I 

I 

Stratigraphy of the 

Owens Valley Group (Permian), 

Southern lnyo Mountains, California 

U.S. GEOLOGICAL SURVEY BULLETIN 1692 

Stratigraphy of the 

Owens Valley Group (Permian), 

Southern lnyo Mountains, California 

By PAUL STONE and CALVIN H. STEVENS 

U.S. GEOLOGICAL SURVEY BULLETIN 1692 
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. 

Stratigraphy of the Owens Valley Group (Permian), 

southern lnyo Mountains, California. 

(U.S. Geological Survey Bulletin 1692) 

Bibliography 

Supt. of Docs. No.: I 19.3:1692 

1. Owens Valley Group (Calif.). 2. Geology-Californialnyo Mountains. I. Stevens, Calvin H. II. Title. Ill. Series: 

U.S. Geological Survey Bulletin 1692. 

QE75.B9 No. 1692 557.3 s 86-600363 

[QE67 4] [551.7'56'0979487] 
CONTENTS 

Abstract 1 

Introduction 1 

Lone Pine Formation 2 

Conglomerate Mesa Formation 1 

Regional extent of the Lone Pine and Conglomerate Mesa Formations 10 

Depositional history 10 

References cited 11 

Measured sections 12 

FIGURES 

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

2. Chart showing comparison of stratigraphic nomenclature used in this report 

with that of Merriam and Hall (1957) 3 

3. Geologic map of area northwest of Cerro Gordo mine, Inyo Mountains, 

California 4 

4. Measured stratigraphic sections 1-6 6 

5. Geologic map of area between Reward mine and Union Wash, Inyo Mountains, 

California 8 

Ill 

Stratigraphy of the Owens Valley Group (Permian), 

Southern lnyo Mountains, California 

By Paul Stone and Calvin H. Stevens 

Abstract 

The name Owens Valley Formation has been 

applied to Permian rocks in the southern Inyo 

Mountains and neighboring ranges since the formation 

was defined in 1957. Recent work has shown that at 

its type locality, the Owens Valley Formation consists 

of a Lower Permian lower part and an Upper Permian 

upper part that are separated by an angular 

unconformity. We herein raise the Owens Valley to 

group rank and introduce the new names Lone Pine 

Formation and Conglomerate Mesa Formation for the 

rocks below and above the unconformity, respectively, 

to make up the group. The Lone Pine Formation is 

composed of fine-grained sedimentary rocks of deepwater marine origin, mainly calcareous and siliceous 

mudstone, but locally within its upper part it contains 

conglomerate and quartzite of shallow-water marine 

or nonmarine origin (the herein-reassigned Reward 

Conglomerate Member). The Conglomerate Mesa 

Formation is composed of sandy limestone, 

conglomerate, and sandstone of shallow-water marine 

and nonmarine origin. The rmconformity between the 

Lone Pine and Conglomerate Mesa Formations 

represents an episode of uplift and tilting during which 

at least 500 m of the Lone Pine Formation was locally 

removed by subaerial erosion. 

INTRODUCTION 

Merriam and Hall (1957) applied the name Owens 

Valley Formation to a thick sequence of Permian 

sedimentary rocks exposed in the southern Inyo 

Mountains of east-central California, designating a 

type locality between the Reward mine and Union 

Wash on the west flank of the range (fig. 1). Recent 

work has shown that the Owens Valley Formation, at 

its type locality and elsewhere in the southern Inyo 

Mountains, consists of a Lower Permian lower part and 

an Upper Permian upper part that are separated by an 

angular unconformity (Conley, 1978; Stone and others, 

1979, 1980; Stone, 1984; Stone and Stevens, 1984). In 

this report, we raise the Owens Valley Formation in 

the southern Inyo Mountains to group rank and 

introduce the new names Lone Pine Formation and 

Conglomerate Mesa Formation for the rocks below and 

above the unconformity, respectively, to make up the 

group (fig. 2). In an earlier paper (Stone and Stevens, 

1984), we used the informal name Formation A for the 

rocks we herein name the Lone Pine Formation and the 

informal name Formation D for the rocks we herein 

name the Conglomerate Mesa Formation. 

In their original description, Merriam and Hall 

(1957) informally divided the Owens Valley Formation 

into a lower, a middle, and an upper part. Their lower 

part consists of not only the rocks that comprise our 

Lone Pine Formation but also coeval rocks in the 

Conglomerate Mesa area, the Darwin Hills, and the 

northern Argus Range that are lithologically distinct 

from the Lone Pine Formation (fig. 1). We specifically 

exclude those rocks from the Lone Pine Formation, 

although we consider them to be part of the Owens 

Valley Group. The upper part of Merriam and Hall's 

(1957) Owens Valley Formation is largely equivalent to 

our Conglomerate Mesa Formation. No rocks 

equivalent in age or lithology to the middle part of 

Merriam and Hall's (1957) Owens Valley Formation are 

present in either the Lone Pine Formation or the 

Conglomerate Mesa Formation; that stratigraphic 

interval is represented by the unconformity between 

the Lone Pine and Conglomerate Mesa Formations. 

Regional stratigraphic studies (Stone, 1984; Stone and 

Stevens, 1984) have shown that the middle part of 

Merriam and Hall's (1957) Owens Valley Formation is 

largely confined in outcrop distribution to the 

Conglomerate Mesa area where it was first described. 

The type sections of the Lone Pine and 

Conglomerate Mesa Formations are on a hill Merriam 

and Hall (1957) informally called Permian Bluff (SE 1/4 

New York Butte 15-minute quadrangle), high on the 

west slope of the Inyo Mountains about 5 km northwest 

of the Cerro Gordo mine and about 20 km southeast of 

the Reward mine-Union Wash area (fig. 1). The 

locations of the type sections and five nearby 

reference sections (primarily in the lenticular, 

lithologically variable Conglomerate Mesa Formation) 

are shown on the geologic map of the area around 

Permian Bluff (fig. 3). These sections (fig. 4) show the 

lithologic features of the Lone Pine and Conglomerate 

Mesa Formations better than do sections between the 

Reward mine and Union Wash, where both formations 

are extensively altered and metamorphosed. Detailed 

descriptions of these sections follow the main text. 

We here designate the type locality of Merriam and 

Hall's (1957) Owens Valley Formation (herein revised 

as the Owens Valley Group) as a reference locality for 

both the Lone Pine and Conglomerate Mesa 

Formations (fig. 5). 

Introduction 1 
LONE PINE FORMATION 

The Lone Pine Formation, which is here named 

after the town of Lone Pine in Owens Valley, Inyo 

County (fig. 1), conformably overlies the Keeler 

\ 

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Canyon Formation (Merriam and Hall, 1957) of 

Pennsylvanian and Early Permian age and is 

unconformably overlain by the Conglomerate Mesa 

Formation. Where the Conglomerate Mesa Formation 

is not present, the Lone Pine Formation is 

I 

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~.Spring 

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EXPLANATION 

Paved road 

---- Unpavedroad 

AREA OF MAP 

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Panamint t:. Butte 

10 20 KILOMETERS 

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Figure 1. Region between Owens and Death Valleys, California, showing type locality of the Owens Valley 

Group (area of fig. 5), type localities of the Lone Pine and Conglomerate Mesa Formations (area of fig. 3), and 

other localities mentioned in text. 

2 Stratigraphy of the Owens Valley Group, Southern Inyo Mountains, California 
unconformably overlain by unnamed Lower and 

Middle(?) Triassic strata that have been described by 

Kirk (1918) and Merriam (1963). 

The Lone Pine Formation is here divided into 

four members (fig. 2). In ascending order, the lower 

three of these are informally designated members A, 

B, and C; the uppermost member is the Reward 

Conglomerate Member, which Kirk (1918) originally 

named the Reward Conglomerate and which Merriam 

and Hall (1957) and Ross (1965) later revised to be a 

member of the Owens Valley Formation. We here 

reassign the Reward to the Lone Pine Formation. All 

four members of the Lone Pine Formation are present 

in the area between the Reward mine and Union Wash 

(fig. 5). Only members A and B, however, are present 

at the type locality of the formation (fig. 3), probably 

owing to erosion of member C and the Reward 

Conglomerate Member beneath the unconformity at 

the base of the overlying Conglomerate Mesa 

Formation (fig. 2). 

At its type locality (fig. 3), the Lone Pine 

Formation is a slope-forming unit composed mainly of 

thin-bedded to laminated calcareous mudstone and 

other fine-grained rocks. The formation contrasts 

MERRIAM AND HALL 

AGE ( 1957) 

sharply with the underlying Keeler Canyon Formation, 

which is composed primarily of thick-bedded, mediumto coarse-grained limestone. The type section of the 

Lone Pine Formation at Permian Bluff (section 1, figs. 

3 and 4) has a measured thickness of 309 m; member A 

is 237 m thick and member B is 72 m thick. 

Member A of the Lone Pine Formation at the 

type locality consists predominantly of medium- to 

dark-gray, thin-bedded to laminated calcareous and 

dolomitic mudstone. The mudstone is composed of 

microcrystalline calcite and dolomite with less than 10 

percent quartz silt, is rich in organic matter, and 

contains abundant authigenic pyrite. It is interbedded 

with subordinate medium- to dark-gray, thin-bedded 

siltstone and very fine to fine-grained sandstone that 

commonly shows delicate plane lamination and 

crosslamination. Also present are scattered, relatively 

thick beds (20 to 80 em) of medium- to dark-gray 

micritic limestone and dolomite, some of which 

contain abundant calcified sponge spicules and 

radiolarians. 

