Mesozoic and Tertiary Rocks near Elko, 

Nevada Evidence for Jurassic to Eocene 

Folding and Low-Angle Faulting

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Chapter C

Mesozoic and Tertiary Rocks near Elko, 

Nevada Evidence for Jurassic to Eocene 

Folding and Low-Angle Faulting

By KEITH B. KETNER and ANDREW G. ALPHA

A multidisciplinary approach to research studies of sedimentary 

rocks and their constituents and the evolution of 

sedimentary basins, both ancient and modern

U.S. GEOLOGICAL SURVEY BULLETIN 1988

EVOLUTION OF SEDIMENTARY BASINS EASTERN GREAT BASIN 

HARRY E. COOK and CHRISTOPHER J. POTTER, Project Coordinators
U.S. DEPARTMENT OF THE INTERIOR 

MANUEL LUJAN, JR., Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director

Any use of trade, product, or firm names in this publication is for descriptive purposes only and 

does not imply endorsement by the U. S. Government

UNITED STATES GOVERNMENT PRINTING OFFICE: 1992

For sale by

Book and Open-File Report Sales 

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Denver, CO 80225

Library of Congress Cataloging-in-Publication Data

Ketner, Keith Brindley, 1921-

Mesozoic and Tertiary rocks near Elko, Nevada evidence for Jurassic to Eocene 

folding and low-angle faulting / by Keith B. Ketner and Andrew G. Alpha.

p. cm. (U.S. Geological Survey bulletin ; 1988-C) 

(Evolution of sedimentary basins Eastern Great Basin ; ch. C.)

Includes bibliographical references.

1. Folds (Geology) Nevada Elko Region. 2. Geology Stratigraphic 

Mesozoic. 3. Geology, Stratigraphic Tertiary. 4. Geology Nevada Elko 

Region. I. Alpha, Andrew G. II. Series. III. Series: Evolution of sedimentary 

basins Eastern Great Basin ; ch. C.

QE75.B9 no. 1988-C

[QE606.5.N3] 

557.3 s-dc20

[551.8'7'0979316] 92-10217

CIP
CONTENTS

Abstract Cl

Introduction Cl

Stratigraphy of Mesozoic and Paleogene rocks Cl

Lower Triassic sequence of the northern Adobe Range Cl

Upper Jurassic sequence of the northern Cortez Mountains C2

Cretaceous Newark Canyon Formation of the northern Cortez Mountains 

and Pinon Range C3

Uppermost Cretaceous to Eocene conglomerate C3

Eocene Elko Formation C3

Eocene rhyodacite of Elko Mountain C5

Eocene and Oligocene Indian Well Formation C6 

Deformation of Mesozoic and Eocene age C9

Northern Adobe Range CIO

Peko Hills CIO

Northern Cortez Mountains CIO

Piflon Range CIO

Elko Hills Cll

Folds and low-angle faults in the Elko area: Contractional or extensional? Cll 

Comparison with the Idaho-Wyoming-Utah Thrust Belt C12 

References cited C12

FIGURES

1. Map of Elko area, northeastern Nevada, showing trends of folds and attitudes of 

steeply dipping beds in Big Pole Formation C2

2. Map and cross section in Coal Mine Basin area, northern Adobe Range, showing generalized geology and structural relations C4

3. Map of part of northern Cortez Mountains showing generalized geology and structural features C6

4. Map of Emigrant Spring area in northern Pinon Range showing generalized geology 

and structural features C7

5. Map and cross sections of Elko Hills showing generalized geology and structural 

features C8

Contents III

EVOLUTION OF SEDIMENTARY BASINS EASTERN GREAT BASIN

Mesozoic and Tertiary Rocks near Elko, Nevada Evidence 

for Jurassic to Eocene Folding and Low-Angle Faulting

By Keith B. Ketner and Andrew G. Alpha

Abstract

Post-Early Triassic, large-scale folds broken by low-angle 

faults form a family of north- to northeast-trending structures in 

the Elko, Nevada, area. Some folds can be dated only as 

post-Early Triassic and pre-Eocene; others are of Eocene age. 

In the Adobe Range Triassic and older units are tightly folded, 

overridden by Permian to Ordovician strata and overlain 

unconformably by Eocene rocks. In the Peko Hills Paleozoic 

strata as young as mid-Permian are also tightly folded and overridden by Triassic to Mississippian rocks. In the Cortez Mountains steeply dipping Upper Jurassic volcaniclastic rocks are 

overlain by mid-Cretaceous strata that dip gently in the opposite direction suggesting latest Jurassic to early Cretaceous 

deformation. In the Pifion Range Eocene and Mississippian 

rocks are folded to form a syncline that plunges below relatively undeformed latest Eocene and Oligocene volcanic 

strata. In the Elko Hills Eocene and late Paleozoic rocks are 

folded and overridden discordantly by late Paleozoic strata. 

Characteristic features of highly extended terranes, such as 

extremely rotated fault blocks, younger over older low-angle 

faults with omission of strata, and extremely attenuated strata, 

are scarce in the Elko area. In contrast, large-scale southeastverging folds broken by older over younger faults that involve 

juxtaposition of contrasting facies are the rule and are interpreted to indicate at least intermittently contractional conditions beginning in the Late Jurassic and ending in the late 

Eocene.

INTRODUCTION

1982; Coats and Riva, 1983; Ketner, 1984, 1987, 1990; 

Clark, 1985; Ehman, 1985; Coats, 1987; Little, 1987; Ketner 

and Evans, 1988; Ketner and Ross, 1990; Thorman and others, 1991). Some evidence of Paleogene folding was 

described previously (Smith and Ketner, 1976) but has 

received little attention. In this report we update the Mesozoic and Paleogene stratigraphic sequence, review some of 

the published evidence for post-Paleozoic folding and lowangle faulting in the Elko area, and attempt to demonstrate 

that post-Paleozoic upper crust contractional tectonism in 

the Elko area began as early as the Late Jurassic and ended 

in the late Eocene.

Acknowledgments. We benefitted from comments by 

Harald D. Drewes, Thomas D. Fouch, Richard K. Hose, 

David M. Miller, Lucian B. Platt, Charles A. Sandberg, 

Arthur W. Snoke, and Robert C. Speed. However, the 

authors are solely responsible for the interpretations 

expressed herein.

STRATIGRAPHY OF MESOZOIC AND 

PALEOCENE ROCKS

Mesozoic and Paleogene strata in the Elko area include 

detrital sedimentary and volcanic deposits whose nature and 

ages are useful for dating the tectonic events in the area, and 

they are therefore discussed in detail as a necessary preliminary to a discussion of structure.

