Mineral Resources of the Massacre Rim 

Wilderness Study Area, 

Washoe County, Nevada

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Chapter E

Mineral Resources of the Massacre Rim 

Wilderness Study Area, 

Washoe County, Nevada

By JOEL R. BERGQUIST, DONALD PLOUFF, and 

ROBERT L. TURNER 

U.S. Geological Survey

J. DOUGLAS CAUSEY 

U.S. Bureau of Mines

U.S. GEOLOGICAL SURVEY BULLETIN 1707

MINERAL RESOURCES OF WILDERNESS STUDY AREAS: 

NORTHWESTERN NEVADA
DEPARTMENT OF THE INTERIOR 

DONALD PAUL MODEL, Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director

Any use of trade names and trademarks 

in this publication is for descriptive 

purposes only and does not constitute 

endorsement by the U.S. Geological Survey

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1988

For sale by the

Books and Open-file Reports Section

U.S. Geological Survey

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Denver, CO 80225

Library of Congress Cataloging-in-Publication Data

Mineral resources of the Massacre Rim Wilderness Study 

Area, Washoe County, Nevada.

(U.S. Geological Survey bulletin ; 1707-E)

Bibliography: p.

Supt. of Docs. no. : I 19.3:1707-E

1. Mines and mineral resources Nevada Massacre Rim 

Wilderness. 2. Massacre Rim Wilderness (Nev.) 

I. Bergquist, Joel R. II. Series.

QE75.B9 no. 1707-E 557.3 s 88-600136 

[TN24.N3] [553'.09793'55]
STUDIES RELATED TO WILDERNESS

Bureau of Land Management Wilderness Study Area

The Federal Land Policy and Management Act (Public Law 94-579, October 21, 1976) requires the 

U.S. Geological Survey and the U.S. Bureau of Mines to conduct mineral surveys on certain areas to 

determine the mineral values, if any, that may be present. Results must be made available to the public 

and be submitted to the President and the Congress. This report presents the results of a mineral survey 

of part of the Massacre Rim Wilderness Study Area (CA-020-1013), Washoe County, Nevada.

CONTENTS

Summary El

Abstract 1

Character and setting 1

Identified resources 1

Mineral resource potential 1 

Introduction 3

Area description 3

Previous investigations 3

Present investigations 3

Acknowledgments 5 

Appraisal of identified resources 5

Mining history and production 5

Mines, prospects, claims, and mineralized sites 6 

Assessment of mineral resource potential 6

Geology 6

Geochemical studies 7

Geophysical studies 7

Mineral resource potential 8 

References cited 10 

Appendixes

Definition of levels of mineral resource potential and certainty of assessment 14

Resource/reserve classification 15

Geologic time chart 16

FIGURES

1. Index map showing location of Massacre Rim Wilderness Study Area, Washoe County, Nevada E2

2. Map showing mineral resource potential and generalized geology of Massacre Rim Wilderness Study 

Area, Washoe County, Nevada 4

Contents V

MINERAL RESOURCES OF WILDERNESS STUDY AREAS: 

NORTHWESTERN NEVADA

Mineral Resources of the Massacre Rim 

Wilderness Study Area, 

Washoe County, Nevada

By Joel R. Bergquist, Donald Plouff, and Robert L. Turner 

U.S. Geological Survey

J. Douglas Causey 

U.S. Bureau of Mines

SUMMARY 

Abstract

The part of the Massacre Rim Wilderness Study Area 

(CA-020-1013) for which mineral surveys were requested by 

the U.S. Bureau of Land Management encompasses 23,260 

acres northeast of Massacre Lake, about 15 miles northeast of 

Vya, Nev. Geological, geochemical, geophysical and mineral surveys were conducted by the U.S. Geological Survey 

and the U.S. Bureau of Mines in 1985 to assess the mineral 

resources (known) and mineral resource potential (undiscovered) of the study area. No identified metallic or nonmetallic 

resources occur within the study area. There is moderate 

mineral resource potential for gold, silver, and mercury in 

hydrothermal deposits in the eastern part of the study area. 

There is moderate mineral resource potential for uranium 

throughout the study area. There is no potential for oil and 

gas in the study area. The potential for geothermal resources 

is unknown. In this report, references to the "Massacre Rim 

Wilderness Study Area" or "study area" refer only to lands for 

which mineral surveys were requested by the U.S. Bureau of 

Land Management.

Character and Setting

The Massacre Rim Wilderness Study Area is in 

northwest Nevada, about 22 mi east of the California border, 16 mi south of the Oregon border, and 16 mi northeast 

of Vya, Nev. (fig. 1). The regional setting is transitional 

between the Basin and Range and the Columbia Plateau 

physiographic provinces. This region is characterized by 

volcanic uplands of moderate relief and alluviated valleys. 

The study area is almost wholly within an upland area. 

Elevations range from 5,630 ft near Massacre Lake to 

6,370 ft at Bitner Table (fig. 1). Access to the margins of

Publication authorized by the Director, U.S. Geological Survey, Jan. 6, 1988.

the study area is provided by unpaved roads leading north 

from Nevada Highway 8A and by a jeep trail that leads 

south from Nevada Highway 34A.

The study area is underlain mostly by basalt flows of 

Miocene age (see appendixes for geologic time chart). The 

basalt mostly covers older Tertiary rhyolite and tuffaceous 

alluvial and lake deposits of Tertiary to Holocene age. In 

many places in the region the basalt has been eroded, 

exposing the underlying older rocks and tuffaceous sediments. Because the tuffaceous sediments which underlie 

the basalt flows are relatively incompetent, there has been 

extensive landsliding in the region.

No mines have been developed within the study area, 

and there are no known prospects or mineralized areas. 

The nearest prospecting was for gold, silver, and mercury 

in Bald Mountain Canyon in the Lone Pine mining district 

about 4 mi northwest of the study area.

Identified Resources

No identified resources exist within the Massacre 

Rim Wilderness Study Area. Basalt from the study area 

could be used as road metal or for other industrial purposes, 

but it is not considered to be a resource because of the 

abundance of other suitable materials in the region.

Mineral Resource Potential

The study area has moderate mineral resource potential for gold, silver, and mercury in hydrothermal deposits 

associated with a caldera on the east side. The entire study 

area has moderate resource potential for uranium in volcaniclastic deposits. There is no resource potential for oil 

and gas. The potential for geothermal energy is unknown.

Mineral Resources of the Massacre Rim Wilderness Study Area, Washoe County, Nevada E1
42°00' 1 20°00 19°00'

41°45' -

APPROXIMATE BOUNDARY 

OF

MASSACRE RIM WILDERNESS 

STUDY AREA (CA-020-1013)

41°00'

Figure 1. Index map showing location of Massacre Rim Wilderness Study Area, Washoe County, Nevada. 

E2 Mineral Resources of Wilderness Study Areas Northwestern Nevada
INTRODUCTION

This mineral resource study is the result of a cooperative effort by the U.S. Geological Survey and the U.S. 

