarse 

grained, plane laminated; one 

graded bed; contains bioclastic 

debris ••••••••••••••••••••••••••••••• 

54. Limestone, as in 57 •••••••••••••••••• 

53. Siltstone and very fine grained 

sandstone, as in 73; some beds 

have spherical medium-gray limestone 

concretions 2 to 4 em in diameter •••• 

52. Limestone, as in 57 •••••••••••••••••• 

1.5 

0.5 

22.5 

0.2 

3.0 

12.0 

0.3 

1.0 

72.0 

0.5 

Measured Sections 19 
Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Panamint Springs Member--Continued 

51. Siltstone and very fine grained 

sandstone, as in 73 •••••••••••••••••• 

50. Limestone (calcisiltite), silty, 

light gray; one bed •••••••••••••••••• 

49. Siltstone and very fine grained 

sandstone, as in 73 •••••••••••••••••• 

48. Limestone (calcisiltite), silty, 

light brown; one bed; laminated •••••• 

47. Covered interval; silty limestone 

scree •• ............................•• 

46. Limestone (calcisiltite), silty, 

medium gray; one bed; plane 

laminated •••••••••••••••••••••••••••• 

45. Siltstone or very fine grained 

sandstone, brown ••••••••••••••••••••• 

44. Limestone, silty, as in 46; one 

bed ••••••••••••••••• •. •. • • • • • • • • • • • • • 

43. Siltstone or very fine grained 

sandstone, as in 45 •••••••••••••••••• 

42. Limestone, silty, as in 46; one bed •• 

41. Siltstone or very fine grained 

sandstone, as in 45 •••••••••••••••••• 

40. Limestone, silty, as in 46; one bed •• 

39. Limestone (calcisiltite), silty, 

light gray, laminated; poorly 

exposed •••••••••••••••••••••••••••••• 

38. Limestone (calcisiltite), silty, 

medium gray, laminated; contains 

irregular brown-weathering layers 5 

to 10 em thick; small limestone 

concretions at top of interval; 

forms a massive ledge •••••••••••••••• 

37. Covered interval ••••••••••••••••••••• 

36. Sandstone, as in 24; one bed ••••••••• 

35. Limestone (calcisiltite), light 

gray; one bed; dark-gray limestone concretions on upper 

bedding surface •••••••••••••••••••••• 

34. Sandstone, as in 24; one bed ••••••••• 

33. Mudstone, as in 24 ••••••••••••••••••• 

32. Sandstone, as in 24; one bed ••••••••• 

31. Mudstone, as in 24 ••••••••••••••••••• 

30. Covered interval ••••••••••••••••••••• 

29. Sandstone, as in 24; one bed ••••••••• 

28. Mudstone, as in 24 ••••••••••••••••••• 

27. Sandstone, as in 24; one bed ••••••••• 

26. Mudstone, as in 24 ••••••••••••••••••• 

25. Limestone (calcisiltite), 

light gray, laminated; locally 

contains dark-gray limestone 

concretions; silty layers 2 to 5 

em thick in upper part ••••••••••••••• 

24. Sandstone (65 percent) and 

mudstone (35 -percent); in 

Thickness 

meters 

4.5 

0.3 

9.0 

1.5 

2.5 

0.8 

0.2 

0.7 

0.3 

o.s 

0.3 

0.6 

5.5 

6.5 

1.2 

0.3 

0.1 

3.5 

0.1 

0.4 

0.2 

3.5 

0.5 

0.2 

0.4 

0.1 

2.0 

Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Panamint Springs Member--Continued 

alternating beds. Sandstone, 

quartzose, variably calcareous 

and calcarenitic, gray to 

brown on weathered surface, 

very fine grained; in beds 

20 em to 2.8 m thick; mean 

bed thickness about 80 em; 

generally plane laminated; 

commonly gently crosslaminated and convolute 

laminated; bedding surfaces 

sharp. Mudstone, siliceous 

to calcareous, light brown to 

light gray; in beds 2 em to 

1.1 m thick; mean bed thickness 

Thickness 

meters 

about 40 em.......................... 10.2 

23. Limestone (calcarenite), silty, 

light gray, fine grained; one bed.... 0.4 

22. Sandstone (75 percent) and mudstone 

(25 percent), as in 24. Sandstone 

in beds 15 em to 2.3 m thick; mean 

bed thickness about 75 em. Mudstone 

in beds 10 to 75 em thick; mean bed 

thickness about 25 em; locally 

contains dark-gray limestone 

concretions.......................... 11.2 

Total thickness Panamint Springs Member 

not including basal limestone unit....... 307.0 

Basal limestone unit: 

21. Limestone (calcisiltite) and 

siltstone; in irregular beds 5 

to 20 em thick. Limestone, 

variably silty, light to 

medium gray; siltstone, 

light brown, calcareous.............. 7.0 

20. Covered interval..................... 2.0 

19. Limestone (fine-grained calcarenite 

and calcisiltite), silty, light to 

medium gray; one graded bed.......... 2.0 

18. Mudstone (60 percent) and limestone 

{fine-grained calcarenite and 

calcisiltite) (40 percent); in 

alternating beds. Mudstone, 

siliceous to calcareous, light brown 

to light gray; in beds 10 to 80 em 

thick; mean bed thickness about 

55 em. Limestone, silty and sandy, 

light to medium gray; in beds 15 

to 80 em thick; mean bed thickness 

about 40 em; unlaminated to plane 

laminated, crosslaminated, and 

convolute laminated; bedding 

surfaces sharp....................... 7.3 

17. Limestone {fine-grained 

calcarenite or calcisiltite), 

medium gray, indistinctly bedded; 

forms flaggy outcrops •••••••••••••••• 

16. Mudstone (80 percent) and 

sandstone (20 percent); in 

alternating beds. Mudstone, 

siliceous, gray, brown, and 

reddish gray, generally in beds 

3.5 

20 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 
Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Panamint Springs Member--Continued 