Member B consists predominantly of greenishgray, pale-red, yellowish-brown, and pale-brown 

mudstone, siltstone, and very fine to fine-grained 

THIS REPORT 

AREA NW OF CERRO GORDO MINE REWARD MINE-UNION WASH AREA 

u "0 ~- - c: .......... (/) Unnamed Unnamed Unnamed 0 Q) 

(/) 

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Q) 

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r-' ~ ......... ("""'--- n IlJJJI[ Middle part 

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<( >. >. c: Member B >. 0 Member B Q) Q) 0 Q) E - - - ·- - '- ::2: - - - - 0 

0:: 0 0 0 0 LL 

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0 0 c: 0 Q) Member A a.. Member A c: 

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Keeler Canyon Keeler Canyon Keeler Canyon 

Formation (part) Formation (part) Formation (part) 

Figure 2. Comparison of stratigraphic nomenclature used in this report with that used by Merriam and Hall 

(1957). 

Lone Pine Formation 3 
36° 

35' 

36° 

32' 

30" 

2 KILOMETERS 

Figure 3. Geologic map of area northwest of Cerro Gordo mine in the Inyo Mountains, California, showing 

locations of type and reference sections of the Lone Pine and Conglomerate Mesa Formations. See figure 1 for 

location of map. Base from U.S. Geological Survey, 1:62,500, New York Butte quadrangle, 1950 (contour 

interval 80 feet). Geology mapped in 1974, 1975, and 1982. 

4 Stratigraphy of the Owens Valley Group, Southern Inyo Mountains, California 
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EXPLANATION 

Alluvium (Quaternary) 

Aplite dikes (Cretaceous or Jurassic) 

Mafic to intermediate dikes (Jurassic)--

Correlated with Independence dike swarm. Arrow indicates dip 

Quartz monzonite (Jurassic?) 

Volcanic and volcaniclastic rocks (Jurassic or Triassic) 

Marine sedimentary rocks (Middle? and Lower 

Triassic)--Yellow shale and gray to bluishgray limestone; minor siltstone and 

sandstone; sandy limestone at base 

Owens Valley Group (Upper and Lower Permian)--

In this area, consists of: 

Conglomerate Mesa Formation (Upper Permian)--

Light-gray sandy limestone, conglomerate, 

and gray to yellowish-brown sandstone 

Lone Pine Formation (Lower Permian)--Lower 

part (member A) composed of medium- to 

dark-gray, thin-bedded calcareous and 

dolomitic mudstone, calcareous siltstone to 

very fine grained sandstone, and micritic 

dolomite. Upper part (member B) composed 

of light-colored mudstone, siltstone, very 

fine grained sandstone, and locally 

abundant medium- to dark-gray bioclastic 

1 imestone 

Keeler Canyon Formation (Lower Permian and 

Pennsylvanian)--Limestone and minor 

mudstone 

Rest Spring Shale (Upper Mississippian)--Dark- brown shale 

Perdido Formation (Mississippian)--Light-brown siltstone 

Tin Mountain Limestone (Lower Mississippian)--

Dark-gray limestone 

Lost Burro Formation (Oevonian)--Liqht- to 

medium-gray limestone and dolomite 

Contact--Dashed where approximately located 

_Jl_ __ .. Fault--Showing dip. Dashed where approximately 

located; dotted where concealed 

~ Anticline 

~ Syncline 

55 

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ol7 

Strike and dip of beds 

Inclined 

Vertical 

Overturned 

Line of measured section 

Fossil locality 

Figure 3. Continued. 

sandstone that are distinguished from the strata of 

member A primarily by their lighter color. In addition, 

mudstone of member B differs from that of member A 

in being less calcareous and richer in clay minerals. 

Scattered in member B are relatively thick beds of 

olive-gray to greenish-gray micritic limestone and 

dolomite that are like the relatively thick limestone 

and dolomite beds in member A except in color. The 

contact between members A and B is gradational over 

a stratigraphic interval ranging between 10 and 20 m 

in thickness. 

A short distance northwest of the Lone Pine type 

section (area of section 4, figs. 3 and 4), member B 

contains abundant medium- to dark-gray, thin- to 

thick-bedded bioclastic limestone and limestone 

conglomerate in addition to light-colored, fine-grained 

siliceous rocks. The limestone beds, which range in 

thickness from about 5 em to 4.5 m, contain abundant 

fusulinids, echinodermal debris, brachiopod shell 

fragments, coral fragments, and angular to subrounded 

limestone clasts as much as 20 em in diameter. Many 

of the limestone beds are graded and some show 

convolute lamination and other evidence of softsediment deformation. 

The Lone Pine Formation thickens appreciably 

northwest of its type locality, reaching a thickness of 

about 1,000 m in the northwestern part of the area 

shown in figure 3. Southeast of the type locality, the 

formation thins and wedges out over a distance of 

about 3 km (fig. 3), probably as the combined result of 

depositional thinning and the erosion that was 

responsible for the unconformity at the top of the 

formation (Stone, 1984). 

Three fusulinid collections from Bioclastic 

limestone beds in member B of the Lone Pine 

Formation at its type locality (fossil locs. 17, 20, and 

22, fig. 3) yielded the following taxa: 

Schwagerina spp. 

Pseudoschwagerina cf. P. convexa 

(Thompson) -

Cuniculinella aff. C. calx 

(Thompson and Wheeler) 

Cuniculinella? spp. 

This fusulinid assemblage suggests a late Wolfcampian 

age (Stone, 1984). Beds near the top of the underlying 

Keeler Canyon Formation contain abundant early 

middle Wolfcampian fusulinids, establishing the base of 

the Lone Pine Formation as no older than middle 

Wolfcampian in age (Merriam and Hall, 1957; Riggs, 

1962; Merriam, 1963; Stone, 1984). 

In the area between the Reward mine and Union 

Wash, the Lone Pine Formation, cut by numerous 

intrusive bodies and extensively altered and silicified, 

is about 1,000 m thick. Of this thickness, member A 

comprises about 500 m, member B about 180 m, 

member C about 120 m, and the Reward Conglomerate 

Member about 200 m (fig. 5). These four units, which 

were first distinguished by Conley (1978), constitute a 

conformable sequence that is overlain with angular 

unconformity by the Conglomerate lVIesa Formation. 

The unconformity truncates the Reward Conglomerate 

Member and members C and B of the Lone Pine 

Formation from northwest to southeast within the area 

(fig. 5). 

Lone Pine Formation 5 
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EXPLANATION 

Conglomerate- Chert and 

quartzite gravel predominant 

Conglomerate- Limestone 

gravel predominant 

Sandstone 

Siltstone and very fine 

grained sandstone 

Mudstone 

Calcareous and dolomitic 

mudstone 

Bioclastic limestone 

Micritic dolomite (includes 

minor limestone) 

Sandy limestone- Unlaminated, 

contains disseminated sand 

and chert gravel 

Sandy limestone- Laminated, 

contains lenses of sandstone and chert- clast cgl. 

Sandy limestone- Unlaminated, 

contains shells 

Sandy limestone-Wavy, 

irregular bedding surfaces 

Covered interval 

Correlation line 

Unconformity 

Figure 4. Measured stratigraphic sections 1-6 at type localities of the Lone Pine and Conglomerate Mesa 

Formations. Section 1 contains type sections of both formations. Locations of sections shown in figure 3. 

6 Stratigraphy of the Owens Valley Group, Southern Jnyo MoWltains, California 
Member A, which is particularly well exposed on 

the south side of Union Wash, consists of reddishbrown-weathering, thin-bedded siliceous hornfels, 

siltite, and very fine grained quartzite. Thin sections 

show that much of the silica in this member is of 

replacement origin; the protoliths probably were 

dominantly fine-grained calcareous rocks like those in 

member A of the formation at the type locality. At 

the head of Union Wash, the basal beds of member A 

sharply overlie a massive 15-m-thick bed of limestoneboulder conglomerate that we regard as the uppermost 

bed in the Keeler Canyon Formation. This boulder bed 

may be equivalent to the limestone breccia zone that 

Merriam and Hall (1957, p. 8-9) considered to mark the 

base of their Owens Valley Formation. 

Members B and C of the Lone Pine Formation in 

this area are best exposed on the steep mountain slope 

directly east of Fossil Hill (fig. 5). Member B is 

composed of greenish-gray, thin-bedded calc-hornfels 

and calcareous siltite along with a few thick beds of 

bioclastic marble. Except for its metamorphosed 

nature, this unit is lithologically similar to member B 

of the formation at the type locality. Member C is 

composed of massive dark-brown-weathering hornfels 

interbedded with minor fine- to coarse-grained 

quartzite and chert-pebble conglomerate. This unit 

appears to have no lithologic counterpart at the type 

locality of the Lone Pine Formation. 

The Reward Conglomerate Member is a cliffforming unit consisting mainly of thick-bedded, 

medium- to coarse-grained quartzite and chert-pebble 

conglomerate. Crossbedding and scour structures are 

common in these rocks. The lowermost part of the 

member is marked by a thin, persistent zone of lightgray sandy marble. Kirk (1918) designated no type 

locality for the Reward Conglomerate, but we consider 

it to be located about 1 km south of the Reward mine 

(NE 1/4 T. 14 S., R. 36 E., Union Wash 7.5-minute 

quadrangle). However, faulting occurs at the base of 

the unit at that locality (fig. 5). A better section is 

present about 0.5 km southeast of Fossil Hill, where 

both the stratigraphic base and the unconformably 

truncated top of the Reward Conglomerate Member 

are exposed (fig. 5). The Reward Conglomerate 

Member also is well exposed near Coyote Spring a few 

kilometers north of the area shown in figure 5 (Ross, 

1965). Like the underlying member C, the Reward 

Conglomerate Member is not present at the type 

locality of the Lone Pine Formation. 