Bureau of Mines. Mineral assessment methodology and 

terminology are discussed in Goudarzi (1984). Identified 

resources are classified according to a system that is a 

modification of that described by McKelvey (1972) and 

U.S. Bureau of Mines and the U.S. Geological Survey 

(1980). See appendixes for the definition of levels of 

mineral resource potential and certainty of assessment and 

for the classification of identified resources. Studies by the 

U.S. Geological Survey are designed to provide a reasonable scientific basis for assessing the potential for undiscovered mineral resources by determining geological units 

and structures, possible environments of mineral deposition, presence of geophysical and geochemical anomalies, 

and applicable ore-deposit models. The U.S. Bureau of 

Mines evaluates identified resources at individual mines 

and known mineralized areas by collecting data on current 

and past mining activities and through field examination of 

mines, prospects, claims, and mineralized areas.

Area Description

The Bureau of Land Management requested mineral 

surveys of 23,260 acres within the Massacre Rim Wilderness Study Area (CA-020-1013). The study area is in 

northern Washoe County, Nev., although it is administered 

by the Bureau of Land Management office in Susanville, 

Calif. The Charles Sheldon Antelope Range borders the 

eastern side of the study area and is within one-tenth mile 

of the northern part of the study area (fig.l). The Sheldon 

National Antelope Refuge is about 3 mi north of the study 

area.

The study area is in the transition zone between the 

Basin and Range and the Columbia Plateau physiographic 

provinces. This region is typical northern Great Basin open 

plateau, having volcanic uplands and alluviated valleys. 

There are numerous perennial and ephemeral alkali lakes in 

the region. Massacre Lake, the largest in the area, is about 

1 mi southwest of the study area and covers 6 to 8 mi2. 

Fatty Martin Lake is within the southern part of the study 

area and covers about 0.3 mi2. A few other small ephemeral lakes are wholly or partly in the study area. The 

western part of the Massacre Rim Wilderness Study Area 

consists mostly of Bitner Table, a relatively flat surface of 

basalt flows that have been faulted and dissected in part. 

The eastern part of the study area consists of a northwesttrending box canyon that drains through a 120-ft-deep 

notch into Badger Creek, which flows northwest along the 

eastern side of the study area.

The region has an arid to semiarid climate, with an 

average annual precipitation of about 4 to 8 in. (Houghton

and others, 1975). The study area has a few intermittent 

streams. Antelope, coyotes, badgers, martens, skunks, and 

raccoons are the largest mammalian residents of the area. 

Vegetation is sparse and consists mostly of sagebrush, 

grasses, and scattered juniper trees.

Previous Investigations

Bonham (1969) described the geology and mineral 

deposits of Washoe County, Nev. His report includes a 

geologic map of the region at a scale of 1:250,000, discussions of the geologic units found in the study area, and 

information on the nearby Lone Pine mining district. 

Bailey and Phoenix (1944), and Ross (1941) discussed the 

mercury occurrences in the Lone Pine mining district. Park 

(1983) mapped and described the geology of an area that 

includes the eastern part of the study area. The U.S. 

Geological Survey and U.S. Bureau of Mines (1984) made 

a four-part study of the Charles Sheldon Wilderness Study 

Area, which adjoins the Massacre Rim Wilderness Study 

Area. Greene's (1984) geologic map of that area, at a scale 

of 1:125,000, includes the eastern and northern parts of the 

present study area, and the text includes discussions of the 

geologic units and structure. Plouff (1984) interpreted 

aeromagnetic and gravity data for that area and reported 

evidence for a buried caldera that may underlie the eastern 

part of the Massacre Rim Wilderness Study Area. Cathrall 

and others (1984) did a geochemical evaluation of that area, 

and some of their samples were collected from the northern 

and eastern margins of the Massacre Rim Wilderness Study 

Area. Tuchek and others (1984) wrote an economic appraisal of the Charles Sheldon Wilderness Study Area and 

described the mineral commodities, mines, and prospects in 

areas north and east of the Massacre Rim Wilderness Study 

Area. Mineral resource appraisals of other nearby wilderness study areas were done by Ach and others (1987), 

Bergquist and others (1988), Keith and others (1987), 

Noble and others (1987a, b), and Turrin and others (1988). 

Larson and Beal (1978) described the geologic framework 

and uranium favorability of the region. Howell (1979) 

discussed the geology and mineral resources of the Vya, 

Nev., 1° by 2° quadrangle.

Present Investigations

The U.S. Geological Survey conducted field investigations in the summer of 1985. This work consisted of 

geologic mapping, collecting gravity data, and geochemical 

sampling of bedrock and stream sediments. The rock 

samples were collected from representative and possibly 

mineralized parts of each lithologic unit found in the study 

area. The analyses of these samples provide data that can 

be used to help identify mineralization and potential resources.

Mineral Resources of the Massacre Rim Wilderness Study Area, Washoe County, Nevada E3
APPROXIMATE BOUNDARY

OF

MASSACRE RIM

WILDERNESS STUDY AREA

(CA-020-1013)

Figure 2. Mineral resource potential and generalized geology of Massacre Rim Wilderness Study Area, Washoe County, 

Nevada.

E4 Mineral Resources of Wilderness Study Areas Northwestern Nevada
EXPLANATION

$;;gsg|$ Area with moderate mineral resource potential (M); data 

only suggest certainty level (B)

Au

Ag

Hg 

u

Commodities

Gold 

Silver 

Mercury 

Uranium

[ ] Types of deposits

Hot-spring gold-silver 

Hot-spring mercury 

Volcanogenic uranium

Correlation of map units

UATERNARY

 Miocene -TERTIARY

Qal 

Qls

Qp 

Tb

Tts

Trc

Tcr

Description of geologic map units

Alluvium and colluvium (Quaternary)--Stream

deposits of clay, silt, sand, gravel, and boulders, and 

colluvium

Landslide deposits (Quaternary)--Chaotic masses 

and blocks of basalt and tuffaceous sedimentary 

rocks; arrow shows direction of movement

Playa and lacustrine deposits (Quaternary)-- 

Clay, silt, sand, and alkali salts

Basalt of Catnip Creek of Greene (1984) 

(Miocene)--Brownish-black- to black-weathering 

basalt flows; dark to medium gray on fresh surfaces; 

individual flows typically 10 to 20 ft thick; locally 

vesicular to scoriaceous

Tuffaceous sedimentary rocks (Miocene)-- 

Unconsolidated to weakly consolidated, weakly to 

distinctly bedded, mostly lacustrine deposits of 

volcanic ash, claystone, siltstone, volcaniclastic 

sandstone, and pumice-rich, air-fall, and water-laid 

tuffs. Rock colors are white, light shades of gray and 

brown, light pink, and reddish

Rhyolite of Catnip Mountain of Greene (1984) 

(Miocene)--Light- to medium-gray rhyolite, locally 

streaked light reddish gray, locally pumiceous or 

glassy; minor amounts of obsidian; phenocrysts of 

quartz, alkali feldspar, and sodic amphibole in 

aphanitic groundmass

Canon Rhyolite of Merriam (1910) (Miocene)-- 

Reddish-gray to maroon rhyolite, streaked and 

mottled medium to light gray; banded, lithophysal, 

and vesicular textures; phenocrysts of quartz, alkali 

feldspar, and biotite in aphanitic groundmass

Contact-Dashed where approximate 

Fault-Dashed where approximate. Bar and ball on

downthrown side 

Flow ridges in basalt 

Inferred margin of buried caldera 

Area of anomalous radioactivity

Figure 2. Continued.

The U.S. Bureau of Mines reviewed information relating to current and past mining and prospecting activities 

in and near the study area. U.S. Bureau of Mines personnel 

examined (1) U.S. Bureau of Mines files, (2) the U.S. 

