Paleozoic Rocks in the 

Black Pine Mountains, 

Cassia County, Idaho 

GEOLOGICAL SURVEY BULLETIN 1536 

Paleozoic Rocks in the 

Black Pine Mountains, 

Cassia County, Idaho 

By]. FRED SMITH, JR. 

GEOLOGICAL SURVEY BULLETIN 1536 

Descriptions of eleven rock units which range 

in age from Devonian to Permian, the thickest 

parts being Early Pennsylvanian to· Early Permian 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1983 
UNITED STATES DEPARTMENT OF THE INTERIOR 

JAMES G. WATT, Secretary 

GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

Library of Congress Cataloging in Publication Data 

Smith, J. Fred (Joe Fred), 1911-1982 

Paleowic rocks in the Black Pine Mountains, Cassia County, Idaho. 

(Geological Survey Bulletin 1536) 

Bibliography: 36 p. 

Supt. of Docs. No.: I 19.3: 

1. Geology, Stratigraphic-Paleozoic. 2. Geology-Idaho-Black Pine Mountains. I. Title. II. Series. 

QE75.B9 no. 1536 557.3s [551.7'2'0979639] 81-607193 

[QE.654] AACR2 

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402 
CONTENTS 

Page 

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Stratigraphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

Rocks south of West Dry Canyon fault . . . . . . . . . . . . . . . . . . . . . . . 8 

Lower plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Devonian System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Jefferson Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Mississippian and Pennsylvanian Systems . . . . . . . . . . . . . . . . 9 

Manning Canyon Shale . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

Middle plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Pennsylvanian System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Oquirrh Formation, limestone member . . . . . . . . . . . . . . . 11 

Lower part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Middle part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

Upper part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

Oquirrh Formation, limestone, sandstone, and quartzite member . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

Oquirrh Formation, limestone and dolomite member . . . . . 18 

Upper plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 

Pennsylvanian and Permian Systems . . . . . . . . . . . . . . . . . . . 21 

Oquirrh Formation sandstone and siltstone member . . . . . 21 

Rocks north of West Dry Canyon fault . . . . . . . . . . . . . . . . . . . . . . . 23 

Plate I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 

Pennsylvanian and Permian Systems . . . . . . . . . . . . . . . . . . . 23 

Beds of West Dry Canyon . . . . . . . . . . . . . . . . . . . . . . . 23 

Permian System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 

Unit A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 

Unit B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 

Plate II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 

Permian System ............ ". . . . . . . . . . . . . . . . . . . . . 32 

Dark-gray limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 

Limestone, silicified limestone, some chert . . . . . . . . . . . . 33 

Conclusions regarding temperatures reached by rocks exposed in this area . 34 

References cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 

ILLUSTRATIONS 

FIGURE 1. Index map showing location of Black Pine Mountains and locations 

of measured stratigraphic sections . . . . . . . . . . . . . . . . . . . . 

2. Generalized geologic map of Paleozoic rocks in the Black Pine Mountains showing conodont localities and color alteration indices . 

3. Correlation chart of Paleozoic rock units in the Black Pine Mountains 

III 

Page 

3 

4 

6 
IV PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

TABLES 

Page 

TABLE 1. Brachiopods collected from the lower part of the limestone member 

of the Oquirrh Formation . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

2. Fusulinid collections and ages from the sandstone and siltstone member of the Oquirrh Formation . . . . . . . . . . . . . . . . . . . . . . . 24 
PALEOZOIC ROCKS IN THE 

BLACK PINE MOUNTAINS, 

CASSIA COUNTY, IDAHO 

By J. FRED SMITH, JR. 

ABSTRACT 

The Black Pine Mountains in the Strevell 15-minute quadrangle are immediately 

north of the Utah-Idaho boundary in the southeast corner of Cassia County, Idaho. 

This quadrangle contains 11 Paleozoic rock units, which range in age from Devonian 

to Permian. All of their contacts except one and probably two are faults of chiefly 

low dips, and younger rocks are faulted over older ones, or over rocks of partly 

equivalent ages. 

A fault transverse to the mountains-here called the West Dry Canyon fault-separates the range into two parts. The area south of this fault is considered to consist 

of three plates-lower, middle, and upper; and the area north of the fault consists 

oftwo plates, called I and II. 

The lower plate to the south contains two formations, in ascending order: the Devonian Jefferson Formation, which has a minimum thickness of 276 m and consists of 

light-gray to almost white dolomite and lesser amounts of gray limestone and sandstone 

and quartzite, and the Upper Mississippian and Lower Pennsylvanian Manning Canyon 

Shale, which consists principally of dark-gray to black argillite and has an exposed 

estimated thickness of 2,000 m. 

The middle plate contains three Pennsylvanian units that are partly age equivalent. 

These three rock sequences in part equivalent but not themselves in stratigraphic 

sequence are here considered as informal members of the Oquirrh Formation. The 

limestone member in the southern part of the quadrangle has a minimum thickness 

of about 2,300 m and is composed of three parts: a lower one of sandy and silty 

limestone, which is very fossiliferous in places, and some sandstone, quartzite, and 

shale; a middle part of limestone, which makes massive outcrops in places, less silty 

and sandy limestone, and some dolomite; and an upper part of mainly gray silty limestone. A limestone, sandstone, and quartzite member of the Oquirrh in the eastern 

part of the quadrangle has an exposed thickness of about 180 m. The third member 

of the Oquirrh in this middle plate and in the eastern part of the quadrangle has 

a minimum thickness of 430 m and consists of gray limestone and light- and dark-gray 

and black dolomite; both rock types make some massive and ledge-forming outcrops. 

This member is similar to the middle part of the limestone member but contains 

more dolomite. 

The upper plate contains a Middle Pennsylvanian (Des Moinesian) to Lower Permian 

(Wolfcampian) sandstone and siltstone member of the Oquirrh Formation, is partly 

equivalent to rocks in the middle plate, and has overridden both the middle and lower 

plates. This member is composed principally of gray, calcareous, tan- and brownweathering quartz sandstone and siltstone. Beds of gray silty limestone are less 

abundant. The estimated thickness is 2, 700 m. 1 
2 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

Rocks north of the West Dry Canyon fault transverse to the range are in two 

plates. In the lower plate, plate I, the beds of West Dry Canyon consist of limestone, 

sandy and silty limestone, and calcareous sandstone and siltstone. They have a thickness of about 2,200 m and range in age from Late Pennsylvanian (Virgilian) to Early 

Permian (Leonardian). These rocks are thus partly equivalent to the sandstone and 

siltstone member of the Oquirrh south of the transverse fault but as a whole differ 

from it lithologically. Unit A lies conformably above the beds of West Dry Canyon. 

It is distinguished by interbedded sequences of dark-gray to black chert and limestone, 

silty limestone, dolomite, siltstone, and sandstone, has a thickness of about 1,480 m, 

and is Lower Permian (probably upper Leonardian). A unit of the same age and 

similar lithology (except for a lack of dolomite) crops out in the northeastern part 

of the quadrangle. This unit is not in contact with any Paleozoic formation in the 

quadrangle; it may grade into or interfinger with unit A, but in the study area the 

two units are separated by Cenozoic deposits and their direct relations cannot be 

seen. 

Plate II, the upper plate north of the fault across the mountains, consists of two 

rock units. The older one is composed of dense dark-gray limestone, which weathers 

light gray and commonly forms platy fragments, and of silty and sandy beds, which 

make up a small percentage of the 745-m thickness. The dark-gray limestone unit 

is the same Early Permian (Leonardian) age as unit A and its equivalent in plate 

I. 

What is apparently the youngest Paleozoic rock unit in the area comprises sandy 

limestone, calcareous sandstone, some chert, and silicified limestone, some of which 

is mostly breccia. The minimum thickness is between 120 and 145 m. These beds 

are presumably Permian. The contact with the underlying dark-gray limestone appears 

to be conformable but may be a fault. 

Color alteration indices (CAl) determined on conodonts from 32 collections indicate 

that the host rocks attained temperatures generally in the range of 190°-300°C north 

of the fault across the mountains and in the range of 300°-400°C south of the fault; 

some rock temperatures in the south possibly surpassed 400°C. These temperatures 

suggest that a postmature or high-temperature methane stage of petroleum generation 

was reached. 

INTRODUCTION 

Eleven Paleozoic map or rock units ranging in age from Devonian 

to Permian are recognized in the Black Pine Mountains and Strevell 

15-minute quadrangle in southeastern Idaho (fig. 1). All contacts except one and possibly two are faults, of chiefly low dips (fig. 2), and 

so total thicknesses are not exposed or measurable for any formation. 

Furthermore, all except possibly the oldest unit are allochthonous or 

at least parallochthonous, and the areas of deposition of the rock units 

are uncertain. Younger rocks are faulted over older ones, or over 

rocks of partly equivalent ages. 

The rock units are separated into a number of plates by these lowangle faults, and they are separated in addition by a fault across the 

mountains partly near West Dry Canyon. South of the West Dry Canyon fault, the range is considered to consist of three principal plates 

(fig. 3). The lower plate contains the Devonian Jefferson Formation 
42"15' 

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w 

_, 

~ 

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cr 

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ii: 

RAFT RIVER 

MOUNTAINS 

INTRODUCTION 

STREVELL 

I 

I 

I 

I 

I 

(/) 

c 

OJ 

§ 

__ l __ 

10 15 KILOMETERS 

3 

FIGURE 1.-Index map showing location of Black Pine Mountains (Strevell15-minute 

quadrangle), Cassia County, Idaho, and locations of measured stratigraphic sections A through F. 

and the Upper Mississippian and Lower Pennsylvanian Manning Canyon Shale. The middle plate contains three Pennsylvanian carbonate 

rock units of partly equivalent ages; the lowest part of one unit is 

also time equivalent to the highest part of the Manning Canyon Shale 

in the lower plate. The upper plate contains a Middle Pennsylvanian 

to Lower Permian sandstone and siltstone member of the Oquirrh 
4 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

1 42°l~'r------------------~-----,-,;nr------m;:mn;v----r-=-'l 

' ' ' ' ' ' ' 

1 0 KILOMETERS 

' ' '\ 

' 

FIGURE 2.-Generalized geologic map of Paleozoic rocks in the Black Pine Mountains 

(Strevell quadrangle), Idaho, showing conodont localities and color alteration indices 

(CAl) of conodonts. Twenty-six collections were studied by B. R. Wardlaw, 4 by John 

Repetski, and 2 by Anita G. Harris. 

Formation and has overridden all other plates and older rocks exposed. Near the southwest corner of the Strevell quadrangle, sandstone and limestone were penetrated in a borehole from a depth of 
INTRODUCTION 

EXPlANATION 

Unlabeled areas are Cenozoic rocks 

Lower 

Permian 

Upper 

Pennsylvanian 

Middle 

Pennsylvanian 

PERMIAN 

PENNSYLVANIAN 

Lower 

Pennsylvanian 

Upper 

Mississippian 

~} 

~ Upper and Middle Devonian 

MISSISSIPPIAN 

} DEVONIAN 

ROCKS NORTH OF WEST DRY CANYON FAULT 

PLATE II 

Limestone, silicified limestone and chert 

gl Dark-gray limestone 

PLATE I 

a Unit A 

b Unit B 

wd Beds of West Dry Canyon 

ROCKS SOUTH OF WEST DRY CANYON FAULT 

UPPER PLATE 

Oquirrh Formation 

OS Sandstone and siltstone member 

MIDDLE PLATE 

Oquirrh Formation 

Is Limestone, sandstone, and quartzit~ member 

ol Limestone member 

od Limestone and dolomite member 

LOWER PLATE 

m Manning Canyon Shale 

Jefferson Dolomite 

---- CONTACT 

---- FAULT -Dashed where approximately located 

---"-..._-'"'-- FAULT OF CHIEFLY LOW DIP-Sawteeth on upper plate 

CONODONT LOCALITIES AND COLOR ALTERATION INDICES (CAl) 

5.5-6.5 (4 collns.) 

o 4 .5-5.5 (15 collns.) 