Basal limestone unit--Continued 

1 to 2 m thick. Sandstone, 

quartzose, strongly calcarenitic, 

gray to brown on weathered 

surface, very fine grained; 

in beds 15 to 80 em thick; 

mean bed thickness about 35 em; 

commonly plane laminated, 

less commonly ripple crosslaminated and convolute laminated; 

bedding surfaces sharp ••••••••••••••• 

15. Covered interval ••••••••••••••••••••• 

14. Sandstone (80 percent) and 

mudstone (20 percent), as in 

16. Sandstone in beds 20 em 

to 1.0 m thick, mudstone in 

beds 2 to 50 em thick •••••••••••••••• 

13. Covered interval ••••••••••••••••••••• 

12. Limestone (calcarenite), silty, 

light gray to light brown, fine 

grained; in irregular beds 5 to 

10 em thick defined by variations 

in silt content; plane laminated ••••• 

11. Covered interval ••••••••••••••••••••• 

10. Sandstone, as in 16; two beds 33 

and 55 em thick separated by 

20 em of mudstone •••••••••••••••••••• 

9. Mudstone, as in 16 ••••••••••••••••••• 

8. Limestone (calcarenite), 

medium gray, fine grained; 

plane laminated but indistinctly 

bedded; contains thin lenticular 

partings of brown siliceous 

muds tone ••••••••••••••••••••••••••••• 

7. Mudstone, siliceous, brown; 

contains a 7-cm-thick bed of 

medium-gray, fine-grained limestone 

1.0 m above base ••••••••••••••••••••• 

6. Sandstone, as in 16; two beds 45 

and 33 em thick separated by 10 em 

of light-gray calcareous mudstone •••• 

5. Covered interval ••••••••••••••••••••• 

4. Sandstone, as in 16; one bed; 

lamina ted •••••••••••••••••••••••••••• 

3. Mudstone, siliceous, brown; 

weathers to small chips •••••••••••••• 

2. Limestone (calcarenite and 

calcisiltite) (35 percent) and 

mudstone (65 percent); in 

alternating beds. Limestone, 

variably silty, light to 

medium gray; generally fine 

grained but rarely medium to 

coarse grained at bases of beds; 

in graded and ungraded beds 10 to 

40 em thick; mean bed thickness 

about 20 em; faintly laminated; 

has a strong tectonic cleavage. 

Mudstone, siliceous, brown; in beds 

10 em to 1.1 m thick; mean bed 

thickness about 50 em •••••••••••••••• 

Thickness 

meters 

15.5 

0.9 

3.6 

1.0 

4.5 

1.0 

1.1 

0.5 

3.0 

1.4 

0.9 

0.8 

0.6 

2.0 

5.8 

Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Panamint Springs Member--Continued 

Basal limestone unit--Continued Thickness 

meters 

1. Covered interval..................... 0.8 

Total thickness basal limestone unit....... 65.2 

Total thickness Panamint Springs Member.... 372.2 

Millers Spring Member (incomplete): 

Unit 7: 

7. Sandstone (80 percent) and 

mudstone (20 percent); in 

alternating beds. Sandstone, 

quartzose, variably calcareous 

and calcarenitic, gray to 

brown on weathered surface; in 

beds 40 em to 1.9 m thick; 

generally plane laminated, less 

commonly crosslaminated and 

convolute laminated; bedding 

surfaces sharp. Mudstone, 

light gray, light brown, and 

purplish gray; in beds 10 to 

40 em thick •••••••••••••••••••••••••• 

6. Interval occupied by crosscutting 

dike ••••••••••••••••••••••••••••••••• 

5. Sandstone (70 percent) and 

mudstone (30 percent), as in 7. 

Sandstone in beds 20 to 50 em 

thick. Mudstone in beds 10 to 

40 em thick •••••••••••••••••••••••••• 

4. Interval occupied by crosscutting 

dike ••••••••••••••••••••••••••••••••• 

3. Sandstone, as in 7; two amalgamated 

beds 26 and 30 em thick •••••••••••••• 

2. Limestone (calcarenite), 

echinodermal, medium gray, 

coarse grained; one graded 

bed (Bouma Ta); base erosional ••••••• 

1. Sandstone (55 percent) and 

mudstone (45 percent), as in 

7. Sandstone in beds 5 em to 

2.7 m thick; mean bed thickness 

about 60 em. Mudstone in beds 

2 em to 2.3 m thick; mean bed 

thickness about 50 em •••••••••••••••• 

Total thickness unit 7 ••••••••••••••••••••• 

Unit 6E (uppermost bed, not measured): 

Mudstone, calcareous, conglomeratic, 

pink, massive; contains scattered 

fusulinids, echinodermal debris, 

and limestone clasts ••••••••••••••••• 

Incomplete thickness Millers Spring 

5.5 

4.0 

2.9 

1.0 

0.6 

0.5 

24.9 

39.4 

Member.. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 39.4 

Incomplete thickness Darwin Canyon 

Formation •••••••••••••••••••••••••••••••••• 411.6 

Measured Sections 21 
Section 2: Lower Permian--Continued 

Section 2C. Units 6A, 6B (incomplete due to faulting); type 

section of units 6C-6E, Millers Spring Member. 

Darwin Canyon Formation (Lower Permian) 

(incomplete): 

Millers Spring Member (incomplete): 

Unit 7 (not measured): 

Sandstone, quartzose, gray to 

brown, very fine grained, 

thick bedded; interbedded 

with light-gray to light-brown 

calcareous mudstone •••••••••••••••••• 

Unit 6E: 

4. Mudstone, calcareous, conglomeratic, 

pink, massive; contains limestone 

clasts and bioclasts averaging 1 em 

in diameter; echinodermal debris 

and fusulinids abundant; crude 

normal grading defined by upward 

decrease in abundance of clasts 

(clasts rare in upper 5 m of bed) •••• 

3. Limestone, medium gray; one bed 

(Bouma Tab); grades from limestone conglomerate at base to 

laminated calcisiltite at top; 

contains limestone clasts to 5 em 

Thickness 

meters 

10.0 

in diameter.......................... 3.6 

2. Covered interval; pink mudstone 

scree................................ 2.0 

1. Limestone, medium gray; one bed 

(Bouma Ta); grades from limestone conglomerate at base to 

medium-grained echinodermal 

calcarenite at top except for 

uppermost 25 em which is 

inversely graded to coarsegrained calcarenite; contains 

limestone clasts to 10 em in 

diameter; dark-gray spherical 

limestone clasts 2 to 5 em in 

diameter abundant at base of 

bed. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 3. 7 

Total thickness unit 6E.................... 19.3 

Unit 6D: 

Sandstone (35 percent) and mudstone (65 percent); in alternating beds. Sandstone, quartzose, 

variably calcareous and calcarenitic, very fine grained; in 

planar beds 10 em to 1.0 m thick; 

mean bed thickness about 40 em; 

generally plane laminated, less 

commonly crosslaminated and 

convolute laminated. Mudstone, 

light gray to pinkish gray; in 

beds 5 em to 2.5 m thick (mean 

bed thickness about 70 em)........... 25.5 

Total thickness unit 6D •••••••••••••••••••• 

Unit 6C: 

6. Limestone, medium gray; one bed 

(Bouma Tabc); grades from 

limestone-pebble conglomerate 

at base to laminated calcisiltite 

25.5 

Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Hillers Spring Member--Continued 

Unit 6C--Continued Thickness 

meters 

at top; upper 20 em is ripple 

laminated............................ 2.3 

5. Mudstone.. • • • • • • • • • • • • • • • • • • • • • • • • • • • 0. 3 

4. Limestone-cobble conglomerate; 

one ungraded bed (Bouma Ta); 

contains tectonically stretched 

clasts............................... 1.5 

3. Covered interval..................... 0.5 

2. Limestone (calcarenite), silty, 

fine grained; one bed................ 0.1 

1. Limestone, medium gray; one bed 

(Bouma Tabc); grades from 

limestone conglomerate at base to 

laminated calcisiltite at top; 

contains tectonically stretched 

limestone clasts to 15 em long; 

clasts tightly packed; upper 

15 em of bed is ripple laminated; 

capped by 2 em of mudstone ••••••••••• 

Total thickness unit 6C •••••••••••••••••••• 

Unit 6B: 

2. Mudstone; thin sandstone bed 

present 0,8 m above base ••••••••••••• 

Fault; small but indeterminate amount 

of section missing. 