Intensive upper crustal folding and low-angle faulting of 

post-Paleozoic, mainly Mesozoic, age throughout northeastern Nevada are well documented (Ketner and Smith, 1974,

Manuscript approved for publication January 31,1992.

Lower Triassic Sequence of the 

Northern Adobe Range

Lower Triassic rocks of the northern Adobe Range (figs. 

1, 2) are thinly laminated limy shale and argillaceous

Jurassic to Eocene Folding and Faulting, Nevada C1
limestone representing distal turbidite deposition, but they 

also include sporadic debris flows and isolated large blocks 

derived mainly from the mid-Permian Gerster Limestone 

(Ketner and Ross, 1990). The Gerster is a parautochthonous, 

abundantly fossiliferous, shallow-marine shelf unit of the 

Nevada-Utah border area. Although the Triassic sequence is 

allochthonous in the Adobe Range, the presence of coarse

116°00' 115°45' 115°30'

41° 

15'

41° 

00'

40° 

45'

40° 

30'

40° 

15'

Peko 

Hills

Emigrant 

Spring

 Figure 4

15MI

10 20 KM

EXPLANATION 

Anticline showing crest line

Syncline showing trough line

Attitude of bed showing direction 

of dip

Figure 1. Map of Elko area, northeastern Nevada, showing 

trends of folds and, in Cortez Mountains, attitudes of steeply 

dipping beds in Jurassic Big Pole Formation. Locations of 

figures 2-5 also shown.

debris flows composed of Gerster-derived detritus indicates 

that the sequence is indigenous to the northeastern Nevada 

area. Presence of the easterly derived olistostromes also indicates that the Triassic sediments were deposited on, or at the 

foot of, a slope that probably faced generally westward or 

northwestward away from the probable source of debris. The 

age of the Adobe Range Triassic sequence was determined 

to be Smithian (mid-Early Triassic) on the basis of its 

ammonoid fauna (N.J. Silberling, U.S. Geological Survey, 

written commun., 1967). The sequence has also yielded Triassic conodonts. Triassic rocks occupy the center of the 

Adobe Range Syncline. If younger strata ever had been 

deposited on the Triassic rocks prior to folding, they are now 

entirely absent. The same formation at other localities in 

northeastern Nevada has yielded Griesbachian (lowest Triassic) and Spathian (uppermost Lower Triassic) conodonts 

(Bruce Wardlaw, U.S. Geological Survey, oral commun., 

1990). The formation therefore originally probably spanned 

the entire Lower Triassic interval.

Upper Jurassic Sequence of the Northern 

Cortez Mountains

An area of at least 150 mi2 (388 km2) in the northern 

Cortez Mountains (fig. 3) is underlain by extrusive rocks and 

volcaniclastic sedimentary rocks assigned to the Jurassic 

Pony Trail Group and by numerous stocks of Jurassic age 

(Muffler, 1964; Smith and Ketner, 1976). The Pony Trail is 

composed of three formations separated by unconformities 

(in ascending order): the Big Pole Formation, the Sod House 

Tuff, and the Frenchie Creek Rhyolite. The Big Pole consists 

mostly of volcaniclastic sedimentary rocks, tuffs, and rhyodacitic flows "deposited in a rapidly subsiding basin in a tectonically active area" (Muffler, 1964, p. 25). Whether the 

basin was marine or continental has not been determined. 

The Sod House Tuff, the Frenchie Creek Rhyolite, and clasts 

of the Big Pole Formation are of rhyolitic to dacitic composition. The age of the Frenchie Creek Rhyolite, the youngest 

unit of the Pony Trail Group, as determined by R.L. Armstrong (Smith and Ketner, 1976), is 151±3 Ma (K-Ar, 

biotite). Several granitic plutons intrude Paleozoic rocks in 

the area and the Pony Trail Group. They range in composition from alaskite to diorite, but predominant rock types are 

granodiorite and monzonite. Radiometric ages, determined 

by R.L. Armstrong (1963) and reported by Muffler (1964), 

are granodiorite 150-8+23 Ma (K-Ar, hornblende), alaskite 

125-6+19 and 145-7+22 Ma (K-Ar, hornblende). The age of 

a monzonite stock, determined by G.H. Curtis (Gilluly and 

Masursky, 1965), is 151 Ma (K-Ar, biotite). The deformed 

Pony Trail Group is overlain unconformably by gently dipping lower Upper Cretaceous beds of the Newark Canyon 

Formation (fig. 3).

C2 Evolution of Sedimentary Basins Eastern Great Basin
Cretaceous Newark Canyon Formation of the 

Northern Cortez Mountains and Pihon Range

to the basal part of the Elko Formation with equal validity, 

but they are here left unassigned pending better dating.

Lake and alluvial deposits of the Cretaceous Newark 

Canyon Formation cover a large area in the Cortez Mountains, and scattered erosional remnants indicate that the formation originally covered a large area in the southern Pinon 

Range (Smith and Ketner, 1978). Cretaceous beds in the 

Cortez Mountains consist of coarse heterogeneous conglomerate, sandstone, and mudstone, whereas in the Pinon Range 

they consist mostly of shale and sandstone. Most of the 

larger clasts in the conglomerate were derived from local 

formations of Mississippian to Jurassic age (Biglow, 1986), 

but some were derived from lower Paleozoic units.

Exposures of the Newark Canyon Formation are widely 

scattered elsewhere in northeastern and central Nevada. The 

formation typically includes coarse, locally derived conglomerate and attains thicknesses of 1,800 ft (549 m) in the 

Newark Canyon area near Eureka (Nolan and others, 1956) 

and more than 2,500 ft (762 m) in the Cortez Mountains. Its 

age, based on a fauna of fish, dinosaurs, plants, and ostracodes, is Early and Late Cretaceous and possibly Paleocene. 

Evidence from the Newark Canyon area near Eureka, 

Nevada, indicates a late Early Cretaceous age for the formation, and evidence from the Cortez Mountains indicates an 

early Late Cretaceous age. An Early Cretaceous age of the 

ostracode fauna from younger beds at the principal Pinon 

Range locality has been questioned by Fouch and others 

(1979) and the fauna tentatively assigned a Late Cretaceous 

and (or) Paleocene age, but the original determination of 

Early Cretaceous for older beds at that locality (I.G. Sohn in 

Smith and Ketner, 1976, p. B13) has not been questioned.