+ 3 (one colln .)-4 (nine collns.) 

FIGURE 2.-Continued 

5 

about 350 m to 645 m, where they overlie metamorphosed lower Paleozoic rocks similar to those in the Raft River Mountains (Oriel and 

others, 1978). I interpret the sandstone and limestone to be part of 

the upper plate rocks and the structurally lower plates to be lacking. 
6 

z 

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~ 

z 

< z 

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>- (/) 

z 

z 

~ 

PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

SYSTEM/ 

SERIES 

Leonardian 

Wolfcampian 

Virgil ian 

Missourian 

Des Moinesian 

Atokan 

Morrowan 

Chesterian 

-< 

>-

-< 

>-

-< 

>-

-<\ 

>-

-< 

>-

-< 

>-

-< 

'-

Upper and { 

Middle 

Devonian 

ROCKS OF STREVELL 

QUADRANGLE 

PLATE II 

Limestone, silicified 

limestone, some chert PLATE I 

Dark-gray limestone Unit A Unit B 

WEST DRY 

UPPER PLATE Beds of 

West Dry 

Canyon 

Oquirrh 

Formation: 

sandstone CANYON FAULT 

and 

siltstone 

MIDDLE PLATE 

member 

Oquirrh 

Formation: 

Oquirrh limestone 

Formation: and MIDDLE PLATE limestone dolomite 

Oquirrh Formation: member member 

limestone, sandstone 

and quartzite member 

LUWER PLATE 

Manning Canyon 

Shale 

Jefferson Formation 

'------------' 

LARGER REGION 

Phosphoria Formation 

including Meade Peak 

Phosphatic Shale 

Member 

Oquirrh Formation 

Hyrum Dolomite 

FIGURE 3.-Correlation chart of Paleozoic rock units in the Black Pine Mountains 

(Strevell quadrangle), Idaho. Some probably correlative formations in the region are 

also shown. Upper, middle, and lower plates are general structural units south of 

the West Dry Canyon fault. Plates I and II are north of this fault. 

The nature of the contact on the metamorphic rocks is unknown, but 

it probably is a fault. 

North of the fault across the range (West Dry Canyon fault), the 

rocks are in two plates (I and II) and are mostly younger than rocks 

south of the fault. However, the oldest unit north is partly an age 

equivalent of the youngest one south but largely differs from it 

lithologically. Plate I consists of an Upper Pennsylvanian and Lower 

Permian sequence of sandstone in the lowest part grading up into 

calcareous siltstone, silty limestone, and limestone, which is overlain 

apparently conformably by the Lower Permian unit A. Plate II, the 

upper one, contains a Lower Permian dark-gray limestone unit equivalent in age to unit A. This limestone is overlain by a thin unit of 

mostly limestone and silicified limestone of probable Early Permian 
STRATIGRAPHY 7 

age, although its age is uncertain because it is the only rock unit 

in the area from which no fossils were recovered. 

Recognition of the ages and rock types in the Black Pine Mountains 

would add more to the understanding of the regional Paleozoic facies 

relations if the geographic positions of deposition of these units were 

known. All formations south of the West Dry Canyon fault have 

moved an unknown distance in an uncertain, but probably generally 

eastward, direction on the low-angle faults. Juxtaposition of somewhat 

different facies in part of the rock units on each side of the West 

Dry Canyon fault suggests that one or the other or both facies were 

moved long distances into their present positions. On the other hand, 

if this area is one of rapid facies change from one facies to the other, 

no great lateral displacement would have been required to juxtapose 

them. 

For assistance in the field I appreciate the work done by Stephen 

Thompson in 1974, Clyde L. Yancey and Gary Citron in 1975, B. 

T. Brady in 1976, and James N. Surabian in 1977. My thanks also 

go to several paleontologists, identified at appropriate places in the 

text, for their studies of our fossil collections, and particularly to 

Raymond C. Douglass and Bruce R. Wardlaw, each of whom reported 

on more than 20 collections. Their age determinations are essential 

to the stratigraphic and general geologic interpretations. Identifications of conodonts are accompanied by a CAl (color alteration index) 

value that indicates the postdepositional temperature reached by the 

host rock, as established by Epstein, Epstein, and Harris (1977). 

The localities of the fossils recorded in this report are shown by 

the number on the geologic map of the Strevell quadrangle (Smith, 

1982), to which reference should be made for information on outcrop 

areas and detailed structural interpretations as well as fossil localities. 

Few previous geologic studies have been made in the Black Pine 

Mountains. Anderson (1931) reported on a reconnaissance examination 

of eastern Cassia County, and brief mention of rock units in these 

mountains has appeared in field trip guidebooks. French (1975) 

examined the southeastern part of the mountains for a thesis at Utah 

State University. Several references to the Black Pine mining district 

that do not contribute data on the stratigraphy of the area are not 

listed in the references cited. 

STRATIGRAPHY 

In the following discussions, the rock descriptions are presented 

in the measured stratigraphic sections for those units well enough 

exposed for good measured sections. Stratigraphic sections were not 
8 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

measured of four of the mapped units and part of a fifth, so only 

brief narrative descriptions are presented for them. The three structural plates south of the West Dry Canyon fault include units from 

the base up in stratigraphic order, and the two plates north of the 

fault fit in general stratigraphic sequence above those to the south. 

ROCKS SOUTH OF WEST DRY CANYON FAULT 

LOWER PLATE 

DEVONIAN SYSTEM 

JEFFERSO;\J FORMA TIO;\J 

The Jefferson Formation is composed principally of light-gray to 

almost white dolomite and also contains about 25 percent gray limestone and 8 to 10 percent sandstone and quartzite. The total area 

of exposure of these rocks in the Black Pine Mountains is slightly 

more than 0.5 km2

• Faults bound the formation on all sides, and so 

the measured thickness of 276 m must be a minimum. 

Distorted forms of the corals Cladopora?, Thamnopom? sp., and 

Tabulophyllum? sp. (USGS 9696-SD; loc.- No. 1 on geologic map 

(Smith, 1982)) establish the age of this formation as Devonian according to W. A. Oliver, who reported (written commun., 1976) that 

Tabulophyllum? suggests a Middle or Late Devonian age with Frasnian (early Late Devonian) being most likely. Two other collections 

contained Amphipora sp. (USGS 9535-SD; loc. No. 2 on geologic map 

(Smith, 1982)) and Aulopora? sp., Thamnopora sp., and cf. 

Cemtophyllum sp. (USGS 9536-SD; loc. No. 3 on geologic map 

(Smith, 1982)). These were reported by Oliver (written commun., 

1975) to suggest a Middle Devonian age. 

SECTION B.-Jefferson Formation 

[Measured in sees. 32 and 33, T. 15 S., R. 29 E.; location on fig. 1] 

Pennsylvanian and Mississippian Systems. 

Manning Canyon Shale. 

Thrust fault. 

Devonian System: 

Jefferson Formation: 

Limestone, gray and almost white, gray-weathering; sugary texture 

of fine to medium-size grains; alternating gray and white beds commonly a few millimeters to as much as 20 em thick; prominent 10-mthick unit at base. Sparse layers as much as 4 mm thick of sandy 

limestone with angular, medium-size quartz grains occur particuMeters 

larly near the base . . . . . . . . . . . . . . . . . . . . . . . . . 36 
STRATIGRAPHY 9 

Meters 

Devonian System-Continued: 

Jefferson Fonnation -Continued: 

Quartzite, gray, gray-weathering; lenticular . . . . . . . . . . . . . . 10 

Dolomite and limestone, gray, gray-weathering, banded; some beds as 

much as 50 em thick . . . . . . . . . . . . . . . . . . . . . . . . . 27 

Sandstone, gray, brownish-gray-weathering, fine-grained, calcareous; 

mostly angular grains of quartz . . . . . . . . . . . . . . . . . . . 12 

Rubble-covered slope; appears to be mostly light gray to almost white 

dolomite with some sandstone and light- and dark-banded sugary 

limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 

Dolomite, light gray to almost white, very light gray weathering; bedding indistinct except for float of banded rock on slope in upper part. 

Checkered weathered surfaces in places. Some blocks of gray, brownweathering calcareous sandstone are on slope about 30 m above base 

of unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 

Dolomite and limestone, light- and dark-gray; much is thin bedded in 

layers commonly 1--3 mm and as much as about 12 em thick. Limestone, some sugary, ranges from dark gray to almost white; gradations between dolomite and limestone. White calcite occurs in wiggly 

seams and podlike fonns as much as 2 em long and Y4 em thick. 

Beds fonn prominent light and dark bands in places; individual bands 

are as much as 40 em thick. Prominent outcrops. Distorted corals 

from collection USGS 96~D about 22 m above base . . . . . 41 

Dolomite, dark-gray, light-gray to dark-gray-weathering, dense; beds 

commonly 1 mm to 20 em thick; bedding very indistinct in places 

on weathered surfaces as light and dark banding. White calcite veinlets and pods 1 em across occur locally. Upward, some beds are more 

massive and appear to be as much as 1 m thick; checkered weathered 

surfaces. Coral Amphipora in float in upper part 72 

Total Jefferson Formation in Black Pine Mountains area. . . . . . . . . . . . 276 

Fault. 

Pennsylvanian and Mississippian Systems. 

Manning Canyon Shale. 

MISSISSIPPIAN AND PENNSYLVANIAN SYSTEMS 

MA~~I~G CA~YO~ SHALE 

The Manning Canyon Shale in these mountains consists principally 

of dark-gray to black siltstone that has been metamorphosed to argillite over most of the area of exposure. Black shale crops out in a 

few localities. The argillite has distinct slaty cleavage and bedding 

is obscure in many places. Locally, however, the bedding is quite 

distinct; some small-scale crossbeds and scour-and-fill structures a few 

millimeters deep occur very locally. Ripple marks with wave lengths 

of 4-5 em were noted in a few localities. Quartz is the chief constituent 

of the argillite, which also contains micaceous minerals that produce 

a glitter on rock surfaces in places. Cubic cavities and forms of limonite after pyrite are abundant locally. 
10 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

In a study of the metamorphism of the Manning Canyon and Chainman Shales, Christensen (1975, p. 121) determined by X-ray diffraction, infrared absorption, and petrographic examination that the Manning Canyon argillite in the Black Pine Mountains contains quartz, 

illite, chlorite, paragonite, paragonite/phengite, andalusite, chloritoid, 

pyrite, hematite, magnetite, and carbonaceous matter. These minerals 

are listed here without regard to their quantity or origin, whether 

detrital or authigenic. Christensen further stated (1975, p. 111) that 

these rocks were altered by dynamothermal metamorphism and that 

the temperatures "exceeded 350°C, based on appearance of chloritoid, 

but were less than 450°, the breakdown temperature of phengite." 

In this regard, Anita G. Harris reported (oral commun., 1977) that 

the color alteration index on conodonts from this formation indicates 

that the host rock reached a temperature of between 300°C and 400°C. 