Bureau of Mines computerized Mineral Industry Location 

System (MILS), (3) U.S. Bureau of Land Management 

records of mining claims, land status, and land use, and (4) 

Washoe County records of mining claims. The field study 

in 1985 consisted of a reconnaissance for mines, prospects, 

claims, and mineralized areas. Complete results of studies 

by the U.S. Bureau of Mines were given by Causey (1987).

U.S. Bureau of Mines personnel collected four 

samples of rock and one of alluvium from areas of possible 

mineral concentrations within and adjacent to the study 

area. All samples were analyzed by semiquantitative spectrographic analyses for 40 elements to determine anomalous concentrations. The rock samples were assayed for 

gold and silver using a combined fire assay-inductively 

coupled plasma method. One rock sample was analyzed 

for mercury by X-ray fluorescence. One sample of tuff was 

analyzed by X-ray diffraction for the presence of zeolites. 

The sample of alluvium was concentrated and examined for 

gold, scheelite, ilmenite, garnet, zircon, and magnetite. 

Complete analytical data are on file at the U.S. Bureau of 

Mines, Western Field Operations Center, E. 360 Third 

Avenue, Spokane, WA 99202.

Acknowledgments

Joseph McFarlan and other members of the Cedarville, Calif., District Office of the U.S. Bureau of Land 

Management provided help and the use of Stevens Camp. 

Don Coops permitted access to the study area through his 

ranch. Dr. Donald C. Noble of the University of Nevada, 

Reno, led an informative field trip through the region for 

Bureau of Land Management and U.S. Geological Survey 

personnel.

APPRAISAL OF IDENTIFIED RESOURCES

By J. Douglas Causey 

U.S. Bureau of Mines

Mining History and Production

There are no identified resources in the Massacre Rim 

Wilderness Study Area, and no mines, prospects, claims, or 

indications of mineralized zones were found. The nearest 

prospecting activity is in Bald Mountain Canyon in the 

Lone Pine mining district, about 4 mi northwest of the 

study area. That area was first prospected for gold, but 

none was found in mineable amounts, and the district was

Mineral Resources of the Massacre Rim Wilderness Study Area, Washoe County, Nevada E5
inactive until the discovery of mercury as cinnabar in 1929 

(Ross, 1941; Bailey and Phoenix, 1944; Bonham, 1969). A 

small amount of mercury was produced, but there is no 

known production of gold or silver from the district. Present prospecting in the area of Bald Mountain Canyon is for 

gold and associated silver in silicified and altered andesite 

and interbedded tuff.

Mines, Prospects, Claims, and Mineralized Sites

No gold, silver, mercury, or zeolites were observed in 

samples of rock submitted for analysis. These samples 

consisted of basalt, pumiceous volcanic rocks, brecciated 

tuff, and tuff altered to montmorillonite. No anomalous 

concentrations of valuable minerals were detected in the 

sample of alluvium.

No industrial commodities were observed. Basalt 

from the study area could be used for stone products or 

crushed for use as road metal. It is not classified as an 

identified resource because basalt is abundant in the region, 

and other sources are closer to existing markets.

ASSESSMENT OF MINERAL RESOURCE 

POTENTIAL

By Joel R. Bergquist, Donald Plouff, and Robert L. Turner 

U.S. Geological Survey

Geology

Rocks in the Massacre Rim Wilderness Study Area 

comprise a series of late Tertiary volcanic flows, intrusive 

rocks, and volcaniclastic sediments (fig. 2). Most of the 

area is covered by basalt flows that largely cover the older 

rocks and older sediments. The rocks of the area have been 

fractured by numerous steeply dipping normal faults, most 

of which trend northwest. The oldest rocks in the study 

area are mapped as equivalents of the Canon Rhyolite 

(Merriam, 1910) of Miocene age. They are exposed in a 

small area in the northeastern part of the study area. The 

rhyolite is predominantly reddish gray to maroon and is 

streaked and mottled medium to light gray. The rock is an 

aphanitic porphyry with phenocrysts of quartz, alkali 

feldspar, and biotite. Banded, lilhophysal, and vesicular 

textures are present. Because the outcrops of Canon 

Rhyolite in the study area are found only in a small area 

near a valley bottom, little is known about the extent or 

thickness of this unit.

The younger rhyolite of Catnip Mountain (Greene, 

1984) is found in the central and northwestern parts of the 

study area. This unit was previously included in the Canon 

Rhyolite (Bonham, 1969). This rhyolite is predominantly 

light to medium gray and locally streaked light reddish

gray. Phenocrysts of quartz, alkali feldspar, and sodic 

amphibole are found in an aphanitic groundmass. Textures 

are banded (eutaxitic), lithophysal, and vesicular. The 

rhyolite varies locally from light gray and pumiceous to 

dark gray or black and glassy. Minor amounts of small 

black obsidian (volcanic glass) pebbles derived from this 

unit can be found in the colluvium.

Stratigraphically above the rhyolites is a sequence of 

tuffaceous sedimentary rocks that are interbedded with 

basalt flows near the top of the section. The section of 

sedimentary rocks comprises volcanic ash, claystone, 

siltstone, volcaniclastic sandstone and pumice-rich, air-fall, 

and water-laid tuffs. The rocks are typically 

unconsolidated to weakly consolidated and weakly to 

distinctly bedded. They occur in various colors, including 

white, light shades of gray, light brown, light pink, and red. 

The coarser clastic rocks are typically poorly sorted and 

contain angular to rounded fragments of volcanic rock, 

pumice, volcanic glass, and opalized wood in a clayey to 

silly matrix. The presence of opalized wood, gastropod 

shells, and bedding structures indicates that most of these 

beds were deposited in freshwater lakes.

The basalt of Catnip Creek of Miocene age (Greene, 

1984, p. 29) overlies and is interbedded with the uppermost 

beds of the tuffaceous sedimentary rocks. Basalt forms 

most of the bedrock in the study area and vicinity. Some 

of the thin basalt flows that are interbedded with the 

tuffaceous sedimentary rocks show weathered, pillow-like 

structures which indicate that the lava flowed into lakes and 

was quenched. The numerous thin basalt flows (each 10 to 

20 ft thick) have a minimum aggregate thickness of 300 ft 

based on measurements in fault scarps about 10 mi north of 

the study area at Racetrack Reservoir. Greene (1984) 

described a continuous sequence of 24 basalt flows on the 

east side of Racetrack Reservoir. Columnar jointing was 

observed in some of the flows exposed in the study area.

The basaltic lavas were erupted from numerous vents 

and fissures in the region, a few of which are found within 

the study area. Bitner Butte on the northern boundary of 

the study area is a prominent vent complex and is the 

source of the youngest basalt flows in the area. Basalt 

flows radiate outward from the summit of this 400-ft-high 

conical vent.

The basalt of Catnip Creek is typically dark to 

medium gray on fresh surfaces, is fine grained to aphanitic, 

and contains 25-60 percent plagioclase, 7-30 percent 

olivine, 12-50 percent clinopyroxene, 2-12 percent 

magnetite, and 1-10 percent voids between plagioclase 

crystals (Greene, 1984, p. 29). Microphenocrysts of olivine 

and plagioclase locally make up as much as a few percent 

of the basalt (Greene, 1984), but the rock is typically 

equigranular. The basalt weathers to brownish black or 

black. Tops and bottoms of flows are vesicular to 

scoriaceous, and the bottoms of flows locally include 

aulobrcccia.

