Mineral Resources of the Disaster Peak 

Wilderness Study Area, Harney and 

Malheur Counties, Oregon, and 

Humboldt County, Nevada

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Chapter A

Mineral Resources of the Disaster Peak 

Wilderness Study Area, Harney and 

Malheur Counties, Oregon, and 

Humboldt County, Nevada

By SCOTT A. MINOR, ROBERT L. TURNER, 

and DONALD PLOUFF 

U.S. Geological Survey

ANDREW M. LESZCYKOWSKI 

U.S. Bureau of Mines

U.S. GEOLOGICAL SURVEY BULLETIN 1742

MINERAL RESOURCES OF WILDERNESS STUDY AREAS: 

TROUT CREEK MOUNTAINS REGION, OREGON
DEPARTMENT OF THE INTERIOR 

DONALD PAUL HODEL, 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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Library of Congress Cataloging-in-Publication Data

Mineral resources of the Disaster Peak Wilderness Study 

Area, Harney and Malheur Counties, Oregon, and 

Humboldt County, Nevada.

(Mineral resources of wilderness study areas 

Trout Creek Mountains Region, Oregon ; ch. A) (U.S. 

Geological Survey Bulletin ; 1742A)

Bibliography: p.

Supt. of Docs. no. : I 19.3:1742-A

1. Mines and mineral resources Disaster Peak 

Wilderness (Or. and Nev.) 2. Disaster Peak Wilderness 

(Or. and Nev.) I. Minor, Scott A. II. Series. 

III. Series: U.S. Geological Survey bulletin ; 1742A. 

QE75.B9 no. 1742-A 557.3 s 88-600128 

[TN25.D57] [553'.09795'95]
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 submitted to the President and the Congress. This report presents the results of a mineral survey of 

the Disaster Peak Wilderness Study Area (OR-003-153/NV-020-859), Harney and Malheur Counties, 

Oregon, and Humboldt County, Nevada.

CONTENTS

Summary Al

Abstract 1

Character and setting 1

Identified resources 3

Mineral resource potential 3 

Introduction 3

Location and physiography 3

Previous investigations 5

Present investigations 6

Acknowledgments 6 

Appraisal of identified resources 6

Mining history 6

Prospects, claims, and mineralized areas 7 

Assessment of mineral resource potential 7

Geology 7

Geochemical studies 9

Geophysical studies. 10

Mineral and energy resource potential 11 

References cited 12 

Appendixes

Definition of levels of mineral resource potential and certainty of assessment 16

Resource/reserve classification 17

Geologic time chart 18

FIGURES

1. Index map showing location of Disaster Peak Wilderness Study Area, Harney and Malheur Counties, 

Oregon, and Humboldt County, Nevada A2

2. Map showing generalized geology and mineral resource potential of Disaster Peak Wilderness Study 

Area, Hamey and Malheur Counties, Oregon, and Humboldt County, Nevada 4

TABLE

1. Prospect and claims in and adjacent to the Disaster Peak Wilderness Study Area, Harney and Malheur 

Counties, Oregon, and Humboldt County, Nevada A8

Contents V

MINERAL RESOURCES OF WILDERNESS STUDY AREAS: 

TROUT CREEK MOUNTAINS REGION, OREGON

Mineral Resources of the Disaster Peak 

Wilderness Study Area, Harney and 

Malheur Counties, Oregon,and 

Humboldt County, Nevada

By Scott A. Minor, Robert L. Turner, and Donald Plouff 

U.S. Geological Survey

Andrew M. Leszcykowski 

U.S. Bureau of Mines

SUMMARY

Abstract

The Disaster Peak Wilderness Study Area (OR-003-153/ 

NV-020-859) is located in the south Trout Creek Mountains 

in southeastern Oregon and northern Nevada. At the request 

of the U.S. Bureau of Land Management, 30,195 acres of the 

Disaster Peak Wilderness Study Area were evaluated for 

mineral resources (known) and mineral resource potential 

(undiscovered). In this report, the area studied is referred to 

as the "Disaster Peak Wilderness Study Area" or the "study 

area." Field work for this report was done in 1986. No 

resources were identified within the study area. There is high 

and low potential for gold resources in quartz veins in the 

southern part and low potential for epithermal gold, silver, 

mercury, and uranium resources in the northeastern part of 

the study area. The study area has no potential for sand and 

gravel, oil and gas, or geothermal energy resources.

Character and Setting

The Disaster Peak Wilderness Study Area (OR-003- 

153/NV-020-859) is located in the south Trout Creek 

Mountains in Harney and Malheur Counties, Oreg., and 

Humboldt County, Nev., about 23 mi west of McDermitt, 

Nev. (fig. 1). The study area contains the 7,000- to 8,500- 

ft-high crestline of the north-tilted plateau that forms the 

Trout Creek Mountains and caps the escarpments in the

Publication authorized by the Director, U.S. Geological Survey, Mar. 15, 1988.

southern and eastern parts of the study area. The rugged 

and steep southern escarpment, which crests at Orevada 

View (8,506 ft) and Disaster Peak (7,781 ft), has more than 

3,000 ft of relief to the Kings River Valley south of the 

study area. The southern part of the study area is underlain 

by Cretaceous (see appendixes for geologic time chart) 

granitic rocks (fig. 2). An approximately flat-lying 

sequence of Tertiary volcanic and pyroclastic flows 

unconformably onlaps the granitic rocks and is exposed 

within most of the remainder of the study area. The Long 

Ridge caldera, located just east of the study area, is a 

collapse structure resulting from the eruption of an ashflow tuff that forms the top of the flow sequence. The 

caldera is filled largely by tuffaceous sedimentary rocks. 

Numerous arcuate, north- to northeast-striking caldera ring 

faults displace rocks in and near the northeastern part of the 

study area. Younger, north-northwest-striking normal 

faults that have large displacements cut rocks west of the 

caldera in the study area.

County mining records show that more than 100 

mining claims have been located in or near the study area 

since 1892 when the first claims were recorded. Current 

mineral exploration in and adjacent to the study area is 

primarily for gold and is centered in two areas containing 

claims and a prospect. Five mercury mines, including the 

producing McDermitt mine, are located in the Opalite 

mining district 10 to 20 mi east of the study area (fig. 1). 

The Opalite district also contains a uranium mine and 

several prospects. Two mines just southeast of the study 

area are active for clay minerals.

Mineral Resources of the Disaster Peak Wilderness Study Area, Oregon and Nevada A1
APPROXIMATE BOUNDARY

OF

DISASTER PEAK ^ 

WILDERNESS STUDY AREA ^ 

(OR-003-15 3 / NV-020-859)

LONG RIDGE CALDERA

(Pan of McDermitt caldera complex)

41°30' L

Figure 1. Index map showing location of Disaster Peak Wilderness Study Area, Harney and Malheur Counties, Oregon, and 

Humboldt County, Nevada.

A2 Mineral Resources of Wilderness Study Areas Trout Creek Mountains Region, Oregon
Identified Resources

The Disaster Peak Wilderness Study Area has no 

identified mineral resources. However, the study area 

contains occurrences of gold of unknown extent for which 

identified resource amounts could not be estimated.