Quartzite and limestone lenses make up a relatively small part of 

the Manning Canyon; the quartzite forms prominent outcrops. The 

largest quartzite lens has a maximum thickness of about 20 m and 

exposed length of about 2 km with one end at a fault. This lens is 

a gray-, tan-, brown-, and gray-weathering orthoquartzite with scattered 4-5-mm-diameter grains, many of which are well rounded, in 

a matrix of angular grains of silt and very fine grained sand. Even 

beds, commonly 1-15 mm thick, occur prominently in this lens. Some 

quartzite that is dark gray to almost black does not crop out prominently, but must be lenticular also. It is made of medium, commonly 

well rounded quartz grains scattered through angular, very fine quartz 

grains; stringers and patches of black siliceous material give the rock 

its color. One lens a few meters long consists of rounded and ovalshaped pebbles of light-gray quartzite composed of medium quartz 

grains and of smooth angular pebbles of black quartzite composed 

of silt-size grains. 

Only three limestone lenses were found in this formation, and they 

appear to be short and thin; poor exposures preclude any positive 

determinations of their sizes or shapes, and other similar lenses may 

be present. One lens is light gray; the others are dark gray to black 

and weather tannish gray. They consist of very fine grained, dense 

carbonate rocks containing widely scattered, angular, fine quartz 

grains. 

No thickness of the Manning Canyon Shale has been measured in 

these mountains because of obvious internal structural complexities 

and the lack of a key bed or beds that could be traced far enough 

to determine the structure and stratigraphic sequence of the formation. About 2, 000 m is a reasonable estimate of the exposed thickness. 

Contacts with other stratigraphic units are faults. 

The Manning Canyon Shale in the region is Upper Mississippian 
STRATIGRAPHY 11 

and Lower Pennsylvanian (Trimble and Carr, 1976, p. 29). From the 

Black Pine Mountains a conodont collection (USGS 26140-PC; loc. No. 

7 on geologic map (Smith, 1982)) was reported by Anita G. Harris 

(written commun., 1975) to have a range of uppermost Mississippian 

(uppermost Chesterian) through Lower Permian based on three poorly 

preserved elements, including one platform fragment of Adetognathus? sp. The color alteration index is 5, indicating that the host 

rock reached a temperature of 300° to 400°C. Pectinoid clams cf. Aviculopecten identified by B. R. Wardlaw (written commun., 1978) were 

found on bedding surfaces of argillite at one locality (Field No. F -17, 

loc. No. 8 on geologic map (Smith, 1982)). The age of the Manning 

Canyon Shale in these mountains is presumed to be latest Mississippian (latest Chesterian) to Early Pennsylvanian. 

MIDDLE PLATE 

PENNSYLVANIAN SYSTEM 

OQUIRRH FORMATION, LIMESTONE MEMBER 

This member of chiefly limestone and silty and sandy limestone is 

composed of three parts: a lower· part consisting of sandy and silty 

limestone, which is very fossiliferous in places, and of some sandstone, 

quartzite, and shale; a middle one of limestone, some dolomite, and 

less silty and sandy limestone; and an upper one of mostly silty limestone. Contacts between the parts of this member are gradational 

through thicknesses of several meters or even tens of meters, and 

the separate parts are not satisfactory mappable units. In places along 

the west side of the mountains, it is difficult to determine whether 

the exposures represent the middle or upper part. A minimum thickness of about 2,300 m is partly measured in the field and partly estimated from the geologic map (Smith, 1982). 

The Pennsylvanian age of the limestone member of the Oquirrh 

is established particularly from 12 fossil collections containing conodonts studied by B. R. Wardlaw (except where noted) and 2 collections 

containing fusulinids studied by Raymond C. Douglass. 

LOWER PART 

The lower part of the limestone member of the Oquirrh Formation 

is more heterogeneous than either of the other two parts. It consists 

of silty and sandy limestone, sandstone and quartzite, some shale, 

and many limy beds containing fossils or fossil hash. Abrupt changes 

in bedding attitudes and poor exposures in some areas make accurate 
12 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

thickness measurements essentially impossible. A minimum thickness 

of 450 m is estimated from the geologic map (Smith, 1982) and from 

ground observations. 

Silty and sandy limestones are mostly shades of gray and tan and 

some shades of pink and brown. They weather from light gray to 

dark gray and bluish gray, and to tan, reddish tan, brown, and some 

pink tints. Although a very few limestone beds are fairly pure, most 

contain silt- and sand-size grains and range from silty and sandy limestone to calcareous sandstone and siltstone. Quite commonly, bedding 

in the limestone is as thin as a few millimeters and ranges from a 

few millimeters to about 15 em, but it is not distinct everywhere. 

In places, the slopes are covered with platy fragments of thin-bedded 

units. Massive beds crop out locally but are much less common than 

in the middle and upper parts of the member. Small-scale cross beds 

and scours a few centimeters deep were noted in a very few places 

in the sandy limestone. 

Sandstone, calcareous sandstone, and quartzitic sandstone make up 

much less of the lower part of the limestone unit than do the limestones, but they are important in the recognition of this part. The 

sandstone is gray and tan, weathers the same colors, and is composed 

almost entirely of angular to well-rounded quartz grains that range 

from fine to coarse sizes and are poorly to fairly well sorted. Ferruginous stains speckle some beds. Bedding ranges from very thin to thick 

and is indistinct in some units. Regular layers of light and dark grains 

form prominent bands from 3 to about 15 mm thick in local units. 

Planar crossbeds in layers 25-50 em thick form a 4-m-thick exposure 

at one locality. 

Gray and light-purple calcareous siltstone and black shale are interbedded locally with the limestone and sandstone. 

Units in this lower part are very fossiliferous in places. The fossils 

are commonly broken, and beds of fossil hash consist of fragments 

of bryozoans, brachiopod shells and spines, and crinoid columnals. Corals occur locally, and one bed of colonial corals can be traced a few 

meters around the axis of an overturned anticline. Worm borings 6-12 

mm across and several centimeters long were observed covering a 

bedding surface at one locality. 

Conodont collections, studied by B. R. Wardlaw (written commun., 

1977 and 1978), from the lower fossiliferous part of the limestone member indicate a Lower Pennsylvanian (lower Morrowan) position and 

include the following (numbered localities appear on geologic map 

(Smith, 1982)): USGS 25535-PC, loc. No. 9, Rhachistognathus cf. R. 

muricatus (Dunn), probably Lower Pennsylvanian (Morrowan), CAl 

5 (300°-400°C); USGS D30-PC, loc. No. 10, Adetognathus gigantus 

(Gunnell), Lower Pennsylvanian (Morrowan), CAl 5 (300°-400°C); 
STRATIGRAPHY 13 

USGS 26116--PC, loc. No. 11, Adetognathus sp. and Rhachistognathus 

muricatus (Dunn), Lower Pennsylvanian (Morrowan), CAl 5 (300°-

4000C); USGS D57-PC, loc. No. 12, Adetognathus gigantus (Gunnell), 

Rhachistognathus muricatus (Dunn), and Spathognathodus?, Lower 

Pennsylvanian (probably lowermost Morrowan), CAl 5 (300°-400°C); 

field No. F-108, loc. No. 13, Adetognathus spathus (Dunn), bar and 

blade fragment, Lower Pennsylvanian (Morrowan), CAl 5 (300°-

4000C). According to Wardlaw, Rhachistognathus muricatus is diagnostic of latest Chesterian (Mississippian) and earliest Morrowan 

(Pennsylvanian) age rocks, whereas Adetognathus is rare in latest 

Chesterian and common in the Morrowan, and its occurrence with 

Rhachistognathus in the same sample indicates a position very close 

to the Mississippian-Pennsylvanian boundary, probably lowermost 

Morrowan. 

Several collections of bryozoans were examined by 0. L. Karklins 

(written commun., 1974 and 1976), who identified Rhabdomeson sp. 

indet., Ascopora?, and Rhornbopora? sp. but found that replacement 

by silica had obliterated the significant skeletal structures and made 

specific identification impossible. He did, though, state that the forms 

were late Paleozoic and typical Carboniferous-Permian genera. Corals 

reported by W. J. Sando (written commun., 1974 and 1975) are 

Heintzella? (USGS 26116--PC, loc. No. 11 (Smith, 1982), and USGS 

25538-PC, loc. No. 14 (Smith, 1982)), and Amplexus (USGS 26117-PC, 

loc. No. 15 (Smith, 1982)). This last sample also contained conodonts 

Bispathodus cf. B. aculeatus (Branson and Mehl), Gnathodus?, and 

unidentified bar fragments (B. R. Wardlaw, written commun., 1977). 

The Bispathodus has a narrow range from uppermost Upper Devonian 

to Lower Mississippian (Kinderhookian), but the conodont elements 

appear to be abraded, and they must be detrital in these Pennsylvanian rocks. Brachiopods (table 1) collected at several localities are 

mostly poorly preserved and are commonly present as scrappy bits, 

according to B. R. Wardlaw. 

MIDDLE PART 

The middle part of the limestone member consists principally of 

gray limestone, which characteristically forms more massive beds than 

are found in the lower and upper parts. These massive units make 

bold outcrops in many areas, and they also weather locally to produce 

slopes covered with platy or chunky pieces. Silty or slightly sandy 

beds are present but are much less abundant than in the upper and 

lower parts. Very widely scattered, small chert nodules are found 

chiefly as loose fragments. This middle part contains few megascopic 

fossils. A thickness of 450 m is estimated from the geologic map 

(Smith, 1982) and from other field data. 
14 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

TABLE !.-Brachiopods collected from the lower part of the limestone member of the 

Oquirrh Formation 

[Identifications by B. R. Wardlaw, 1977 and 1978; leaders(--), not present] 

Locality no. on geologic map 9 14 (Smith, 1982) 

USGS fossil collection no. 25535 35536 

PC PC 

Field collection no. F-1 F-13 

AnthPaeoapiPi[eP sp.----

AnthPaeoapiPifeP?-------

Antiquatonia-----------

Antiquatonia------------

Buxtonia?---------------

CanePinella sp.---------

ChoPiatitea sp.---------

CleiothyPidina sp.------

Compoaita 

aubtilita (Hall)-----

Compoaita sp.-----------

CPeniapiPi[eP sp.-------

DePbyia sp.-------------

DePbtua?----------------

Dielaama sp.------------

HetePaloaia?------------

Huatedia sp.------------ KutoPginella?-----------

LinopPoduetua sp.-------

Liaaoehonetea sp.-------

NeoapiPi[eP sp.---------

PunetoapiPi[eP sp.------

PunetoapiPifep?---------

RetieulaPiina sp.-------

Rhipidome lla cf. 

F. nevadenaia--------

Stenoeiama sp.----------

Echinoconchid------------ --

Spiriferoid-------------- --

Large spiriferoid cf. 

NeoapiPifep---------

16 

F-15 

F-18 

and 

F-30 

X 

X 

17 18 19 13 20 

25541 

PC 

F-19 F-33 F-108 F-112 F-113 

21 

The limestone in the middle part is light to dark gray and weathers 

to shades of gray. It is most commonly dense but is finely crystalline 

in places. Bedding is completely or almost completely obscured in 

many massive outcrops, which may weather to form large rounded 

surfaces or ledgy slopes. Single massive units in places attain thicknesses of as much as about 12 m. Well-developed, regular beds from 

15 to 30 em thick occur in places, and laminated sequences of slightly 

sandy or silty limestone beds a few millimeters thick crop out prominently in some areas. A black, shaly and platy, carbonaceous limestone 

was observed only in one exposure about 30 m thick and 0.4 km long 

in the bottom of Formation Canyon. 