1. Sandstone (75 percent) and 

mudstone (25 percent), as in 

unit 6D. Sandstone in beds 

10 em to 1.1 m thick; mean bed 

thickness about 50 em. Mudstone 

in beds 1 to 75 em thick; mean 

bed thickness about 20 em •••••••••••• 

Total thickness unit 6B (incomplete 

due to faulting) ••••••••••••••••••••••••• 

Unit 6A: 

4. Mudstone, calcareous, massive; 

may grade up from underlying 

limestone•••••••••••••••••••••••••••• 

3. Limestone, medium gray; one bed 

(Bouma Tab), grades from limestone 

conglomerate at base (mean clast 

size 1 em) to laminated calcisiltite 

at top; contains fusulinids •••••••••• 

2. Covered interval ••••••••••••••••••••• 

1. Limestone conglomerate; one 

bed (Bouma Ta); contains 

dark-gray micritic limestone 

clasts averaging 1 em in 

diameter; matrix is light gray to 

pinkish gray; clasts loosely packed •• 

Total thickness unit 6A •••••••••••••••••••• 

Unit 5 (not measured): 

Sandstone and mudstone, as in 

unit 6D •••••••••••••••••••••••••••••• 

Incomplete thickness Millers Spring 

Member ••••••••••••••••••••••••••••••••••• 

Incomplete thickness Darwin Canyon 

Formation •••••••••••••••••••••••••••••••• 

1.6 

6.3 

1.3 

16 0 7 

18.0 

3.5 

3.7 

1.5 

1.5 

10.2 

79.3 

79.3 

22 Pennsylvanian and Permian Stratigraphy, Nortbern Argus Range and Darwin Canyon Area, California 
Section 2: Lower Permian--Continued 

Section 2B. Unit 4 (incomplete), type section of units 5, 6A 

and 6B; unit 6C (incomplete), Millers Spring Member. 

Top of section faulted. 

Darwin Canyon Formation (Lower Permian) 

(incomplete): 

Millers Spring Member (incomplete): 

Unit 6C (incomplete): 

8. Limestone conglomerate, 

medium gray; one graded bed; 

median clast size 2 em at 

base and 5 mm at top; top of 

Thickness 

meters 

bed faulted.......................... 1.0 

7. Covered interval..................... 1.0 

6. Limestone (calcarenite), silty, 

medium gray, fine grained; one 

bed; laminated....................... 0.5 

5. Limestone (calcarenite), 

echinodermal, medium gray, 

medium to fine grained; one 

graded bed (Bouma Tab)............... 0.5 

4. Covered interval..................... 3.0 

3. Limestone conglomerate, 

bioclastic, medium gray; one 

graded bed (Bouma Ta); contains 

limestone clasts to 10 em in 

diameter and broken fasciculate 

rugose corals; median clast 

diameter at top of bed 1 em; 

clasts tightly packed •••••••••••••••• 

2. Covered interval ••••••••••••••••••••• 

1. Limestone, medium gray; one bed 

(Bouma Ta); grades from limestone 

conglomerate at base to 

fine-grained calcarenite at top; 

contains limestone clasts to 5 em 

in diameter; clasts strongly 

imbricated (possibly a tectonic 

fabric) •••••••••••••••••••••••••••••• 

Incomplete thickness unit 6C ••••••••••••••• 

Unit 6B: 

Sandstone, quartzose; gray to 

brown on weathered surface; 

very fine grained; in beds 10 em 

to 1.5 m thick; poorly exposed ••••••• 

Total thickness unit 6B •••••••••••••••••••• 

Unit 6A: 

7. Mudstone, calcareous, purplish 

gray, massive; may grade up from 

underlying limestone ••••••••••••••••• 

6. Limestone, medium gray; one bed 

(Bouma Tab); grades from 

coarse-grained bioclastic 

calcarenite at base to laminated 

calcisiltite at top; contains 

fusulinids. Fusulinid collection 

DC'S: Schwagerina aff. ~· 

thompsoni, Pseudoschwagerina 

convexa •• ••••••••.••••••••••••••••••• 

5. Covered interval ••••••••••••••••••••• 

2.0 

0.8 

2.0 

10.8 

32.7 

32.7 

3.0 

3.7 

0.8 

Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 6A--Continued 

4. Limestone conglomerate; one 

ungraded bed (Bouma Ta); composed 

of micritic limestone clasts and 

bioclasts (maximum diameter 2 em) 

in a light-gray to pinkish-gray 

micritic matrix •••••••••••••••••••••• 

3. Limestone, medium gray; one bed 

(Bouma Ta); grades from coarsegrained bioclastic calcarenite at 

base to medium-grained calcarenite 

at top ••••••••••••••••••••••••••••••• 

2. Sandstone, quartzose, brown, very 

fine grained ••••••••••••••••••••••••• 

1. Limestone conglomerate, bioclastic; 

one ungraded bed (Bouma Ta); 

composed of medium-gray micritic 

limestone clasts (maximum diameter 

2 em, median diameter 1 em) and 

subordinate bioclasts, including 

fusulinids and broken fasciculate 

rugose corals, in a light-gray 

micritic matrix; clasts 

loosely packed ••••••••••••••••••••••• 

Total thickness unit 6A •••••••••••••••••••• 

Unit 5: 

16. Covered interval ••••••••••••••••••••• 

15. Sandstone, quartzose, strongly 

calcarenitic, brown, very fine 

grained; one bed ••••••••••••••••••••• 

14. Covered interval ••••••••••••••••••••• 

13. Sandstone, as in 15; one bed ••••••••• 

12. Mudstone ••••••••••••••••••••••••••••• 

11. Limestone, medium gray; one 

bed (Bouma Tab); grades from 

coarse-grained bioclastic 

calcarenite at base to laminated 

calcisiltite at top; contains 

fusulinids ••••••••••••••••••••••••••• 

10. Sandstone (50 percent) and 

mudstone (50 percent); in 

alternating beds. Sandstone, 

quartzose, strongly calcarenitic, 

light gray; in beds 10 em to 1.5 m 

thick, generally plane laminated 

and crosslaminated, commonly 

convolute laminated; bedding 

surfaces sharp. Mudstone, 

calcareous, purplish gray; in beds 

5 em to 1.0 m thick; mean bed 

thickness about 50 em •••••••••••••••• 

9. Mudstone, purplish gray, massive; 

contains spherical to subspherical 

dark-gray limestone concretions 2 

to 5 em in diameter •••••••••••••••••• 

8. Limestone, medium gray; one bed 

(Bouma Tabc); grades from 

medium-grained echinodermal 

calcarenite at base to laminated 

calcisiltite at top •••••••••••••••••• 

7. Mudstone, purplish gray •••••••••••••• 

Thickness 

meters 

2.0 

0.8 

1.5 

3.5 

15.3 

0.2 

1.2 

2.0 

1.7 

0.1 

1.2 

7.4 

0.7 

0.7 

0.3 

Measured Sections 23 
Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 5--Continued 

6. Sandstone, quartzose, in part 

weakly calcareous and calcarenitic; 

generally brown on weathered 

surface; very fine grained; thick 

bedded; poorly exposed ••••••••••••••• 

5. Sandstone (45 percent) and 

mudstone (55 percent), as in 10. 