Mineral Resource Potential

Areas having high potential for gold resources and low 

potential for gold, silver, mercury, and uranium resources 

have been delineated in the Disaster Peak Wilderness Study 

Area (fig. 2).

Quartz veins mineralized with gold crosscut granitic 

rocks in an area of about 1 mi2 in the southern part of the 

study area. The gold is accompanied by minor silver and 

associated sulfide minerals. The mineralized veins yield 

geochemical anomalies of gold, antimony, arsenic, 

molybdenum, silver, tellurium, and tungsten. The 

geometry and extent of the gold-bearing veins are poorly 

known, but weak geochemical anomalies-elsewhere within 

the granitic rocks suggest that other undiscovered 

auriferous veins may be present. The quartz, gold, and 

associated minerals may have precipitated from residual 

magmatic fluids along faults and joints soon after intrusion 

of the granitic rocks or may have formed from 

hydrothermal fluids at some later time prior to eruption of 

the Steens Basalt. The mineralized area in the southern 

part of the study area has high potential for gold resources 

in quartz veins, and the surrounding area of granitic rock, 

having weak geochemical anomalies, has low resource 

potential for gold in quartz veins (fig. 2).

Epithermal gold, mercury, and uranium mineralization 

that affected a zone about 1 mi east of the study area may 

have also affected the northeastern part of the study area. 

The mineralized zone outside the study area contains strong 

geochemical anomalies of gold, antimony, arsenic, 

mercury, and uranium and weaker anomalies of silver. 

Visible metalliferous minerals, however, are sparse. The 

mineralized zone, which locally contains highly fractured 

and brecciated rock, is cut by numerous north- to northeaststriking, arcuate ring faults that border the Long Ridge 

caldera (fig. 2). The zone has characteristics similar to 

those of reported epithermal mercury and uranium 

occurrences and ore deposits within other parts of the 

caldera, including hydrothermally altered rock and sulfide 

minerals. Those more distant mineral occurrences and 

deposits were formed by hydrothermal systems during late 

stages of caldera development. Although the geochemical 

signatures of those occurrences and deposits are similar to 

those of the mineralized zone adjacent to the study area, 

they differ in that they lack anomalous concentrations of 

gold. Nevertheless, the timing, style, and causes of 

mineralization are believed to be nearly identical. The 

northeastern part of the study area resembles the adjacent

mineralized zone in that it contains north- to northeaststriking caldera ring faults and similar, although weak, 

geochemical anomalies However, this part of the study 

area generally lacks epithermal alteration or mineralization. 

Thus, the northeastern part of the study area has low 

potential for resources of gold, silver, mercury, and 

uranium in epithermal deposits.

The study area has no potential for oil and gas and 

geothermal energy resources because the geologic 

environment is not conducive for such resources. Sand and 

gravel deposits along intermittent streams are too small to 

constitute a potential resource.

INTRODUCTION

This mineral survey was requested by the U.S. Bureau 

of Land Management and is the result of a cooperative 

effort by the U.S. Geological Survey and the U.S. Bureau 

of Mines. An introduction to the wilderness review 

process, mineral survey methods, and agency 

responsibilities was provided by Beikman and others 

(1983). 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. 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 U.S. Geological Survey (1980). 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 geologic units and 

structures, possible environments of mineral deposition, 

presence of geochemical and geophysical anomalies, and 

applicable ore-deposit models. Goudarzi (1984) discussed 

mineral assessment methodology and terminology as they 

apply to these surveys. See appendixes for the definition of 

levels of mineral resource potential and certainty of 

assessment and for the resource/reserve classification.

Location and Physiography

The Disaster Peak Wilderness Study Area (OR-003- 

153/NV-020-859) is located in Harney and Malheur 

Counties, Oreg., and Humboldt County, Nev., about 23 mi 

west of McDermitt, Nev. (fig. 1). The study area, which 

encompasses 30,195 acres, is situated in the southern part 

of the Trout Creek Mountains (fig. 1), a broad, gently 

north-tilted, moderately dissected plateau. The study area 

is somewhat V-shaped, with the west and north segments 

coinciding with northwest- and north-trending escarpments, 

respectively, that converge southward at 7,781-ft Disaster 

Peak. The escarpments bound the highest (7,000 to 8,500 

ft) part of the Trout Creek Mountains plateau, which forms 

the central and northwesternmost parts of the study area.

Mineral Resources of the Disaster Peak Wilderness Study Area, Oregon and Nevada A3
118°0730"

APPROXIMATE BOUNDARY

OF

DISASTER PEAK

WILDERNESS STUDY AREA

(OR-003-153 / NV-020-859)

42° 

00'

Figure 2. Generalized geology and mineral resource potential of Disaster Peak Wilderness Study Area, Harney and MalheurCounties, 

Oregon, and Humboldt County, Nevada.

A4 Mineral Resources of Wilderness Study Areas Trout Creek Mountains Region, Oregon
EXPLANATION

Area having high mineral resource potential 

(H)

Area having low mineral resource potential (L)

Level of certainty of assessment

B Data only suggest level of potential 

C Data give good indication of level of 

potential

Commodities

Au Gold

Ag Silver

Hg Mercury

U Uranium

[ ] Type of deposit or occurrence

1 Epithermal

2 Quartz veins

Prospects and claims See table for description

1 Albisu prospect

2 Au claim group

Geologic map units

Qal Alluvium (Quaternary)

Tcs Caldera-fill sedimentary rocks (Miocene)

Ttl Tuff of Long Ridge and, locally, tuff of

	Trout Creek Mountains (Miocene) 

Tif Intermediate lava flows (Miocene) 

Ts Steens Basalt (Miocene) 

Twt Dacitic welded tuff (Eocene) 

Kg Granitic rocks (Cretaceous)

 Contact Dashed where approximately 

located

 Fault Dashed where approximately located; 

dotted where concealed. Bar and ball on 

downthrown side

Figure 2. Continued.

The escarpment extending northwest from Disaster Peak is 

precipitous, having more than 3,000 ft of relief from 

Orevada View (8,506 ft), the highest point in the study 

area, to the Kings River Valley to the south. Major 

intermittent streams draining this escarpment include the 

Kings River in the southwestern part of the study area and 

China Creek in the southeasternmost part (fig. 1). The 

lowest point in the study area, at about 5,300 ft, is located 

where China Creek crosses the south boundary. In contrast 

to the escarpment described above, the one crossing the 

eastern part of the study area is less steep; it descends 

eastward to the gently rolling lower McDermitt Creek 

drainage basin adjacent to the east edge of the study area 

(fig. 1). The intermittent Sage Creek and North Fork and 

main fork of McDermitt Creek, having incised canyons as 

deep as about 800 ft into the east-facing escarpment, are the 

most prominent drainages in the northern part of the study 

area (fig. 2). Vegetation of the study area is similar to that 

growing elsewhere in mountain ranges of the northern 

Great Basin. Sage and seasonal desert grasses are common 

throughout the study area, and mountain mahogany and 

aspen only grow in the more elevated parts.