The only fossils we have found in the Lone Pine 

Formation in the area between the Reward mine and 

Union Wash are poorly preserved inflated fusulinids in 

the basal part of the Reward Conglomerate Member. 

These fusulinids could indicate either a Wolfcampian 

or Leonardian age. Elongate fusulinid molds that we 

have observed in a similar stratigraphic position near 

Coyote Spring may represent the typical Leonardian 

genus Parafusulina. Lithostratigraphic correlations 

suggest that both member C and the Reward 

Conglomerate Member are younger than any part of 

the Lone Pine Formation at its type locality. 

The Lone Pine Formation was deposited in 

environments ranging from deep-water marine for the 

lower part to nonmarine or very shallow water marine 

for the upper part. The pyrite-bearing calcareous and 

dolomitic mudstone that makes up most of the 

formation at the type locality probably was deposited 

in deep, quiet, oxygen-poor water on a featureless 

basin floor, either by slow fallout from suspension or 

by relatively rapid fallout from dilute turbidity 

currents. The dolomite presumably is of diagenetic 

origin. The thin interbeds of laminated siltstone and 

sandstone probably are turbidites. We interpret the 

bioclastic and conglomeratic limestone beds in 

member B as sediment-gravity-flow deposits derived 

from basin-rimming carbonate banks or shelves. The 

abundant soft-sediment deformation features in these 

beds suggest deposition in a slope environment. The 

lithologic characteristics of the coarsely clastic 

Reward Conglomerate Member suggest that this 

member was deposited in either an alluvial-fan or a 

high-energy nearshore-marine environment. 

CONGLOMERATE MESA FORMATION 

The Conglomerate Mesa Formation is here 

named after Conglomerate Mesa, which is located 

about 5 km south of the Cerro Gordo mine (fig. 1). 

This lenticular formation unconformably overlies the 

Lone Pine Formation and is paraconformably overlain 

by unnamed marine strata of Early and Middle(?) 

Triassic age. The formation is composed primarily of 

sandy limestone, sandstone, and conglomerate that 

typically form rugged cliffs and ridges between the 

slope-forming Lone Pine Formation and Triassic 

marine strata. 

Near its type locality at Permian Bluff (fig. 3), 

the Conglomerate Mesa Formation ranges to about 225 

m thick in a lenticular outcrop belt 8 km long. 

Northwest and southeast of this outcrop belt, the 

Conglomerate Mesa Formation is missing and Triassic 

strata unconformably overlap the Lone Pine 

Formation. Because no angular discordance with the 

overlying Triassic strata exists, we interpret the 

lenticularity of the Conglomerate Mesa Formation to 

be the product of depositional thinning rather than 

postdepositional erosion. 

The type section of the Conglomerate Mesa 

Formation at Permian Bluff (section 1, figs. 3 and 4) 

has a thickness of 173 m and is here divided into three 

informally designated members. In ascending order, 

these are called members A, B, and C, which are 34, 

99, and 40 m thick, respectively. In an incomplete 

section at hill 8350 (the informally named Shell Ridge 

of Merriam and Hall, 1957) (section 3), members A and 

B are 26 and 125 m thick, respectively; in another 

incomplete section 0.8 km south of Permian Bluff 

(section 2), member C is 32 m thick. 

Member A of the Conglomerate Mesa Formation 

at the type locality consists of grayish-orange to 

yellowish-brown, fine- to coarse-grained quartzitic 

sandstone and sandy conglomerate. Most of the 

sandstone is plane laminated or gently 

crosslaminated. The conglomerate is arranged in welldefined size-sorted layers averaging 10 to 15 em 

thick. Clasts in the conglomerate are mostly angular 

pebbles of white to light-gray chert. 

Member B consists of light-gray, thick-bedded 

sandy limestone that stands out in rugged hogbacks 

above the somewhat less resistant underlying rocks. 

The limestone is composed of 60 to 85 percent 

Conglomerate Mesa. Formation '1 
118°02'30" 118'00' 

2 KILONETERS 

Figure 5. Geologic map of area between Reward mine and Union Wash, Inyo Mountains, California (type locality 

of Owens Valley Group). See figure 1 for location of map. Base from U.S. Geological Survey, 1:24,000, Union 

Wash quadrangle, 1982 (contour interval 20 meters). Geology mapped in 1981. 

8 Stratigraphy of the Owens Valley Group, Southern Inyo Mountains, California 
echinodermal sand and 15 to 40 percent quartz sand, 

tightly cemented with calcite. Limestone in the lower 

part of the unit, although massive in general 

appearance, is plane laminated on a fine scale and 

alternates with thin lenses and beds of coarse-grained 

sandstone and chert-pebble conglomerate. In contrast, 

limestone in the upper part of the unit is unlaminated, 

lacks distinct interbeds of sandstone and 

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EXPLANATION 

Alluvium and talus (Quaternary) 

Mafic to intermediate dikes (Jurassic)--

Correlated with Independence dike swarm 

Pat Keyes pluton of Ross (1965) (Jurassic)--

Ouartz monzonite, granodiorite, and 

diorite 

Altered porphyritic granitoids (Jurassic?) 

Volcanic and volcaniclastic rocks (Jurassic or Triassic) 

Marine sedimentary rocks (Middle? and Lower 

Triassic)--Gray shale, siltstone, and 

limestone; sandy limestone at base 

Owens Valley Group (Upper and Lower Permian)--

In this area, consists of: 

Pc Conglomerate Mesa Formation (Upper Permian)--

Liqht-gray sandy limestone; minor shale, 

siltstone, and sandstone 

Lone Pine Formation (Lower Permian)--Divided 

into: 

Plr Reward Conglomerate Member--Massive and 

thick-bedded chert-pebble conglomerate 

and quartzite; sandy marble at base 

Plc Member C--Massive hornfels; minor quartzite 

and chert-pebble conglomerate 

Plb Member B--Thin-bedded calc-hornfels and 

calcareous siltite; minor marble 

Pla Member A--Thin-bedded siliceous hornfels, 

siltite, and very fine-grained quartzite 

Pla-c Members A, B, and C, undivided 

P~k Keeler Canyon Formation (Lower Permian and 

t 

* 

55 ___L_ 

+ 

Pennsylvanian)--Thick-bedded limestone 

and marble 

Contact--Dashed where approximately located 

Fault--Dashed where approximately located, 

dotted where concealed 

Anticline 

Svncline 

Strike and dip of beds 

Inclined 

Vertical 

Figure 5. Continued. 

conglomerate, and contains randomly distributed 

coarse sand and chert pebbles. Whole and fragmented 

shells, mostly brachiopods and gastropods, are locally 

abundant in the unlaminated limestone but are not 

present in the laminated limestone. 

Member C is composed of conglomerate, 

conglomera tic sandstone, and sandstone. 

Conglomerate dominates the lower part of the unit and 

sandstone the upper part. The conglomerate, which 

ranges from massive to well bedded, contains angular 

to subrounded chert, quartzite, and limestone clasts in 

a poorly sorted, fine- to coarse-grained sandstone 

matrix. Among the limestone clasts are (1) light-gray 

sandy limestone similar in lithology to that in the 

immediately underlying member B; (2) medium- to 

dark-gray, fusulinid-bearing limestone similar in 

lithology to that in member B of the Lone Pine 

Formation; and (3) light-gray, fusulinid- and coralbearing limestone similar in lithology and fossil 

content to Lower Permian limestone that we have 

examined near Conglomerate Mesa. The chert clasts, 

most of which are white to light gray, and the 

quartzite clasts generally are of pebble size; the 

limestone clasts commonly are of cobble or boulder 

size. The sandstone that makes up most of the upper 

part of the member is predominantly yellowish brown, 

thin bedded, and fine grained. Plane lamination, 

ripple-crosslamination, and ripple marks are developed 

locally. The sandstone is interbedded with subordinate 

thin conglomera tic layers. 

West of the area of sections 1, 2, and 3 (fig. 3), 

member B of the Conglomerate Mesa Formation thins 

and wedges out, and on the next line of ridges to the 

west (area of sections 4, 5, and 6) the formation has a 

maximum thickness of about 100 m and is composed 

mainly of conglomerate and sandstone. However, a 

thick lens of sandy limestone like that of member B is 

present near the top of the formation at hill 8043 

(section 5), and thinner lenses of the same lithology 

are present nearby as seen in section 6. 

The Conglomerate Mesa Formation at the type 

locality is overlain by gray to brownish-gray sandy 

limestone that marks the base of the thick, unnamed 

Lower and Middle(?) Triassic marine sequence 

described by Merriam (1963). This limestone, which is 

characterized by wavy, irregular bedding, the presence 

of dark-gray limestone nodules, and the local 

abundance of tiny, phosphate-filled gastropod shells, 

stands out in bold hogbacks above the underlying 

sandstone and conglomerate. 