Sandstone, strongly calcarenitic; 

in beds 25 em to 1.5 m thick; 

mean bed thickness about SO em. 

Mudstone, in beds 5 em to 1.0 m 

thick; mean bed thickness about 

60 em •••••••••••••••••••••••••••••••• 

4. Covered interval ••••••••••••••••••••• 

3. Interval occupied by crosscutting 

dike ••••••••••••••••••••••••••••••••• 

2. Limestone, medium gray; one bed 

(Bouma Tab); grades from finegrained calcarenite at base to 

calcisiltite at top •••••••••••••••••• 

1. Sandstone (45 percent) and 

mudstone (55 percent), as in 10. 

Sandstone, strongly calcarenitic; 

in beds 10 em to 1.0 m thick; mean 

bed thickness about 40 em. Mudstone, in beds 10 em to 1.0 m 

thick; mean bed thickness about 

50 em ••••••••••••••••••••••••••••••• 

Total thickness unit 5 •••••••••••••••••••• 

Unit 4 (incomplete): 

25. Limestone, dark gray; one bed 

(Bouma Tab); grades from 

coarse-grained bioclastic 

calcarenite at base to laminated 

fine-grained calcarenite at top; 

contains fusulinids •••••••••••••••••• 

24. Mudstone, calcareous ••••••••••••••••• 

23. Limestone (fine-grained 

calcarenite or calcisiltite), 

silty; one bed ••••••••••••••••••••••• 

22. Hudstone, calcareous; thin 

limestone interbeds •••••••••••••••••• 

21. Limestone (fine-grained 

calcarenite or calcisiltite) 

silty; one bed ••••••••••••••••••••••• 

20. Hudstone, calcareous ••••••••••••••••• 

19. Limestone, medium gray; one bed 

(Bouma Tab); grades from 

coarse-grained echinodermal 

calcarenite at base to laminated 

calcisiltite at top; well sorted ••••• 

18. Covered interval ••••••••••••••••••••• 

17. Limestone (fine-grained calcarenite 

and calcisiltite) (60 percent) and 

mudstone (40 percent); in 

alternating beds. Limestone, silty, 

medium to dark gray, very fine to 

fine grained; in beds 10 to 55 em 

thick; mean bed thickness about 

30 em; generally plane laminated 

Thickness 

meters 

13.7 

10.9 

3.0 

2.0 

2.0 

11.9 

59.0 

1.2 

0.8 

0.2 

3.0 

0.3 

0.8 

1.5 

1.0 

Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 4--Continued 

and commonly convolute laminated; 

some beds may contain more than 

50 percent quartz silt and very 

fine sand. Mudstone, calcareous, 

gray to purplish gray; in beds 5 

to 60 em thick; mean bed thickness 

about 25 em •••••••••••••••••••••••••• 

16. Mudstone, calcareous, purplish gray, 

massive; contains scattered diffuse 

clasts of medium-gray limestone •••••• 

15. Limestone (fine-grained calcarenite 

or calcisiltite); one bed •••••••••••• 

14. Mudstone ••••••••••••••••••••••••••••• 

13. Limestone, medium gray; one bed 

(Bouma Tab); grades from limestone 

conglomerate at base to silty 

fine-grained calcarenite at top; 

contains limestone clasts to 5 em 

in diameter •••••••••••••••••••••••••• 

12. Limestone and calcareous mudstone; 

one massive bed, graded from 

well-sorted echinodermal calcarenite in lower 3 m to pinkishgray calcareous mudstone in upper 

11 m; mudstone contains large 

rounded limestone clasts with 

diffuse borders •••••••••••••••••••••• 

11. Mudstone••••••••••••••••••••••••••••• 

10. Limestone-pebble conglomerate, 

bioclastic; one ungraded bed 

(Bouma Ta); clasts loosely packed; 

fusulinids present at base ••••••••••• 

9. Muds tone ••••••••••••••••••••••••••••• 

8. Limestone-pebble conglomerate, 

bioclastic; one crudely graded bed 

(Bouma Ta); fusulinids abundant •••••• 

7. Mudstone, calcareous, purplish gray •• 

6. Limestone (fine-grained calcarenite 

or calcisiltite); one bed •••••••••••• 

5. Mudstone, calcareous, 

grayish orange, massive; 

contains indistinct limestone 

clasts ••••••••••••••••••••••••••••••• 

4. Limestone (fine-grained 

calcarenite or calcisiltite); 

one bed •••••••••••••••••••••••••••••• 

3. Hudstone, calcareous, purplish gray •• 

2. Limestone conglomerate, bioclastic, 

medium gray; one ungraded bed 

(Bouma Ta); contains micritic 

limestone clasts to 6 em in diameter 

and broken fasciculate rugose 

corals; clasts tightly packed and 

strongly imbricated •••••••••••••••••• 

1. Limestone (40 percent) and 

mudstone (60 percent), as in 17. 

Limestone, in beds 10 to 60 em 

thick. Mudstone, in beds 10 to 

70 em thick •••••••••••••••••••••••••• 

Thickness 

meters 

6.3 

3.0 

0.9 

0.1 

1.0 

14.0 

0.1 

o.s 

0.1 

4.0 

0.4 

0.1 

2.5 

0.4 

0.7 

0.6 

4.1 

24 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 
Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 4--Continued Thickness 

meters 

Incomplete thickness unit 4................ 47.6 

Incomplete thickness Millers Spring 

Member.. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 165.4 

Incomplete thickness Darwin Canyon 

Formation.. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 165.4 

Base of section covered. 

Section 2A. Unit 1 (incomplete); type section of units 2-4, 

Millers Spring Member. 

Top of section faulted. 