The most direct access to the northern and eastern parts 

of the study area consists of a maintained unpaved road 

west of the paved Cordero mine road about 5 mi west of the 

town of McDermitt (fig. 1). This unpaved road, which 

roughly follows McDermitl Creek, forms the northern 

boundary of the study area and is intersected by several 

jeep trails that extend into the central part of the study area. 

Access to the southern and southwestern parts of the study 

area is by way of a partly maintained, unpaved county and 

ranch road that follows the northeast side of the Kings 

River valley from the south (fig. 1). Several jeep trails 

extend northeast into the study area from this road, 

including a road following China Creek that forms part of 

the southeast boundary.

i

Previous Investigations

Yates (1942) mapped and described the geology and 

quicksilver deposits of the Opalite district east of the study 

area. The geology of mercury deposits in Nevada and in 

Malheur County, Oreg., was examined by Benson (1956). 

Willden (1964) investigated the geology and mineral 

deposits of Humboldt County, Nev., and prepared a 

reconnaissance geologic map of the county. A 

reconnaissance geologic map of the Adel 1° by 2° 

quadrangle, which includes the Oregon part of the study 

area, was published by Walker and Repenning (1965). 

Greene (1976) described the general geology of the feature 

initially named McDermitt caldera (now known as Long 

Ridge caldera) and included a generalized geologic map of 

an area that includes most of the study area. Revised and 

more detailed descriptions and interpretations of the 

geology of the McDermitt caldera complex were presented

Mineral Resources of the Disaster Peak Wilderness Study Area, Oregon and Nevada A5
by Rytuba (1976), Rytuba and Conrad (1981), and Rytuba 

and McKee (1984). Rytuba and Glanzman (1978), 

Glanzman and others (1978), Rytuba and others (1979), 

and Rytuba and Conrad (1981) investigated mineral 

deposits associated with the McDermitt caldera complex. 

The geology of an area adjacent to the west side of the 

study area was mapped and described in detail by Minor 

(1986). The geology of the southern Trout Creek 

Mountains, including the eastern and western parts of the 

study area, were mapped by JJ. Rytuba (written commun., 

1980) and S.A. Minor (unpub. data, 1985), respectively.

Geochemical and geophysical reconnaissance surveys 

were conducted for the U.S. Department of Energy's 

National Uranium Resource Evaluation (NURE) program 

to assess the radioactive mineral potential of the region 

(Erikson and Curry, 1977; Geodata International, Inc., 

1979, 1980). Preliminary geochemical and mineral 

evaluations of several wilderness study areas in southeast 

Oregon, including the Oregon part of the Disaster Peak 

Wilderness Study Area, were conducted by the Oregon 

Department of Geology and Mineral Industries (DOGAMI) 

(Gray and others, 1983). Barringer Resources, Inc., 

conducted supplementary geochemical evaluations of the 

Oregon study areas in conjunction with the DOGAMI study 

(Bukofski and others, 1984) and conducted a similar 

geochemical study as part of an evaluation of the U.S. 

Bureau of Land Management Winnemucca District 

(Conners and others, 1982) in the part of the study area in 

Nevada.

Present Investigations

In 1986 the U.S. Geological Survey (USGS) conducted 

field investigations in the study area, which consisted of 

checking, refining, and completing earlier geologic 

mapping, searching for altered or mineralized areas, taking 

gravity measurements, and collecting geochemical samples. 

All of the 49 rock samples and 37 stream-sediment and 

heavy-mineral-concentrate samples collected were 

analyzed geochemically to reveal areas having anomalous 

concentrations of elements of interest. Linear features that 

appear in Landsat multispectral-scanner images of the 

region were mapped by photogeologic interpretation (D.L. 

Sawatzky, written commun., 1987).

Work by the U.S. Bureau of Mines (USBM) included 

perusal of all literature on the geology, mines, and 

prospects in the vicinity of the study area. Federal, state, 

and county records were examined to ascertain the location 

of mines or mineral claims in the study area. Field studies, 

conducted in 1986, included the examination, mapping, and 

geochemical sampling of prospects and claims in and 

adjacent to the study area; 4 alluvial and 41 rock samples 

were collected primarily from a prospect and a group of

claims. The alluvial samples were concentrated and 

examined for economic minerals, and the rock samples 

were geochemically analyzed. Sampling procedures and 

results of the USBM investigations of the study area are 

described by Leszcykowski (1987). Sample data are 

available at Western Field Operations Center, E. 360 Third 

Ave., Spokane, WA 99202.

Acknowledgments

The assistance of John Muntean during the USGS 

field investigation was invaluable. James Rytuba of the 

USGS supplied useful information on the geology and 

mineral deposits in the region. The assistance and 

information provided by Tom Whittle and Ken Holtz of 

McDermitt Mine and Jim LeBret was greatly appreciated.

APPRAISAL OF IDENTIFIED RESOURCES

By Andrew M. Leszcykowski 

U.S. Bureau of Mines

Mining History

The study area is partly within the unorganized 

Disaster Peak mining district. County mining records 

indicate that more than 100 mining claims have been 

located in or near the study area. The earliest recorded 

claims were in 1892, with most of the activity in the 1900's 

and minor activity from the 1920's to the 1940's. There 

was an increase in claims in the 1950's and during the past 

decade; the impetus for the latter was due to uranium, 

mercury, and gold exploration.

The unorganized Opalite mining district, located 10 to 

20 mi east of the study area, includes the past-producing 

Opalite, Bretz, Ruja, and Cordero mercury mines and the 

currently (1988) producing McDermitt mercury mine (fig. 

1). The McDermitt mine was on standby in 1987 until the 

mercury market improved.

Several uranium deposits have been explored in the 

region, including the deposit at the Moonlight mine south 

of the study area (fig. 1). A lithium occurrence was 

discovered within the Opalite district directly east of the 

study area during the past decade (Glanzman and others, 

1978). Beneficiation tests on lithium-bearing clay from the 

deposit were run in 1980 by the USBM (May and others, 

1980).

Clay minerals are being mined by J.M. Huber Co. and 

American Colloid Co. on the east side of the Montana 

Mountains.

Current mineral exploration in and near the study area 

is focused on two sites, the Albisu prospect and the Au 

claim group (fig. 2). The McDermitt Mine company has

A6 Mineral Resources of Wilderness Study Areas Trout Creek Mountains Region, Oregon
leased the Albisu prospect, which is located less than 1 mi 

east of the study area, for the purpose of evaluating goldbearing structures at the site. The prospect consists of three 

claim blocks composed of 69 claims (table 1, No. 1). 

Claim notices and workings at the prospect indicate that the 

first mineral exploration was in about 1907. McDermitt 

Mine leased the Albisu prospect in 1985 and conducted an 

extensive soil sampling program followed by drilling in 

1986. Extensive evaluation work was planned (1987), 

including additional drill holes.