Uppermost Cretaceous to 

Eocene Conglomerate

Tracts of generally poorly dated and unnamed conglomeratic lake and lake-margin sequences are widespread in the 

Elko area. The thickness of one tract in the Pinon Range was 

estimated to be more than 2,000 ft (610 m) (Smith and Ketner, 1976). The stratigraphic positions of these sequences, 

their lack of tuffaceous beds, and their heterogeneous compositions, which commonly include clasts of Permian rocks, 

suggest a Cretaceous to earliest Tertiary age and probable 

stratigraphic equivalence to the Sheep Pass Formation of 

east-central Nevada (Fouch and others, 1979). Ostracodes 

and charophytes collected from one of these tracts between 

the Elko Hills and the Pinon Range indicate an age within the 

latest Cretaceous to Eocene interval (I.G. Sohn and R.E. 

Peck in Smith and Ketner, 1976). These conglomeratic units 

could be assigned either to the Newark Canyon Formation or

Eocene Elko Formation

Eocene lake beds and associated alluvial deposits are 

here divided into three units (in ascending order): basal conglomeratic unit, cherty limestone, and shaly unit. The basal 

conglomeratic unit lies unconformably on Ordovician to Triassic strata or, rarely, on Cretaceous rocks. This conglomeratic unit, consisting of beds of alluvial sand, pebbles, and 

cobbles, grades laterally into fine-grained lake sediments. 

The lithic composition of the clasts generally reflects that of 

the underlying formations. Sandy beds display strong crossbedding and, in places, are convoluted as if deformed by 

swift currents. Sorting of clasts is poor and degree of rounding is varied. In some exposures the conglomeratic unit 

encloses beds of rhyolitic tuff.

Commonly overlying the basal conglomeratic unit is a 

thick sequence of argillaceous and tuffaceous lake limestone 

that generally contains variously colored replacement chert 

nodules. This unit is widespread in the Pinon Range-Elko 

Hills area (figs. 4, 5) but absent from the northern Adobe 

Range.

Next above is an extremely varied sequence characteristically shaly and so easily weathered that outcrops are scarce. 

This uppermost unit consists of shale, kerogenous oil shale, 

claystone, siltstone, cherty limestone, dolomite, sandstone, 

conglomerate, and, rarely, tuff. The lithic composition varies 

widely from place to place and reflects varied depositional 

conditions in a lake environment.

The term Elko Formation has been used inconsistently by 

different authors and applied inconsistently to exposures in 

different areas. To avoid further confusion we here propose 

a revised definition. The name Elko Formation has been 

applied either to the upper unit of the tripartite Eocene 

sequence here described (Solomon and others, 1979) or to 

the upper two units (Smith and Ketner, 1976; Server and 

Solomon, 1983). In this report the three units commonly 

comprising the concordant Eocene sequence basal conglomeratic unit, cherty limestone, and shaly unit are 

regarded as the informally designated lower, middle, and 

upper members of the Elko Formation.

This usage is justified as follows. The type section of the 

Elko Formation in the Pinon Range as originally mapped and 

described by Smith and Ketner (1976, p. B19; 1978) and 

later by Server and Solomon (1983) explicitly includes the 

cherty limestone unit, although in adjacent areas the cherty 

limestone was mapped as a separate unnamed unit (Smith 

and Ketner, 1976,1978). The basal conglomeratic unit is discontinuous stratigraphically below limestone beds in the 

type section but was not originally recognized as Tertiary

Jurassic to Eocene Folding and Faulting, Nevada C3
41° 

15'

115°45' 115°32'30"

41° 

07' 

30"

ftb

4 KM

GARAMENDI 

ANTICLINE

Tsv

Projected basepf^Sv,

"ADOBE ~~~- 

RANGE SYNCLINE

A'

X Tsv

Figure 2 (above and facing page). Map and cross section in Coal Mine Basin area, northern Adobe Range, northeastern Nevada. 

Plates of lower Paleozoic, Permian, and Triassic rocks were emplaced over undeformed Mississippian and Pennsylvanian units on 

low-angle faults. This tectonic stack was then folded to form Adobe Range Syncline and Caramendi Anticline. Next, lower Paleozoic western facies rocks (Roberts Mountains allochthon) and slices of local Permian and Triassic rocks were thrust over these 

folds. Finally, the Eocene Elko Formation was deposited with profound unconformity on the highly deformed units and was itself 

mildly deformed. Location of map area shown on figure 1. Modified from Ketner and Ross (1990).

C4 Evolution of Sedimentary Basins Eastern Great Basin
EXPLANATION

Sedimentary and volcanic rocks (Quaternary and upper

Tertiary) Gravel, sand, and tuff

Sedimentary and volcanic rocks (Eocene and Oligocene?) 

Conglomerate, sandstone, shale, limestone, and tuff

Argillaceous and calcareous rocks (Lower Triassic) 

Limestone and shale constituting an allochthon emplaced 

prior to formation of the Adobe Range Syncline

Siliceous detrital rocks (Mississippian) Sandstone, shale, 

and conglomerate

Sedimentary rocks (Permian, Silurian, and undated) 

Sandstone limestone, chert, and siltstone constituting an 

allochthon emplaced prior to formation of Adobe Range 

Syncline

Sedimentary rocks (Ordovician, Silurian, Devonian, 

Mississippian, Permian, Triassic) Chert, argillite shale, 

siltstone, limestone, and sandstone constituting a complexly 

deformed allochthon emplaced after formation of Adobe 

Range Syncline

30

Contact 

High-angle fault

Low-angle fault, sawteeth on upper plate; open 

triangles indicate emplacement prior to formation 

of Adobe Range Syncline

Low-angle fault, sawteeth on upper plate; solid 

triangles indicate emplacement after formation 

of Adobe Range Syncline

Anticline showing crest line

Overturned anticline showing direction 

of dip of limbs

Syncline showing trough line

Attitude of beds showing strike and degree of dip

Inclined

Vertical

Horizontal

and was erroneously assigned to the underlying Mississippian strata. This basal conglomeratic unit should be included 

in the Elko Formation because as a conformable, genetically 

related part of the sequence it would have been included in 

the type section if its Tertiary age had been recognized. 

Moreover, in the Elko Hills the basal conglomeratic beds 

locally are interbedded with lenses of kerogenous oil shale, 

which are a typical and essential component of the Elko Formation as originally defined and usually conceived. Accordingly, the Tertiary conglomeratic beds, which are here 

regarded as comprising the basal part of the redefined type 

section of the Elko Formation and equivalent strata elsewhere, are here assigned to the Elko Formation.