Dolomite constitutes possibly no more than 10 percent of the middle 

part of the limestone member but is prominent in some areas. It is 

dense or medium to fine crystalline, gray and very dark gray, and 

weathers light to very dark gray; it commonly presents a finely checkered surface. The dolomite occurs as irregular blobs in the limestone 

and as beds as much as 4 m thick. 
STRATIGRAPHY 15 

Over much of the southern part of the Black Pine Mountains, the 

limestone has been much fractured and is laced with seams of calcite, 

commonly 3-5 em and as much as 25 em apart. In places the rock 

is also brecciated and recrystallized. 

The middle part of the limestone member of the Oquirrh Formation 

is Middle Pennsylvanian, because one conodont collection from it is 

no older than Middle Pennsylvanian and it is overlain by the Middle 

Pennsylvanian silty limestone forming the upper part of the member. 

Conodont collection numbers and identified and dated forms (B. R. 

Wardlaw, written commun., 1977; except as noted) follow: field No. 

F -52, loc. No. 22, on geologic map (Smith, 1982), Adetognathus sp. 

and Idiognathodus cf. I. delicatus Gunnell, Pennsylvanian (upper Morrowan to lower Virgilian), CAl 5 (300°-400°C); USGS D29--PC, loc. 

No. 23 (Smith, 1982), Streptognathodus cf. S. oppletus Ellison and 

Ozarkodina sp., Middle to Upper Pennsylvanian (probably lower Des 

Moinesian to Missourian), CAl 6 (400°-500°C); USGS 27018-PC, loc. 

No. 24 (Smith, 1982), one poorly preserved Idiognathodus sp., Lower 

Pennsylvanian (Morrowan) to Lower Permian (Wolfcampian), CAl 

about 5 (at least 300°C) (John Repetski, written commun., 1977); and 

field No. F-74, loc. No. 25 (Smith, 1982), one small encrusted, slightly 

broken specimen of N eognathodus?, probably Pennsylvanian, CAl 

(300°-400°C). 

UPPER PART 

Silty limestone forms the characteristic lithology of the upper part 

of the limestone member of the Oquirrh Formation, and, commonly, 

platy fragments of silty limestone cover the slopes. However, more 

nonsilty beds occur than are indicated by the measured stratigraphic 

section. Massive limestone crops out locally to make prominent exposures, but laterally these massive beds pass into areas covered with 

the platy fragments. Pieces of black chert are sparse and widely scattered. In the southwestern part of the mountains, tan-weathering, 

calcareous and noncalcareous sandstone and siltstone compose a 400-

m-thick zone of lenticular rock units in the lower half of this upper 

part. These tan units appear to interfinger with and probably grade 

northward into silty gray limestone. Gray, tan, and pink siltstone, 

some of which is calcareous, and less claystone also occur with the 

silty limestones. The thickness of 1,360 m measured for this upper 

part is a minimum figure because the top is covered with gravel at 

the mountains' edge. 

The silty limestone upper part of the limestone member of the 

Oquirrh is also Middle Pennsylvanian. Fusulinid collection USGS 

f13813 (loc. No. 26 on geologic map (Smith, 1982)) contained Middle 

Pennsylvanian (probably upper Atokan) Fusulinella sp. and collection 
16 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

USGS f13814 (loc. No. 27 (Smith, 1982)) also contained Middle Pennsylvanian Fusulinella (R. C. Douglass, written commun., 1977). Conodonts compatible with the Middle Pennsylvanian designation from 

collection USGS D56-PC (loc. No. 28 (Smith, 1982)) are Adetognathus 

and Neognathodus cf. N. medadultimus Merrill, Morrowan to lower 

DesMoinesian, CAl 4.5-5 (240°-400°C) (B. R. Wardlaw, written commun., 1977) and from collection USGS 27019-PC (loc. No. 29 (Smith, 

1982)), Idiognathodus cf. I. delicatus Gunnell, Neognathodus cf. N. 

bothrops Merrill, Al (hindeodelliform) element, and 0 ( ozarkodiniform) 

element, Morrowan through Des Moinesian, CAl 5-5.5 (300° +C) 

(John Repetski, written commun., 1977). Corals identified by W. J. 

Sando (written commun., 1975 and 1977) are Caninia sp. and Multithecopora sp. from collection USGS 26848-PC (loc. No. 30 (Smith, 

1982)), and Caninia sp. from collections USGS 26115--PC (loc. No. 

31 (Smith, 1982)) and USGS 26849-PC (loc. No. 32 (Smith, 1982)). 

One collection (USGS 26218-PC; loc. No. 33 (Smith, 1982)) is reported 

by Mackenzie Gordon, Jr. (written commun., 1976) to contain the 

brachiopod Juresania nebrascensis (Owen)?, the pelecypod Phestia 

sp., the gastropod Euconospira? sp. indet., and ammonoids 

Metacoceras sp., Metacoceras (Huanghoceras)? sp. indet., and a schistoceratid form, gen. and sp. indet. According to Gordon the early 

whorls in the schistoceratid appear to be triangularly coiled and thus 

typical of forms in Middle Pennsylvanian rocks. Two collections of 

poorly preserved bryozoans have the general appearance of upper Paleozoic forms (0. L. Karklins, written commun., 1975 and 1976). 

SECTION C.-Upper part of the limestone member of the 

Oquirrh Formation 

[Measured in sees. 22, 23, and 14, T. 16 S., R. 28 E.; location on fig. 1] 

Quaternary System. 

Gravel. 

Pennsylvanian System: 

Oquirrh Formation, limestone member: 

Upper part: 

Limestone, gray, gray-weathering, dense, silty; quartz silt grains 

stand out on weathered surface; scattered outcrops, but mostly 

covered with pieces 2-5 em across; some pieces tinted red or 

tan. Layers of more silty limestone as much as 40 em thick in 

lower part; siltier layers weather grayish tan. Silty layers 5-8 

Meters 

em thick mark bedding in gray limestone in upper 2 m . . 270 

Limestone, gray, gray-weathering, silty; in a few places, mediumsized angular quartz grains are scattered through the rock; platy 

pieces 0.5--1 em thick; thin-bedded very silty limestone is in 

layers as much as 40 em thick; tan and lighter gray pieces more 

abundant on slope near base . . . . . . . . . . . . . . . . . . . . . . 207 
STRATIGRAPHY 

Pensylvanian System-Continued 

Oquirrh Formation, limestone member-Continued 

Upper part-Continued 

Limestone, gray, silty and sandy; scattered outcrops; bedding commonly indistinct. Fusulinid collection USGS f13813 (loc. No. 26 

on geologic map (Smith, 1982)) from about 40 m above the base, 

contains Fusulinella sp. In the upper 4 m the limestone is less 

silty and contains scattered fine- to medium-sized rounded grains 

of quartz; also contains bryozoans and sparse crinoid columnals . 

Limestone, gray, gray-weathering, silty; scattered bryozoans .. 

Siltstone and fine-grained sandstone, light-gray to tan; weather tan 

with brecciated-appearing surfaces in places; gray silty limestone 

makes up less than 1 percent of the unit . . . . . . . . . . . . . 

Sandstone and siltstone, calcareous, tan; less silty limestone. Varying strikes and some vertical dips make the measured thickness 

uncertain ................................... . 

Limestone, gray, gray-weathering; silty, except some near top; 

slopes covered with platy pieces . . . . . . . . . . . . . . . . . . . . 

Limestone, gray; weathers gray and tan in part; silty, although 

some contains only a very few silt grains; both chunky and platy 

pieces on slope; many bryozoans in lower part . . . . . . . . . 

Total, upper part of limestone member of Oquirrh Formation ...... . 

NoTE.-Gradational contact from more to less silty limestone. 

Oquirrh Formation, limestone member: 

Middle part. 

OQUIRRH FORMATION, LIMESTONE, SANDSTONE, 

AND QUARTZITE MEMBER 

17 

Meters 

240 

26 

144 

265 

50 

158 

1,360 

This member consists principally of limestone, which characteristically is silty or sandy in various degrees, and contains sandstone and 

quartzite in lenticular units within a zone perhaps no more than 40 

m thick. A straightforward sequence of the member is not determinable, because bedding attitudes are too variable within a few meters 

or a few tens of meters to make a reliable stratigraphic reconstruction 

possible. For the same reason, a thickness is not determinable. The 

apparent base is overlain by gravel, which covers a normal fault, and 

the top is a thrust fault. So, the following description is generalized 

and is not presented as a stratigraphic sequence. The exposed thickness is estimated to be 180 m. 

Much of the limestone is light gray and weathers to form light-tannish-gray, platy pieces, many of which are 6-12 mm thick. Bryozoans 

are abundant in some beds. Some sandy limestone units are made 

of fine to coarse, well-rounded quartz grains in a gray limestone matrix without visible bedding; weathered fragments on the slopes, however, indicate that the bedding is probably thin. A characteristic 

lithologic type is very sandy, gray limestone in which the sand grains 

form layers 1.5-6 mm thick that weather brown. These layers show 
18 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

small-scale, wavy bedding, scours as much as 12 mm across, smallscale crossbedding, anastamosing or irregular patterns, and some ripple bedding. Fine to medium, mostly well rounded quartz grains make 

up the sand in these beds. Locally, brown-weathering, nodularappearing spots 2-8 em across occur on the gray-weathering limestone 

surfaces. 

Lenticular bodies of grayish-brown calcareous sandstone that weather light brown and consist of fine to coarse quartz grains form some 

prominent outcrops. Other bodies are tannish-gray calcareous sandstone, quartzitic sandstone, and quartzite composed of silt- and sandsized grains, which are well rounded and well sorted in some layers 

but not in others. Oscillation ripple marks with wavelengths of about 

5 em are prominent in a few places. 

The Pennsylvanian age of this member is established on three conodont collections. An Early Pennsylvanian (Morrowan) or Morrowan 

to early Atokan (early Middle Pennsylvania) age seems to be indicated. Conodont collections, their contained forms and ages as reported by John Repetski and Anita G. Harris (written commun., 

1979), and map locations follow: USGS 26154-PC, loc. No. 4 on 

geologic map (Smith, 1982), Declinognathodus sp., CAl 6 (more than 

350°C), Pennsylvanian (Morrowan to early Atokan); USGS 27016-PC, 

loc. No. 5 (Smith, 1982), Adetognathus sp., CAl 5--5.5 (more than 

300°C), Pennsylvanian to Early Permian; and USGS 27017, loc. No. 

6 (Smith, 1982), Declinognathodus sp. and Adetognathus spp., CAl 

5--5.5 (more than 300°C), Pennsylvanian (probably Morrowan). Declinognathodus Dunn (included within Idiognathoides, Streptognathodus, or Gnathodus by various authors) ranges from at or near 

the base of the Morrowan into the Atokan. 

This limestone, sandstone, and quartzite member is an age equivalent of part of the lower part of the limestone member and also part 

of the limestone and dolomite member of the Oquirrh Formation. It 

is somewhat similar to the lower part of the limestone member in 

that it contains sandstone and silty and sandy limestone, but shale 

and prominent fossil-hash beds like those in the limestone member 

were not noted in it and the general lithologic appearance of the two 

members differs. The limestone, sandstone, and quartzite member is 

different from the limestone and dolomite member, which it underlies 

at a low- angle fault contact. 

OQUIRRH FORMATION, LIMESTONE AND DOLOMITE MEMBER 

The limestone and dolomite member of the Oquirrh Formation is 

composed of gray limestone and light- and dark-gray to black dolomite, 

both of which commonly weather with a checkered surface. Beds crop 
STRATIGRAPHY 19 

out on slopes with some ledges and, in places, cliffs. Limestone is 

the dominant exposed rock type in the lower and upper parts; dolomite 

is predominant in the middle part. A characteristic lithologic type, 

particularly in the uppermost part, consists in many places of white, 

sugary-textured calcite surrounding blocks of dolomite. The calcite 

commonly retains the original bedding of the rock, and small tight 

folds are locally common. Relatively short lenticular bodies of ferruginous quartzite were observed at two localities. One body is poorly exposed over a maximum length of about 150 m; the other appears to 

be even shorter and is ovate in cross section. Faults bound this member, and the measured thickness of 430 m is thus a minimum. 