The Au claim group, located in the southern part of the 

study area (table 1 and fig. 2, No. 2), was recently staked 

for gold. Humboldt County records indicate that about 50 

claims were staked in this general area from 1906 to 1910 

and that additional claims were staked in 1938 and 1948. 

No production is known from these claims, although the 

remains of two small mills indicate that some ore was 

processed.

calculations can be made because no continuous quartz 

veins are exposed.

Tuffaceous sedimentary rocks that fill the Long Ridge 

caldera east of the study area contain large amounts of 

lithium within the clay mineral hectorite (Rytuba and 

Glanzman, 1978; Glanzman and others, 1978; May and 

others, 1980). Clay beds within these rocks commonly 

contain from 0.01 to 0.1 percent and as much as 0.65 

percent lithium. Total estimated marginal reserves of 1 

million tons of lithium equivalent (Singleton, 1979) make 

the Long Ridge caldera deposit the world's largest 

identified lithium resource.

Quaternary sand and gravel deposits along intermittent 

streams in the study area are too small to be considered a 

resource.

ASSESSMENT OF MINERAL RESOURCE 

POTENTIAL

Prospects, Claims, and Mineralized Areas

No resources were identified in the Disaster Peak 

Wilderness Study Area. Mineralized areas in and adjacent 

to the study area are limited to the Albisu prospect and the 

Au claim group. These areas contain gold-mineralized 

structures that need further study before resources, if any, 

can be calculated.

The Albisu prospect (table 1 and fig. 2, No. 1) contains 

gold-bearing sulfides along a north-northwest-trending 

fault zone that cuts rhyolite ash-flow tuff. The mineralized 

part of the fault zone, which lies partly within the study 

area, consists of brecciated and hydrothermally altered rock 

bearing sulfides as disseminated grains and veinlets. The 

mineralized fault zone is on the perimeter of the Long 

Ridge caldera (figs. 1 and 2), a regional Miocene collapse 

structure (Rytuba and McKee, 1984), and is probably a 

ring-fracture zone associated with the caldera. Proprietary 

assay data from McDermitt Mine indicating the presence of 

gold in the mineralized area was confirmed by the results 

of the USBM sampling (see table 1); USBM gold values 

from the mineralized zone range from 14 to 380 parts per 

billion (ppb). Calculation of gold resources awaits further 

evaluation by McDermitt Mine.

Gold occuring in quartz veins in Cretaceous granitic 

rocks is also the principal metal at the Au claim group 

(table 1 and fig. 2, No. 1). Smaller concentrations of silver, 

galena, copper sulfides, and carbonate minerals accompany 

the gold. The discontinuous quartz veins, which occur 

sporadically over about 1 mi2, strike approximately northnortheast and dip at low angles toward the northwest The 

vuggy, coarsely crystalline quartz appears to fill fissures. 

Gold assay values of quartz-vein samples range from 0.107 

to 1.120 troy ounces per ton (oz/ton). No gold-resource

By Scott A. Minor, Robert L. Turner, and Donald Plouff 

U.S. Geological Survey

Geology

The Disaster Peak Wilderness Study Area lies within 

the northwestern part of the Basin and Range province, an 

area characterized by north-trending, normal-fault-bounded 

ranges and intervening basins. The Kings River Valley just 

south of the study area is a basin that terminates to the 

north against the southwestern edge of the broad, uplifted 

Trout Creek Mountains plateau (fig. 1). In the vicinity of 

the study area, a sequence of Tertiary volcanic and 

pyroclastic flows > unconformably overlies a basement of 

Cretaceous granitic rocks. A caldera collapse structure, 

which formed as a result of the eruption of the uppermost 

rocks of the sequence, lies adjacent to the study area and is 

filled by younger tuffaceous sedimentary rocks. The 

volcanic and pyroclastic rocks are cut by numerous normal 

faults associated with the caldera and basin-and-range 

extensional deformation.

The oldest rocks consist of Cretaceous granodiorite 

and subordinate amounts of other granitic rocks that are 

exposed in the southern part of the study area in the area 

known as The Granites (fig. 2). These light-colored, 

coarsely crystalline rocks contain, in order of decreasing 

abundance, plagioclase, quartz, potassium feldspar, 

hornblende, biotite, and sphene. Pegmatite and aplite dikes 

and quartz veins locally intrude the granitic rocks. These 

rocks are typically cut by several intersecting joint sets that 

have greatly influenced weathering of the rock, resulting in 

the conspicuous pinnacles and spires of The Granites.

Unconformably overlying the granitic basement rocks 

is a sequence of Tertiary volcanic and pyroclastic rocks

Mineral Resources of the Disaster Peak Wilderness Study Area, Oregon and Nevada A7
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A8 Mineral Resources of Wilderness Study Areas Trout Creek Mountains Region, Oregon
(fig. 2). This sequence was apparently deposited upon a 

relatively flat paleotopographic surface formed on the 

basement rocks.

The oldest part of the sequence consists of brown 

biotite- and hornblende-bearing dacitic welded tuff and 

associated rocks of Eocene age that are exposed a few 

hundred feet south of the southeast corner of the study area 

near China Creek (Greene, 1976) (fig. 2). Within the study 

area, the dacitic welded tuff is not present, and the younger 

(Miocene) Steens Basalt (Fuller, 1931; Piper and others, 

1939) rests directly on the basement rocks. The Steens 

Basalt consists of a thick (as much as 1,800 ft) flow-onflow flood-basalt sequence that is regionally extensive 

(Mankinen and others, 1987). The gray basalt flows, which 

average about 20 ft in thickness, commonly contain 

distinctive large (as long as 2 in.) plagioclase phenocrysts 

that make up as much as 50 percent of the rock. Other 

mineral constituents include olivine, augite, and irontitanium oxides. The Steens Basalt flows tend to form 

prominent ledges and steep cliffs, such as the spectacular 

escarpment just south of Orevada View.

A series of predominantly intermediate-composition 

flows exposed in the northern part of the study area 

conformably overlies the Steens Basalt (fig. 2). Included in 

this series, in order of decreasing age, are porphyritic 

rhyolite flows, porphyritic dacitic flows, latite flows, more 

porphyritic dacitic flows, and andesitic flows (J.J. Rytuba, 

written commun., 1980).

Two Miocene ash-flow tuff sheets cap the Tertiary 

eruptive sequence within the study area. The lower sheet, 

informally named the tuff of Trout Creek Mountains 

(Rytuba and McKee, 1984), consists of minor basal air-fall 

tuff and overlying peralkaline, comenditic, non- to densely 

welded ash-flow tuff. This bluish-green ash-flow tuff, 

which is markedly crystal rich (as much as 35 percent), is 

only present in the northern part of the study area where it 

has a maximum thickness of about 60 ft. The more 

extensive upper tuff sheet, informally named the tuff of 

Long Ridge (Rytuba and McKee, 1984), consists of 

subordinate basal air-fall tuff and overlying non- to densely 

welded ash-flow tuff. This compositionally zoned ash-flow 

tuff consists of a bluish-green, platy, aphyric, peralkaline 

comenditic lower part and a brown, crystal-rich (as much as 

10 percent) rhyolitic upper part. Secondary flow folds and 

lineations are common in the tuff of Long Ridge, which has 

a maximum thickness of about 250 ft in the study area.