E6 Mineral Resources of Wilderness Study Areas Northwestern Nevada
Surficial deposits consist of alluvium and colluvium, 

landslide debris, and lacustrine (lake) and playa sediments. 

The alluvium consists of unsorted stream deposits of clay, 

silt, sand, gravel, and boulders. It includes fine-grained 

marsh sediments along Badger Creek. Landslides and glide 

blocks are common in the region because the tuffaceous 

sediments on which the basalt rests are loosely consolidated 

and easily eroded. This erosion results in instability due to 

oversteepening and ultimately in catastrophic failure of the 

overlying basalt. The landslides are characterized by 

chaotic, broken blocks of lava and tuffaceous sediments. In 

some places, large sections of basalt have slid as relatively 

coherent glide blocks over the underlying sediments.

Playa and lacustrine deposits are found in large and 

small basins throughout the region. The Massacre Lake 

basin southwest of the study area encompasses about 16 

mi2 of lake deposits. Fatty Martin Lake, which is wholly 

within the study area, encompasses about 0.3 mi2. Other 

smaller areas of lacustrine and playa deposits are scattered 

over the study area.

The region is broken by conjugate sets of steep 

normal faults that trend northeast and northwest (the 

dominant direction). The faulting reflects post-Oligocene 

tectonic extension in the Basin and Range province and 

possibly differential settling of overlying rocks into 

depleted subsurface magma reservoirs. Vertical 

displacements on these faults are as much as a few hundred 

feet in the western part of the study area northeast of 

Massacre Lake.

Geochemical Studies

A reconnaissance geochemical survey was conducted 

in the Massacre Rim Wilderness Study Area in the summer 

of 1985. Minus-80-mesh stream sediments and heavymineral concentrates derived from stream sediments were 

collected from 32 sites, and rocks were sampled at 8 sites. 

The bulk stream-sediment samples were collected from the 

active alluvium in stream channels; each one was 

composited from several localities along a channel length 

of about 50 ft. Stream sediments were collected because 

they represent a composite of the rock and soil exposed 

upstream from the sample site. The heavy-mineral 

concentrate includes the ore-forming and ore-related 

minerals and permits determination of some elements that 

are not easily detected in bulk stream sediments.

Rocks were collected from mineralized and 

unmineralized outcrops and from stream beds. Samples 

that appeared fresh and unaltered were collected to provide 

information on geochemical background values. Altered or 

mineralized samples were collected to determine the suite 

of elements associated with the observed alteration or 

mineralization. The rocks were crushed and pulverized to 

a fine powder before analysis.

The heavy mineral concentrates, stream sediments, 

and rocks were analyzed for 31 elements by direct-current 

arc, semiquantitative, emission spectrographic analysis 

(Grimes and Marranzino, 1968; Crock and others, 1983). 

The rocks were also analyzed for arsenic, bismuth, 

cadmium, antimony, and zinc (O'Leary and Viets, 1986), 

for gold (Thompson and others, 1968), and for mercury 

(Koirtyohann and Khalil, 1976). Analytical data and a 

description of the sampling and analytical techniques are 

given in Adrian and others (1988).

For this study, anomalous geochemical values were 

determined by inspection of histograms of the data from 

both the study area and the surrounding region and by 

comparing the data to the average abundances in silicic 

volcanic rocks. For most elements, a value was considered 

anomalous if it exceeded the mean value for the element by 

two standard deviations.

The eastern part of the study area is delineated as 

weakly anomalous on the basis of geochemical data. This 

area contains stream sediments that are anomalous in 

cadmium (1.0-6.0 parts per million, ppm) and weakly 

anomalous in zinc (160-200 ppm). The heavy-mineral 

concentrates are anomalous in gold (0.10 ppm or less) and 

weakly anomalous in mercury (0.16-0.20 ppm) and zinc 

(200-320 ppm). However, the rocks sampled in the eastern 

part of the study area contained no anomalous ore-forming 

or ore-related elements. There is a postulated caldera ring 

fracture zone on the northeast side of the study area (Plouff, 

1984). Anomalous mercury in heavy-mineral concentrates 

from this part of the study area may indicate hydrothermal 

activity along the ring fractures of the caldera. Anomalous 

elements in the northern part of the study area are found in 

or down stream from outcrops of peralkaline Miocene 

rhyolites.

The weakly anomalous mercury and zinc may reflect 

high background values found in basalt and peralkaline 

rhyolite. Some of the basalt in the region has background 

values of mercury that range from 0.10 to 1.0 ppm, and 

peralkaline rhyolite may contain background zinc of 200 

ppm or more (James J. Rytuba, written commun., 1987). 

Numerous mercury prospects in rhyolite are found in Bald 

Mountain Canyon about 4 mi north-northwest of the study 

area. The weak mercury anomalies may indicate the 

extension of this mercury mineralization, possibly 

accompanied by gold mineralization, into the study area.

Geophysical Studies

Geophysical evaluation of the mineral resources of 

the study area is based on interpretations of aerial gammaray, gravity, and aeromagnetic surveys.

Radiometric data were compiled by Geodata International, Inc. (1979) for the National Uranium Resource 

Evaluation (NURE) program of the Department of Energy.

Mineral Resources of the Massacre Rim Wilderness Study Area, Washoe County, Nevada E7
Coverage of the study area includes one north-south flightline located about 1 mi west of the east edge of the study 

area and three east-west flightlines spaced at 3-mi intervals 

starting at the northern edge of the study area. Readings of 

gamma-ray flux from radioactive isotopes of uranium, 

thorium, and potassium were recorded. Flight altitudes 

over the study area ranged from 400 to 550 ft above the 

ground. The flux level for all three isotopes is at or below 

normal background level except for one location. Count 

rates exceeded three standard deviations above mean background level over a 0.5-mi east-west line segment centered 

near a jeep trail located at near the center of the study area 

(lat 41°43.2'N., long 119°30.3'W.). The source of the sharp 

anomaly, however, is uncertain without confirmation by a 

ground scintillometer survey.

Six gravity stations were established in the study 

area, another station was along the boundary of the study 

area, and 10 stations were within 3 mi of the boundary 

(Donald Plouff, unpub. data, 1985). These data were 

supplemented by gravity values from Plouff (1977) for 1 

station in the study area, 2 stations along the boundary, and 

13 stations within 3 mi of the boundary.

A gravity map of the area (Donald Plouff, unpub. 

data, 1985) shows that the eastern 2 mi of the study area 

overlies the west margin of a caldera described by Greene 

and Plouff (1981). The caldera is defined by a 12- by 30- 

mi gravity low having an amplitude of about 20 milligals 

(mGal). The gravity low presumably results from the 

density contrast between the less dense tuffaceous sedimentary rocks that fill the caldera and the denser country rocks 

outside the caldera rim. The caldera is concealed beneath 

flat-lying sediments and younger volcanic rocks. The 

density contrast between an underlying former magma 

reservoir and the surrounding basement rocks also may 

contribute to the amplitude of the anomaly.