In the area between the Reward mine and Union 

Wash, where it overlies the Lone Pine Formation with 

an angular discordance of about 15°, the Conglomerate 

Mesa Formation forms a lenticular outcrop belt about 

3 km long (fig. 5). Within this belt the formation 

thickens northwestward from a wedgeout near Union 

Wash to about 150 m on Fossil Hill. The section at 

Fossil Hill, the base of which is covered by alluvium, 

consists of about 50 m of yellowish-brown siltstone and 

sandstone overlain successively by a thin zone of pink 

shale and about 100 m of cliff-forming light-gray 

sandy limestone. The limestone is lithologically 

similar to that of member B of the formation in the 

type section. Sections near the formational wedgeout 

consist entirely of sandy limestone. A persistent 

brachiopod coquina at the top of the Conglomerate 

Conglomerate Mesa Formation 9 
Mesa Formation can be traced from Fossil Hill 

southeastward to the formational wedgeout, providing 

evidence that the wedgeout is the result of 

southeastward depositional onlap. The coquina is 

sharply but concordantly overlain by 30 to 40 m of 

mottled, medium- to dark-gray, irregularly bedded 

sandy limestone. We correlate this mottled limestone 

with the basal sandy limestone of the unnamed Lower 

and Middle(?) Triassic sequence that overlies the 

Conglomerate Mesa Formation at its type locality. 

This limestone contains tiny gastropod shells like those 

in the basal beds of the Triassic sequence elsewhere in 

the southern Inyo Mountains. 

The contact between the Conglomerate Mesa 

Formation and the overlying 30 to 40 m of Triassic 

sandy limestone in the area between the Reward mine 

and Union Wash is subtle, although sharp, because both 

units are of generally similar lithology. Kirk (1918) did 

not recognize this contact and defined a single 

formation, the Owenyo Limestone, to comprise both of 

these units; he considered the Owenyo to be entirely 

Permian in age. Merriam and Hall (1957) did not 

recognize this contact either and revised the Owenyo 

as a member of the Permian Owens Valley 

Formation. Outside the Reward mine-Union Wash 

area, however, as at Permian Bluff, the uppermost 

rocks of the Conglomerate Mesa Formation and the 

lowermost rocks of the overlying Triassic sequence are 

of markedly different lithology and have always been 

assigned to separate formations (Merriam and Hall, 

1957; Merriam, 1963; Stone, 1984; Stone and Stevens, 

1984). Thus, the name Owenyo is not applicable 

outside the Reward mine-Union Wash area. Therefore, 

we here abandon the little-used name Owenyo and 

reassign the rocks of its lower part to the 

Conglomerate Mesa Formation and those of its upper 

part to the overlying unnamed Lower and Middle(?) 

Triassic sequence. 

Brachiopods, gastropods, and rare cephalopods of 

relatively young Permian age have long been known in 

sandy limestone that we assign to the Conglomerate 

Mesa Formation (Kirk, 1918; Merriam and Hall, 1957; 

Gordon and Merriam, 1961; Merriam, 1963). The 

presently accepted age of Late Permian (late 

Guadalupian) for these rocks is based on the reported 

presence of the ammonoid Timorites, a primary index 

fossil of the Upper Permian Capitanian Stage of 

Furnish (1973), in beds exposed near the type section 

of the Conglomerate Mesa Formation (Gordon and 

Merriam, 1961). The associated brachiopods, which 

Gordon and Merriam (1961) and earlier workers 

considered to be typical early Guadalupian species, are 

now thought to have been misidentified (Wardlaw and 

Collinson, 1978, p. 1179). 

The Conglomerate Mesa Formation was 

deposited in nonmarine and very shallow water marine 

environments. Conglomerate and sandstone in the 

formation most likely are alluvial-fan or braidedstream deposits, although some of these rocks may be 

of shallow-water marine origin. The sandy limestone 

probably was deposited in a variety of wave-dominated 

intertidal to shallow-subtidal marine environments. 

The laminated facies of the sandy limestone probably 

represents strandline deposition, whereas the 

unlaminated, shell-bearing facies probably represents 

shoreface deposition. 

REGIONAL EXTENT OF THE LONE PINE AND 

CONGLOMERATE MESA FORMATIONS 

The Lone Pine Formation is present throughout 

much of the southern Inyo Mountains, encompassing 

rocks mapped by previous workers (Merriam, 1963; 

Ross, 1965) as part of the Owens Valley Formation. 

The formation also is present near the Ubehebe mine 

in the southern extension of the Last Chance Range 

(fig. 1), encompassing rocks mapped by McAllister 

(1956) as the shale and upper limestone members of 

the Bird Spring(?) Formation and by Burchfiel (1969) as 

the Owens Valley Formation. As noted earlier, the 

Lone Pine Formation is not recognized in the 

Conglomerate Mesa area, the Darwin Hills, or the 

northern Argus Range, where coeval rocks are of such 

strongly contrasting lithology that different 

formational names must be used (Stone and Stevens, 

1984). Lower Permian rocks in the central Argus 

Range, the Cottonwood Mountains, and the Panamint 

Range (fig. 1) resemble those in the northern Argus 

Range and also are excluded from the Lone Pine 

Formation. 

We have identified the Conglomerate Mesa 

Formation at three localities in addition to its type 

locality and the area between the Reward mine and 

Union Wash-(1) the Conglomerate Mesa area in the 

southeastern Inyo Mountains and the (2) Bendire 

Canyon and (3) Water Canyon areas in the central 

Argus Range. The rocks herein assigned · to the 

Conglomerate Mesa Formation in these areas were 

previously mapped as part of the Owens Valley 

Formation (Hall and McKevett, 1962; Moore, 1976). In 

all three areas, the Conglomerate Mesa Formation is 

conformably overlain by Lower and Middle(?) Triassic 

strata correlative with those that overlie the 

formation at its type locality and in the area between 

the Reward mine and Union Wash. 

DEPOSITIONAL HISTORY 

The Lone Pine Formation was deposited largely 

in a deep marine basin that regional studies (Stone, 

1984; Stone and Stevens, 1984) have shown lay near the 

edge of the western continental margin of North 

America. By late Wolfcampian or early Leonardian 

time, when the Reward Conglomerate Member was 

accumulating, this basin had shoaled and probably had 

become subaerially exposed. An ensuing episode of 

uplift, tilting, and erosion probably spanned most of 

Leonardian and part of Guadalupian time. At least 500 

:n of strata (the combined thickness of members B, C, 

and the Reward Conglomerate Member of the Lone 

Pine Formation) was removed by erosion in the area 

between the Reward mine and Union Wash. The 

shallow-water marine and nonmarine Conglomerate 

Mesa Formation and the paraconformably overlying 

Lower and Middle(?) Triassic strata were deposited 

after this episode of uplift and erosion, which 

evidently ended by the late Guadalupian. 

10 Stratigraphy of the Owens Valley Group, Southern Inyo Mountains, California 
REFERENCES CITED 

Burchfiel, B.C., 1969, Geology of the Dry Mountain 

quadrangle, Inyo County, California: California 

Division of Mines and Geology Special Report 99, 

19 p. 

Conley, D.E., 197 8, Stratigraphy and depositional 

history of the Owens Valley Formation at the type 

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

San Jose State University, M.S. thesis, 63 p. 

Furnish, W. M., 1973, Permian stage names, in Lo5an, 

A., and Hills, L.V., eds., The Permian andTriassic 

Systems and their mutual boundary: Alberta 

Society of Petroleum Geologists Memoir 2, p. 522-

548. 

Gordon, MacKenzie, Jr., and Merriam, C. W., 1961, 

Late Permian ammonoids in the Inyo Range, 

California, and their significance, in Geological 

Survey Research 1961: U.S. Geological Survey 

Professional Paper 424-D, p. D238-D239. 

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. 

Kirk, Edwin, 1918, Stratigraphy of the Inyo Range, in 

Knopf, Adolph, A geologic reconnaissance of the 

Inyo Range and the eastern slope of the southern 

Sierra Nevada, California: U.S. Geological Survey 

Professional Paper 110, p. 19-48. 

McAllister, J.F., 1956, Geology of the Ubehebe Peak 

quadrangle, Inyo County, California: U.S. 

Geological Survey Geologic Quadrangle Map GQ95, scale 1:62,500. 

Merriam, C. W., 1963, Geology of the Cerro Gordo 

Mining District, Inyo County, California: U.S. 

Geological Survey Professional Paper 408, 83 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. 

Riggs, E.A., 1962, Fusulinids of the Keeler Canyon 

Formation, lnyo County, California: Urbana, Til., 

University of Illinois, Ph.D. dissertation, 133 p. 

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

quadrangle, Inyo County, California: U.S. 

Geological Survey Bulletin 1181-0, 64 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. dissertation, 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~ursions, v. 4: Geological 

Society of America, Field Trip Guidebook, 1984 

annual meeting, p. 94-119. 

Stone, Paul, Stevens, C. H., and Cavi t, C. D., 1980, A 

regional Early Permian angular unconformity in 

eastern California [abs.l: Geological Society of 

America Abstracts with Programs, v. 12, no. 3, p. 

154. 

Stone, Paul, Stevens, C.H., and Conley, D.E., 1979, 

Late Permian orogenic strata in the southern Inyo 

Mountains, California [ abs. ]: Geological Society of 

America Abstracts with Programs, v. 11, no. 3, p. 

130. 

Wardlaw, B.R., and Collinson, J. W., 1978, Stratigraphic 

relations of Park City Group (Permian) in eastern 

Nevada and western Utah: American Association 

of Petroleum Geologists Bulletin, v. 62, p. 1171-

1184. 

References Cited 11 
MEASURED SECTIONS 

(Locations shown on fig. 3; generalized lithology shown on fig. 4) 

Section 1. Type section of the Conglomerate Mesa and Lone 

Pine Formations. Measured at Permian Bluff in August 1974. 

Top of section faulted. 

Unnamed marine strata (Lower and Middle? 