Eruption of the tuff of Long Ridge about 15.6 million 

years ago resulted in the formation of the Long Ridge 

caldera, a large collapse feature located directly east of the 

study area, which forms part of the McDermitt caldera 

complex (Rytuba and McKee, 1984) (fig. 1). A northstriking feeder dike of the tuff of Long Ridge in the 

northern part of the study area (fig. 2) probably was a vent 

for the tuff (JJ. Rytuba, oral commun., 1987). Numerous 

north- to northeast-striking arcuate normal faults within and 

outside the easternmost part of the study area (fig. 2) are

Mineral Resources

ring faults associated with the caldera. Tuffaceous fluvial 

and lacustrine sedimentary rocks fill much of the basin 

resulting from caldera subsidence and lap onto the older 

wall rocks near the eastern edge of the study area (fig. 2). 

These sedimentary rocks consist primarily of tan to lightgray, well-bedded, fine- to medium-grained tuffaceous 

sandstone, siltstone, shale, and water-laid tuff.

Several large-displacement, north-northwest-striking 

normal faults cut rocks in the northern and western parts of 

the study area (fig. 2). These faults form the east edge of 

a broad, north-northwest-trending, complexly faulted zone 

that extends for more than 30 mi north and south of the 

study area (Walker and Repenning, 1965; Minor, 1986). 

Most of these faults formed soon after caldera collapse, 

probably during regional basin-and-range extension.

The aforementioned hydrothermally altered area within 

the Albisu prospect follows north- to northeast-striking ring 

faults and fractures bordering the Long Ridge caldera from 

an area about 2.5 mi northeast of Disaster Peak to as far 

north as Sage Creek (fig. 2). The alteration has affected 

both caldera-wall and caldera-fill rocks. All of the altered 

rocks are highly silicified and bleached light gray to white 

such that original textures are rarely identified. Numerous 

fractures and areas of brecciated rock within the prospect 

are stained with reddish iron oxides and typically contain 

limonite and (or) secondary clays. Less commonly, the 

rocks show signs of argillic alteration, in particular feldspar 

phenocrysts replaced by kaolinite.

Minor amounts of stream sand and gravel are present 

along larger drainages in the study area.

Geochemical Studies

A reconnaissance geochemical study conducted by the 

USGS in and near the study area consisted of the 

collection, analysis, and evaluation of rock, streamsediment, and heavy-mineral-concentrate samples.

Forty-nine fresh, mineralized, and altered rocks were 

sampled from outcrop and, rarely, from stream float. 

Samples that appeared fresh and unaltered were collected to 

provide information on geochemical background values, 

and those that seemed altered or mineralized were collected 

to determine the suite of elements associated with the 

alteration or mineralization.

Thirty-seven sites along stream channels containing 

recent alluvium were sampled for stream sediments and 

heavy-mineral concentrates. Stream sediments represent a 

composite of rock and soil exposed upstream from the 

sample site. In contrast, heavy-mineral concentrates 

include ore-bearing and ore-related minerals, and they 

permit determination of some elements that are not easily 

detected in bulk stream sediments.

The rock, stream-sediment, and heavy-mineralconcentrate samples were analyzed for 31 elements by 

semiquantitative emission spectroscopy, using the methods

of the Disaster Peak Wilderness Study Area, Oregon and Nevada A9
of Grimes and Marranzino (1968). Elements of special 

interest or which have high lower limits of determination 

by emission spectrography were also analyzed by other 

means. Gold and mercury contents were determined by 

atomic absorption, and antimony, arsenic, bismuth, 

cadmium, and zinc contents were determined by 

inductively coupled, argon plasma-atomic emission 

spectroscopy, using methods described by Crock and others 

(1987). Anomalous values were determined by considering 

the range and distribution of the elemental concentrations 

as well as by comparison with published average elemental 

abundances associated with certain rock types. Analytical 

data and a detailed description of the sampling and 

analytical techniques are provided by M.S. Erickson 

(unpub. data, 1987).

An anomalous north-northeast-trending zone about 1 

mi east of the study area was delineated by analyses of 

geochemical samples. This zone is defined by stream 

sediments anomalous in arsenic (10 to 25 parts per million, 

ppm) and mercury (0.16 to 0.69 ppm), nonmagnetic 

fraction of the heavy-mineral concentrates enriched in 

bismuth (as much as 50 ppm) and copper (as much as 7,000 

ppm), and rocks anomalous in silver (as much as 1 ppm), 

antimony (4 to 28 ppm), arsenic (19 to 320 ppm), and 

mercury (0.28 to 24 ppm). Gray and others (1983) and 

Corners and others (1982) reported weakly anomalous 

concentrations of gold (as much as 20 parts per billion, 

ppb), arsenic, mercury, and uranium oxide (as much as 6.1 

ppm) in rock and stream-sediment samples from this part of 

the study area. This geochemically anomalous zone 

coincides with the zone of caldera-related ring faults and 

fractures (fig. 2). The highest antimony, arsenic, and 

mercury concentrations are in rocks from the area of 

hydrothermal alteration in the Albisu prospect northeast of 

Disaster Peak. The ring-fracture zone of the Long Ridge 

caldera was the controlling structure for reported mercury 

and uranium mineralization less than 20 mi to the east and 

south (Rytuba and Glanzman, 1978; Rytuba and others, 

1979) and was probably the controlling structure for the 

mineralization that occurred near the study area. Many of 

the anomalous elements (antimony, arsenic, mercury, silver 

and uranium) found in and near the eastern part of the study 

area are part of the suite of elements associated with 

hydrothermally altered and mineralized areas in the 

McDermitt caldera complex (Rytuba and others, 1979). 

Anomalous antimony, arsenic, bismuth, copper, and 

mercury, all present in the study area, also characterize 

gold-silver-base-metal (arsenic, antimony, mercury, 

tellurium, thallium, uranium, lead, zinc, and copper) 

epithermal deposits (Berger, 1982).

Scattered low-level gold (up to 6 ppb) and arsenic (up 

to 8 ppm) anomalies were detected by Conners and others 

(1982) in stream sediments from the southwestern part of 

the study area. In the present study, only anomalous 

mercury (0.55 ppm) was observed in stream sediments

collected from this area. These stream sediments were 

derived in part or entirely from granitic rocks exposed in 

the area (fig. 2), and, thus, the anomalies may reflect goldmineralized quartz veins in the granitic rock such as those 

at the Au claim group. The fact that veins were only 

observed in the granitic rock suggests that vein 

emplacement and gold mineralization occurred prior to the 

inception of Miocene volcanism in the region and perhaps 

during the waning stages of plutonism.

Geophysical Studies

Geophysical evaluation of the mineral resources of the 

study area was based on interpretations of three kinds of 

geophysical surveys. These were aerial gamma-ray, 

aeromagnetic, and gravity surveys.