The limestone and dolomite member resembles the middle part of 

the limestone member of the Oquirrh but contains much more dolomite. Massive limestone in the two units is very much alike, and the 

dolomites are alike also but are generally much thicker in the limestone and dolomite member. According to B. R. Wardlaw (oral commun., 1978), conodont collections indicate that the lowest part of the 

limestone member of the Oquirrh is older than the limestone and dolomite member. The limestone and dolomite member must be at least 

partly the same age as the middle part of the limestone member, 

to which it is similar lithologically, and it may be equivalent to much 

of the limestone member. 

A Pennsylvanian age for this member is established on two conodont 

collections studied by B. R. Wardlaw (written commun., 1977). Collection USGS D54-PC, loc. No. 34 on geologic map (Smith, 1982), from 

the topographically lower part of the member, contains Adetognathus 

lautus Gunnell, Anchignathodus minutus (Ellison), Idiognathodus cf. 

T. delicatus Gunnell, and Xaniognathus sp. and is Lower to Upper 

Pennsylvanian (upper Morrowan to Missourian), CAl 6.5 (more than 

450°C). Collection USGS D5&-PC, loc. No. 35 (Smith, 1982), from 

the topographically higher part of the formation, contains Adetognathus lautus Gunnell, Idiognathodus cf. I. delicatus Gunnell, Idiognathoides cf. I. macer (Wirth) and is Lower Pennsylvanian, CAl 5.5 

(350°-450°C). According to Wardlaw, the occurrence of the large-platform type of I diognathodus with this type of I diognathoides identifies 

the containing beds as middle Morrowan and indicates that they are 

older than those containing the first and topographically lower collection (USGS D54-PC). This suggests that the member may be overturned or that it may be faulted. No indication of either structural 

possibility was recognized on the hill where the fossils were collected 

and the stratigraphic section was measured, although a low-angle fault 

does repeat part of the member on the next ridge to the north. Structural relations to other rock units suggest that this unit as a whole 

is right side up and it is considered to be so in this report, but with 
20 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

the understanding that it may be overturned or that repetition of 

beds by unrecognized faults may have occurred. In either position, 

the general sequence of mostly dolomite in the middle part and mostly 

limestone in the lower and upper parts is the same. 

SECTION A.-Limestone and dolomite m~mber of the Oquirrh Formation 

[Measured in the south part of sec. 34, T. 15 S., R. 28 E.; location on fig. 1) 

Pennsylvanian System: 

Oquirrh Formation, limestone member. 

Low-angle fault. 

Oquirrh Formation, limestone and dolomite member: 

Limestone, gray; some in massive units; irregular masses of very dark 

gray dolomite as much as 0.6 m across. Unit is mostly limestone; 

Meters 

a layer of dark-gray dolomite 1 m thick is about 3 m below the top . 35 

Limestone, much light-salmon-colored, and light-gray, massive; calcite, 

but less than in unit below . . . . . . . . . . . . . . . . . . . . . . . . . . 29 

Limestone, light-gray, light-gray-weathering, finely crystalline; some 

very pale salmon, fine-grained limestone; much coarse breccia with 

angular pieces of gray limestone as much as 1 m long in a white 

calcite matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 

Limestone, light-gray, light-gray-weathering; dense as well as some 

very fine, sugary texture; in massive units as much as 6 m thick; 

calcite seamed. Some dolomite in irregular round clumps in limestone; 

dolomite is light gray and weathers same color, but is slightly darker 

than limestone; many dark-gray dolomite pieces are on slope upward 

from 50 m above base, and a 1-m-thick dolomite bed crops out near 

top; much rubble cover over upper part . . . . . . . . . . . . . . . . . 80 

Dolomite, light- and dark-gray, light-gray- to very dark gray weathering, massive; many loose blocks on slope. Limestone makes up about 

5 percent of this unit. Across valley to north, dolomite, much of which 

is very dark, forms bluffs about 20 m high . . . . . . . . . . . . . . . 41 

Dolomite and limestone, both gray; dolomite is predominant; some very 

dark gray, very finely crystalline dolomite weathering very dark 

gray. Thin calcite veinlets cut the dolomite . . . . . . . . . . . . . . . 25 

Limestone, gray, gray- to light-gray-weathering, mostly dense; and gray 

dense dolomite weathering light gray; limestone predominant and in 

massive units, bedding obscure. A little limestone is slightly silty; 

brown-weathering, irregular knobby bands of limestone about 2-15 

em wide occur in places. Dolomite appears to be in units as much 

as 5 m thick. Percentage of dolomite increases upward in upper 25 

m. In places in upper part, white crystalline calcite has replaced dolomite and surrounds blocks of dolomite commonly as much as 3 m 

across . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 

Limestone, gray, light-gray- to dark-gray-weathering, mostly dense; 

some light-gray, fine-grained sugary limestone. Many calcite veinlets 

trending in all directions; also veins 0.3 m wide and irregular calcite 

clumps 0.6 m across and 0.5-1 m long; coarsely crystalline calcite 

in veins as much as 0.6 m thick . . . . . . . . . . . . . . . . . . . . . . . 58 

Total exposed thickness of limestone and dolomite member . . . . . . . . . 430 

NoTE.-Base of limestone and dolomite member not exposed; covered with 

gravel; a normal fault is concealed by the gravel. 
STRATIGRAPHY 21 

UPPER PLATE 

PENNSYLVANIAN AND PERMIAN SYSTEMS 

OQUIRRH FORMATION, SANDSTONE AND SILTSTONE MEMBER 

The sandstone and siltstone member of the Oquirrh Formation in 

the Black Pine Mountains consists principally of light-gray, mediumlight-gray, and light-yellowish-gray, poorly sorted calcareous quartz 

siltstone and sandstone, which weather tan and brown. Sparse beds 

of light-gray and pink calcareous sandstone weather to form light-pink 

plates 6-12 mm thick and 7-10 em across on some slopes. A few beds 

are noncalcareous and some are quartzitic. A much lesser percentage 

of the member consists of gray and dark-gray silty limestone that 

weathers gray. The limestone layers 0.3-0.6 m thick are scattered 

through the tan siltstone and sandstone, in units interlayered with 

calcareous siltstone and sandstone through several tens of meters, 

and in sections of mostly silty limestone a few meters thick; silty 

limestone also makes up most of the lowest part of the member. Exposures of the sandstone and siltstone member are good locally but are 

poor over extensive areas. In many places, bedding shows most clearly 

in the more calcareous gray beds where layers 1 mm to 30 em thick 

are common. Some of the tan siltstones and sandstones are in beds 

as much as 30 em thick but also occur in massive units with no obvious 

bedding and in outcrops that are entirely breccia. These breccias make 

prominent exposures in many parts of the area. 

As well as being interlayered, the siltstones and sandstones and 

gray silty limestone must grade into and interfinger with one another, 

although exposures are generally too poor to permit observance of 

such relations. Along the west canyon wall of the largest tributary 

on the north side of Kelsaw Canyon, about 180 m of almost entirely 

tan weathering siltstone and sandstone appear to interfmger across 

about a 1-km-long rubbly slope into an interlayered sequence of tanweathering rocks and gray silty limestone. The tan- and brownweathering beds contain angular quartz grains of very fine sand 

and silt, scattered large quartz grains mostly of medium and less 

commonly of coarse sand sizes, and various percentages of calcite 

cement. The larger grains commonly are rounded and have etched 

or sutured margins. 

The gray silty limestone beds also contain scattered fine to medium 

quartz grains in some layers and very sparse coarse grains. These 

limestones are fusulinid bearing in many places. 

Conglomerate was noted at three places and probably occurs at 

others, but it certainly equals only a trace of the total thickness of 

the sandstone and siltstone member. One distinctive conglomerate bed 

(in NW% sec. 26, T. 15 S., R. 29 E.) in the lower part of the member 
22 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

is composed of closely packed chert pebbles, mostly light gray with 

some dark gray and pink. They are set in a slightly calcareous matrix 

containing chert and quartz grains. The rock weathers gray and pink. 

Most pebbles are angular; a few are rounded; the largest pebble noted 

is 1 em across. The other two conglomerates occur in the middle part 

of the member, as established by ages of fusulinids. One (in NW¥4 

sec. 23, T. 15 S., R. 28 E.), seen only as fragments on the ground 

surface, is made of flat limestone pebbles commonly 3 em across; one 

clast observed was 25 em long and 10 em thick. The other conglomerate (in NE¥4 sec. 21, T. 15 S., R. 29 E.) in the middle part of the 

member forms a bed 0.6--0.76 m thick and of an unknown but probably 

short length. Rounded and flattened gray limestone pebbles that weather dark blue gray are embedded in a coarse-grained sandy limestone 

matrix. The longest pebble seen was 5 em long and 6 mm thick, and 

the largest round pebble, 4 em in diameter. 

The oldest recognized part of the member consists chiefly of silty 

gray limestone at and just south of the head of West Dry Canyon. 

This limestone is similar to that in other parts of the member, but 

it is not abundantly fossiliferous and it makes a fairly continuous limestone sequence rather than being interlayered with tan siltstone and 

sandstone beds. This limestone constitutes essentially a different 

lithologic unit from the rest of the member, but the change upward 

into the tan sandstone and siltstone is so gradual through a broad 

interval in an area of generally poor exposures that the lower limestone was not mapped separately. This lowest part also contains some 

thin, mostly nonsilty strata. As a unit it is similar to the upper part 

of the limestone member of the Oquirrh Formation. The only fossils 

found in this oldest part of the sandstone and siltstone member are 

Fusulinella sp. and Beedeina sp. (USGS f13944, loc. No. 37, and 

USGS f14008, loc. No. 36 on geologic map (Smith, 1982)) of Middle 

Pennsylvanian (Des Moinesian) age (R. C. Douglass, written commun., 1977 and 1978) and poorly preserved conodonts Adetognathus 

sp., I diognathodus sp., and bar fragments (Field No. 124, No. 36a 

(Smith, 1982)) with an age range of Early Pennsylvanian (late Morrowan) to Early Permian (late Wolfcampian), CAl 5 (300°-400°C) (B. 

R. Wardlaw, written commun., 1980). Thus, these strata are about 

the same age as the upper part of the limestone member, which may 

indicate that the contact between the limestone member and the sandstone and siltstone member of the Oquirrh is gradational. The two 

members are readily separable farther south in the Black Pine Mountains, where the contacts are faults and more contrasting rock types 

are against each other. 

An accurately determined stratigraphic sequence for the sandstone 

and siltstone member of the Oquirrh has not been established, princi-
STRATIGRAPHY 23 

pally because exposures are poor over wide areas and key beds useful 

in fitting pieces together have not been recognized. However, as a 

result of the study of 22 collections of fusulinids (table 2) by R. C. 

Douglass (written commun., 1974, 1975, 1976, 1977, and 1978), a general age sequence is recognized. A fit of the lithologic types to this 

sequence suggests that, except for the more continuous gray silty 

limestone in the lowest part, there are no significant lithologic differences of different ages. The chert pebble conglomerate does occur 

in the lower part and the limestone pebble conglomerates somewhere 

near the middle, but none of these was traceable far enough to establish its use as a stratigraphic marker over any large area. 