Triassic) (incomplete): 

Limestone, sandy, and calcareous 

sandstone, fine to medium grained 

in beds 2 to 25 em thick. Limestone, light to medium gray; commonly 

weathers grayish orange; locally 

mottled; bedding surfaces wavy and 

irregular. Sandstone, light brown to 

brownish gray; bedding surfaces planar. 

Rare beds and lenses of coarse-grained 

sandstone and chert-pebble conglomerate 3 to 25 em thick. Interval 

Thickness 

meters 

forms craggy hogbacks................ 37.7 

Incomplete thickness unnamed Lower and 

Middle(?) Triassic sedimentary rocks..... 37.7 

Paraconformable contact. 

Conglomerate Mesa Formation (Upper 

Permian): 

Member C: 

2. Sandstone (40 percent), conglomerate 

(40 percent), and cover (20 percent). 

Sandstone, calcareous, light gray to 

yellowish brown or grayish orange; 

fine to coarse grained, locally conglomeratic; moderately to well sorted; 

beds 1 to 10 em thick; laminated. 

Conglomerate, composed of 30 to 50 

percent gravel in a calcareous sandstone matrix; beds 5 to 50 em thick. 

Gravel is white to gray chert (angular 

to subangular, median diameter 5 mm to 

1 em; maximum diameter 6 em)......... 17.4 

1. Conglomerate, composed of 40 to 60 percent gravel in a light-gray to grayishorange calcareous sandstone matrix; 

beds 15 em to 1 m thick; gravel generally oriented parallel to bedding. 

Gravel is 50 to 60 percent white to 

gray chert (angular to subangular, 

median diameter 5 mm to 1 em, maximum diameter 10 em); 20 to 30 percent 

gray, fine-grained calcareous quartzite 

(angular to subrounded, medium diameter 

3 em, maximum diameter 10 em); 5 to 20 

percent light-gray sandy limestone 

(angular to subrounded, median diameter 

5 em, maximum diameter 70 em); and 0 to 

10 percent light- to dark-gray bioclastic limestone containing echinodermal debris and fusulinids (angular 

to subrounded, median diameter 8 em, 

maximum diameter 50 em). Lenticular 

interbeds of fine- to coarse-grained, 

laminated and crosslaminated 

sandstone less than 20 em thick..... 22.6 

Total thickness member C.................. 40.0 

Member B: 

5. Limestone (calcarenite), sandy; light 

Section 1: Upper Permian--Continued 

Conglomerate Mesa Formation--Continued 

Member B--Continued 

to medium light gray, grayish orange, 

and yellowish brown; generally fine to 

medium grained but locally contains 

coarse-grained quartz sand and white to 

dark-gray, angular to subangular chert 

gravel to 1 em in diameter; poorly 

sorted; massively bedded but commonly 

fractures along wavy surfaces 2 to 5 mm 

apart; echinodermal debris abundant; 

silicified brachiopods (including a 

punctate spiriferid) and gastropods 

(including Euphemitopsis) present 

Thickness 

meters 

locally.............................. 37.3 

4. Limestone (calcarenite), sandy, light 

to medium light gray and grayish 

orange; fine to medium grained, well 

sorted; massively bedded but plane 

laminated to gently crosslaminated; 

lamination defined by differences in 

sand content. Interbedded with numerous 

lenses of sandy chert-pebble conglomerate 2 to 30 em thick (chert gravel 

white to gray, subangular to rounded, 

median diameter 5 mm); plane lamination and low-angle crosslamination 

common. Interbeds of yellowish-brown, 

fine- to medium-grained calcareous 

sandstone 5 mm to 1 em thick present 

in basal 5 m of interval. Interval 

forms cliffs........................ 22.7 

3. Limestone (calcarenite), sandy, and 

minor calcareous sandstone; interval 

about 50 percent covered. Limestone, 

light gray to grayish orange, very 

fine grained, indistinctly bedded; 

contains scattered laminations and 

thin beds of medium- to coarse-grained 

sandstone and chert-pebble conglomerate 

(chert gravel white to gray, subangular 

to rounded, medium diameter 5 mm). 

Sandstone, grayish orange to 

yellowish brown, locally conglomeratic; 

beds 7 to 25 em thick; rarely 

lamina ted.. • • • • • • • • • • • • • • • • • • • • • • • • • 23. 6 

2. Covered interval.................... 13.4 

1. Limestone (calcarenite), sandy, 

grayish orange to yellowish brown; 

fine to medium grained; beds 5 to 

15 em t hie k • • • • • • • • • • • • • • • • • • • • • • • • • 1 • 8 

Total thickness member B.................. 98.8 

Member A: 

6. Covered interval.................... 4.9 

5. Sandstone, calcareous, grayish orange 

to yellowish brown, fine to medium 

grained; beds 5 to 8 em thick........ 4.0 

4. Covered interval..................... 5.8 

3. Sandstone (70 percent) and conglomerate (30 percent), grayish orange to 

yellowish brown, thin bedded. Sandstone, fine to coarse grained and 

locally conglomeratic. Conglomerate, 

composed of subangular to rounded, 

white to gray chert gravel (median 

diameter 5 mm to 1 em, maximum 

12 Stratigraphy of the Owens Valley Group, Southern Inyo Mountains, California 
Section 1: Upper Permian--Continued 

Conglomerate Mesa Formation--Continued 

Member A--Continued 

diameter 3 em) in a calcareous 

sandstone matrix; gravel concentrated 

Thickness 

meters 

in planar laminations............... 4.3 

2. Covered interval..................... 5.8 

1. Sandstone (60 percent) and conglomerate 

(40 percent), calcareous, yellowish 

brown; beds 2 to 25 em thick. Sandstone, laminated, fine to medium 

grained. Conglomerate, composed of 

angular to subangular, white to gray 

chert gravel (median diameter 5 mm to 

1 em, maximum diameter 5 em) in a 

calcareous sandstone matrix; gravel 

oriented parallel to bedding......... 9.0 

Total thickness member A................... 33.8 

Total thickness Conglomerate Mesa 

Formation.............................. 172.6 

Unconformable contact. 

Lone Pine Formation (Lower Permian): 

Member B: 

Interval about 30 percent covered. 

Exposed part of interval consists of 

mudstone, siltstone, and very fine to 

fine-grained sandstone (95 percent) 

and dolomite and limestone (5 percent). 

Mudstone, siltstone, and sandstone 

occur as graded beds 4 to 15 em thick 

that typically consist of, from base 

to top: 5 mm to 2 em of pale-red to 

pale-brown, plane-laminated to crosslaminated calcareous sandstone; 2 to 

4 em of pale-brown to grayish-orange 

calcareous to noncalcareous siltstone; 

and 2 to 10 em of greenish-gray to palebrown micaceous noncalcareous mudstone. 

Basal bed contacts sharp. Dolomite 

and limestone, micritic, olive gray to 

greenish gray; beds 10 to 30 em thick 

and spaced an average of about 7 m 

apart. Member grades transitionally 

upward from top of member A.......... 71.5 

Total thickness member B................... 71.5 

Member A: 

Interval about 25 percent covered. 

Exposed part of interval consists of 

mudstone (65 percent), siltstone and 

very fine to fine-grained sandstone 

(30 percent), and limestone and dolomite (5 percent). Mudstone, calcareous, pyritic and rich in organic 

material; medium to dark gray;. beds 

1 mm to 20 em thick; fissile. 

Siltstone and sandstone, calcareous, 

medium to dark gray, commonly 

weathers grayish orange to 

yellowish brown; beds 5 mm to 6 em 

thick; plane laminated and crosslaminated; ripple marks present 

locally; bases and tops of beds 

sharp. Limestone and dolomite, 

generally micritic but rarely calcarenitic, medium light to dark gray, 

commonly weathers grayish orange to 

yellowish brown; beds 15 to 80 em 

thick and spaced an average of 6 to 

Section 1: Lower Permian--Continued 

Lone Pine Formation--Continued 

Member A--Continued 

Thickness 

meters 

7 m apart; some beds graded; bases 

and tops of beds sharp; many beds 

have tension gashes filled with 

coarsely crystalline calcite. All 

lithologies characterized by even, 

planar bedding....................... 237.0 

Total thickness member A................... 237.0 

Total thickness Lone Pine Formation........ 308.5 

Conformable contact (poorly exposed, obscured 

by dikes). 

Keeler Canyon Formation (Lower Permian and 

Pennsylvanian) (not measured): 

Limestone (calcarenite) and mudstone. 

Limestone, bioclastic and silty, 

medium to dark gray, medium to thick 

bedded, coarse-grained; shows Ta, Tb, 

and Tc divisions of the Bouma sequence; 

echinodermal debris and fusulinids 

locally abundant; forms craggy 

resistant outcrops. Mudstone, 

calcareous, dark gray, laminated, 

nonresistant ••••••••••••••••••••••••• 

Section 2. Conglomerate Mesa Formation (incomplete). 

Measured 0.8 km south of Permian Bluff in August 1974. 

Thickness 

meters 

Top of section conformably overlain by 

additional unnamed marine strata of 

Early and Middle(?) Triassic age. 

Unnamed marine strata (Lower and Middle? 

Triassic) (incomplete): 

Limestone, sandy, and calcareous 

sandstone; medium gray, commonly 

weathers yellowish brown; locally 

mottled; fine grained; beds 

average about 3 em thick; bedding 

surfaces crinkled and irregular; 

rare thin interbeds of chert-pebble 

conglomerate ••••••••••••••••••••••••• 

Incomplete thickness unnamed Lower and 

Middle(?) Triassic sedimentary rocks ••••• 

Paraconformable contact. 