Radiometric data were compiled by Geodata 

International, Inc. (1979, 1980) for the NURE program of 

the Department of Energy. The coverage in Oregon 

consists of two east-west flightlines spaced 3 mi apart and 

totalling about 8 mi in length. Flight altitudes ranged from 

300 to 600 ft above the ground. One east-west flightline in 

Nevada was flown at an unacceptably high elevation and 

was unusable. Recordings were made of spectra that are 

associated with gamma-ray flux from radioactive isotopes 

of uranium, thorium, and potassium. Count rates exceeded 

background levels for all three isotopes over the eastern 

half of the study area in Oregon. Radiometric data also 

were collected at a spacing of 0.33 mi and a flight altitude 

of 400 to 600 ft above the ground (U.S. Geological Survey, 

1982). The data, however, only include about 30 line-miles 

(23 east-west lines) in the eastern part of the study area. 

Radioelement count rates recorded in the latter survey 

markedly correlate with surface geology. The count 

rates especially for equivalent uranium are low over the 

Steens Basalt and intermediate-composition flows, 

somewhat higher and more variable over Cretaceous 

granitic rocks, and high over rhyolitic ash-flow tuff sheets 

exposed to the east of the study area. A concentration of 

equivalent uranium (greater than 12 ppm) is indicated about 

1.5 mi outside the study area in a location that coincides 

with the most geochemically anomalous part of the Albisu 

prospect (fig. 2).

Regional aeromagnetic surveys were flown over the 

study area at a constant barometric elevation of 9,000 ft 

above sea level with east-west flightline spacings of 2 mi 

(U.S. Geological Survey, 1972a, b). Conspicuous magnetic 

lows, especially intense over topographic highs such as 

Disaster Peak, occur in most of the study area. The 

magnetic lows reflect exposed, reversely magnetized rocks 

of Steens Basalt (Mankinen and others, 1987)

The USGS established 23 gravity stations in and 

within 3 mi of the study area in 1986 (Plouff, 1987). These 

data supplemented a larger set of previously established

A10 Mineral Resources of Wilderness Study Areas Trout Creek Mountains Region, Oregon
stations located mostly to the east of the study area (Plouff, 

1977). A preliminary gravity map prepared from these data 

shows a north-trending gravity high centered along the east 

edge of the study area (Donald Plouff, unpub. data). 

Gravity values rather uniformly decrease westward about 

20 milligals in 8 mi across the study area and eastward 

about 15 milligals in 8 mi. Within and to the south of the 

southeastern part of the study area, the gravity high is 

centered near the eastern edge of exposed Cretaceous 

granitic rocks mapped by JJ. Rytuba (written commun., 

1980) (fig. 2). The gravity high apparently reflects the 

contrast in density between Cretaceous basement rocks and 

surrounding Tertiary rocks near the surface and at depth. 

The gravity gradient to the east of the gravity high overlies 

the margin of the Long Ridge caldera and may reflect the 

west edge of Miocene pluton(s) under the caldera. 

Concealed Cenozoic pluton(s) of low density also may 

exist at progressively shallower depths to the west of the 

gravity high.

Mineral and Energy Resource Potential

The mineral resource potential of the Disaster Peak 

Wilderness Study Area was assessed on the basis of 

geologic investigations, geochemical and geophysical 

studies, a study of prospects and claims, and reported 

mineral occurrences and deposits in the region. The study 

area has resource potential for gold (in two types of 

deposits), silver, mercury, and uranium. Data suggest lack 

of resource potential for geothermal energy, oil, and gas.

A study of the Au claim group in the southern part of 

the study area (table 1 and fig. 2, No. 2) indicates that 

quartz veins crosscutting the granitic basement rocks have 

been mineralized with gold, Gold within the veins occurs 

in concentrations of at least 1.120 oz/ton and is 

accompanied by minor native silver, galena, copper 

sulfides, and carbonate minerals. Although poorly 

exposed, the veins are subparallel, occupy faults or other 

fissures, and are limited to the area of the Au claim group. 

However, weakly anomalous concentrations of gold and 

arsenic within stream sediments derived partly from other 

areas of granitic rock suggest that similar undiscovered 

mineralized veins may be present elsewhere. The quartz 

veins have some attributes of low-sulfide gold-quartz veins 

described in the ore-deposit model of Berger (1986a). The 

Mother Lode veins in California are perhaps the best 

known example of this type of deposit. In this model, 

quartz, gold, and accessory minerals crystallize from fluids 

migrating along fault and joint systems along continentalmargin erogenic belts following regional metamorphism 

and emplacement of granitic batholiths. In the study area, 

the mineralized quartz veins may have formed during the 

Late Cretaceous, soon after intrusion of the granitic rocks. 

Alternatively, the veins may have formed during some later 

magmatic hydrothermal event but prior to the inception of

Miocene volcanism in the area. The area of the Au claim 

group in the southern part of the study area has high 

potential, certainty level B, for gold resources in quartz 

veins (fig 2). Although economically significant 

concentrations of gold have been detected in the claim area 

in a geologic environment favorable for ore deposition, the 

geometry, extent, and quality of the mineralized veins are 

not well defined. The surrounding area of granitic rock that 

lacks known quartz veins, in which weak but significant 

geochemical anomalies are present, has low resource 

potential, certainty level B, for gold in quartz veins.

Results of the present study, and reported near-by 

mining activity, indicate that epithermal gold, mercury, and 

uranium mineralization occurred in an area adjacent to, and 

possibly within, the northeastern part of the study area. 

Adjacent to the study area, the area of hydrothermally 

altered and mineralized rock within the Albisu prospect is 

controlled by north- to northeast-striking arcuate faults and 

fractures associated with the Long Ridge caldera (fig. 2). 

The hydrothermally affected area contains highly 

anomalous concentrations of gold, antimony, arsenic, 

mercury, and uranium as well as weakly anomalous 

amounts of silver. A pronounced radiometric anomaly over 

the area (see geophysical studies, above) also indicates 

anomalous concentrations of uranium. Surrounding this 

area, but still within the zone of caldera ring faults and 

including the northeastern part of the study area (fig. 2), are 

scattered, weak geochemical and radiometric anomalies of 

these elements. Epithermal occurrences and ore deposits of 

mercury and uranium formed by hydrothermal activity 

during late stages of caldera development are present 

elsewhere within the McDermitt caldera complex (Rytuba 

and Glanzman, 1978; Rytuba and others, 1979; Rytuba and 

Conrad, 1981). Some of the uranium, such as at the 

Moonlight mine about 10 mi south of the study area (fig. 

1), was hosted by rhyolite domes and ring intrusions. Both 

mercury and uranium were deposited in caldera-fill 

sedimentary and volcanic rocks, typically near the caldera 

margin. Rhyolite that erupted within the caldera complex, 

including the tuff of Long Ridge that is present in the study 

area, contains high background concentrations of uranium 

and mercury (Rytuba and others, 1979). Thus, the rhyolite 

is inferred to be the main source of the mercury and 

uranium in the occurrences. Although most of the 

anomalous elements in the Albisu mineralized area 

adjacent to the study area are also associated with the other 

mercury and uranium occurrences in the caldera complex, 

no significant gold concentrations have been reported in 

other parts of the caldera complex.