Darwin Canyon Formation (Lower Permian) 

(incomplete): 

Millers Spring Member (incomplete): 

Unit 4: 

16. Limestone, dark gray; one bed 

(Bouma Tab); grades from 

coarse-grained bioclastic 

calcarenite at base to 

laminated fine-grained 

calcarenite at top; contains 

fusulinids. Section faulted 

immediately above this bed, 

which is correlated with the 

uppermost bed in unit 4 of the 

Millers Spring Member in 

Thickness 

meters 

section 2B........................... 1.1 

15. Limestone (fine-grained calcarenite 

and calcisiltite) (50 percent) 

and mudstone (50 percent); in 

alternating beds. Limestone, 

medium gray, silty; in beds 15 

to 40 em thick, all with 

pervasive plane lamination and 

many with convolute lamination; 

bedding surfaces sharp. Mudstone, 

calcareous, yellowish brown; in 

beds 5 to 50 em thick................ 4.2 

14. Mudstone, calcareous, yellowish 

brown, light gray, and 

pinkish gray; indistinctly bedded.... 1.4 

13. Limestone (fine-grained 

calcarenite or calcisiltite); 

one bed; crosslaminated and 

convolute laminated.................. 0.4 

12. Mudstone, calcareous................. 1.0 

11. Limestone, medium gray; one bed 

(Bouma Tab); grades from 

coarse-grained echinodermal 

calcarenite at base to laminated 

calcisiltite at top.................. 1.0 

10. Limestone (fine-grained calcarenite 

and calcisiltite), silty, medium 

to dark gray; in beds 25 to 50 em 

thick; plane laminated and 

crosslaminated; poorly exposed; 

subordinate gray to brown calcareous 

mudstone occurs mainly as float...... 11.9 

Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 4--Continued 

9. Limestone, medium gray; one bed 

(Bouma Tab); grades from 

coarse-grained echinodermal 

calcarenite at base to laminated 

fine-grained calcarenite at 

top •••••••••••••••••••••••••••••••••• 

8. Mudstone, calcareous ••••••••••••••••• 

7. Limestone (calcarenite), 

echinodermal, fine grained; one 

ungraded bed (Bouma Ta) •••••••••••••• 

6. Limestone and calcareous mudstone; 

one massive bed, grades from 

well-sorted echinodermal calcarenite 

in lower 3 m to pinkish-gray 

calcareous mudstone in upper 11 m; 

mudstone contains scattered diffuse 

rounded clasts of medium-gray 

micritic limestone ••••••••••••••••••• 

5. Mudstone, calcareous, pink, 

massive; lenticular •••••••••••••••••• 

4. Limestone conglomerate, bioclastic; one crudely graded bed 

(Bouma Ta); contains micritic 

limestone clasts that decrease 

in maximum diameter from 5 em 

at base to less than 1 em at 

top, broken fasciculate rugose 

corals, and fusulinids; clasts 

loosely to tightly packed •••••••••••• 

Minor fault; small amount of section 

probably missing. 

3. Limestone (fine-grained calcarenite and calcisiltite) (70 

percent) and cover (30 percent). 

Limestone, silty; in beds 10 to 

40 em thick; plane and convolute 

lamination common •••••••••••••••••••• 

2. Mudstone, calcareous, pink, massive; 

contains scattered clasts of 

medium-gray micritic limestone; 

clast borders diffuse, blending 

with matrix; may grade up from 

underlying limestone ••••••••••••••••• 

1. Limestone, medium gray; one bed 

(Bouma Ta); grades from 

coarse-grained bioclastic 

calcarenite at base to mediumgrained echinodermal calcarenite 

at top; contains fusulinids. 

Fusulinid collection DC8: 

Schwagerina spp., 

Eoparafusulina cf. ~· 

linear is . ..••....•..........••....•. 

Total thickness unit 4 •••••••••••••••••••• 

Unit 3: 

14. Sandstone (65 percent) and 

mudstone (35 percent); in 

alternating beds. Sandstone, 

quartzose, variably calcareous 

and calcarenitic, gray to brown 

on weathered surface, very fine 

grained; in beds 15 em to 2.1 m 

Thickness 

meters 

1.0 

0.2 

0.1 

14.0 

10.0 

6.0 

1.4 

4.5 

2.7 

60.9 

Measured Sections 25 
Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 3--Continued 

thick; mean bed thickness about 

60 em; commonly plane laminated 

and crosslaminated, less commonly 

convolute laminated; bedding 

surfaces sharp. Mudstone, 

light gray, in beds 10 to 90 em 

thick; mean bed thickness 

about 35 em •••••••••••••••••••••••••• 

13. Mudstone and siltstone, calcareous, 

light gray, thin bedded •••••••••••••• 

12. Sandstone (55 percent) and 

mudstone (45 percent), as in 14. 

Sandstone, strongly calcarenitic; 

in beds 20 to 55 em thick; 

contains well-developed convolute 

lamination. Mudstone in beds 40 

to 45 em thick ••••••••••••••••••••••• 

11. Covered interval ••••••••••••••••••••• 

10. Sandstone (65 percent) and mudstone 

(35 percent), as in 14. Sandstone in beds 10 em to 2.5 m 

thick; mean bed thickness about 

70 em. Mudstone in beds 5 em 

to 1 m thick; mean bed thickness 

about 35 em •••••••••••••••••••••••••• 

9. Limestone, medium gray; one bed 

(Bouma Tab), grades from 

coarse-grained bioclastic 

calcarenite at base to laminated 

fine-grained calcarenite at top; 

contains fusulinids •••••••••••••••••• 

8. Sandstone (45 percent) and 

mudstone (55 percent), as in 14. 

Sandstone in beds 5 to 85 em 

thick; mean bed thickness about 

20 em. Mudstone in beds 2 to 40 

em thick; mean bed thickness 

about 25 em•••••••••••••••••••••••••• 

7. Limestone, medium gray; one bed 

(Bouma Tabe); grades from 

coarse-grained bioclastic 

calcarenite at base to micrite 

at top ••••••••••••••••••••••••••••••• 

6. Mudstone, calcareous, light gray ••••• 

5. Covered interval ••••••••••••••••••••• 

4. Sandstone, quartzose, brown, very 

fine grained (lower 50 em); grades 

upward into light-gray calcareous 

siltstone and mudstone 

(upper 1. 6 m) •••••••••••••••••••••••• 

3. Limestone, medium gray; one bed 

(Bouma Tab); grades from 

coarse-grained bioclastic 

calcarenite at base to laminated 

calcisiltite at top •••••••••••••••••• 

2. Mudstone, calcareous, light gray; 

contains scattered unsorted 

dark-gray limestone clasts to 

30 em in diameter; largest clasts 

are in upper part of bed •••••••••••• 

1. Sandstone (40 percent) and 

mudstone (60 percent), as in 14. 