Conglomerate Hesa Formation (Upper Permian) 

(incomplete): 

Member C: 

3. Sandstone (85 percent) and conglomerate 

(15 percent). Sandstone, yellowish 

brown, fine grained; beds 1 to 10 em 

thick; laminated. Conglomerate, composed 

of 30 to 35 percent gravel in a poorly 

sorted, fine- to coarse-grained calcareous 

sandstone matrix; beds 20 to 30 em thick. 

Gravel is 85 to 90 percent white to lightgray chert and medium-gray calcareous 

quartzite (angular to subrounded, median 

diameter 5 mm to 1 em, maximum diameter 

4 em) and 10 to 15 percent medium-gray 

limestone (median diameter 1 to 2 em, 

28.2 

28.2 

Measured Sections 13 
Section 2: Upper Permian--Continued 

Conglomerate Mesa Formation--Continued 

Member C--Continued 

maximum diameter 3 em) ••••••••••••••• 

Thickness 

meters 

11.4 

2. Conglomerate, composed of 30 to 50 percent gravel in a poorly sorted, fineto coarse-grained calcareous sandstone 

matrix; beds 15 em to 1.5 m thick, 

decreasing in thickness gradually 

from base to top of interval; gravel 

generally oriented parallel to bedding. 

Gravel is 30 to 40 percent white to 

gray chert (angular to subangular, 

median diameter 5 mm to 1 em, maximum 

diameter 7 em); 15 to 30 percent lightto medium-gray bioclastic limestone 

containing fusulinids (angular to 

subrounded, median diameter 3 to 5 em, 

maximum diameter 18 em); 15 to 30 percent 

light- to medium-gray calcareous quartzite 

(subangular to subrounded, median diameter 

2 to 3 em, maximum diameter 9 em); and 15 

to 25 percent light-gray sandy limestone 

(angular to subrounded, median diameter 2 

to 3 em, maximum diameter 20 em). Median 

gravel size and percentage of limestone 

gravel decrease gradually from base to top 

of interval. Scattered interbeds of lightto medium-gray, fine-grained calcareous 

sandstone generally less than 2 em 

thick................................ 17.4 

1. Conglomerate, composed of 50 percent 

gravel in a poorly sorted, fine- to 

coarse-grained calcareous and argillaceous matrix; massive; gravel generally 

oriented parallel to bedding. Gravel is 

30 to 35 percent gray chert (angular to 

subangular, median diameter 5 mm to 1 em, 

maximum diameter 14 em); 30 to 35 percent 

light- to medium-gray bioclastic limestone 

containing echinodermal debris and 

fusulinids (subangular to subrounded, 

median diameter 10 em, maximum diameter 

75 em); 10 to 15 percent light-gray sandy 

limestone (median diameter 5 to 6 em, 

maximum diameter 45 em); and 5 to 

10 percent calcareous quartzite (subangular to subrounded, median diameter 

1 to 2 em, maximum diameter 12 em)... 2.7 

Total thickness member C: •••••••••••••••••• 

Member B (incomplete): 

5. Limestone (calcarenite) (75 percent) 

and conglomerate (25 percent); intergradational vertically and laterally; 

beds generally less than 5 em thick, 

lenticular. Limestone, sandy, grayish 

orange to yellowish brown, fine to 

medium grained. Conglomerate, composed 

of 40 to 60 percent gravel in a poorly 

sorted, fine- to coarse-grained calcareous sandstone matrix; gravel 

generally oriented parallel to 

bedding. Gravel is more than 

95 percent gray chert and calcareous 

quartzite (angular to subangular, 

median diameter 3 to 4 mm, maximum 

diameter 2 em) and less than 5 percent 

light- to medium-gray limestone 

(median diameter 1 to 2 em, maximum 

diameter 4 em) ••••••••••••••••••••••• 

31.5 

3.0 

Section 2: Upper Permian--Continued 

Conglomerate Mesa Formation--Continued 

Member B--Continued 

4. Limestone (calcarenite), sparsely 

Thickness 

meters 

sandy, light to medium gray, massively 

bedded but commonly fractures along wavy 

surfaces 2 mm to 1 em apart; locally 

contains bryozoans, brachiopod shells, 

and coarse echinodermal debris. Thin 

lenticular interbeds of coarse-grained 

sandstone and chert-pebble 

conglomerate......................... 7.2 

3. Conglomerate, composed of 40 to 

60 percent gravel in a poorly sorted, 

fine-to coarse-grained calcareous 

sandstone matrix; massive; gravel 

subrounded to rounded, discoidal, and 

generally oriented parallel to bedding. 

Gravel is 60 to 70 percent gray calcareous quartzite (median diameter 2 to 

3 em, maximum diameter 10 em) and 30 to 

40 percent gray chert (median 

diameter 1 em)....................... 1.8 

2. Sandstone, calcareous, yellowish brown, 

medium to coarse grained and locally 

conglomeratic; gravel is gray chert 

(maximum diameter 5 mm); beds 1 to 2 em 

thick••••••••••••••••••••••••••••••• 2.1 

1. Limestone (calcarenite), sandy, light 

gray, commonly weathers light brown; 

massively bedded but finely laminated; 

generally fine grained but locally 

contains medium- to coarse-grained 

quartz sand and coarse echinodermal 

debris. Lenticular interbeds of sandy 

chert-pebble conglomerate 5 to 15 em 

thick (maximum gravel diameter 

1 em)................................ 12.8 

Incomplete thickness member B.............. 26.9 

Incomplete thickness Conglomerate Mesa 

Formation................................. 58.4 

Base of section faulted. 

Section 3. Conglomerate Mesa Formation (incomplete). 

Measured at hill 8350 (Shell Ridge) in August and September 

1974. 

Top of section covered by colluvium and talus. 

Top of section about 40 to 50 m below base 

of unnamed Lower and Middle(?) Triassic 

marine strata. 

Conglomerate Mesa Formation (Upper Permian) 

(incomplete): 

Member C (incomplete): 

3. Sandstone (50 percent) and conglomerate 

(50 percent). Sandstone, calcareous, 

grayish orange to pale red; generally 

fine to medium grained but locally 

coarse grained to conglomeratic; beds 

3 mm to 3 em thick; grades laterally 

into conglomerate. Conglomerate, 

Thickness 

meters 

14 Stratigraphy of the Owens Valley Group, Southern Inyo Mountains, California 
Section 3: Upper Permian--Continued 

Conglomerate Mesa Formation--Continued 

Member C--Continued 

composed of 25 to 35 percent grave:! in 

a poorly sorted, fine- to coarsegrained sandstone matrix; beds 5 em to 

1 m thick. Gravel is more than 95 percent white to light-gray chert 

(angular to subangular, median diameter 

5 nun to 1 em, maximum diameter 3 c:m) 

and less than 5 percent light-gray 

calcareous quartzite (subrounded, 

median diameter 2 em, maximum diameter 

Thickness 

meters 

3 em)................................ 15.2 

2. Conglomerate (80 percent) and sandstone 

(20 percent). Conglomerate, composed 

of 25 to 35 percent gravel in a poorly 

sorted, fine- to coarse-grained sandstone matrix; beds 15 em to 1 m thick; 

gravel oriented parallel to bedding. 

Gravel is 60 to 90 percent white to 

light-gray chert and medium-gray calcareous quartzite (angular to subrounded, 

median diameter 1 em, maximum diameter 

6 em); and 10 to 40 percent light-· to 

medium-gray limestone, some sandy and 

some bioclastic (angular to subrounded, 

median diameter 1 to 2 em, maximum 

diameter 8 em). Sandstone, calcareous, 

grayish orange to pale red, fine to 

medium grained; forms intervals 1 to 

2 m thick between conglomerate 

intervals; beds 1 to 2 em thick; grades 

laterally and vertically into 

conglomerate......................... 23.2 

1. Conglomerate, composed of 50 percent 

gravel in a poorly sorted, fine- to 

coarse-grained sandstone matrix; 

massive in lower part of interval, 

beds 15 em to 1 m thick in upper 

part. Gravel is 35 to 40 percent 

light-gray sandy limestone (subangular to subrounded, median dia-· 

meter 4 to 8 em, maximum diameter 

50 em); 15 to 40 percent light- to 

medium-gray bioclastic limestone 

containing echinodermal debris and 

fusulinids (angular to subrounded, 

median diameter 5 to 10 em, maximum 

diameter 50 em); 20 to 25 percent 

white to light-gray chert (angular 

to subangular, median diameter 1 em, 

maximum diameter 8 em); and 5 to 25 

percent light- to medium-gray calcareous quartzite (subangular to subrounded, median diameter 3 to 4 em, 

maximum diameter 8 em). Median 

gravel size decreases from base to 

top of interval. Channeling observed 

at base of interval.................. 6.7 

Incomplete thickness member c.............. 45.1 

Member B: 

7. Limestone (calcarenite), sandy, 

light gray to pale brown; generally 

fine to medium grained but contains 

scattered coarse-grained siliceous 

sand and chert gravel; massive. 