Strata in the Elko Hills mapped as limestone and limestone-clast conglomerate and conglomerate, sandstone, and 

shale by Solomon and Moore (1982a, b) are here assigned to 

the lower member of the Elko Formation. The strata mapped 

as cherty limestone by Smith and Ketner (1976) and as the 

cherty limestone member (of the Elko Formation) by Server 

and Solomon (1983) in the Pinon Range and as the cherty 

limestone unit by Solomon and Moore (1982a, b) in the Elko 

Hills are here assigned to the middle member of the Elko 

Formation. An exposure of uniquely chert-free limestone 12 

mi (19 km) east of the type section of the Elko Formation 

(limestone unit of Smith and Ketner, 1978) is also assigned 

to the middle member. The shaly member is the essence of 

the Elko Formation, and its assignment to the upper part of 

the formation is noncontroversial. The Elko Formation, as 

revised herein, lies with angular unconformity on rocks as 

old as earliest Mississippian in the Pinon Range and as old as 

Ordovician in the Adobe Range.

The Elko Formation is of Eocene age. Tuff beds were 

dated at 43.3±0.3,38.910.3, and 37.1±1.0 Ma (K-Ar, biotite; 

Solomon and others, 1979). Formerly the unit was regarded

as Eocene and Oligocene(?) (Smith and Ketner, 1976; 

Solomon and others, 1979) because a tuff bed near the middle of the type section was dated radiometrically at 38.6±1.2 

Ma, approximately on the Eocene-Oligocene boundary as 

formerly determined. Adjustment of the Eocene-Oligocene 

boundary from an indefinite point between 37 and 38 Ma 

(Harland and others, 1964) to 35.4 Ma (Harland and others, 

1990) has eliminated the necessity for specifying a possible 

extension of the age of the formation into the Oligocene. 

Moreover, the Indian Well Formation, which unconformably overlies the Elko Formation, was dated as old as 37.6 

Ma (Smith and Ketner, 1976) and is therefore now partly 

Eocene.

Eocene Rhyodacite of Elko Mountain

On Elko Mountain, the highest of the Elko Hills, the Elko 

Formation partly overlies, and partly merges laterally with, 

an altered extrusive rhyodacite sequence herein called the 

rhyodacite of Elko Mountain. This unit is almost completely 

altered hydrothermally to kaolinite and quartz. The rhyodacite of Elko Mountain has been misidentified both as an 

intrusive rock (Stewart and Carlson, 1978; Jaeger, 1987) and 

as the Jurassic Frenchie Creek Rhyolite (Coats, 1987). However, the rhyodacite sequence sporadically includes agglomerate, tuff, flow rocks with polygonal shrinkage joints, and 

interlayered conglomerate, sandstone, shale, and coal. Interbedded stratigraphic relations with the Eocene Elko Formation and a fission track age of 39.5±0.7 Ma on apatite from a 

vitrophyre in the middle part of the sequence (R.A. Zimmerman, U.S. Geological Survey, written commun., 1987) indicate that the rhyodacite of Elko Mountain is Eocene in age. 

Unnamed rhyodacitic ignimbrites widely exposed in northeastern Nevada range from 42.5 to 39.3 Ma in age (Coats,

Jurassic to Eocene Folding and Faulting, Nevada C5
40°25'

40°20'

QTu

4 KM

QTu

Kn

Ja

Jgm

Ju

Jb

60

EXPLANATION

Alluvium and colluvium (Quaternary 

and Tertiary) Gravel and sand

Newark Canyon Formation (Cretaceous) 

Conglomerate, sandstone and mudstone

Alaskite (Late Jurassic) Stocks of quartz-rich 

granitic rock

Granodiorite and monzonite (Late Jurassic) 

Large stock

Frenchie Creek Rhyolite (Upper Jurassic) 

and Sod House Tuff (Upper? Jurassic) 

Tuff and rhyolite flow rocks

Big Pole Formation (Upper? Jurassic) 

volcaniclastic, conglomeratic sedimentary 

rocks, tuff, and flow rocks

Contact

Fault, bar and ball on downthrown side

Attitude of beds showing strike and degree of 

dip

Figure 3. Map of part of northern Cortez Mountains, northeastern Nevada, showing contrast between steep dips of Late(?) Jurassic 

Big Pole Formation and gentle dips of Cretaceous Newark Canyon Formation. Location of map area shown on figure 1. Modified 

from Muffler (1964) and Smith and Ketner (1978).

1987) and are therefore partly correlative with the rhyodacite 

of Elko Mountain.

Eocene and Oligocene Indian Well Formation

The Indian Well Formation, which crops out widely 

between the Elko Hills and the Cortez Mountains and 

probably in the northern Adobe Range, is composed primarily of coarse volcaniclastic sedimentary rocks, agglomerate, 

flow rocks, and both welded and nonwelded tuff. Its composition is mainly rhyolite, but locally it includes andesite. The

Indian Well Formation overlies the Elko Formation unconformably throughout the Elko area. In several places 

between the Elko Hills and the Pinon Range it overlies preTertiary rocks as old as Devonian. Although the contact 

between the Elko and Indian Well Formations is poorly 

exposed, map patterns (as in fig. 4) indicate that the unconformity is angular and that the Indian Well is generally much 

less deformed than the Elko Formation. Seven radiometric 

ages (Smith and Ketner, 1976; Solomon and others, 1979) 

indicate that the Indian Well ranges in age from latest 

Eocene to late Oligocene on the basis of a 35.4-Ma date for 

the Eocene-Oligocene boundary.

C6 Evolution of Sedimentary Basins Eastern Great Basin
116°

40° 

37' 

30"

40° 

35'

PMdw

PMdw

Tes

Tel

Tec

PMdw

30

68

EXPLANATION 

Alluvium (Quaternary) Sand and gravel

Indian Well Formation (Oligocene and 

Eocene) Tuff and volcaniclastic sedimentary 

rocks

Elko Formation (Eocene) Divided into: 

Dolomitic shale and tuff 

Shale, oil shale, and limestone 

Limestone and shale

Cherty limestone; includes discontinuous 

conglomerate beds at base

Diamond Peak Formation, Chainman Shale, 

and Webb Formation, undivided (Lower 

Pennsylanian and Mississippian) Conglomerate, 

sandstone, siltstone, and shale

Contact

High-angle fault

Thrust fault, sawteeth on upper plate

Axis of syncline showing trough line and direction of 

plunge, dotted beneath undeforrned strata

Axis of anticline showing crest line

Attitude of beds showing strike and degree of dip

Inclined

Vertical

Overtimed

Horizontal 

Road

Figure 4. Map of Emigrant Spring area in northern Pinon Range, northeastern Nevada, showing axis of east-verging Emigrant 

Spring Syncline, axis of an adjacent subparallel anticline, and a minor thrust fault. Mississippian formations and Eocene Elko Formation are folded, but uppermost Eocene and Oligocene Indian Well Formation is undeforrned and Emigrant Spring Syncline 

plunges southward beneath it. Location of map area shown on figure 1. Modified from Smith and Ketner (1978) and Server and 

Solomon (1983).