Thickness 

meters 

7.4 

2.5 

2.9 

2.0 

14.6 

0.3 

10.4 

0.7 

0.5 

2.5 

2.1 

0.8 

3.0 

Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 3--Continued 

Sandstone in beds 10 to 70 em 

thick; mean bed thickness about 

30 em. Mudstone in beds 5 em 

Thickness 

meters 

to 1.4 m thick, poorly exposed....... 6.0 

Total thickness unit 3..................... 55.7 

Unit 2: 

9. Mudstone, calcareous, conglomeratic, light gray, grayish 

orange, and grayish pink; 

one massive bed; contains 

abundant matrix-supported 

clasts that include micritic 

limestone clasts to 50 em in 

diameter, broken fasciculate 

rugose corals, fusulinids, 

echinodermal debris, and other 

bioclasts; limestone clasts have 

sharp borders........................ 17.0 

8. Sandstone, very fine grained, 

and calcareous siltstone; 

thin bedded and laminated; 

poorly exposed....................... 3.0 

7. Mudstone, calcareous, light gray 

to grayish pink, massive; contains 

large rounded micritic limestone 

clasts with diffuse borders; may 

grade up from underlying limestone... 12.0 

6. Limestone (calcarenite), bioclastic, 

medium gray; one graded bed 

(Bouma Ta); contains fusulinids. 

Fusulinid collection DC3: 

Schwagerina spp., 

Pseudoschwagerina sp................. 3.5 

5. Mudstone, calcareous, 

light gray; one massive bed; 

contains medium-gray micritic 

limestone clasts with diffuse 

borders in basal 1.0 m; lenticular... 7.0 

4. Limestone; one bed (Bouma 

Tab); grades from medium-gray 

limestone-granule conglomerate 

at base to laminated light-gray 

calcisiltite at top.................. 1.2 

3. Limestone-pebble conglomerate, 

medium gray; one graded bed (Bouma 

Ta); clasts strongly imbricated...... 0.8 

2. Limestone, medium gray; one bed 

(Bouma Ta); grades from bioclastic 

limestone conglomerate at base to 

echinodermal calcarenite at top; 

contains micritic limestone clasts 

to 4 em in diameter and broken 

fasciculate rugose corals............ 1.2 

1. Mudstone, calcareous, 

yellowish brown; one massive bed; 

contains large fragments of 

medium-gray bioclastic limestone 

and limestone conglomerate........... 5.0 

Total thickness unit 2..................... 50.7 

26 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 
Section 2: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 1 (incomplete): 

3. Sandstone (55 percent) and 

mudstone (45 percent); in 

alternating beds. Sandstone, 

quartzose, variably calcareous 

and calcarenitic, brown to 

reddish brown on weathered 

surface; in beds 10 em to 

1.5 m thick, generally plane 

laminated and and crosslaminated, 

less commonly convolute laminated. 

Mudstone, gray to purplish gray; 

Thickness 

meters 

in beds 10 to 60 em thick............ 5.8 

2. Limestone, medium gray; one bed 

(Bouma Tab); grades from 

coarse-grained bioclastic calcarenite at base to laminated calcisiltite at top; contains fusulinids.. 0.9 

1. Sandstone (60 percent) and 

mudstone (10 percent), as in 3; 

covered intervals (30 percent) 

probably represent unexposed 

mudstone intervals. Sandstone 

in beds 40 em to 1.4 m thick. 

Hudstone in beds 10 to 

30 em thick.......................... 5.8 

Incomplete thickness unit 1................ 12.5 

Incomplete thickness Millers Spring 

Hember................................... 179.8 

Incomplete thickness Darwin Canyon 

Formation.. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 179.8 

Base of section covered. 

Section 3. Unit 6B (incomplete) and units 6C-7, Millers Spring 

Member, and Panamint Springs Member (incomplete) of the 

Darwin Canyon Formation. Measured in the hills south of 

Darwin Canyon in June 1981. 

Section ends at axis of syncline. 

Darwin Canyon Formation (Lower Permian) 

(incomplete): 

Panamint Springs Member (incomplete): 

13. Limestone, medium gray, and 

light-brown siltstone •••••••••••••••• 

12. Siltstone and very fine grained 

sandstone, light brown; in thin 

graded beds that commonly have 

parallel and convolute lamination •••• 

11. Limestone, medium gray, and 

light-brown siltstone; subordinate 

pink shale••••••••••••••••••••••••••• 

10. Siltstone and very fine grained 

sandstone, as in 12 •••••••••••••••••• 

9. Limestone, light gray, and 

light-brown siltstone. Limestone 

in graded beds as thick as 30 em; 

contains fusulinids, coarse 

Thickness 

meters 

9.1 

35.1 

13.7 

93.0 

Section 3: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Panamint Springs Member--Continued 

Thickness 

meters 

echinodermal debris, and chert 

clasts to 3 mm in diameter. 

Fusulinid collection I1300 from 25 m 

above base of interval: Schwagerina cf. 

~· crebrisepta, Schwagerina 

diversiformis, Pseudoschwagerina 

convexa, Chalaroschwagerina sp... 29.0 

8. Shale, moderate pink................. 3.0 

7. Siltstone and very fine grained 

sandstone, as in 12; a few thick 

graded calcareous beds contain 

fusulinids, echinodermal debris, 

chert clasts, and occasional 

limestone clasts to 6 mm in 

diameter ••••••••••••••••••••••••••••• 143.3 

6. Siltstone, calcareous, 

moderate orange to grayish orange 

pink; contains nodules of mediumgray limestone 15 to 25 em long...... 9.1 

5. Limestone, medium light gray, 

fine grained; contains about 40 

percent dark-gray elongate to 

spherical limestone nodules.......... 21.3 

4. Siltstone, medium light gray and 

grayish orange....................... 3.0 

3. Limestone, medium gray, massive; 

contains dark-brown siliceous layers 

and nodules•••••••••••••••••••••••••• 29.0 

2. Sandstone, quartzose, calcareous, 

medium light gray to grayish orange, 

very fine grained; in beds 50 em to 

1m thick•••••••••••••••••••••••••••• 16.8 

Incomplete thickness Panamint Springs 

Hember not including basal limestone 

unit. 