A thickness of about 2, 700 m is estimated for the sandstone and 

siltstone member of the Oquirrh in the Black Pine Mountains. This 

estimate is based on bedding attitudes plotted on the the geologic 

map (Smith, 1982) and on the stratigraphic sequence as indicated by 

the fusulinid collections. 

The sandstone and siltstone member of the Oquirrh Formation 

ranges in age from Middle Pennsylvanian (Des Moinesian) to Early 

Permian (early Wolfcampian). Upper Pennsylvanian Virgilian strata 

are widespread in the member and together with lower Wolfcampian 

rocks make up most of the member. One fossil collection of corals 

(USGS 26580-PC, loc. No. 58 on geologic map (Smith, 1982)) contained 

Caninia sp. and Multithecopora sp. of probable Middle or Late Pennsylvanian age (W. J. Sando, written commun., 1977) and one conodont 

Tdiognathodus magnificus Stauffer and Plummer, CAl 5 (300°-400°C), 

of Atokan to early Virgilian age (B. R. Wardlaw, written commun., 

1979). Two other conodont samples from no more than 15 m stratigraphically below this collection are included under loc. No. 58 on the 

map. Sample Field No. F-125A contained Adetognathus sp., Idiognathodus magnificus Stauffer and Plummer, and bar fragments of 

Atokan to early Virgilian age, CAl 5 (300°-400°C), and F -127 contained abraded and rounded fragments of Adetognathus sp. and I diognathodus sp. of late Morrowan to late Wolfcampian age, CAl 5 (300°-

4000C) (B. R. Wardlaw, written commun., 1980). These are from an 

area of Upper Pennsylvanian rocks, based on fusulinids. 

ROCKS NORTH OF WEST DRY CANYON FAULT 

PLATE I 

PENNSYLVANIAN AND PERMIAN SYSTEMS 

BEDS OF WEST DRY CANYO~ 

The beds of West Dry Canyon consist of limestone, sandy and silty 

limestone, and calcareous sandstone and siltstone. Silty limestone is 

the most prominent lithology. In the lower 600 m these strata are 
TABLE 2.-Fusulinid collections and ages from the sandstone and siltstone member of the Oquirrh Formation 

USGS fossil 

collection no. 

f13642--------

f13639--------

f13646--------

f13645--------

fl3811--------

f13812--------

f13638--------

f24994--------

Lidentifications and age determinations by R. C. Douglass] 

No. on geologic 

map 

(Smith, 1982) 

57 

56 

55 

54 

53 

52 

51 

50 

Fusulinids 

Seh~agePina sp. and 

TPitieites sp. 

TPitieites sp.; fairly 

well preserved. 

Possible Seh~agePina sp. 

and TPitieites sp. 

suggested; some stretched 

and crushed. 

TPitieites sp.; abundant. 

TPitieites, possibly two 

species, and 

PseudofusuZineZZa sp.; 

stretched and squeezed. 

TPitieites sp. and 

PseudofusuZineZZa sp. 

TPitieites sp.; fairly well 

preserved specimens. 

TPitieites sp.; scattered 

fragments. 

Age 

Early Permian; early 

Wolfcampian. 

Early Permian?; early 

Wolfcampian suggested. 

Early Permian?; if some 

specimens are Seh~agePina 

sp., Early Permian is 

indicated 

Late Pennsylvanian-Early 

Permian?; suggests late 

Virgilian or early Wolfcampian. 

Late Pennsylvanian or Early 

Permian. 

Late Pennsylvanian or Early 

Permian. 

Late Pennsylvanian: 

Virgil ian. 

Do. 

~ 

~ t"4 

tz:l 

0 

~ 

0 

-

0 

~ 

0 

0 

~ 

z 

"':3 

= tz:l 

td 

t"4 

> 0 

:;:.::: 

'"C 

z 

tz:l 

~ ~ 

z 

~ 

z 

00 
£13647--------

£24995--------

£24993--------

£24992--------

£13806--------

£13807--------

£13808--------

£13809--------

£13640--------

£13641--------

£13643--------

£13644--------

£13944--------

£14008--------

49 

48 

47 

46 

45 

44 

43 

42 

41 

40 

39 

38 

37 

36 

Tr>iticites sp. and possibly 

PseudofusuLinella sp. 

Traiticites sp. fairly common, 

PseudofusulineLLa? sp. rare 

and staffellid rare. 

Traiticites sp.; scattered 

fragements 

---do------------------------

Traiticites sp. and 

PseudofusulinelLa sp. 

Traiticites sp. abundant. 

Traiticites sp. aff. T. 

culLomensis common and 

PseudofusulinelLa sp. rare. 

Troiticites sp. 

Traiticites ? sp.; abraded 

and crushed. 

Troiticites? sp.; fragement s. 

Troiticites sp.; broken and 

abraded. 

Traiticites spp.; broken and 

abraded. 

FusuLinelLa sp. and Beedeina 

sp. 

---do--------------------------

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Late Pennsylvanian? 

Late Pennsylvanian? 

Late Pennsylvanian; late 

Missourian to early 

Virgilian. 

Do. 

Middle Pennsylvanian; 

Des Moinesian. 

Do. 

~ 

~ 1-3 

~ > "0 

::I: 

~ 

~ 

0'1 
26 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

nearly all calcareous siltstone and sandstone, which weather tan and 

brown and are similar to beds in the sandstone and siltstone member 

of the Oquirrh Formation. The thickness of about 2,220 m was partly 

measured on the ground and partly measured from the geologic map 

(Smith, 1982). It must be a minimum thickness because the base is 

covered by gravel and the top where measured is a fault. About 1 

km north of the section and northward, the upper contact with unit 

A appears to be conformable and possibly to interfrnger in places. 

Very little rock thickness at the top seems to be missing at the line 

of section. 

A Late Pennsylvanian (Virgilian) to Early Permian (Leonardian) 

age for these rocks is established by two fusulinid and four conodont 

collections. Fusulinids (USGS f13810, loc. No. 59 on geologic map 

(Smith, 1982)) from the lower sandstone and siltstone about 320 m 

above the gravel-covered base are Triticites sp. of Virgilian age (R. 

C. Douglass, written commun., 1976). Conodonts from three collections in ascending order and spaced about equally through the upper 

half of the formation were reported on by B. R. Wardlaw (written 

commun., 1977) as follows: USGS D51-PC, loc. No. 60 on geologic 

map (Smith, 1982), Adetognathus n. sp., Anchignathodus sp., Streptognathodus elongatus Gunnell, and bar fragments, Upper Pennsylvanian (Virgilian), CAl 4 (190°-300°C); USGS D52-PC, loc. No. 61 on 

geologic map (Smith, 1982), Neogondolella cf. N. idahoensis 

(Youngquist, Hawley, and Miller), Lower Permian, CAl 4 (190°-

3000C); and USGS D53-PC, loc. No. 62 (Smith, 1982), Sweetognathus 

whitei (Rhodes), Lower Permian (upper Wolfcampian), CAl 4 (190°-

3000C). A poorly preserved and encrusted conodont, Streptognathodus 

cf. S. elongatus Gunnell, of a probable Pennsylvanian (Virgilian) to 

Permian (Wolfcampian) age (B. R. Wardlaw, written commun., 1978) 

occurs in a sample (field No. F-111, loc. No. 63 (Smith, 1982)) from 

about 3 km north of the other three. This has a CAl of 4 (190°-300°C). 

Collections containing the youngest fauna from this formation are from 

a small area of mudstone, siltstone, and some limestone along the 

West Dry Canyon fault. Collection USGS f24996, loc. No. 64 (Smith, 

1982), contained fusulinids Schwagerina sp. or an early form of 

Parafusulina sp. of Early Permian age, reasonably a late Wolfcampian to early Leonardian equivalence (R. C. Douglass, written commun., 1974). Another collection from the same locality, USGS 25537-

PC, loc. No. 64 (Smith, 1982) also contained conodonts Anchignathodus sp., Neogondolella n. sp. D of Wardlaw and Collinson, and 

bar fragments of Leonardian age, CAl 3 (110°-200°C) (B. R. Wardlaw, 

written commun., 1977). Other fossils from this locality included a 

gastropod Cinclidonema sp. and a fragment of an orthoconic nautiloid, 

possibly Mooreoceras sp. indet. (Mackenzie Gordon, Jr., written commun., 1974). 
STRATIGRAPHY 27 

These beds of West Dry Canyon are thus equivalent in age to much 

of the sandstone and siltstone member of the Oquirrh Formation. As 

pointed out, the lower part of the West Dry Canyon unit is similar 

lithologically to the sandstone and siltstone member of the Oquirrh, 

but the upper part is not, and two somewhat different rock facies 

of the same age are near each other in the vicinity of the West Dry 

Canyon fault. 

SECTION D.-Beds of West Dry Canyon 

[Measured in sees. 5, 4, and 3, T. 15 S., R. 28 E. and sec. 34, T. 14 S., R. 28 E.; location on fig. 1] 

Meters 

Tertiary System: 

Sedimentary rocks. 

Fault. 

Permian and Pennsylvanian Systems: 

Beds of West Dry Canyon: 

Limestone, silty, gray, gray-, tan-, and pale-pink-weathering; small 

chunky and platy pieces; small fragments of black chert scattered 

sparsely over the surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 

Limestone, silty, gray; weathers mostly tan and in small chunky pieces; 

very light gray, calcareous siltstone; fragments of black chert about 

11

/4 em square scattered sparsely over the slope . . . . . . . . . . . 145 

Limestone, silty, gray and dark-gray, tan- and gray-weathering; some 

pink-weathering, platy pieces several centimeters across and 6 mm 

thick; minor calcareous quartz siltstone . . . . . . . . . . . . . . . . . . 290 

Limestone, gray, dense, gray-weathering; some calcareous siltstone; entire slope is covered with gray platy pieces in contrast to varicolored 

pieces of unit below . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 

Limestone, nearly all silty, gray and dark-gray; weathers gray, tan, 

pale pink, and some rusty; bedding in some small outcrops is thin, 

commonly a few mm; surface covered with platy fragments mostly 

8 em or less across; minor tan and light-red limestone and calcareous 

sandstone. Scattered fragments of black chert; some contain cubes 

of limonite altered from pyrite. One thin bed of gray crystalline 

crinoidal limestone noted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 

Siltstone and fine-grained sandstone, calcareous, gray and tan . . . 160 

Limestone, silty, gray; and tan siltstone . . . . . . . . . . . . . . . . . . . 110 

Limestone, silty, gray, gray-weathering; contains widely scattered, 

medium, well-rounded quartz grains; about 1 percent is calcareous 

sandstone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 

Limestone, much silty, gray, gray-weathering; some containing medium, 

well-rounded quartz grains; gray and tan calcareous sandstone; float 

suggests that sandstone similar to that in sandstone and siltstone 

member of the Oquirrh is dominant rock type. In lower 60 m, beds 

are crinoidal; some contain bryozoans and a few corals . . . . . . . 310 

Siltstone and fine-grained sandstone; both slightly calcareous; light gray 

and weathering tan and brown; bedding obscure; angular to rounded 

quartz grains, moderately well sorted; a 15-cm-thick bed of gray 

sandy limestone noted. At top a 0.6-m-thick bed of gray limestone 

contains bryozoans, crinoid columnals, spines (probably of 

brachiopods), and fusulinids; USGS colln. f13810 contains Triticites 

sp. of Late Pennsylvanian (Virgilian) age (R. C. Douglass, written 

commun., 1976) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 
28 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

Permian and Pennsylvanian Systems-Continued 

Beds of West Dry Canyon-Continued 

Limestone, silty, gray, gray- and light-gray-weathering; tan-weathering, 

calcareous siltstone containing scattered fine quartz grains; interbedded gray silty limestone, 0.6 m thick, and brown- and dark-brownweathering calcareous siltstone form some distinctive outcrops . . 