Lenticular interbeds of chert-pebble 

conglomerate present throughout; 

conglomerate lenses containing 

Section 3: Upper Permian--Continued 

Conglomerate Mesa Formation--Continued 

Member B--Continued 

limestone cobbles and boulders present 

Thickness 

meters 

in upper 7 m•••••••••••••••••••••••••• 21.5 

6. Covered interval..................... 4.6 

5. Limestone (calcarenite), sandy, light 

gray; generally fine to medium grained 

but contains abundant coarse-grained 

siliceous sand, chert gravel (maximum 

diameter 5 em), coarse echinodermal 

debris, and whole and fragmented 

brachiopod and gastropod shells; thick 

bedded to massive. Limestone is 

locally replaced by large irregular 

patches of pale-red to brown 

jasperoid............................ 22.9 

Break in section; covered interval about 

30 m wide that may mark the trace of a 

minor fault across which a small amount 

of section may be cut out or duplicated. 

4. Limestone (calcarenite), sandy, 

light to medium gray and grayish 

orange; generally fine to medium 

grained but contains abundant coarsegrained siliceous sand, chert gravel, 

coarse echinodermal debris, and whole 

and fragmented brachiopod and gastropod shells; thick bedded to massive. 

Irregular patches of pale-red to 

grayish-orange jasperoid present 

locally.............................. 20.9 

3. Interval largely covered; scattered 

outcrops of sandy limestone as in the 

underlying interval.................. 9.8 

2. Limestone (calcarenite), sandy, light 

to medium gray and grayish orange, 

fine to medium grained, well sorted; 

massive in general appearance but 

plane laminated to gently crosslaminated on a fine scale; alternates with 

lenticular interbeds of coarsegrained calcareous sandstone and chertpebble conglomerate generally about 2 

to 10 em thick but locally as thick as 

75 em (median gravel diameter 

3 to 5 mm)........................... 39.8 

1. Limestone (calcarenite), sandy, grayish 

orange, fine to medium grained; 

fractures into slabs less than 2 em 

thick................................ 5.2 

Total thickness member B................... 124.7 

Member A: 

4. Sandstone, calcareous, light gray, 

fine to medium grained, indistinctly 

bedded; interval more than 50 percent 

covered.............................. 4.9 

3. Conglomerate, composed of 60 percent 

gravel in a poorly sorted, fine- to 

coarse-grained sandstone matrix; 

gravel concentrated in size-sorted 

layers 10 to 15 em thick and 

Measured Sections 15 
Section 3: Upper Permian--Continued 

Conglomerate Mesa Formation--Continued 

Nember A--Continued 

oriented parallel to bedding. Gravel 

is gray chert (angular to subangular, 

median diameter 5 mm to 1 em, maximum 

diameter 6 em) ••••••••••••••••••••••• 

2. Sandstone, calcareous, light gray to 

yellowish brown, fine to medium 

grained; fractures into slabs less 

than 1 em thick; interval more than 

50 percent covered ••••••••••••••••••• 

1. Conglomerate, composed of 50 to 60 

percent gravel in a poorly sorted, 

fine- to coarse-grained sandstone 

matrix; gravel concentrated in sizesorted layers 5 to 15 em thick and 

oriented parallel to bedding. Gravel 

is white to light-gray chert (angular 

to subangular, median diameter 6 to 

8 rom, maximum diameter 5 em). Basal 

30 em of interval is yellowish-brown, 

thin-bedded to laminated, mediumgrained calcareous sandstone ••••••••• 

Total thickness member A ••••••••••••••••••• 

Incomplete thickness Conglomerate 

Mesa Formation ••••••••••••••••••••••••••• 

Unconformable contact. 

Lone Pine Formation (member B) (Lower Permian) 

(not measured): 

Mudstone, siltstone, and very fine to 

fine-grained sandstone, calcareous 

and noncalcareous, yellowish brown, 

pale red, and greenish gray; beds 10 

em thick or less, planar, graded. 

Rare beds of light- to medium-gray 

micritic to bioclastic limestone 

15 em to 1m thick ••••••••••••••••••• 

Thickness 

meters 

1.2 

13.0 

6.4 

25.5 

195.3 

Section 4. Conglomerate Mesa. Formation and member B of the 

Lone Pine Formation (incomplete). Measured 1.1 km southeast 

of hill 8043 in August 1974 and August 1975. 

Unnamed marine strata (Lower and Middle? 

Triassic) (not measured): 

Limestone, sandy, light gray, 

weathers gray to brown, fine to 

medium grained; beds 1 to 10 em 

thick; bedding surfaces wavy and 

irregular •••••••••••••••••••••••••••• 

Paraconformable contact. 

Conglomerate Mesa Formation (Upper Permian): 

Thickness 

meters 

5. Covered interval..................... 4.6 

4. Conglomerate, composed of 30 to 70 

percent gravel in a light-gray to 

grayish-orange sandstone matrix; beds 

25 em to 2 m thick; gravel generally 

oriented parallel to bedding. Gravel 

is 25 to 40 percent gray, finegrained calcareous quartzite (angular 

to subrounded, median diameter 2 to 

3 em, maximum diameter 5 em); 10 to 

35 percent white to light-gray chert 

(angular to subangular, median 

Section 4: Upper Permian--Continued 

Conglomerate Mesa Formation--Continued 

diameter 5 to 8 rom, maximum diameter 

2 em); 5 to 40 percent light- to 

dark-gray bioclastic limestone (angular to subrounded, median diameter 2 

to 4 em, maximum diameter 10 em); and 

5 to 40 percent light-gray sandy limestone (subangular to subrounded, median 

diameter 2 to 5 em, maximum diameter 

15 em). Lenticular interbeds of 

yellowish-brown, fine-grained calcareous sandstone less than 20 em 

Thickness 

meters 

thick... • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 8 .4 

3. Conglomerate, composed of 35 to 70 

percent gravel in a poorly sorted, 

fine- to medium-grained sandstone 

matrix; massive; gravel generally 

oriented parallel to bedding. 

Gravel is 30 percent light- to 

medium-gray, fine-grained calcareous 

quartzite (subangular to subrounded, 

median diameter 2 to 3 em, maximum 

diameter 10 em); 25 to 30 percent 

light-gray sandy limestone (subangular to subrounded, median diameter 

2 to 5 em, maximum diameter 20 em); 

20 to 25 percent white to light-gray 

chert (angular to subangular, median 

diameter 5 rom, maximum diameter 3 em); 

and 10 to 15 percent light- to darkgray bioclastic limestone (subangular 

to subrounded, median diameter 3 to 

5 em, maximum diameter 25 em)........ 11.0 

2. Covered interval..................... 6.1 

1. Conglomerate, composed of 75 percent 

gravel in a poorly sorted, fine- to 

coarse-grained sandstone matrix; 

massive; gravel generally oriented 

parallel to bedding. Gravel is 30 

to 50 percent medium- to dark-gray 

bioclastic limestone containing 

echinodermal debris and fusulinids 

(subangular to subrounded, median 

diameter 3 to 6 em, maximum diameter 

30 em); 25 to 45 percent white to 

light-gray chert (angular to subangular, median diameter 5 to 7 rom, 

maximum diameter 3 em); and 10 to 20 

percent light-gray to pale-red calcareous siltstone, very fine grained 

sandstone, and quartzite (angular to 

subangular, tabular, median diameter 

1 to 2 em, maximum diameter 3 em). 

Median gravel diameter decreases 

gradually from base to top of 

interval............................. 6.1 

Total thickness Conglomerate 

Mesa Formation........................... 36.2 

Unconformable contact. 

Lone Pine Formation (Lower Permian) (incomplete): 

Member B (incomplete): 

9. Siltstone and very fine grained sandstone, calcareous, yellowish brown; 

beds 2 rom to 2 em thick; fractures 

into thin slabs...................... 1.7 

8. Limestone, medium gray; one bed (Bouma 

Ta); grades from limestone conglomerate 

16 Stratigraphy of the Owens Valley Group, Southern Inyo Mountains, California 
Section 4: Lower Permian--Continued 

Lone Pine Formation--Continued 

Member B--Continued 

at base to medium-grained calcarenite 

at top; lower part of bed contains 

echinodermal debris, fusulinids, other 

bioclasts, and limestone clasts to 

3 em in diameter; matrix micritic; base 

Thickness 

meters 

and top of bed sharp................. 1.1 

7. Siltstone and mudstone, calcareous, 

yellowish brown; beds 2 mm to 8 em 

thick; fractures into thin, irregular 

slabs. Minor (less than 5 percent of 

interval) medium-gray, fine- to coarsegrained bioclastic limestone; beds 5 

to 10 em thick, graded and ungraded. 

Rare thin-bedded to laminated, greenishgray mudstone........................ 13.1 

6. Limestone (calcarenite), medium gray; 

one bed (Bouma Tab); grades from coarse 

grained at base to fine grained at top; 

upper 10 em plane laminated.......... 0.5 

5. Siltstone, calcareous, yellowish brown, 

thin bedded and laminated; minor 

greenish-gray mudstone............... 3.0 

4. Limestone, medium gray; one bed 

(Bouma Tab); grades from limestone 

conglomerate at base to fine-grained 

calcarenite at top; maximum clast 

diameter 1 em; echinodermal debris 

abundant, fusulinids rare; upper 

10 em plane laminated •••••••••••••••• 

3. Siltstone, calcareous, yellowish 

brown, thin bedded to laminated. 

Scattered beds of medium-gray bioclastic limestone 5 to 7 em thick •••• 

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

1. Siltstone, calcareous, yellowish 

brown, thin bedded to laminated; 

scattered beds of medium-gray, fineto coarse-grained bioclastic limestone 

5 to 30 em thick. Limestone beds show 

Ta and Tb divisions of the Bouma 

sequence .•...•..•••..•............•.. 

Incomplete thickness member B •••••••••••••• 

Incomplete thickness Lone Pine Formation ••• 

Base of section cut by dike. 