Basal limestone unit: 

1. Limestone, medium dark gray; pink 

shale; and grayish-orange to 

moderate-yellowish-brown silty 

limestone; in beds 30 em to 1 m 

thick; felsic dike 1 m thick 

present 6 m below top of interval •••• 

405.4 

86.9 

Total thickness basal limestone unit....... 86.9 

Incomplete thickness Panamint 

Springs Member••••••••••••••••••••••••••• 492.3 

Millers Spring Member (incomplete): 

Unit 7: 

Sandstone, quartzose, calcareous, 

medium gray to moderate brown, 

very fine grained; in beds 15 to 

60 em thick•••••••••••••••••••••••••• 44.2 

Total thickness unit 7..................... 44.2 

Unit 6E: 

2. Mudstone, mottled grayish pink to 

moderate pink and medium light gray; 

contains limestone clasts and 

fusulinids. Fusulinid collection 

Ia-305 from 1 m above base of 

MeasuredSections 27 
Section 3: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 6 E --Continued 

interval: Schwagerina aculeata, 

Schwagerina aff. ~· thompsoni, 

Schwagerina sp, Chusenella sp ••••••• 

1. Limestone, light to medium gray; 

in beds 60 em to 1.5 m thick; some 

beds contain fusulinids and some 

contain clasts of fine- to 

medium-grained limestone to 15 em 

in diameter. Fusulinid collection 

Ia-295 from 2 m below top of 

interval: Schwagerina elkoensis, 

Chalaroschwagerina sp., 

Pseudoschwagerina uddeni ••••••••••••• 

Total thickness unit 6E •••••••••••••••••••• 

Unit 6D: 

Sandstone, as in unit 7 •••••••••••••• 

Total thickness unit 6D •••••••••••••••••••• 

Unit 6C: 

Limestone, light to medium gray; in 

graded beds 60 em to 1.5 m thick; 

some beds contain clasts of fine- to 

medium-grained limestone to 15 em in 

diameter ••••••••••••••••••••••••••••• 

Thickness 

meters 

21.4 

18.3 

39.7 

29.0 

29.0 

9.2 

Total thickness unit 6C.................... 9.2 

Unit 6B (incomplete): 

Sandstone, as in unit 7.............. 35.1 

Incomplete thickness unit 6B............... 35.1 

Incomplete thickness Millers Spring 

Member ••••••••••••••••••••••••••••••••••• 157.2 

Incomplete thickness Darwin Canyon 

Formation................................ 649.5 

Base of section covered. 

Section 4. Unit 4 (incomplete), units 5-6, and unit 7 

(incomplete), Millers Spring Member of the Darwin Canyon 

Formation. Measured in the hills south of Darwin Canyon in 

June 1981. 

Top of section faulted. 

Darwin Canyon Formation (Lower Permian) 

(incomplete): 

Millers Spring Member (incomplete): 

Unit 7 (incomplete): 

Sandstone, quartzose, calcareous, 

medium light gray to grayish orange, 

very fine grained, thick bedded; 

convolute lamination common •••••••••• 

Incomplete thickness unit 7 •••••••••••••••• 

Unit 6E: 

2. Mudstone, moderate pink, massive; 

contains medium-light-gray limestone 

clasts to 5 em in diameter, coral 

fragments, and fusulinids. Fusulinid 

collection I975 from 4 m above base 

Thickness 

meters 

36.6 

36.6 

Section 4: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 6E--Continued 

of interval: Schwagerina cf. ~· 

eolata, Pseudoschwagerina 

convexa •••.••.••••••••••••••..•.•.. 

1. Limestone, medium light gray; in 

graded beds averaging about 3 m thick; 

contains medium-light-gray limestone 

clasts to 5 em in diameter and 

Thickness 

meters 

15.3 

coral fragments...................... 15.3 

Total thickness unit 6E.................... 30.6 

Unit 6D: 

Sandstone, quartzose, calcareous, 

very fine grained; and dusky-brown, 

medium-light-gray, and grayish-orange 

silty limestone; in beds as much as 

1.5 m thick; convolute 

lamination common ••••••••••••••••••••• 44.2 

Total thickness unit 6D ••••••••••••••••••••• 44.2 

Unit 6C: 

2. Limestone, medium gray; in thick 

graded beds; contains rounded 

medium-gray limestone clasts to 

8 em in diameter; one bed contains 

imbricated clasts and coral 

fragments •••••••••••••••••••••••••••• 

1. Limestone, medium light gray; one 

graded bed; contains fusulinids and 

coarse echinodermal debris at base ••• 

Total thickness unit 6C •••••••••••••••••••• 

Unit 6B: 

3. Limestone, silty, grayish orange, 

dusky brown, and light gray; 

convolute lamination common •••••••••• 

2. Sandstone, quartzose, calcareous, 

very fine grained; in beds 1 to 

10.7 

4.8 

15.5 

9.2 

1.5 m thick; forms ridge............. 16.8 

1. Sandstone, quartzose, calcareous, 

very fine grained; and grayish-orange, 

dusky-brown, and light-gray silty 

limestone; in beds 30 em to 1.5 m 

thick; convolute lamination common; 

outcrops resistant with 

blocky fracture...................... 16.8 

Total thickness unit 6B.................... 42.8 

Unit 6A: 

Limestone, medium gray; one bed; 

grades upward into laminated, 

medium-light-gray silty limestone; 

contains rounded limestone clasts to 

1 em in diameter and abundant 

fusulinids and echinodermal debris. 

Fusulinid collection 1500 from base 

of interval: Schwagerina cf. S. 

crebrisepta, Schwagerina 

elkoensis, Schwagerina cf. 

~ wellsensis, Stewartina sp. 

Total thickness unit 6A •••••••••••••••••••• 

13.7 

13.7 

28 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 
Section 4: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Thickness 

meters 

Total thickness units 6A-6E •••••••••••••••• 146.8 

Unit 5: 

3. Sandstone, quartzose, calcareous, 

grayish orange, dusky brown, and 

light gray, very fine grained; and 

medium-dark-gray, fine-grained 

limestone; in graded beds 1 to 

1.5 m thick; some beds contain 

fusulinids. Fusulinid collection 

I410 from 14 m above base of 

interval: Schwagerina aculeata, 

Schwagerina diversiformis, 

Pseudoschwagerina uddeni, 

Pseudoschwagerina sp., 

Parafusulina sp. ••••••••••••••••••• 41.2 

2. Sandstone, quartzose, grayish red 

to dusky red, very fine grained, 

massive; forms resistant outcrops 

with blocky fracture................. 12.2 

1. Sandstone, quartzose, calcareous, 

very fine grained; and grayish-orange, 

dusky-brown, and light-gray silty 

limestone; in beds 30 to 60 em thick; 

parallel and convolute lamination 

common... • • • • • • • • • • • • • • • • • • • • • • • • • • • • 30.5 

Total thickness unit 5..................... 83.9 

Unit 4 (incomplete): 

3. Limestone, medium to dark gray, 

in graded beds as much as 60 em 

thick; consists mainly of 

fine-grained echinodermal debris; 

fusulinids present in some beds; 

parallel and convolute lamination 

present in some beds................. 30.5 

2. Limestone, silty, grayish pink and 

medium light gray; grayish-pink 

beds have convolute lamination and 

contain spherical nodules of mediumlight-gray, fine-grained limestone 

to 15 em in diameter; medium-lightgray beds are graded, average about 

30 em thick, and have convolute 

lamination••••••••••••••••••••••••••• 29.0 

1. Limestone, medium light gray; 

in graded beds 45 em to 1 m thick; 

contains rounded limestone clasts 

to 5 em in diameter, echinodermal 

debris, fusulinids, and corals •••••.•••• 9.2 

Incomplete thickness unit 4 ••••••••••••••••• 68.7 

Incomplete thickness Millers Spring 

Member • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 336 • 0 

Incomplete thickness Darwin Canyon 

Formation •••••••••••••••••••••••••••••••• 336.0 

Base of section faulted. 