Jurassic to Eocene Folding and Faulting, Nevada C7
40°55'

40°50'

115040'

I

115°35'

QTac

Figure 5 (above and facing page). Simplified map and cross sections of the Elko Hills, northeastern Nevada. Permian 

to Mississippian and Tertiary strata were folded and overridden by plates of Pennsylvanian to Mississippian rocks. Horizontal scale for cross sections differs from map scale. Location of map area shown on figure 1. Modified from Ketner 

(1990).

C8 Evolution of Sedimentary Basins Eastern Great Basin
A

Ter

:>

Rzu (Pennsylvanian)

A1

"d- Rz (Permian) _ ^

__ *"*-

- -"" _ _ "^~^

" ' "^ ^

s^5=^

^sX x

V^

B

C1

QTac Ter QTac Ter

2 Ml

1 2 KM

NO VERTICAL EXAGGERATION

EXPLANATION

Alluvium and colluvium (Quaternary and upper 

Tertiary) Sand, gravel, and volcanic ash

Humboldt Formation (Miocene) Alluvial sand and 

gravel, volcanic ash, and lake deposits

Elko Formation and rhyodacite of Elko Mountain 

(Eocene) Lake deposits consisting of conglomerate, 

limestone, siltstone, shale, oil shale, rhyodacitic flow 

rocks, agglomerate, and tuff

Paleozoic rocks (Permian to Mississippian) Siltstone, 

sandstone, conglomerate, limestone, and chert

Paleozoic rocks (Permian to Mississippian) 

Conglomerate and limestone; upper plate of Tertiary 

low-angle fault

30

Contact

High-angle fault, bar and ball on downthrown side

Low-angle fault, sawteeth on upper plate

Axis of syncline showing trough line, dashed 

where concealed

Axis of anticline showing crest line, dashed 

were concealed

Attitude of beds showing strike and degree of dip 

Inclined 

Horizontal

DEFORMATION OF MESOZOIC AND 

EOCENE ACE

Evidence for oldest post-Paleozoic tectonism was the 

formation in the Early Triassic of a deep marine basin in the 

Adobe Range area and the accumulation in it of bouldery

debris flows of material eroded from exposed Permian shelf 

rocks.

The apparently total lack of Middle Triassic to lower 

Upper Jurassic marine or continental deposits in the Elko 

area suggests elevation or filling of the Early Triassic basin 

and subsequent external drainage during at least the latter 

part of that interval. The sedimentary record of nearby areas

Jurassic to Eocene Folding and Faulting, Nevada C9
provides no evidence that the region was elevated much 

above sea level. The nearest exposure of Upper Triassic and 

Lower Jurassic sedimentary rocks is in east-central Nevada 

(Stewart, 1980), about 65 mi (104 km) southeast of Elko. 

Those beds, which overlie marine inner shelf limestone of 

Early Triassic age, consist of thin strata of, from base to top, 

pebble conglomerate, red beds of shale and siltstone, and 

eolian crossbedded sandstone. This sequence is similar to the 

Upper Triassic Chinle Formation and Lower Jurassic Navajo 

Sandstone of southern Nevada and much of Utah. Such formations characterize cratonal to inner shelf environments 

and suggest regional stability, not proximity to active tectonism. This apparent interval of middle Mesozoic tectonic 

tranquillity was interrupted abruptly, in the Elko area, in the 

latest Jurassic by an episode of siliceous intrusive and extrusive igneous activity, deposition of conglomeratic sediments, folding, and low-angle faulting that continued 

intermittently through the Eocene.

Northern Adobe Range

Lower Triassic, Permian, and Silurian strata of the northern Adobe Range were stacked over parautochthonous Mississippian and older units by low-angle faulting and folded to 

form the southeast-verging Adobe Range Syncline and 

Garamendi Anticline (fig. 2) (Ketner and Smith, 1974; Ketner, 1987; Ketner and Ross, 1990). The steeply inclined 

limbs of these folds were overridden by plates composed 

mainly of lower Paleozoic deep-water strata such as the 

Ordovician Vinini Formation. These latter faults are classed 

as contractional because they juxtapose overriding deepwater facies with contemporaneous shelf facies. The latter 

are not exposed but are shown to be present by exploratory 

oil wells drilled immediately adjacent to the Adobe Range. 

Folds and low-angle faults of the northern Adobe Range 

were transected unconformably by the Eocene Elko Formation.

The Elko Formation, however, which is exposed extensively around the northeastern and northern parts of the 

Adobe Range, is itself somewhat warped but not detached 

from the underlying Paleozoic rocks. In general, it dips radially away from the range apparently reflecting domal 

upwarping in post-Eocene time. At one locality basal beds of 

the Elko Formation dip 50°, but stratigraphically higher beds 

are less steeply inclined. Unconformably overlying ignimbrite, probably equivalent to the Indian Well Formation, is 

less deformed and is almost horizontal in the northernmost 

areas of exposure as indicated by outcrop patterns in relation 

to topography. Thus, the northern Adobe Range displays a 

clear record of intense folding and low-angle faulting within 

the Middle Triassic to early Eocene interval, followed by an 

episode of erosion, deposition of lacustrine sediments, and 

greatly diminished deformation in the late Eocene.

Peko Hills

In the Peko Hills shallow-water Devonian to Permian 

strata were strongly folded with southeast vergence and 

overridden by Mississippian and Permian deep-water strata 

on low-angle faults (Ketner and Evans, 1988). The telescoping of contrasting facies of Permian rocks confirms the contractional nature of the deformation. Triassic rocks identical 

with those of the northern Adobe Range were involved in the 

low-angle faulting. The Miocene Humboldt Formation is 

undeformed. The time of faulting and folding in the Peko 

Hills, on the basis of local evidence, can therefore be determined to be within the Middle Triassic-Miocene interval.