The Albisu mineralized area has many attributes of 

hot-spring gold-silver (Berger, 1986b) and hot-spring 

mercury (Rytuba, 1986) deposit models, including 

geochemical signatures, geologic environment, and types of 

alteration. The area also resembles the distal part of the 

volcanogenic uranium model described by Bagby (1986),

Mineral Resources of the Disaster Peak Wilderness Study Area, Oregon and Nevada A11
although the model requires a shallow rhyolite intrusive 

host rock a rock type not exposed in the study area. 

Mineralization in the Albisu area probably was caused by 

the circulation of gold-, silver-, mercury-, and uraniumenriched hydrothermal fluids through ring faults and 

fractures during the waning stages of the caldera cycle. 

The driving heat source may have been slowly cooling 

rhyolitic magma emplaced at shallow depth along the ringfracture zone. Gold, silver, mercury, and uranium oreforming minerals have not been identified at the surface 

near the Albisu prospect, suggesting that any undiscovered 

ore deposits of these metals are present at shallow depth.

The northeastern part of the study area resembles the 

adjacent Albisu mineralized area in that it contains caldera 

ring faults and similar, although weak, geochemical 

anomalies. Unlike the Albisu area, however, this part of 

the study area has no claims or prospects and generally 

lacks evidence of epithermal alteration or mineralization. 

The northeastern part of the study area has low potential, 

certainty level C, for resources of gold, silver, mercury, and 

uranium in epithermal deposits (fig. 2).

Sand and gravel suitable for construction use are 

present in the study area, but deposits are too small to 

constitute a resource. No undiscovered sand and gravel 

resources are expected beyond known occurrences, with a 

certainty level of D.

Bliss (1983a, b) compiled lists of thermal springs and 

wells in Oregon and Nevada which include several lowtemperature (less than 90 °C) hot springs located in 

surrounding basins 10 or more miles from the study area. 

However, there is no evidence of recent geothermal activity 

in the study area, such as hot springs, recent volcanism, and 

geothermal wells. Furthermore, it is unlikely that faults in 

the area penetrate to great enough depths to allow for deep 

circulation of ground water. There is no potential for 

geothermal resources, certainty level D, in the study area.

Geologic data indicate the absence of oil and gas 

resources in or near the study area. The Tertiary volcanic 

and pyroclastic sequence that underlies most of the study 

area contains only local, thin, and discontinuous layers of 

sedimentary rock and lacks evidence of hydrocarbons. 

Cretaceous granitic rocks exposed in The Granites area and 

presumably forming the basement rock throughout the 

study area are not a source or reservoir for hydrocarbons, 

nor are the underlying Cenozoic intrusive rocks inferred 

from the gravity data (see geophysical studies, above). 

There are no active oil and gas leases or producing wells in 

or near the study area. The Disaster Peak Wilderness Study 

Area has no potential, certainty level D, for oil and gas 

resources.

REFERENCES CITED

Bagby, W.C., 1986, Descriptive model of volcanogenic U, model 

25f, in Cox, D.P., and Singer, D.A., eds., Mineral deposit

models: U.S. Geological Survey Bulletin 1693, p. 162-164. 

Beikman, H.M., Hinkle, M.E., Frieders, Twila, Marcus, S.M., and

Edward, J.R., 1983, Mineral surveys by the Geological

Survey and the Bureau of Mines of Bureau of Land

Management Wilderness Study Areas: U.S. Geological

Survey Circular 901, 28 p. 

Benson, W.T., 1956, Investigation of mercury deposits in Nevada

and Malheur County, Oregon: U.S. Bureau of Mines Report

of Investigation 5285, 54 p. 

Berger, B.R., 1982, The geological attributes of Au-Ag-base

metal epithermal deposits, in Erickson, R.L., ed.,

Characteristics of mineral deposit occurrences: U.S.

Geological Survey Open-File Report 82-795. 

___ 1986a, Descriptive model of low-sulfide Au-quartz veins,

model 36a, in Cox, D.P., and Singer, D.A., eds., Mineral

deposit models: U.S. Geological Survey Bulletin 1693, p.

239-243. 

___ 1986b, Descriptive model of hot-spring Au-Ag, model 25 a,

in Cox, D.P., and Singer, D.A., eds., Mineral deposit models: 

U.S. Geological Survey Bulletin 1693, p. 143-144.

Bliss, J.D., 1983a, Oregon basic data for thermal springs and 

wells as recorded in Geotherm: U.S. Geological Survey 

Open-File Report 83-435, 242 p.

___ 1983b, Nevada basic data for thermal springs and wells as 

recorded in Geotherm: U.S. Geological Survey Open-File 

Report 83-433A, 101 p.

Bukofski, J.F., Lovell, J.S., and Meyer, W.T., 1984, Mineral 

resource assessment through geochemical studies of heavy 

mineral concentrates from wilderness study areas in the 

Burns, Prineville, and Vale Districts, southeastern Oregon: 

Golden, Colo., Barringer Resources, Inc., 94 p.

Conners, R.A., Robinson, M.L., Bukofski, J.F., Meyer, W.T., and 

Howarth, R.J., 1982, Geochemical and geostatistical 

evaluation of wilderness study areas, Winnemucca District, 

northwest Nevada: Golden, Colo., Barringer Resources, Inc., 

5 v., 24 pi.

Crock, J.G., Briggs, P.H., Jackson, L.L, and.Lichte, F.E., 1987, 

Analytical methods for the analysis of stream sediments and 

rocks from wilderness study areas: U.S. Geological Survey 

Open-File Report 87-84, 35 p.

Erikson, E.H., and Curry, W.E., 1977, Preliminary study of the 

uranium favorability of Tertiary rocks, southeastern Oregon: 

eastern Klamath, southern Lake, Harney, and western 

Malheur Counties: U.S. Energy Research and Development 

Administration Open-File Report GJBX-92(77), 23 p.; 

available through U.S. Geological Survey, Books and OpenFile Reports Section, P.O. Box 25425, Federal Center, 

Denver, CO 80225.

Fuller, R.E., 1931, The geomorphology and volcanic sequence of 

Steens Mountain in southeastern Oregon: University of 

Washington Publications in Geology, v. 3, no. 1, p. 1-130.

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.

___1980, Aerial radiometric and magnetic survey, National 

Topographic Map, Adel, Oregon: U.S. Department of Energy 

Open-File Report GJBX-104 (80), v. 2, 145 p.

Glanzman, R.K., Rytuba, J.J., and McCarthy, J.H., Jr., 1978,

A12 Mineral Resources of Wilderness Study Areas Trout Creek Mountains Region, Oregon
Lithium in the McDermitt Caldera, Nevada and Oregon:

Energy, v. 3, no. 3, p. 347-353. 

Goudarzi, G.H., 1984, Guide to preparation of mineral survey

reports on public lands: U.S. Geological Survey Open-File

Report 84-787, 51 p. 