A gravity high having an amplitude of 3 mGal and a 

diameter of about 3 mi is centered near the south corner of 

the west edge of the study area. The gravity high probably 

reflects a topographic or structural high of volcanic or preCenozoic basement rocks between the caldera to the east 

and a smaller area of subsidence reflected by a 5-mGal, 6- 

by 8-mi gravity low to the west. The gravity high also may 

reflect an igneous plug that has intruded sedimentary rocks 

and less dense volcanic rocks. A small gravity high centered at the northern tip of the study area is located at the 

southwest end of a narrow gravity high that extends more 

that 10 mi to the northeast. A narrow, east-west-elongated 

gravity low between the two gravity highs overlies the 

location of the radioactivity anomaly and may reflect a 

narrow area of subsidence or possible brecciation.

An aeromagnetic map of the region (U.S. Geological 

Survey, 1972; Plouff, 1984, pi. 2) covers the study area. 

The flightlines were flown in an east-west direction at a 

spacing of about 2 mi and a constant barometric elevation 

of 9,000 ft. There is an excellent correlation between a

broad magnetic low and the gravity low that defines the 

large caldera east of the study area. The most conspicuous 

anomaly in the study area is a magnetic high of low 

amplitude, which extends southward from Bitner Butte 

through the southeast corner of the study area. The magnetic high generally reflects topographically higher volcanic rocks having normal magnetization. A small magnetic low is centered about 1 mi southeast of the gravity 

high near the southwest corner of the study area. Therefore, the source of the gravity high may be rocks having 

low magnetization in the pre-Cenozoic basement. The 

magnetic low also reflects subsided sediments or rocks 

having inherently low or altered magnetization, which are 

located above the source of the gravity high.

Mineral Resource Potential

The possible presence of concealed mineral deposits 

is suggested by anomalous concentrations of certain elements, associations of anomalous elements, and geophysical data. In conjunction with permissive rocks and favorable geologic structures, these data lead to the conclusion 

that the study area has moderate potential, certainty level B, 

for gold, silver, and mercury in the eastern part of the study 

area, and moderate potential for uranium, certainty level B, 

throughout the study area. Cathrall and others (1984, 

p. 78) identified the northeastern part of the study area as 

having unspecified mineral resource potential on the basis 

of geological and geophysical evidence.

The eastern part of the study area has mineral resource potential for hot-spring gold and silver deposits. 

Berger (1985,1986) discusses the nature and characteristics 

of this type of deposit. The study area has a number of the 

enumerated characteristics of such deposits. The Tertiary 

rhyolites that are in part porphyritic are permissible host 

rocks. Rocks in the region are fractured by numerous, 

predominantly northwest-trending, high-angle normal 

faults that can act as conduits for mineralizing fluids. 

Geochemical sampling revealed anomalous gold (as much 

as 0.1 ppm) and weakly anomalous mercury (0.16 to 0.20 

ppm). These two elements are part of a suite of elements 

that characterize such deposits. Gold concentrations of less 

than 0.50 ppm have also been found in unspecified rock 

types about 5 mi east of the study area (Cathrall and others, 

1984). The gravity survey indicates that the eastern part of 

the study area overlies the west rim of a buried caldera 

described by Greene and Plouff (1981) and Plouff (1984). 

Intracaldera sediments would have low thermal conductivity and would act as a thermal insulator, thus refracting heat 

toward the edge of the caldera. Ring fractures along the 

edge of the postulated caldera may have provided channels 

for hydrothermal ore-bearing solutions to migrate upward 

toward the surface, and intracaldera sediments could be 

permeated with precipitates of those solutions. The

E8 Mineral Resources of Wilderness Study Areas Northwestern Nevada
McDermitt caldera, about 55 mi east-northeast of the study 

area, for example, is the site of uranium deposits and extensive mercury deposits of this type (Rytuba, 1976). On the 

basis of geochemical and geophysical studies, geologic 

mapping, structural setting, and descriptive ore-deposit 

models, the eastern part of the study area is assigned a 

moderate mineral resource potential, certainty level B, for 

gold and silver in hot-spring type, precious-metal deposits.

The eastern part of the study area also has mineral 

resource potential for hot-spring type deposits of mercury. 

Rytuba (1986) provides descriptive and grade-tonnage 

models of this type of deposit. The study area has several 

characteristics of this type of deposit. The presence of 

Tertiary basalt flows that are found in the study area is 

typical of many areas having hot-spring mercury deposits. 

Rocks of the study area are fractured by high-angle normal 

faults, which can act as conduits for ore-bearing fluids, and 

there are rock types permissive for mercury deposits. 

Geochemical samples obtained from the northern part of 

the study area contain small amounts of both mercury and 

gold. The presence of anomalous gold and weakly anomalous mercury is significant because hot-spring mercury 

deposits in some places are found in association with hotspring gold deposits (Rytuba and Glanzman, 1978, 1979; 

Rytuba, 1986). Cathrall and others (1984) reported mercury anomalies of from 0.20 to 0.60 ppm in rock samples 

collected a few miles east of the study area. These amounts 

are comparable to the magnitude of the mercury anomalies 

found within the study area. As with hot-spring gold 

deposits, ring fractures along the margin of the postulated 

caldera would provide conduits for warm-water mineralizing fluids. On the basis of the evidence, the eastern part 

of the study area is assigned a moderate mineral resource 

potential, certainty level B, for mercury in hot-spring deposits.

Mercury, as cinnabar, and minor amounts of gold are 

found in Bald Mountain Canyon about 4 mi northwest of 

the study area. The host rocks in that area are andesite 

flows and flow breccias with intercalated tuffs (Bonham, 

1969). The mercury is found as cinnabar in veinlets and 

stringers and is disseminated along fractures in silicified 

and argillized andesite. No andesite is found at the surface 

in the study area, but it may occur beneath tuffaceous 

sediments and basalt. Even if mineralized andesite is 

present at depth in the study area, and if the mercury 

mineralization occurs in that unit as in Bald Mountain 

Canyon, the thickness of the overlying rocks in the study 

area would make discovery and exploitation of mercury 

difficult and expensive.

The entire study area has moderate mineral resource 

potential, certainty level B, for uranium in volcanogenic 

deposits. Potential for undiscovered uranium resources in 

volcaniclastic deposits is indicated by the geophysical 

gamma-ray flux anomaly. This anomaly is high, being 3 

standard deviations above mean background level. It was

recorded by an aerial survey, and the anomalous area could 

be more accurately delineated by a ground reconnaissance 

with a scintillometer. The study area has some of the 

characteristics of volcanogenic uranium deposits outlined 

by Bagby (1986). These are (1) peralkaline porphyritic 

rhyolite in shallow intrusives and dome flow rocks, (2) an 

associated nearby caldera, (3) fractured and faulted country 

rock, and (4) the presence of mercury in geochemical 

samples. At the McDermitt caldera complex, 55 mi northnortheast of the study area, Wallace and Roper (1981) 

reported uranium concentrations in a horizon within tuffaceous lake sediments. The study area has extensive tuffaceous lake sediments beneath the overlying basalt. 

Rytuba and Glanzman (1978) also reported that uranium is 

locally associated with mercury deposits at the McDermitt 

caldera. Other loci for uranium concentrations at the 

McDermitt caldera are along geologic contacts, unconformities, and reduction-oxidation boundaries (Wallace and 

Roper, 1981), as well as in ash-flow tuffs, moat-fill sediments, ring domes, and intrusive rocks (Rytuba, 1981). It 

is not known which, if any, of these conditions is the source 

of the radioactivity anomaly in the study area. The anomaly was detected over an area of basalt, but radioactive 

isotopes may be leaking upward through the fractured 

basalt from underlying concealed rocks and structures. 