Northern Cortez Mountains

Upper(?) Jurassic sedimentary beds of the Big Pole Formation in its main exposure and at its type locality strike 

northeast and dip steeply northwestward (fig. 3) (Muffler, 

1964, plate 1). The northeast-trending strike of the Big Pole 

Formation was unaffected by the discordant intrusion of a 

large granitic stock, except directly adjacent to the contact, 

indicating that the structure of the Big Pole probably was not 

caused by forcible igneous intrusion. The Cortez Mountains 

are part of a tilted Basin-Range fault block. If the 10°-20° 

east tilt of the range, as determined from the dips of Cretaceous, Miocene, and younger beds in the vicinity of figure 3, 

were restored to horizontal, the dip of bedding in the Big 

Pole Formation would be steeper, generally approaching 

vertical and in places overturned. The Sod House Tuff and 

Frenchie Creek Rhyolite may be less deformed than the Big 

Pole Formation, although scarcity of sedimentary beds in 

these primarily volcanic units makes their attitudes somewhat uncertain. The Cretaceous Newark Canyon Formation 

in the vicinity of the Big Pole Formation is almost undeformed, and beds would be horizontal on subtraction of Tertiary tilt.

Thus, in the Cortez Mountains, structural evidence indicates that an episode of strong folding or tilting began in the 

Late Jurassic and subsided before the early Late Cretaceous. 

Deposition of coarse, heterogeneous conglomerate near 

Eureka in the late Early Cretaceous provides additional, indirect evidence of deformation during the same time interval.

Pinon Range

Much of the deformation in the Pinon Range is Mesozoic 

to Tertiary in age (Ketner and Smith, 1974; Smith and Ketner, 1977). The Adobe Range Syncline of Triassic to Eocene 

age extends to the northern Pifion Range, and throughout the 

range upper Paleozoic rocks are strongly deformed. The

C10 Evolution of Sedimentary Basins Eastern Great Basin
onset of post-Paleozoic folding and low-angle faulting in the 

Pinon Range is difficult to determine and can be estimated 

only from the age of coarse conglomerate derived from 

Paleozoic rocks in the vicinity. The oldest of these is early 

Late Cretaceous in age.

Much of the deformation took place in the late Eocene, as 

indicated by the structural relations near Emigrant Spring. 

There, Mississippian units and the unconformably overlying 

Elko Formation have been folded in the form of an asymmetrical, south-plunging syncline with east vergence (fig. 4) 

(Smith and Ketner, 1978; Server and Solomon, 1983). An 

anticline and thrust fault, both subparallel with the Emigrant 

Spring Syncline, are exposed in the Paleozoic units just west 

of the syncline. The Emigrant Spring Syncline plunges 

southward and disappears beneath the almost undeformed 

Indian Well Formation. In the Emigrant Spring area, the age 

of deformation is therefore probably late Eocene, close to the 

Eocene-Oligocene boundary as fixed by the ages of the 

youngest radiometrically dated bed of the Elko Formation 

(37.1±1.0 Ma, K-Ar; Solomon and others, 1979) and the oldest dated bed of the Indian Well (37.6±1.3 Ma, K-Ar; Smith 

and Ketner, 1976)

Elko Hills

In the Elko Hills, Lower Mississippian to Lower Pennsylvania^?) siliceous deep-water turbidites were thrust over 

Lower Permian shelf rocks (Ketner, 1990). This contractional event is interpreted to have taken place before eruption 

of the Eocene rhyodacite of Elko Mountain and deposition of 

the Eocene Elko Formation because the upper plate is known 

to lie only on Permian rocks. Subsequently, the rhyodacite of 

Elko Mountain, Elko Formation, and underlying Paleozoic 

units were folded and partially overridden by a plate or plates 

of Paleozoic rocks (fig. 5) (Ketner, 1990). Folds include a 

well-defined anticline, a parallel, poorly defined anticline, 

and a poorly defined syncline. The exposed length of the better defined anticline is about 10 mi (16 km). Trends of the 

fold axes are generally about N. 45° E., almost parallel with 

trends of fold axes in Paleozoic rocks of the Peko Hills 10 mi 

(16 km) to the northeast and with the main trend of the axis 

of the Adobe Range Syncline 5 mi (8 km) to the northwest 

(fig. 1). Tuffaceous beds near the southwest corner of the 

mapped area (fig. 5) assigned to the uppermost Eocene and 

Oligocene Indian Well Formation were interpreted by 

Solomon and Moore (1982b) to be tilted, but not folded, as a 

result of extensional faulting. The upper Miocene Humboldt 

Formation, which crops out east and west of the Elko Hills, 

is undeformed.

On the northeastern flank of Elko Mountain (fig. 5) a 

klippe, composed of the lower part of the Pennsylvanian and 

Permian Strathearn Formation, overlies Permian beds that 

dip 20°-30° and beds of the Elko Formation that dip as much 

as 45°. The low-angle fault on which the Strathearn lies and

beds within the Strathearn dip very gently to the northeast. 

On the northern flank of the mountain two closely spaced 

klippen composed of the Mississippian and Lower Pennsylvanian Diamond Peak Formation overlie Permian beds and 

the Eocene rhyodacite of Elko Mountain. The fault on which 

the Diamond Peak lies is irregular but, in general, dips gently 

to the northwest. Interpolation of fault attitudes among the 

three allochthonous plates suggests that if the plates were 

once connected the fault on which they lie was only slightly 

arched and discordantly spanned the Elko Mountain folds. 

Thus, structural evidence in the Elko Hills suggests that folding took place after deposition of the Eocene Elko Formation 

and the rhyodacite of Elko Mountain, certainly before deposition of the upper Miocene Humboldt Formation, and probably before eruption of the uppermost Eocene and Oligocene 

Indian Well Formation. Low-angle faulting took place probably between the Early Permian and middle Eocene and 

again after deposition and folding of the Elko Formation and 

eruption of the rhyodacite of Elko Mountain.

FOLDS AND LOW-ANCLE FAULTS 

IN THE ELKO AREA: 

CONTRACTIONAL OR EXTENSIONAL?