Total beds of West Dry Canyon ........................... . 

Base not exposed; covered with gravel. 

PERMIAN SYSTEM 

U~ITA 

Meters 

114 

2,220 

Unit A is distinguished by sequences of interbedded dark-gray to 

black chert and limestone, silty limestone, dolomite, siltstone, and 

sandstone; chert beds make the single most distinguishing feature of 

the unit. In some exposures the interbedded dark chert and lighter 

colored carbonate rocks produce a distinctive banding in zones as much 

as about 100 m thick. The base of the unit is placed at the base 

of the lowest bedded chert or at beds into which it appears to grade 

laterally. 

At the north edge of the Strevell quadrangle, this unit joins the 

rock sequence to which R. L. Armstrong (written commun., 1977) 

has applied the name Hudspeth Cutoff Sandstone, which was introduced as a formation in the Sublett Mountains by Cramer (1971). 

Yancey, Ishibashi, and Bingham (1980) have revised the Hudspeth 

Cutoff Sandstone of Cramer (1971) to exclude the lower 340 m and 

the upper 100 m and thus restrict the name to the chiefly sandstone 

sequence. In view of uncertainties regarding the name Hudspeth 

Cutoff in relation to unit A in the Strevell quadrangle, the name is 

not used in this report for any rock unit in that quadrangle. However, 

part of unit A is almost certainly correlative with part of the Hudspeth 

Cutoff regardless of whose definition is used for the Sublett Mountains. 

Lower Permian conodonts and fusulinids determine the age of unit 

A. Conodonts collected from the lower part of the formation and 

studied by B. R. Wardlaw (written commun., 1977) include: USGS 

D31-PC, Joe. No. 65 (Smith, 1982), Neogondolella idahoensis 

(Youngquist, Hawley, and Miller), probably upper Leonardian, CAl 

4 (190°-300°C); and USGS D32-PC, Joe. No. 66 (Smith, 1982), Neostreptognathodus n. sp. C of Wardlaw and Collinson and Ellisonia sp., 

upper Leonardian, CAl 4 (190° -300°C). Fusulinids (USGS f13945, Joe. 

No. 67 (Smith, 1982)) collected within about 150 m of the top of the 

formation were examined by R. C. Douglass (written commun., 1977), 

who reported that the sample contains an abundant fusulinid fauna 

but that the wall structure is destroyed in all specimens; the gross 

structures, however, suggest a schwagerinid of Early Permian (late 
STRATIGRAPHY 29 

Wolfcampian) age. Another collection (field No. F -88, loc. No. 68 

(Smith, 1982)) contained molds of Plagioglypta (scaphopod) and Omphalotrochus (gastropod) (B. R. Wardlaw, written commun., 1977). 

According to Wardlaw the age of the conodonts makes these rocks 

equivalent to the Meade Peak Phosphatic Shale Member of the Phosphoria Formation. In the Sublett Mountains the Meade Peak overlies 

the Hudspeth Cutoff Sandstone as mapped by R. L. Armstrong (written commun., 1977). There is no recognized Meade Peak in the 

Strevell quadrangle. 

Along the upper contact of unit A, several tens of meters of beds 

are truncated by the overlying formation. Very probably this is a 

fault contact as the overlying stratigraphic section here is somewhat 

different from what is presumably the normal sequence exposed in 

the neighboring Sublett Mountains. 

Along the line of the measured stratigraphic section, reliable bedding attitudes are widely scattered in some parts. Dips are consistently northward but vary enough in degrees to make some thickness 

measurements somewhat inaccurate. These inaccuracies have been 

partly compensated for by the use of average dips for parts of the 

measurements. The 1,480 m is probably a reasonable figure for the 

exposed thickness. 

SECTION E.-Unit A 

[Measured in sees. 21 and 16, T. 14 S., R. 28 E., and the upper half in sec. 4, T. 14 S., R. 28 E.; location on fig. l] 

Permian System: 

Dark-gray limestone. 

Probably a fault. 

Unit A: 

Siltstone, mostly gray, chiefly noncalareous, tan-, reddish-tan-, and 

gray-weathering; less fine grained sandstone, some of which is 

bimodal and contains scattered well-rounded coarse quartz grains; 

some dolomitic siltstone and dense gray dolomite. Lenticular chert 

near middle of unit. In upper 60 m, more dense black limestone, 

dark-gray-weathering, and gray crystalline limestone than in lower 

part. About 60 m above base, fine-grained gray sandstone and fineand medium-grained bimodal gray sandstone containing gastropods 

(Omphalotrochus) .................................. . 

Chert, black and dark-gray, and interlayered gray dolomite, siltstone, 

and some limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Siltstone and :tine-grained sandstone, calcareous . . . . . . . . . . . . . . 

Chert, black, and inter layered light-gray, dense dolomite, siltstone, and 

some limestone; chert occurs in layers as much as 10 em thick, in 

irregular nodules about 25 em long, and in blobs not parallel to the 

bedding; small tight folds in places . . . . . . . . . . . . . . . . . . . . . 

Siltstone and fine-grained sandstone, light-gray, calcareous, platy; laminated silty and sandy gray limestone; and some very dark gray, grayweathering limestone which forms mostly 6 mm thick platy and some 

chunky pieces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Meters 

350 

30 

45 

105 

245 
30 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

Permian System-Continued 

Unit A-Continued 

NOTE.-Connection to beds in unit below was made by projection and tracing 

beds along strike. 

Limestone, gray, gray-weathering, thin-bedded; black chert in lower 

3-4 m, sparse chert above; some calcareous siltstone and fine-grained 

sandstone. Limestone in uppermost part is dense and very dark gray 

and similar to limestone in overlying formation . . . . . . . . . . . . 

Rubble covered on flat hilltop with fragments of thin-bedded gray limestone; near top is an outcrop of limestone and scattered small darkgray chert nodules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Limestone, gray, gray-weathering; very thin bedded in places; a few 

pieces of crystalline limestone containing scattered small crinoid fragments; very little black chert ........................ . 

Rubble covered with pieces of limestone and dolomite and sparse chert . 

Rubble covered on bench slopes; fragments indicate limestone, dolomite, 

and more black chert than in unit below . . . . . . . . . . . . . . . . . 

Limestone, gray-, tan-, and pink-weathering, silty, thin-bedded to shaly; 

light-gray, gray-weathering dolomite, even beds as much as 25 em 

thick; interspersed black chert layers 2 em .thick, decrease in number 

downward ...................................... . 

Limestone, gray, silty; black chert; light-gray, light-gray-weathering dolomite; even-bedded dark chert and lighter colored carbonate rocks 

produce distinctive banding; chert layers most commonly 6-20 em 

thick and limestone and dolomite layers 3-9 em. Beds folded and 

faulted on a small scale in places. Weathers to form rusty-brown 

talus slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Limestone; lower part consists of even-bedded, 6-10-cm-thick layers of 

dense, dark-gray, gray-weathering silty limestone and 1-2-cm-thick 

layers of .dense, gray, tan-weathering (with a lavender cast in places), 

slightly silty limestone; upper part is similar but has 30-cm-thick 

layers in places . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Covered; alluvium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Limestone, silty, largely gray and gray weathering; a few small outcrops 

on a mostly rubble covered surface; some weathers tan and pink; 

platy fragments commonly 10-15 em across and a few chunky pieces 

as much as 20 em long. From top to about 30 m above base is much 

black chert in fragments that suggest that beds are 3--6 em thick . 

Rubble-covered slope with pieces of gray-, buff-, and tan-weathering 

silty limestone; many chunky fragments 2.5--5 em across; a very little 

black chert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Rubble-covered slope with pieces of mostly tan and tan-weathering calcareous siltstone and less gray and light-gray-weathering silty limestone in platy pieces 1 em thick; some pink and reddish tints; a few 

pieces of black chert scattered over slope. Gray silty limestone decreases in quantity downward relative to tan siltstone and is much 

Meters 

145 

110 

60 

28 

53 

87 

5 

42 

14 

83 

1 

less prominent below the upper 45 m . . . . . . . . . . . . . . . . . . . 75 

Chert, very dark gray, and gray silty limestone, dolomite, and dolomitic 

siltstone; bedding indistinct but beds appear to be about 8 em thick; 

much brecciated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Total thickness unit A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,480 
STRATIGRAPHY 

NoTE.-Contact apparently conformable with beds of West Dry Canyon below; 

in places, this appears to be an interfingering contact. 

Beds of West Dry Canyon. 

U::'I/IT B 

31 

Unit B of chert, siltstone, and limestone exposed over a few square 

kilometers in the northeast corner of the quadrangle is similar to unit 

A but contains no dolomite. Black chert layers that appear to be as 

much as 25 em thick are interlayered with gray limestone and calcareous siltstone in parts of the sequence, but very little chert occurs 

in other parts. Gray siltstone, mudstone, silty limestone, and limestone occur in thin beds, many of which are laminated and in places 

crossbedded on a small scale. The fine-grained clastic rocks weather 

light gray, brownish gray, and tan or buff, and the limestone beds 

weather gray. This unit is essentially nonfossiliferous, although pieces 

of fossil hash consisting of thin fragments of brachiopod shells in a 

limestone matrix were noted on one slope and small faint worm-like 

trails were observed in buff mudstone at another locality. 

The minimum thickness in the Strevell quadrangle appears to be 

about 750 m, but no top or bottom is exposed. 

This unit is not in contact with any Paleozoic formation in the mapped area. A fault bounding the west edge of the northernmost exposed 

part on the east edge of the quadrangle separates these beds from 

unit A, and probably unexposed fault or faults in the area of Cenozoic 

deposits separate other parts of the two formations. However, as 

these formations are similar lithologically and apparently of the same 

age, they may actually grade into or interfinger with each other. 

A Permian (Leonardian) age for this unit B is established on one 

conodont collection (field No. F-114, loc. No. 69 (Smith, 1982)) from 

a bed that contained fragments of gastropods and well-preserved but 

sparse Neogondolella idahoensis (Youngquist, Hawley, and Miller) (B. 

R. Wardlaw, written commun., 1978). This fossil content indicates 

that the unit is an age equivalent of the rocks containing the youngest 

fossils in the beds of West Dry Canyon and of unit A, to which it 

is very similar lithologically, and also, according to Wardlaw, that 

it is roughly equivalent to the lower part of the Meade Peak Phosphatic Shale Member of the Phosphoria Formation and to the Grandeur 

Member of the Park City Formation. The CAl of the conodonts is 

4, indicating that the host rock attained a temperature of 190° to 

300°C. 

This unit crops out much more extensively east and northeast of 

the Strevell quadrangle. 
32 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

PLATE II 

PERMIAN SYSTEM 

DARK-GRAY LIMESTO;\IE 

The dark-gray limestone forms the most uniform lithologic unit in 

the Black Pine Mountains and consists almost entirely of dark-gray, 

dense limestone that weathers light gray and commonly forms platy 

fragments on the slopes. Some beds are argillaceous. Silt and fine-size 

quartz grains occur in some beds, and a few layers are about half 

quartz and half calcite. Calcareous siltstone makes up a small percentage of the rocks in the formation. Small bryozoan fragments and 

some spines, sections of tiny crinoid columnals, and a very few fragments of ostracodes were found in a few beds. 