0.6 

3.0 

5.3 

21.3 

49.6 

49.6 

Section 5. Conglomerate Mesa Formation (incomplete). 

Measured at hill 8043 in August 1974. 

Unnamed marine strata (Lower and Middle? 

Triassic)(not measured): 

Limestone, sandy, light gray, fine to 

medium grained, thin bedded; bedding 

irregular, wavy; locally mottled due to 

presence of medium-gray, spherical to 

elliposoidal calcareous concretions 1 

to 2 em in diameter •••••••••••••••••• 

Paraconformable contact. 

Thickness 

meters 

Section 5: Upper Permian 

Conglomerate Mesa Formation 

Thickness 

meters 

Conglomerate Mesa Formation (Upper Permian) 

(incomplete): 

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

13. Sandstone, conglomeratic, calcareous; 

light gray to yellowish brown; beds 

15 em to 1 m thick; contains about 

15 percent gravel. Gravel is 40 to 50 

percent white to light-gray chert 

(angular to subangular, median diameter 

5 to 7 mm, maximum diameter 5 em); 40 

to 50 percent gray to grayish-red 

calcareous sandstone (angular to subrounded, median diameter 1 em, maximum 

diameter 5 em); 0 to 5 percent mediumgray bioclastic limestone containing 

echinodermal debris and fusulinids 

(angular to subangular, median diameter 

2 to 3 em, maximum diameter 9 em); and 

0 to 5 percent light-gray sandy limestone (subangular to subrounded, 

median diameter 2 em, maximum diameter 

7 em) •••••••••••••••••••• • • • • • • • • • • • • 

12. Covered interval ••••••••••••••••••••• 

11. Limestone (calcarenite), sandy, light 

to medium gray, fine to medium grained; 

beds 40 em to 1 m thick; contains lenses 

of coarse-grained sandstone and chertpebble conglomerate generally less 

than 5 em thick (chert gravel angular 

to subangular, maximum diameter 1 em. 

10. Conglomerate, composed of white to 

dark-gray chert gravel (angular to 

subrounded, maximum diameter 2 em) 

in a light-gray to yellowish-brown, 

poorly sorted calcarenitic sandstone 

matrix •••••••.•.••••••••••••••••••••• 

9. Limestone (calcarenite), sandy, light 

gray, fine to coarse grained, locally 

conglomeratic •••••••••••••••••••••••• 

8. Conglomerate, composed of white to 

dark-gray chert gravel (angular to 

rounded, median diameter 4 to 5 mm, 

maximum diameter 2 em) in a lightgray to yellowish-brown, poorly sorted, 

fine- to coarse-grained calcarenitic 

sandstone matrix; massive •••••••••••• 

7. Limestone (calcarenite), sandy, 

light gray; beds 2 em to 1 m thick; 

plane laminated; echinodermal debris 

abundant. Alternates with beds and 

lenses of coarse-grained sandstone 

and chert-pebble conglomerate (chert 

gravel angular to rounded, maximum 

diameter 1 em) ••••••••••••••••••••••• 

6. Covered interval ••••••••••••••••••••• 

5. Limestone (calcarenite), sandy, 

light to medium gray, fine to 

medium grained; contains lenses of 

poorly sorted sandstone and chertpebble conglomerate 2 to 10 em 

thick (chert gravel angular to subangular, maximum diameter 1 em); 

gradational from underlying unit ••••• 

4. Conglomerate; composed of 40 to 

45 percent gravel in a fine- to 

coarse-grained calcareous sandstone 

4.3 

1.5 

2.3 

7.3 

1.5 

1.2 

4.3 

4.0 

3.4 

6.7 

Measured Sections 17 
Section 5: Upper Permian--Continued 

Conglomerate Mesa Formation--Continued 

matrix. Gravel is 80 to 85 percent 

white to light-gray chert (angular 

to subangular, median diameter 5 mm 

to 1 em, maximum diameter 6 em); 10 

to 15 percent light-gray calcareous 

quartzite (subangular to subrounded, 

median diameter 4 em, maximum 

diameter 10 em); and 5 percent 

medium-gray bioclastic limestone 

(subangular to subrounded, median 

diameter 5 em, maximum diameter 

14 em). Median gravel diameter 

decreases gradually from base to 

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

Section crosses dike and talus; stratigraphic 

relations unclear across break. About 

10 m of section probably obscured. 

3. Conglomerate and sandstone, thinly 

interbedded and lenticular. Conglomerate, composed of 25 to 40 percent 

gravel in a light- to medium-gray, 

fine- to coarse-grained calcarenitic 

sandstone matrix. Gravel is 60 to 90 

percent white to dark-gray chert 

(angular to rounded, median diameter 

5 mm to 1 em, maximum diameter 8 em); 

5 to 30 percent medium-gray calcareous 

quartzite (subangular to subrounded, 

median diameter 4 em, maximum diameter 

13 em); and 0 to 5 percent medium-gray 

bioclastic limestone (subangular to 

subrounded, median diameter 6 em, 

maximum diameter 17 em). Sandstone, 

calcarenitic, light to medium gray, 

fine to coarse grained and conglomeratic; grades laterally and 

vertically into conglomerate ••••••••• 

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

1. Conglomerate, composed of 50 to 75 

percent gravel in a light- to mediumgray or yellowish-brown, fine- to 

coarse-grained calcarenitic sandstone 

matrix; beds 1 to 3 m thick; subtle 

lamination present; gravel generally 

oriented parallel to bedding. Gravel 

is 85 to 95 percent white to dark-gray 

chert (angular to subrounded, median 

diameter 1 em, maximum diameter 10 em); 

5 to 15 percent calcareous quartzite 

(subangular to rounded, median diameter 

5 em, maximum diameter 15 em); and 0 

to 5 percent medium-gray bioclastic 

limestone, some containing fusulinids 

(subangular to subrounded, median 

diameter 4 to 5 em, maximum diameter 

24 em). Interval forms cliffs ••••••• 

Incomplete thickness Conglomerate 

Mesa Formation •••••••••••••••••••••••••••• 

Underlying strata covered by talus; base of 

section probably is about 15 to 25 m 

above base of Conglomerate Mesa 

Formation. 

Thickness 

meters 

1.8 

4.7 

1.2 

39.0 

83.2 

Section 6. Conglomerate Mesa Formation. Measured 1.0 km 

northwest of hill 8043 in August 1974. 

Thickness 

meters 

Unnamed marine strata (Lower and Middle? 

Triassic) (not measured): 

Limestone, sandy, light to medium 

gray, weathers light brown, fine 

grained; bedding surfaces irregular 

and wavy; poorly exposed ••••••••••••• 

Paraconformable contact. 

Conglomerate Mesa Formation (Upper Permian): 

6. Covered interval..................... 4.6 

5. Conglomerate, composed of 25 percent 

gravel in a light-gray, fine- to coarsegrained calcareous sandstone matrix; 

beds 5 to 15 em thick. Gravel is 95 

percent light- to dark-gray chert 

(angular to subangular, median diameter 

5 to 8 mm, maximum diameter 5 em); 5 

percent light-gray sandy limestone 

(subangular to subrounded, median 

diameter 3 to 4 em, maximum diameter 

10 em); and less than 1 percent mediumgray bioclastic limestone (angular to 

subangular, median diameter 3 em, maximum 

maximum diameter 4 em)............... 3.4 

4. Conglomerate, composed of 50 percent 

gravel in a poorly sorted, fine- to 

coarse-grained sandstone matrix; beds 

15 em to 1 m thick. Gravel is 40 to 

50 percent light-gray sandy limestone 

(angular to subrounded, median diameter 

7 to 10 em, maximum diameter 45 em); 40 

to 50 percent white to light-gray chert 

(angular to subangular, median diameter 

5 mm to 1 em, maximum diameter 10 em); 

5 to 10 percent medium-gray calcareous 

quartzite (median diameter 3 to 4 em, 

maximum diameter 10 em); and 0 to 5 

percent medium- to dark-gray bioclastic limestone (angular to subrounded, median diameter 6 em, maximum 

diameter 15 em). Median gravel 

diameter decreases gradually from base 

to top of interval................... 6.6 

3. Limestone (calcarenite), sandy, 

light gray, massive, generally fine 

to medium grained; locally contains 

coarse-grained quartz and chert 

gravel with a maximum diameter of 

6 mm. Grades laterally into conglomerate that contains large clasts of 

similar sandy limestone.............. 3.4 

2. Covered interval..................... 6.7 

1. Conglomerate, composed of 50 percent 

gravel in a poorly sorted, fine- to 

coarse-grained sandstone matrix; beds 

15 em to 1 m thick except in basal 5 m 

where bedding is massive. Gravel is 

85 to 95 percent white to light-gray 

chert (angular to subangular, median 

diameter 5 to 8 mm, maximum diameter 

8 em) and 5 to 15 percent gray calcareous quartzite (subangular to subrounded, 

median diameter 3 to 5 em, maximum 

diameter 15 em)...................... 27.6 

Total thickness Conglomerate Mesa 

Formation ••••••••••••••••••••••••••• 52.3 

18 Stratigraphy of the Owens Valley Group, Southern Inyo Mountains, California 
Section 6: Lower Permian 

Lone Pine Formation 

Unconformable contact. 

Lone Pine Formation (Lower Permian) 

(not measured): 

Mudstone, siltstone, and very fine 

grained sandstone, grayish orange to 

yellowish brown, slightly calcareous, 

beds 5 mm to 1 em thick; poorly 

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

Thickness 

meters 

Measured Sections 19 
GPO 785-048/48044