Cathrall and others (1984) reported anomalous uranium (12 

ppm) in samples of unspecified rock type from a tributary 

to Badger Creek about 5 mi east of the study area and from 

Bald Mountain Canyon (22 ppm) about 4 mi northwest of 

the area. Their studies of uranium in Virgin Valley, about 

20 mi east of the study area, showed that the area contains 

large low-grade uranium resources in tuffaceous sediments. 

A more complete description of the uranium occurrences in 

Virgin Valley was reported by Levering (1954). On the 

basis of the geophysical evidence, geologic character, 

structural setting, and proximity to other radioactivity 

anomalies, the study area is assigned a moderate mineral 

resource potential, certainty level B, for uranium in volcaniclastic deposits.

There is no evidence of current geothermal activity in 

the study area, and the potential for geothermal resources is 

unknown, certainty level A.

Sandberg (1983) reports that the Massacre Rim Wilderness Study Area has "zero potential" for petroleum. 

Geologic mapping shows a series of rhyolite intrusions 

overlain by tuffaceous sedimentary rocks that are in turn 

overlain by basalt Only the sedimentary rocks could be 

reservoir rocks, but because of extensive erosion that in 

places exposes the entire section of sedimentary rocks in 

many parts of the study area, there are no sufficient traps 

for oil and gas. Also, heat associated with volcanism in the 

area probably would have driven off any pre-existing 

hydrocarbons. Therefore, based on available data, the 

study area has no potential for oil and gas, certainty level 

D.

Mineral Resources of the Massacre Rim Wilderness Study Area, Washoe County, Nevada E9
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J.G., and Taylor, C.D., 1988, Analytical results and sample 

locality map of stream sediments, heavy-mineral concentrate, 

and rock samples from the Massacre Rim Wilderness Study 

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D.P., and Singer, D.A., Mineral deposit models: U.S. 

Geological Survey Bulletin 1693, p. 162-163.

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Nevada: University of Nevada Bulletin, v. 38, no. 5, 

Geology and Mining Series no. 41, 206 p.

Berger, B.R., 1985, Geologic-geochemical features of hot-spring 

precious metal deposits, in Tooker, E.W., ed., Geologic 

characteristics of sediment- and volcanic-hosted 

disseminated gold deposits search for an occurrence model: 

U.S. Geological Survey Bulletin 1646, p. 47-54.

__1986, Descriptive model of hot-spring Au-Ag, in Cox, D.P., 

and Singer, D.A., eds., Mineral deposit models: U.S. 

Geological Survey Bulletin 1693, p. 143-144.

Bergquist, J.R., Plouff, Donald, and Esparza, L.E., 1988, Mineral 

resources of the Sheldon Contiguous Wilderness Study Area, 

Washoe County, Nevada: U.S. Geological Survey Open-File 

Report, 88-246, 9 p.

Bonham, H.F., 1969, Geology and mineral deposits of Washoe 

and Storey Counties, Nevada, with a section on industrial 

minerals, by K.G. Papke: Nevada Bureau of Mines and 

Geology Bulletin 70, 140 p.

Cathrall, J.B., Siems, D.F., Crenshaw, G.L., and Cooley, E.F., 

1984, Geochemical evaluation of the mineral and geothermal 

resources of the Charles Sheldon Wilderness Study Area, 

Nevada and Oregon: U.S. Geological Survey Bulletin 1538- 

C, p. 51-88.

Causey, J.D., 1987, Mineral resources of the Massacre Rim study 

area, Washoe County, Nevada: U.S. Bureau of Mines 

Mineral Land Assessment MLA 9-87, 8 p.

Crock, J.G., Lichte, F.E., and Briggs, P.H., 1983, Determination 

of elements in National Bureau of Standards geological 

reference material SRM 278 obsidian and SRM 668 basalt by 

induction coupled argon plasma-atomic emission 

spectrometry: Geostandards Newsletter, no. 7, p. 335-340.

Geodata International, Inc., 1979, Aerial radiometric and 

magnetic survey national topographic map, Vya, Nevada: 

U.S. Department of Energy Open-File Report GJBX-136 

(79), v. 2, 73 p.

Goudarzi, G.H., 1984, Guide to preparation of mineral reports on 

public lands: U.S. Geological Survey Open-File Report 84- 

787, 51 p.

Greene, R.C., 1984, Geologic appraisal of the Charles Sheldon 

Wilderness Study Area, Nevada and Oregon: U.S. 

Geological Survey Bulletin 1538-A, p. 13-34.

Greene, R.C., and Plouff, Donald, 1981, Location of a caldera 

source for the Soldier Meadow Tuff, northwestern Nevada, 

indicated by gravity and aeromagnetic data: Geological

Society of America Bulletin, v. 92, no. 1, p. 4-6.

Grimes, D.J., and Marranzino, A.P., 1968, Direct-current arc and 

alternating-current spark emission spectrographic field 

methods for the semiquantitative analysis of geologic 

materials: U.S. Geological Survey Circular 591, 6 p.

Houghton, J.G., Sakamoto, C.M., and Gifford, R.O., 1975, 

Nevada's weather and climate: Nevada Bureau of Mines and 

Geology, Special Publication 2, 78 p.

Howell, D.E., 1979, Geology and mineral resources of the Vya 1 

x 2 NTMS quadrangle, Nevada, Oregon, California, in E.I. 

duPont de Nemours & Company, Geology and mineral 

resources of the Caliente, Ely, Klamath Falls, Vya, and Wells 

1x2 NTMS quadrangles: U.S. Department of Energy 

Open-File Report GJBX-7(83), p. 53-96.

Keith, W.J., Turner, R.L., Plouff, Donald, and Peters, T.J., 1987, 

Mineral resources of the Little High Rock Canyon 

Wilderness Study Area, Humboldt and Washoe Counties, 

Nevada: U.S. Geological Survey Bulletin 1707-C, 17 p.

Koirtyohann, S.R., and Khalil, Moheb, 1976, Variables in 

determination of mercury by cold vapor atomic absorption: 

Analytical Chemistry, v. 48, p. 136-139.

Larson, L.T., and Beal, L.H., 1978, Great Basin geologic 

framework and uranium favorability, final report: U.S. 

Department of Energy Open-File Report GJBX-36(78), 226

PLevering, T.G., 1954, Radioactive deposits of Nevada: U.S.

Geological Survey Bulletin 1009-C, 106 p. 

McKelvey, V.E., 1972, Mineral resource estimates and public

policy: American Scientist, v. 60, p. 32-40. 

Merriam, J.C., 1910, Geologic history, Part 1 of Tertiary mammal

beds of Virgin Valley and Thousand Creek in northwestern

Nevada: California University Department of Geology

Bulletin, v. 6, no. 2, p. 21-53. 

Noble, D.C., Plouff, Donald, Bergquist, J.R., Barton, H.N., and

Olson, I.E., 1987a, Mineral resources of the Pahute Peak

Wilderness Study Area, Humboldt County, Nevada: U.S.

Geological Survey Bulletin 1726-C, 12 p. 

Noble, D.C., Plouff, Donald, Bergquist, J.R., Neumann, T.R., and

Close, T.J., 1987b, Mineral resources of the High Rock Lake

Wilderness Study Area, Humboldt County, Nevada: U.S.