The dark-gray limestone is Lower Permian (upper Leonardian), as 

determined on two conodont collections (B. R. Wardlaw, written commun., 1977) from the lower part of the formation and made nearly 

4 km apart. Both collections (USGS D28-PC, loc. No. 70, and D33-PC, 

loc. No. 71 on geologic map (Smith, 1982)) contained N eostreptognathodus n. sp. C of Wardlaw and Collinson, as well as bar fragments; the CAI is 4, indicating that the host rock attained a temperature of 190°-300°C. This same species occurs in unit A below and 

indicates that the dark-gray limestone is equivalent to the Meade Peak 

Phosphatic Shale Member of the Phosphoria Formation. Brachiopod 

collections also studied by Wardlaw (written commun., 1977) contained 

Lissochonetes and a juvenile overtoniid (USGS D27-PC, loc. No. 72 

(Smith, 1982)) of Pennsylvanian to Early Permian age and Leiorhynchoidea cf. L. nobilis (Girty) (field No. F-83, loc. No. 73 (Smith, 

1982)). The latter species according to Wardlaw is common to the 

upper part of the Meade Peak Member and also to siltstones and 

shales in the Lower Permian of the Great Basin. 

Three samples of these Phosphoria age limestones contain less than 

1 percent P20 5 as determined colorimetrically by G. D. Shipley (written commun., 1975). Sample D174844 from about 30m above the base 

of the formation contained 0.33 percent P20 5, sample D174843 from 

about 75 m above the base contained 0.26 percent, and sample 

D174842 from about 25m below the top contained 0.10 percent. 

The upper contact of the dark-gray limestone is presumably conformable, but small tight folds and variable strikes and dips of beds 

near the top of the unit indicate possibly more intense deformation 

there than lower in the formation, and suggest that this contact may 

be a fault. Breccia near the base of the overlying rock sequence supports this possibility. 

The measured 7 45-m thickness of the dark-gray limestone is a 

reasonable figure, but very poor exposures on the dip slopes prevent 

accurate measurements. 
STRATIGRAPHY 

SECTION F.-Dark-gray limestone 

[Measured in sees. 3 and 4, T. 13 S., R. 28 E.; location on fig. 1] 

Permian System: 

Limestone, silicified limestone, some chert. 

Contact not exposed; presumably it is conformable but it may be a fault. 

Dark-gray limestone: 

Limestone, dense to medium-crystalline, dark-gray, gray-weathering; 

beds commonly 6 mm to 8 em thick and in places as much as 30 

em. Small tight folds near top in places make thickness measurements 

33 

Meters 

suspect for the uppermost part . . . . . . . . . . . . . . . . . . . . . . . . 233 

Limestone, dense, dark-gray; weathers gray on platy fragments; some 

light-gray, tan-weathering pieces; in a few outcrops beds are 2 mm 

to 5 em thick and have a rusty weathered surface . . . . . . . . . 128 

Limestone, dense, dark-gray, light-gray-weathering; more tan-weathering silty limestone and calcareous siltstone than lower in formation; 

some tan limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 

Limestone, dense, dark-gray, light-gray-weathering; beds as much as 

10 em thick; some silty limestone and calcareous siltstone weather 

to form gray and tan, platy and chunky fragments. Fine-grained 

sandy limestone near top . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 

Limestone, dense, dark-gray, light-gray-weathering; beds commonly 2-6 

mm thick; argillaceous in some layers; small platy pieces, 2-13 mm 

thick and generally 5--13 em across, cover slopes. Some massive outcrops still weather to form platy fragments. About 175 m above base, 

some beds are lighter gray and weather tan. Spines and small bryozoan fragments were noted about 130 m above the base . . . . . 198 

Total thickness dark-gray limestone . . . . . . . . . . . . . . . . . . . . . . . . . . 745 

Contact inferred to be a fault. 

Unit A. 

LIMESTO~E. SILICIFIED LIMESTO~E, SOME CHERT 

This unit crops out in two small areas at the northeast margin of 

the Black Pine Mountains. It consists of sandy limestone, silicified 

limestone, calcareous sandstone, and some chert. Near the base is 

some silicified limestone breccia. A thickness of between 120 and 145 

m is a reasonable estimate for the exposed rocks, but a lack of good 

bedding attitudes makes an accurate measurement impossible. 

No fossils were found in this unit, and so its Permian age designation is based on its stratigraphic position in relation to the underlying 

upper Leonardian dark-gray limestone. It has no recognized correlative in nearby exposures of Paleozoic rocks, and it certainly is different 

lithologically from the Triassic Dinwoody Formation in the Sublett 

Mountains. 

The following section in the NW% sec. 2, T. 14 S., R. 28 E. is 

not measured, but does describe the stratigraphic sequence: 
34 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

Quaternary System. 

Gravel. 

Permian System: 

Limestone, silicified limestone, some chert. 

Meters 

(estimated) 

Silicified gray limestone, gray- and tan-weathering . . . . . . . . . . . . 7~90 

Gray sandy limestone; limestone has a grainy crystalline texture and 

contains scattered medium-size rounded grains of quartz . . . . . . 15 

Gray calcareous fine-grained sandstone, tan-weathering . . . . . . . . . 2 

Silicified gray limestone, gray- and brown-weathering; mostly a breccia; 

no obvious bedding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-40 

Estimated total thickness ................................ 120-145 

Contact is presumably conformable but may be a fault. 

Dark-gray limestone. 

CONCLUSIONS REGARDING TEMPERATURES 

REACHED BY ROCKS 

EXPOSED IN THIS AREA 

During study of 32 conodont collections in determining ages of rock 

units, the CAl (color alteration indices) of the conodonts and thus 

the temperatures attained by the host rocks were determined as defined by Epstein, Epstein, and Harris (1977). All these rocks reached 

relatively high temperatures, mostly between 190°C and 400°C, although one sample could have been as low as 110°C and another possibly as high as 500°C (fig. 2). 

A temperature disconformity appears to occur across the fault that 

is partly near West Dry Canyon. South of the fault, attained temperatures of 14 of the 22 samples were in the range of 300°C to 400°C 

(CAl 5), one was below at CAl 4.5-5, and the other 7 were above 

with CAl of more than 5. North of the fault, 9 of the 10 collections 

were in the range of 190°C to 300°C. The CAl values north of the 

fault are at least one number lower than the values to the south, 

and the highest temperature attained to the north is about the same 

as the lowest one to the south. The pre-faulting separation, then, 

must have been enough to account for this difference in attained rock 

temperatures. 

The temperatures attained by these rocks have a bearing on any 

search for petroleum in this area. Regardless of consideration of time 

of burial, texture, and composition of rock types, all indicated temperatures, and particularly those above 300°C (CAl 5 and above), suggest 

that a postmature or high-temperature methane stage of petroleum 

generation was reached (for example, Hood and others, 1975, p. 993-

994; Epstein and others, 1977, p. 22-25; and Milner and others, 1977, 

p. 107-108) and that occurrence of oil is unlikely. These temperatures 
STRATIGRAPHY 35 

are determined on collections from exposed rocks that seem to be 

principally allochthonous and that conceivably could rest on lower 

plate units that attained lower temperatures. The existence of cooler 

units is unlikely, however, at the Strevell borehole (Al Griffin-Isabell 

Neilson No. 1) southwest of the Black Pine Mountains about 4 km 

from the edge of Paleozoic outcrops. That borehole penetrated Oquirrh 

rocks at about 345 m and lower Paleozoic metamorphic rock units 

(resembling those in the Raft River Mountains across the valley to 

the southwest) at about 643 m (Oriel and others, 1978). The Oquirrh 

strata penetrated are here interpreted to belong to the siltstone and 

sandstone member of the Oquirrh, and their position on the 

metamorphosed units indicates that no lower plate of once cooler rocks 

exists in the borehole. No positive evidence is available regarding 

the possibility of a cooler lower plate in and near the Black Pine 

Mountains east of the borehole. 

Raised temperatures were required for deposition of the gold and 

base-metal deposits in the Black Pine mining district in the southeast 

part of the mountains near the cluster of conodont collection localities 

east of Black Pine Canyon (fig. 2). These temperatures, however, 

were relatively low and probably did not exceed 125°-200°C (B. T. 

Brady, oral commun., 1977; partly based on information to Brady from 

C. G. Cunningham, 1977). These temperatures, then, appear to have 

been lower than those indicated by the CAl of the conodonts, and, 

if so, metal deposition occurred after the regional heating indicated 

by the CAL 

The Raft River Valley geothermal area (Williams and others, 1976) 

is centered about 12 km west of the Strevell quadrangle. Williams 

and others (1976) attributed the presence of hot water, having a 

maximum measured temperature at depth of 147°C, to deep circulation 

of meteoric water along major faults. These hot waters in the Tertiary 

fill in the valley, although close to the Black Pine Mountains, do not 

appear to have direct relations to any exposed features in the mountains. 

REFERENCES CITED 

Anderson, A. L., 1931, Geology and mineral resources of eastern Cassia County, 

Idaho: Idaho Bureau of Geology and Mines Bulletin 14, 169 p. 

Christensen, 0. D., 1975, Metamorphism of the Manning Canyon andChainma11 Formations: Stanford University Ph. D. thesis, 166 p. 

Cramer, H. R., 1971, Permian rocks from Sublett Range, southern Idaho: American 

Association of Petroleum Geologists Bulletin, v. 55, no. 10, p. 1787-1801. 

Epstein, A. G., Epstein, J. B., and Harris, L. D., 1977, Conodont color alteration-an 

index to organic metamorphism: U.S. Geological Survey Professional Paper 995, 

27p. 
36 PALEOZOIC ROCKS IN THE BLACK PINE MOUNTAINS 

French, D. E., 1975, Geology and mineralization of the southeastern part of the Black 

Pine Mountains, Cassia Co., Idaho: Logan, Utah, Utah State University M.S. 

thesis, 69 p. 

Hood, A., Gutjahr, C. C. M., and Heacock, R. L., 1975, Organic metamorphism and 

the generation of petroleum: American Association of Petroleum Geologists Bulletin, v. 59, no. 6, p. 98~996. 

Milner, C. W. D., Rogers, M. A., and Evans, C. R., 1977, Petroleum transformations 

in reservoirs: Journal of Geochemical Exploration, v. 7, no. 2, p. 101-153. 

Oriel, S. S., Williams, P. L., Covington, H. R., Keys, W. S., and Shaver, K. C., 

1978, Deep drilling data, Raft River geothermal area, Idaho; Standard American 

Oil Co., Malta, Naf, and Strevell petroleum test boreholes: U.S. Geological Survey 

Open-file Report 78-361, 2 sheets. 

Smith, J. F., Jr., 1982, Geologic map of the Strevell 15-minute quadrangle, Cassia 

County, Idaho: U.S. Geological Survey Miscellaneous Geologic Investigations Map 

I-1403. 

Trimble, D. E., and Carr, W. J., 1976, Geology of the Rockland and Arbon quadrangles, Power Co., Idaho: U.S. Geological Survey Bulletin 1399, 115 p. 

Williams, P. L., Mabey, D. R., Zohdy, A. A. R., Ackermann, H., Hoover, D. B., 

Pierce, K. L., and Oriel, S. S., 1976, Geology and geophysics of the southern 

Raft River Valley geothermal area, Idaho: Second United Nations Symposium 

and use of geothermal resources, San Francisco, California, May 20- 29, 1975, 

v. 2,p. 1273-1282. 

Yancey, T. E., Ishibashi, G. D., and Bingham, P. T., 1980, Carboniferous and Permian 

stratigraphy of the Sublett Range, south-central Idaho, in Fouch, T. D., and 

Magathan, E. R., eds., Paleozoic paleogeography of west-central United States: 

Society of Economic Paleontologists and Mineralogists, Rocky Mountain Section 

Paleogeography Symposium I, p. 259-269.