Admittedly, some folds and low-angle faults, considered 

by themselves, may be hard to classify as contractional or 

extensional; however, compatible associations of numerous 

and varied structural features, typical of either shortened or 

extended terranes generally, can be classified more confidently. Typical post-Early Triassic, pre-Basin and Range 

structural features of the area of this report are large-scale 

folds verging toward the southeast quadrant, older over 

younger low-angle faults related to major folds, and tectonic 

juxtaposition of contrasting facies. Each of these features is 

typical of shortened terranes,'but juxtaposition of contrasting 

facies constitutes the best evidence that the fault system and 

related folds are primarily contractional. Extensional faults 

cannot juxtapose contrasting facies but, rather, tend to spread 

them farther apart. Although Late Tertiary Basin and Range 

faults are pervasive in the region, structures typical of terranes that were highly extended in the mid-Tertiary, such as 

extremely rotated fault blocks, younger over older low-angle 

faults with omission of strata, and greatly attenuated strata, 

are not prominent in the area of this report. Younger over 

older faults are present in the northern Adobe Range, but the 

dominant features of that area are large-scale folds broken by 

older over younger faults and telescoping of facies. Steeply 

dipping strata in Jurassic rocks of the Cortez Mountains 

could be interpreted as expressions of a tilted fault block, but 

gently inclined strata in the northernmost exposures suggest 

that a fold axis is present.

Jurassic to Eocene Folding and Faulting, Nevada C11
The origin of large-scale folds and older over younger, 

low-angle faults involving beds as young as Eocene is especially subject to controversy because the age of those structures approaches that of mid-Tertiary extensional structures 

well documented in many parts of Nevada. Moreover, 

Eocene lake deposits in the area can reasonably be interpreted to have been deposited under extensional conditions 

(Vandervoort and Schmitt, 1990). The large-scale folds in 

Eocene strata in the Pifion Range and the Elko Hills are here 

interpreted, however, as probable contractional features 

because they belong to a family of east- to northeasttrending, southeast-verging folds that, in nearby ranges, are 

demonstrably contractional. In addition, large-scale folds 

such as those affecting Eocene strata in the area are the normal expression of compression and are simply less likely to 

have formed under tensional conditions. The older over 

younger fault or faults in the northern Elko Hills could be an 

expression of either compression or tension. We favor the 

former but leave a final resolution of this uncertainty to 

future studies.

COMPARISON WITH THE IDAHOWYOMING-UTAH THRUST BELT

Initial thrust faulting in various sectors of the IdahoWyoming-Utah Thrust Belt began in the latest Jurassic 

(Armstrong and Oriel, 1965; Oriel and Armstrong, 1966; 

Wiltschko and Dorr, 1983) or the late Early Cretaceous 

(Bohannon, 1983; Heller and others, 1986; Villien and Kligfield, 1986). Thrusting ended in the Paleocene (Villien and 

Kligfield, 1986) or the early Eocene (Armstrong and Oriel, 

1965; Oriel and Armstrong, 1966; Wiltschko and Dorr, 

1983). Principal pulses, determined by the ages of the principal conglomeratic deposits, were in the latest Jurassic, Late 

Cretaceous, Paleocene, and early Eocene (Wiltschko and 

Dorr, 1983) or the Early Cretaceous, Late Cretaceous, and 

Paleocene (Villien and Kligfield, 1986). The prevailing concept that the ages of conglomeratic deposits reflect ages of 

principal thrust pulses has been questioned by Blair and 

Bilodeau (1988), but, even if their belief that the ages of finer 

grained foreland sediments (rather than conglomerate) more 

accurately date the orogenic pulses is correct, the interval of 

contractional deformation in the thrust belt remains essentially within the latest Jurassic to early Eocene interval. 

Thus, the interval of faulting and folding in the Elko area, 

here interpreted as primarily contractional, corresponds 

roughly to contractional deformation in the thrust belt.

REFERENCES CITED

Armstrong, F.C., and Oriel, S.S., 1965, Tectonic development of 

the Idaho-Wyoming thrust belt: American Association of 

Petroleum Geologists Bulletin v. 49, no. 11, p. 1847-1866.

Armstrong, R.L., 1963, Geochronology and geology of the eastern 

Great Basin in Nevada and Utah; New Haven, Conn., Yale 

University, Ph.D. thesis, 202 p.

Biglow, C.C., 1986, Stratigraphy and sedimentology of the Cretaceous Newark Canyon Formation in the Cortez Mountains, 

north-central Nevada: Cheney, Eastern Washington University, M.S. thesis, 123 p.

Blair, T.C., and Bilodeau, W.L., 1988, Development of tectonic 

cyclothems in rift, pull-apart, and foreland basins Sedimentary response to episodic tectonism: Geology, v. 16, p. 

517-520.

Bohannon, R.G., 1983, Mesozoic and Cenozoic tectonic development of the Muddy, North Muddy, and northern Black 

Mountains, Clark County, Nevada, in Miller, D.M., Todd, 

V.R., and Howard, K.A., eds., Tectonic and stratigraphic 

studies in the eastern Great Basin: Geological Society of 

America Memoir 157, p. 125-148.

Clark, T.M., 1985, The structure and Precambrian to Cambrian 

stratigraphy in the Bull Run Mountains, Elko County, Nevada: University of California, Davis, M.S. thesis, 137 p.

Coats, R.R., 1987, Geology of Elko County, Nevada: Nevada 

Bureau of Mines and Geology Bulletin 101,112 p.

Coats, R.R., and Riva, J., 1983, Overlapping overthrust belts of late 

Paleozoic and Mesozoic ages, northern Elko County, Nevada, in Miller, D.M., Todd, V.R., and Howard, K.A., eds., 

Tectonic and stratigraphic studies in the eastern Great Basin: 

Geological Society of America Memoir 157, p. 305-327.

Ehman, K.D., 1985, Paleozoic stratigraphy and tectonics of the Bull 

Run Mountains, Elko County, northern Nevada: University 

of California, Davis, Ph.D. dissertation, 174 p.

Fouch, T.D., Hanley, J.H., and Forester, R.M., 1979, Preliminary 

correlation of Cretaceous and Paleogene lacustrine and related nonmarine sedimentary and volcanic rocks in parts of the 

eastern Great Basin of Nevada and Utah, in Armentrout, 

J.M., Cole, M.R., and TerBest, Harry, eds., Cenozoic paleogeography of the western United States, Pacific Coast Paleogeography Symposium 3: Pacific Section, Society of 

Economic Paleontologists and Mineralogists, p. 97-111.

Gilluly, James, and Masursky, Harold, 1965, Geology of the Cortez 

quadrangle, Nevada: U.S. Geological Survey Bulletin 1175, 

117 p.

Harland, W.B., Armstrong, R.L., Cox, A.V., Craig, L.E., Smith, 

A.G., and Smith, D.G., 1990, A geologic time scale 1989: 

Cambridge, England, Cambridge University Press, 262 p.