Geological Survey Bulletin 1707-A, 9 p. 

O'Leary, R.M., and Viets, J.G., 1986, Determination of antimony,

arsenic, bismuth, cadmium, copper, lead, molybdenum,

silver, and zinc in geologic materials by atomic absorption

spectrometry using a hydrochloric acid-hydrogen peroxide

digestion: Atomic Spectroscopy, v. 7, p. 4-8. 

Park, S.L., 1983, Paleomagnetic stratigraphy, geochemistry, and

source areas of Miocene ash-flow tuffs and lavas of the

Badger Mountain area, northwestern Nevada: Reno,

University of Nevada, M.S. thesis, 112 p. 

Plouff, Donald, 1977, List of principal facts and gravity anomalies

for an area between Orovada, Nevada, and Adel, Oregon:

U.S. Geological Survey Open-File Report 77-633, 40 p. 

__1984, Interpretation of aeromagnetic and gravity data, Charles

Sheldon Wilderness Study Area, Nevada and Oregon: U.S.

Geological Survey Bulletin 1538-B, p. 35-50, plate 2, scale

1:125,000. 

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Bulletin 931-B, p. 23-37.

E10 Mineral Resources of Wilderness Study Areas Northwestern Nevada
Rytuba, J.J., 1976, Geology and ore deposits of the McDermitt 

caldera, Nevada-Oregon: U.S. Geological Survey Open-File 

Report 76-535, 9 p.

__1981, Relation of calderas to ore deposits in the western 

United States: Arizona Geological Society Digest, v. XTV, p. 

227-236.

__1986, Descriptive model of hot-spring Hg, in Cox, D.P., and 

Singer, D.A., eds., Mineral deposit models: U.S. Geological 

Survey Bulletin 1693, p. 178-179.

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uranium, and lithium deposits to the McDermitt caldera 

complex, Nevada-Oregon: U.S. Geological Survey OpenFile Report 78-926, 21 p.

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the McDermitt caldera complex, Nevada-Oregon: Nevada 

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Nevada, in Miller, B.M., ed., Petroleum potential of 

wilderness lands in the Western United States: U.S. 

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the High Rock Canyon Wilderness Study Area, Washoe 

County, Nevada: U.S. Geological Survey Bulletin 1707-D, 

14 p.

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part of the McDermitt 1 by 2 quadrangles, Nevada: U.S. 

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resources of the Charles Sheldon Wilderness Study Area, 

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Harney Counties, Oregon: U.S. Geological Survey Bulletin 

1538, 139 p., 2 pi., scale 1:125,000.

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13, p. 73-79.

Mineral Resources of the Massacre Rim Wilderness Study Area, Washoe County, Nevada E11

APPENDIXES
DEFINITION OF LEVELS OF MINERAL RESOURCE POTENTIAL 

AND CERTAINTY OF ASSESSMENT

LEVELS OF RESOURCE POTENTIAL

H HIGH mineral resource potential is assigned to areas where geologic, geochemical, and geophysical characteristics indicate a geologic environment favorable for resource occurrence, where interpretations of data 

indicate a high degree of likelihood for resource accumulation, where data support mineral-deposit models 

indicating presence of resources, and where evidence indicates that mineral concentration has taken place. 

Assignment of high resource potential to an area requires some positive knowledge that mineral-forming processes 

have been active in at least part of the area.

M MODERATE mineral resource potential is assigned to areas where geologic, geochemical, and geophysical 

characteristics indicate a geologic environment favorable for resource occurrence, where interpretations of data 

indicate reasonable likelihood for resource accumulation, and (or) where an application of mineral-deposit models 

indicates favorable ground for the specified type(s) of deposits.

L LOW mineral resource potential is assigned to areas where geologic, geochemical, and geophysical characteristics 

define a geologic environment in which the existence of resources is permissive. This broad category embraces 

areas with dispersed but insignificantly mineralized rock, as well as areas with little or no indication of having 

been mineralized.

N NO mineral resource potential is a category reserved for a specific type of resource in a well-defined area.

U UNKNOWN mineral resource potential is assigned to areas where information is inadequate to assign a low, 

moderate, or high level of resource potential.

LEVELS OF CERTAINTY

A Available information is not adequate for determination of the level of mineral resource potential.

B Available information only suggests the level of mineral resource potential.

C Available information gives a good indication of the level of mineral resource potential.

D Available information clearly defines the level of mineral resource potential.

Z

UJ

oQ_ 

UJ

U

LL.

O

UJ

A

U/A

UNKNOWN POTENTIAL

B

H/B

HIGH POTENTIAL

M/B

MODERATE POTENTIAL

L/B

LOW POTENTIAL

C

H/C

HIGH POTENTIAL

M/C

MODERATE POTENTIAL

L/C

LOW POTENTIAL

D

H/D

HIGH POTENTIAL

M/D

MODERATE POTENTIAL

L/D

LOW POTENTIAL

N/D

NO POTENTIAL

LEVEL OF CERTAINTY

Abstracted with minor modifications from:

Taylor, R.B., and Steven, T.A., 1983, Definition of mineral resource potential: Economic Geology, v. 78, no. 6, p. 1268-1270.

Taylor, R.B., Stoneman, R.J., and Marsh, S.P., 1984, An assessment of the mineral resource potential of the San Isabel National Forest, south-central Colorado: U.S.

Geological Survey Bulletin 1638, p. 40-42. 

Goudarzi, G.H., compiler, 1984, Guide to preparation of mineral survey reports on public lands: U.S. Geological Survey Open-File Report 84-0787, p. 7, 8.

E14 Mineral Resources of Wilderness Study Areas: Northwestern Nevada
RESOURCE/RESERVE CLASSIFICATION

ECONOMIC

MARGINALLY 

ECONOMIC

SUBECONOMIC

IDENTIFIED RESOURCES

Demonstrated

Measured Indicated

Reserves

1

1 

Marginal 

Reserves

I

Demonstrated 

Subeconomic

Resources

i

Inferred

Inferred 

Reserves

Inferred 

Marginal 

Reserves

Inferred 

Subeconomic 

Resources

UNDISCOVERED RESOURCES

Probability Range

Hypothetical Speculative

Major elements of mineral resource classification, excluding reserve base and inferred reserve base. Modified from McKelvey, V.E., 1972, Mineral 

resource estimates and public policy: American Scientist, v. 60, p. 32-40; and U.S. Bureau of Mines and U.S. Geological Survey, 1980, Principles 

of a resource/reserve classification for minerals: U.S. Geological Survey Circular 831, p. 5.

Mineral Resources of the Massacre Rim Wilderness Study Area, Washoe County, Nevada E15
GEOLOGIC TIME CHART

Terms and boundary ages used by the U.S. Geological Survey in this report

EON

Phanerozoic

Proterozoic

pre-Archean2

ERA

Cenozoic

Mesozoic

Paleozoic

Late Proterozoic

Middle Proterozoic

Early Proterozoic

Late Archean

Middle Archean

Early Archean

PERIOD

Neogene

Subperiod

Tertiary

Paleogene 

Subperiod

L- retaceou s

Jurassic

Triassic

Permian

Pennsylvanian 

Carboniferous

Mississippian

Devonian

Silurian

Ordovician

Cambrian

(ianr\?\

EPOCH

Holocene

Pleistocene

Pliocene

Miocene

Oligocene

Eocene

Paleocene

Late

Early

Late 

Middle 

Early

Late 

Middle 

Early

Late 

Early

Late 

Middle 

Early

Late 

Early

Late 

Middle 

Early

Late 

Middle 

Early

Late 

Middle 

Early

Late 

Middle 

Early

ACE ESTIMATES OF 

BOUNDARIES (in Ma)

 0.010

1.7

5

1 A

1Q

55

 66

yo

1 IB

205

1 A f\

 290 

^.-j-jn

 360

 410

*J\J\J

 '-570

J\J\J

 1600 

 2500

 3400

'Rocks older than 570 Ma also called Precambrian, a time term without specific rank, 

informal time term without specific rank.