Gray, J.J., Peterson, J.C., Clayton, Janine, and Baxter, Gary, 1983,

Geology and mineral resources of 18 BLM wilderness study

areas, Harney and Malheur Counties, Oregon: Oregon

Department of Geology and Mineral Industries Open-File

Report 0-83-2, 106 p. 

Greene, R.C., 1976, Volcanic rocks of the McDermitt caldera,

Nevada-Oregon: U.S. Geological Survey Open-File Report

76-753, 80 p. 

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. 

Leszcykowski, A.M., 1987., Mineral resources of the Disaster

Peak study area, Harney and Malheur Counties, Oregon, and

Humboldt County, Nevada: U.S. Bureau of Mines Open-File

Report MLA 65-87, 16 p. 

Mankinen, E.A., Larson, E.E., Gromme, C.S., Prevot, Michel, and

Coe, R.S., 1987, The Steens Mountain (Oregon) geomagnetic

polarity transition 3. Its regional significance: Journal of

Geophysical Research, v. 92, no. B8, p. 8057-8076. 

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

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

May, J.T., Witkowski, D.S., and Seidel, D.G., 1980, Extracting

lithium from clays by roast-leach treatment: U.S. Bureau of

Mines Report of Investigation 8432, 16 p. 

Minor, S.A., 1986, Stratigraphy and structure of the western Trout

Creek and northern Bilk Creek Mountains, Harney County,

Oregon, and Humboldt County, Nevada: Boulder, Colo.,

University of Colorado, M.S. thesis, 189 p. 

Piper, A.M., Robinson, T.W., Jr., and Park, C.F., Jr., 1939,

Geology and ground-water resources of the Harney Basin,

Oregon: U.S. Geological Survey Water-Supply Paper 841,

189 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 77-683, 40 p. 

___1987, Gravity observations by the U.S. Geological Survey

in northwest Nevada, southeast Oregon, and northeast

California, 1984-1986: U.S. Geological Survey Open-File

Report 87-639, 33 p. 

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. 

___ 1986, Descriptive model of hot-spring Hg, model 27a, in

Cox, D.P., and Singer, D.A., eds., Mineral deposit models:

U.S. Geological Survey Bulletin 1693, p. 178-179.

Rytuba, J.J., and Conrad, W.K., 1981, Petrochemical 

characteristics of volcanic rocks associated with uranium 

deposits in the McDermitt caldera complex, in Goodell, P.C., 

and Waters, A.C., eds., Uranium in volcanic and 

volcaniclastic rocks: American Association of Petroleum 

Geologists Studies in Geology, no. 13, p. 63-72.

Rytuba, J.J., and Glanzman, R.K., 1978, Relation of mercury, 

uranium, and lithium deposits to the McDermitt caldera 

complex, Nevada-Oregon: U.S. Geological Survey OpenFile Report 78-926, 28 p.

Rytuba, J.J., Glanzman, R.K., and Conrad, W.K., 1979, Uranium, 

thorium, and mercury distribution through the evolution of 

the McDermitt caldera complex, in Newman, G.W., and 

Goode, H.D., eds., Rocky Mountain Association of 

Geologists Basin and Range Symposium and Great Basin 

Field Conference: Rocky Mountain Association of 

Geologists Meeting, Las Vegas, 1979, Guidebook, p. 405- 

412.

Rytuba, J.J., and McKee, E.H., 1984, Peralkaline ash-flow tuffs 

and calderas of the McDermitt volcanic field, southeast 

Oregon and north central Nevada: Journal of Geophysical 

Research, v. 89, no. BIO, p. 8616-8628.

Singleton, R.H., 1979, Lithium: U.S. Bureau of Mines Mineral 

Commodity Profiles, 24 p., available from Publications 

Distribution Branch, Bureau of Mines, 4800 Forbes Avenue, 

Pittsburgh, PA 15213.

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, 5 p.

U.S. Geological Survey, 1972a, Aeromagnetic map of the Adel 

and parts of the Bums, Boise, and Jordan Valley lo by 2o 

quadrangles, Oregon: U.S. Geological Survey open-file 

report, scale 1:250,000.

___1972b, Aeromagnetic map of the Vya and part of the 

McDermitt 1° by 2° quadrangle, Nevada: U.S. Geological 

Survey open-file report, scale 1:250,000.

___1982, Spectral radiometric and total-field magnetic survey

of the McDermitt calderas, NV-OR: U.S. Geological Survey 

Open-File Report 82-323, 41 p., 96 sheets, scale 1:62,500.

Walker, G.W., and Repenning, C.A., 1965, Reconnaissance 

geologic map of the Adel quadrangle, Lake, Harney, and 

Malheur Counties, Oregon: U.S. Geological Survey 

Miscellaneous Geological Investigations Map 1-446, scale 

1:250,000.

Willden, Ronald, 1964, Geology and mineral deposits of 

Humboldt County, Nevada: Nevada Bureau of Mines and 

Geology Bulletin 59, 145 p.

Yates, R.G., 1942, Quicksilver deposits of the Opalite district, 

Malheur County, Oregon, and Humboldt County, Nevada: 

U.S. Geological Survey Bulletin 931-N, p. 319-348.

Mineral Resources of the Disaster Peak Wilderness Study Area, Oregon and Nevada A13

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.

rz

LLJ

oQ_

LLJ

U

Oco

LU

,

O

_J

LU 

LU

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.8., 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.

A16 Mineral Resources of Wilderness Study Areas Trout Creek Mountains Region, Oregon
RESOURCE/RESERVE CLASSIFICATION

ECONOMIC

MARGINALLY 

ECONOMIC

SUBECONOMIC

IDENTIFIED RESOURCES

Demonstrated

Measured

Rese

Indicated

jrves

Marginal 

Reserves

Demonstrated 

Subeconomic 

Resources

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, 1 980, Principles 

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

Mineral Resources of the Disaster Peak Wilderness Study Area, Oregon and Nevada A17
GEOLOGIC TIME CHART

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

EON

Phanerozoic

Proterozoic

Archean

ERA

Cenozoic

Mesozoic

Paleozoic

Late Proterozoic

Middle Proterozoic

Early Proterozoic

Late Archean

Middle Archean

Early Archean

PERIOD

Quaternary

Neogene 

Subperiod

Tertiary 

Paleogene

Subperiod

Cretaceous

Jurassic

Triassic

Permian

Pennsylvanian 

Carboniferous

Periods

Mississippian

Devonian

Silurian

Ordovician

Cambrian

fi«nn?\

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

pre-Archean2

AGE ESTIMATES OF 

BOUNDARIES (in Ma)

 0.010

1.7

5

ia

 55

 66

1 1Q

205

 "> A r\

 290

 -330 

 360

 410

 500

 ' "^7n

 1600

i^v\r\

 3400

 /ic:c:r» 

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

informal time term without specific rank.

A18 Mineral Resources of Wilderness Study Areas Trout Creek Mountains Region, Oregon

GPO 585-045/78055
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