Section 5. Unit 1 (incomplete), units 2-6, and unit 7 

(incomplete), Millers Spring Member of the Darwin Canyon 

Formation. Measured in the hills south of Darwin Canyon in 

June 1981. 

Top of section covered. 

Darwin Canyon Formation (Lower Permian) 

(incomplete): 

Millers Spring Member (incomplete): 

Unit 7 (incomplete): 

Sandstone, quartzose, calcareous, 

light gray, grayish orange, and 

grayish brown on weathered surface, 

very fine grained; thick bedded, 

laminated; convolute lamination 

con:unon • •••••••••••••••••••••••••••••• 

Thickness 

meters 

40.0 

Incomplete thickness unit 7.................. 40.0 

Unit 6E: 

2. Mudstone, calcareous, moderate 

pink; contains fusulinids, coral 

fragments, and rounded mediumgray limestone clasts to 2 em 

in diameter. Fusulinid 

collection 1I1605 from 1 m 

below top of interval: 

Schwagerina SPP•••••••••••••••••••••• 7.6 

1. Limestone, medium gray; in thick, 

graded beds; contains rounded 

medium-gray limestone clasts to 

5 em in diameter and abundant coral 

fragments; tops of beds fine 

grained and plane laminated.......... 12.2 

Total thickness unit 6E •••••••••••••••••••• 19.8 

Unit 6D: 

Sandstone, as in unit 7 ••••••••••••••• 27.4 

Total thickness unit 6D..................... 27.4 

Unit 6C: 

Limestone, medium gray; in graded 

beds 1 to 3 m thick; contains 

fusulinids, coral fragments, 

and gray limestone clasts to 

5 em in diameter; clasts 

strongly imbricated in some beds..... 19.8 

Total thickness unit 6C.................... 19.8 

Unit 6B: 

Sandstone, as in unit 7.............. 47.3 

Total thickness unit 6B.................... 47.3 

Unit 6A: 

Limestone, medium gray; in thick 

graded beds; contains rounded, 

medium-gray limestone clasts to 

1 em in diameter, fusulinids, 

coral fragments, and coarse 

echinodermal debris. Fusulinid 

collection 1I1220 from 4 m below 

top of interval: Schwagerina 

aculeata, Schwagerina sp............. 19.8 

Total thickness unit 6A.................... 19.8 

Total thickness units 6A-6E •••••••••••••••• 134.1 

Measured Sections 29 
Section 5: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Thickness 

meters 

Unit 5: 

5. Siltstone, grayish brown to 

brownish black; contains nodules 

and lenses of fine-grained gray 

limestone 8 to 30 em long; 

subordinate medium-gray limestone 

in graded beds containing 

fusulinids (2 beds present). 

Fusulinid collection II1150 

from base of interval: 

Schwagerina cf. ~· 

crebrisepta, Schwagerina 

elkoensis •••••••••••••••••••••••••••• 

4. Sandstone, quartzose, brownish gray, 

brownish black, and pale reddish 

brown on weathered surface, very 

fine grained; in beds as much as 

1.5 m thick; forms ridges; 

crosscutting dike present 15 m 

below top of interval •••••••••••••••• 

3. Covered interval ••••••••••••••••••••• 

2. Limestone, medium gray, fine grained, 

thin to medium bedded; plane and 

convolute laminated; some graded beds 

contain coarse echinodermal debris 

and fusulinids ••••••••••••••••••••••• 

1. Sandstone, as in 4 ••••••••••••••••••• 

Total thickness unit 5 ••••••••••••••••••••• 

Unit 4: 

Limestone, medium gray, fine grained, 

thin to medium bedded; beds commonly 

graded. One 2-m-thick graded bed 

46 m above base of interval contains 

medium-gray limestone clasts to 1 em 

in diameter, fusulinids, and coral 

fragments. Fusulinid collection 

6.1 

45.7 

10.7 

4.6 

6.1 

73.2 

II850 from this bed: Schwagerina aculeata, 

Chusenella compacta, 

Pseudofusulina? aff. 

..!:· loringi, Cuniculinella spp. 

Total thickness unit 4 ••••••••••••••••••••• 

Unit 3: 

2. Sandstone, quartzose, calcareous, 

very fine grained, and 

yellowish-brown- to grayish-orangeweathering silty limestone; in 

laminated beds as much as 1 m 

thick; convolute lamination common ••• 

1. Limestone, silty limestone, and 

quartzose sandstone. Limestone, 

medium gray, medium grained; in 

70.1 

70.1 

67.1 

Section 5: Lower Permian--Continued 

Darwin Canyon Formation--Continued 

Millers Spring Member--Continued 

Unit 3--Continued 

graded beds 25 em to 1 m thick. 

Sandstone and silty limestone, 

yellowish brown to grayish orange 

on weathered surface; in laminated 

beds to 1 m thick; convolute 

lamination common •••••••••••••••••••• 

Total thickness unit 3 ••••••••••••••••••••• 

Unit 2: 

3. Mudstone, calcareous, moderate pink; 

one massive bed; contains rounded to 

subangular, light- to medium-gray 

limestone clasts to 75 em in 

diameter and fusulinids, corals, 

and echinodermal debris •••••••••••••• 

2. Limestone, shaly, moderate pink •••••• 

1. Limestone, medium gray; in thick 

graded beds; contains rounded, 

medium-gray limestone clasts, 

fusulinids, and coral fragments; 

clasts imbricated. Fusulinid 

collection II155 from 12 m above 

base of interval: Schwagerina 

elkoensis?, Chusenella 

compacta, Paraschwagerina sp., 

Pseudoschwagerina uddeni, 

Pseudoschwagerina sp., 

Stewartina? spp.; 

fusulinid collection II175 from 

18 m above base of interval: 

Schwagerina cf. S. eolata, 

Schwagerina aff .-i.-t'iiOiiiPsoni, 

Chusenella compacta, 

Stewartina moranensis, 

Thickness 

meters 

21.3 

88.4 

25.0 

4.6 

Stewartina sp. • • • • • • • • • • • • • • • • • • • • • • 32 .o 

Total thickness unit 2..................... 61.6 

Unit 1 (incomplete): 

Sandstone, quartzose, calcareous, 

very fine grained, and paleyellowish-orange-weathering silty 

limestone; in laminated beds as 

much as 75 em thick; convolute 

lamination common.................... 35.1 

Incomplete thickness unit 1................ 35.1 

Incomplete thickness Millers Spring 

Member.. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 502.5 

Incomplete thickness Darwin Canyon 

Formation •••••••••••••••••••••••••••••••• 502.5 

Base of section covered. 

30 Pennsylvanian and Permian Stratigraphy, Northern Argus Range and Darwin Canyon Area, California 

GPO 785-048/48043