E16 Mineral Resources of Wilderness Study Areas Northwestern Nevada
Mineral Resources of 

Wilderness Study Areas: 

Northwestern Nevada

This volume was published as chapters A E

U.S. GEOLOGIGAL SURVEY BULLETIN 1707
DEPARTMENT OF THE INTERIOR 

DONALD PAUL MODEL, Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director
CONTENTS

[Letters designate the separately published chapters]

(A) Mineral Resources of the High Rock Lake Wilderness Study Area, Humboldt 

County, Nevada, by Donald C. Noble, Donald Plouff, Joel R. Bergquist, Terry R. 

Neumann, and Terry J. Close.

(B) Mineral Resources of the East Fork High Rock Canyon Wilderness Study Area, 

Washoe and Humboldt Counties, Nevada, by Jay A. Ach, Donald Plouff, Robert L. 

Turner, and Steven W. Schmauch.

(C) Mineral Resources of the Little High Rock Canyon Wilderness Study Area, 

Humboldt and Washoe Counties, Nevada, by William J. Keith, Robert L. Turner, 

Donald Plouff, and Thomas J. Peters.

(D) Mineral Resources of the High Rock Canyon Wilderness Study Area, Washoe 

County, Nevada, by Brent D. Turrin, Joel R. Bergquist, Robert L. Turner, Donald 

Plouff, Carl W. Ponader, and Douglas F. Scott.

(E) Mineral Resources of the Massacre Rim Wilderness Study Area, Washoe County, 

Nevada, by Joel R. Bergquist, Donald Plouff, Robert L. Turner, and J. Douglas 

Causey.

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SELECTED SERIES OF U.S. GEOLOGICAL SURVEY PUBLICATIONS

Periodicals

Earthquakes & Volcanoes (issued bimonthly). 

Preliminary Determination of Epicenters (issued monthly).

Technical Books and Reports

Professional Papers are mainly comprehensive scientific reports of 

wide and lasting interest and importance to professional scientists and engineers. Included are reports on the results of resource studies and of 

topographic, hydrologic, and geologic investigations. They also include 

collections of related papers addressing different aspects of a single scientific topic.

Bulletins contain significant data and interpretations that are of lasting scientific interest but are generally more limited in scope or 

geographic coverage than Professional Papers. They include the results 

of resource studies and of geologic and topographic investigations; as well 

as collections of short papers related to a specific topic.

Water-Supply Papers are comprehensive reports that present significant interpretive results of hydrologic investigations of wide interest 

to professional geologists, hydrologists, and engineers. The series covers 

investigations in all phases of hydrology, including hydrogeology, 

availability of water, quality of water, and use of water.

Circulars present administrative information or important scientific 

information of wide popular interest in a format designed for distribution 

at no cost to the public. Information is usually of short-term interest.

Water-Resources Investigations Reports are papers of an interpretive nature made available to the public outside the formal USGS publications series. Copies are reproduced on request unlike formal USGS 

publications, and they are also available for public inspection at 

depositories indicated in USGS catalogs.

Open-File Reports include unpublished manuscript reports, maps, 

and other material that are made available for public consultation at 

depositories. They are a nonpermanent form of publication that may be 

cited in other publications as sources of information.

Maps

Geologic Quadrangle Maps are multicolor geologic maps on 

topographic bases in 71/2- or 15-minute quadrangle formats (scales mainly 1:24,000 or 1:62,500) showing bedrock, surficial, or engineering geology. Maps generally include brief texts; some maps include structure 

and columnar sections only.

Geophysical Investigations Maps are on topographic orplanimetric 

bases at various scales; they show results of surveys using geophysical 

techniques, such as gravity, magnetic, seismic, or radioactivity, which 

reflect subsurface structures that are of economic or geologic significance. 

Many maps include correlations with the geology.

Miscellaneous Investigations Series Maps are on planimetric or 

topographic bases of regular and irregular areas at various scales; they 

present a wide variety of format and subject matter. The series also includes 71/2-minute quadrangle photogeologic maps on planimetric bases 

which show geology as interpreted from aerial photographs. Series also 

includes maps of Mars and the Moon.

Coal Investigations Maps are geologic maps on topographic or 

planimetric bases at various scales showing bedrock or surficial geology, stratigraphy, and structural relations in certain coal-resource areas.

Oil and Gas Investigations Charts show stratigraphic information 

for certain oil and gas fields and other areas having petroleum potential.

Miscellaneous Field Studies Maps are multicolor or black-andwhite maps on topographic or planimetric bases on quadrangle or irregular areas at various scales. Pre-1971 maps show bedrock geology 

in relation to specific mining or mineral-deposit problems; post-1971 

maps are primarily black-and-white maps on various subjects such as 

environmental studies or wilderness mineral investigations.

Hydrologic Investigations Atlases are multicolored or black-andwhite maps on topographic or planimetric bases presenting a wide range 

of geohydrologic data of both regular and irregular areas; principal scale 

is 1:24,000 and regional studies are at 1:250,000 scale or smaller.

Catalogs

Permanent catalogs, as well as some others, giving comprehensive listings of U.S. Geological Survey publications are available under 

the conditions indicated below from the U.S. Geological Survey, Books 

and Open-File Reports Section, Federal Center, Box 25425, Denver, 

CO 80225. (See latest Price and Availability List.)

"Publications of the Geological Survey, 1879-1961" may be purchased by mail and over the counter in paperback book form and as a 

set of microfiche.

"Publications of the Geological Survey, 1962-1970" may be purchased by mail and over the counter in paperback book form and as a 

set of microfiche.

"Publications of the U.S. Geological Survey, 1971-1981" may be 

purchased by mail and over the counter in paperback book form (two 

volumes, publications listing and index) and as a set of microfiche.

Supplements for 1982,1983,1984,1985,1986, and for subsequent 

years since the last permanent catalog may be purchased by mail and 

over the counter in paperback book form.

State catalogs, "List of U.S. Geological Survey Geologic and 

Water-Supply Reports and Maps For (State)," may be purchased by mail 

and over the counter in paperback booklet form only.

"Price and Availability List of U.S. Geological Survey Publications," issued annually, is available free of charge in paperback booklet form only.

Selected copies of a monthly catalog "New Publications of the U.S. 

Geological Survey" available free of charge by mail or may be obtained 

over the counter in paperback booklet form only. Those wishing a free 

subscription to the monthly catalog "New Publications of the U.S. 

Geological Survey" should write to the U.S. Geological Survey, 582 

National Center, Reston, VA 22092.

Note. Prices of Government publications listed in older catalogs, 

announcements, and publications may be incorrect. Therefore, the 

prices charged may differ from the prices in catalogs, announcements, 

and publications.
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