Harland, W.B., Smith, A.G., and Wilcock, Bruce, eds., 1964, The 

Phanerozoic time-scale A symposium dedicated to Professor Arthur Holmes: Geological Society of London Quarterly 

Journal, Supplement, v. 120,458 p.

Heller, P.L., Bowdler, S.S., Chambers, H.P., Coogan, J.C., Hagen, 

E.S., Shuster, M.W., Winslow, N.S., and Lawton, T.F., 1986, 

Time of initial thrusting in the Sevier orogenic belt, IdahoWyoming and Utah: Geology, v. 14, p. 388-391.

Jaeger, K.B., 1987, Structural geology and stratigraphy of the Elko 

Hills, Elko County, Nevada: Laramie, University of Wyoming, M.S. thesis, 70 p.

Ketner, K.B., 1984, Recent studies indicate that major structures in 

northeastern Nevada and the Golconda thrust in north-central 

Nevada are of Jurassic or Cretaceous age: Geology, v. 12, p. 

483^186.

___1987, Post-Early Triassic, pre-middle Eocene folds and 

thrust faults, northern Adobe Range, Nevada: Cordilleran 

Section, Geological Society of America Centennial Field 

Guide, p. 91-94.

C1 2 Evolution of Sedimentary Basins Eastern Great Basin
___1990, Geologic map of the Elko Hills, Elko County, Nevada: U.S. Geological Survey Miscellaneous Investigations 

Map 1-2082, scale 1:24,000.

Ketner, K.B., and Evans, J.G., 1988, Geologic map of the Peko 

Hills, Elko County, Nevada: U.S. Geological Survey Miscellaneous Investigations Map 1-1902, scale 1:24,000.

Ketner, K.B., and Ross, R.J., Jr., 1990, Preliminary geologic map 

of the northern Adobe Range, Elko County, Nevada: U.S. 

Geological Survey Miscellaneous Investigations Map 

1-2081, scale 1:24,000.

Ketner, K.B., and Smith, J.F., Jr., 1974, Folds and overthrusts of 

Late Jurassic or Early Cretaceous age in northern Nevada: 

U.S. Geological Survey Journal of Research, v. 2, no. 4, p. 

417^119.

____1982, Mid-Paleozoic age of the Roberts thrust unsettled by 

new data from northern Nevada: Geology, v. 10, p. 298-303.

Little, T.A., 1987, Stratigraphy and structure of metamorphosed 

upper Paleozoic rocks near Mountain City, Nevada: Geological Society of America Bulletin, v. 98, p. 1-17.

Muffler, L.J.P., 1964, Geology of the Frenchie Creek quadrangle, 

north-central Nevada: U.S. Geological Survey Bulletin 1179, 

99 p.

Nolan, T.B., Merriam, C.W., and Williams, J.S., 1956, The stratigraphic section in the vicinity of Eureka, Nevada: U.S. Geological Survey Professional Paper 276,76 p.

Oriel, S.S., and Armstrong, F.C., 1966, Times of thrusting in IdahoWyoming thrust belt; reply: American Association of Petroleum Geologists Bulletin, v. 50, p. 2614-2621.

Server, G.T., Jr., and Solomon, B.J., 1983, Geology and oil shale 

deposits of the Elko Formation, Pifion Range, Elko County, 

Nevada: U.S. Geological Survey Miscellaneous Field Studies Map MF-1546, scale 1:24,000.

Smith, J.F., Jr., and Ketner, K.B., 1976, Stratigraphy of post-Paleozoic rocks and summary of resources in the Carlin- Pinon 

Range area, Nevada: U.S. Geological Survey Professional 

Paper 867-B, p. B1-B48.

____1977, Tectonic events since early Paleozoic in the 

Carlin-Pinon Range area, Nevada: U.S. Geological Survey 

Professional Paper 867-C, 18 p.

___1978, Geologic map of the Carlin-Pinon Range area, Elko 

and Eureka Counties, Nevada: U.S. Geological Survey Miscellaneous Investigations Map 1-1028, scale 1:62,500.

Solomon, B.J., McKee, E.H., and Andersen, D.W., 1979, Stratigraphy and depositional environments of Paleogene rocks near 

Elko, Nevada, in Armentrout, J.M., Cole, M.R., and TerBest, 

Harry, Jr., eds., Cenozoic paleogeography of the western 

United States, Pacific Coast Paleogeography Symposium 3: 

Pacific Section, Society of Economic Paleontologists and 

Mineralogists, p. 75-88.

Solomon, B.J., and Moore, S.W., 1982a, Geologic map and oil 

shale deposits of the Elko West quadrangle, Elko County, 

Nevada: U.S. Geological Survey Miscellaneous Field Studies Map MF-1410, scale 1:24,000.

___1982b, Geologic map and oil shale deposits of the Elko East 

quadrangle, Elko County, Nevada: U.S. Geological Survey 

Miscellaneous Field Studies Map MF-1421, scale 1:24,000.

Stewart, J.H., 1980, Geology of Nevada: Nevada Bureau of Mines 

and Geology Special Publication 4,136 p.

Stewart, J.H., and Carlson, J.E., 1978, Geologic map of Nevada: 

U.S. Geological Survey, scale 1:500,000.

Thorman, C.H., Ketner, K.B., Brooks, W.E., Snee, L.W., and Zimmerman, R.A., 1991, Late Mesozoic-Cenozoic tectonics in 

northeastern Nevada, in Raines, G.L., Lisle, R.E., Schafer, 

R.W., and Wilkinson, W.H., eds., Geology and ore deposits 

of the Great Basin: Geological Society of Nevada Symposium Proceedings, v. 2, p. 25-45.

Vandervoort, D.S., and Schmitt, J.G., 1990, Cretaceous to early 

Tertiary paleogeography in the hinterland of the Sevier thrust 

belt, east-central Nevada: Geology, v. 18, p. 567-570.

Villien, Alain, and Kligfield, R.M., 1986, Thrusting and synorogenic sedimentation in central Utah, in Peterson, J.A., ed., 

Paleotectonics and sedimentation in the Rocky Mountain 

region, United States: American Association of Petroleum 

Geologists Memoir 41, p. 281-307.

Wiltschko D.V., and Dorr, J.A., Jr., 1983, Timing of deformation in 

overthrust belt and foreland of Idaho, Wyoming, and Utah: 

American Association of Petroleum Geologists Bulletin, v. 

67, no. 8, p. 1304-1322.

*U.S. GOVERNMENT PRINTING OFFICE: 1992-673-049/66004 Jurassic to Eocene Folding and Faulting, Nevada C13



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