Mineral Resources of the High Steens 

and Little Blitzen Gorge Wilderness 

Study Areas, Harney County, Oregon

U.S. GEOLOGICAL SURVEY BULLETIN 1740-A

CHAPTER A

Mineral Resources of the High Steens and 

Little Blitzen Gorge Wilderness Study Areas, 

Harney County, Oregon

By SCOTT A. MINOR and DONALD PLOUFF 

U.S. Geological Survey

LEON E. ESPARZA and THOMAS J. PETERS 

U.S. Bureau of Mines

U.S. GEOLOGICAL SURVEY BULLETIN 1740

MINERAL RESOURCES OF WILDERNESS STUDY AREAS: STEENS 

MOUNTAIN RINCON REGION, OREGON
DEPARTMENT OF THE INTERIOR 

DONALD PAUL MODEL, Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1987

For sale by the

Books and Open-File Reports Section

U.S. Geological Survey

Federal Center, Box 25425

Denver, CO 80225

Library of Congress Cataloging-in-Publication Data

Mineral resources of the High Steens and Little Blitzen 

Gorge Wilderness Study Areas, Harney County, Oregon.

U.S. Geological Survey Bulletin 1740-A

Bibliography

Supt. of Docs. No.: I 19.3:1740-A

I. Mines and mineral resources Oregon High Steens 

Wilderness. 2. Mines and mineral resources Oregon 

Little Blitzen Gorge Wilderness. 3. Geology Oregon 

High Steens Wilderness. 4. Geology Oregon Little 

Blitzen Gorge Wilderness. 5. High Steens Wilderness (Or.) 

6.Little Blitzen Gorge Wilderness (Or.) I. Minor, Scott A.

II. Geological Survey (U.S.) 111. Series.

QE75.B9 No. 1740-A 557.3 s 86-607939

[TN24.07] |553'.09795'95l
STUDIES RELATED TO WILDERNESS

Bureau of Land Management Wilderness Study Areas

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 a part of the 

High Steens (OR-002-085F) and Little Blitzen Gorge (OR-002-086F) Wilderness Study 

Areas, Harney County, Oregon.

CONTENTS

Summary Al

Abstract 1

Character and setting 1

Identified resources 3

Mineral resource potential of the High Steens Wilderness Study Area 3

Mineral resource potential of the Little Blitzen Gorge Wilderness

Study Area 3 

Introduction 5

Location and physiography 5 

Previous and present investgations 5 

Acknowledgments 6 

Appraisal of identified resources 6 

History and production 6 

Mineral deposits 6

Assessment of mineral resource potential 8 

Geology 8

Geochemical studies 8 

Geophysical studies 9

Mineral and energy resources of the High Steens Wilderness Study Area 10 

Gold, mercury, and uranium 10 

Zeolites 11 

Perlite 12

Geothermal energy 12 

Oil and gas 12

Mineral and energy resources of the Little Blitzen Gorge Wilderness 

Study Area 12

Gold, mercury, and uranium 12 

Oil and gas 12 

References 13 

Appendix 1. Definition of levels of mineral resource potential and

certainty of assessment and geologic time scale 15

Appendix 2. Mines, prospects, and claims in and adjacent to the High Steens 

Wilderness Study Area, Harney County, Oregon 17

FIGURES

1. Index map showing location of the High Steens and Little Blitzen Gorge Wilderness 

Study Areas, Harney County, Oregon A2

2. Map showing mineral resource potential and geology of the High Steens and Little 

Blitzen Gorge Wilderness Study Areas, Harney County, Oregon 4

3. Map showing location of mines, prospects, and claims in and adjacent to the High 

Steens Wilderness Study Area, Harney County, Oregon 7

MINERAL RESOURCES OF WILDERNESS STUDY AREAS: STEENS 

MOUNTAIN RINCON REGION, OREGON

Mineral Resources of the High Steens and 

Little Blitzen Gorge Wilderness Study Areas, 

Harney County, Oregon

By Scott A. Minor and Donald Plouff 

U.S. Geological Survey

Leon E. Esparza and Thomas J. Peters 

U.S. Bureau of Mines

SUMMARY

Abstract

The contiguous High Steens (OR-002-085F) and 

Little Blitzen Gorge (OR-002-086F) Wilderness Study 

Areas are located along east-central Steens Mountain, 

Harney County, southeastern Oregon. At the request 

of the U.S. Bureau of Land Management, a total of 

35,930 acres of the High Steens and 6,430 acres of the 

Little Blitzen Gorge Wilderness Study Areas were 

studied. In this report, the combined area studied is 

referred to simply as "the study area." Field work for 

this report was conducted between 1983 and 1985. 

About 500 claims and prospects have been located 

within and adjacent to the High Steens Wilderness 

Study Area, 52 of which are still active. No mining 

claims or prospects have been recorded within the 

Little Blitzen Gorge Wilderness Study Area. Perlite, 

with inferred marginal reserves totaling about 400,000 

tons, is the only identified resource within the High 

Steens Wilderness Study Area. No identified resources 

are located in the Little Blitzen Gorge Wilderness 

Study Area.

The potential for uranium resources is high in 

two areas along the southeast edge of the High Steens 

Wilderness Study Area; the potential for mercury 

resources is also high in one of these areas and the 

potential for gold resources is moderate in both 

areas. The potential for gold, mercury, and uranium 

resources in adjacent areas along the southeast and 

central-east edges of the High Steens Wilderness Study 

Area is moderate. The potential for resources of these 

commodities in an area along the northeast margin of

the High Steens Wilderness Study Area is low. The 

western part of the High Steens Wilderness Study Area 

west of the Steens Mountain crest has unknown 

potential for these resources. The mineral resource 

potential for zeolites is low within a large area 

surrounding the southeast edge of the High Steens 

Wilderness Study Area; a low potential for perlite 

resources is assigned to the western part of this area. 

The potential for geothermal energy resources is low 

within a strip along the east margin of the High Steens 

Wilderness Study Area. The areas of known mineral 

resource potential and nearby mineral occurrences are 

related to a major basin-and-range fault zone existing 

along the base of the east escarpment of Steens 

Mountain. The entire High Steens Wilderness Study 

Area as well as the Little Blitzen Gorge Wilderness 

Study Area have a low potential for oil and gas 

resources. The Little Blitzen Gorge Wilderness Study 

Area has unknown potential for gold, mercury, and 

uranium resources.

Character and Setting

The High Steens (OR-002-085F) and Little 

Blitzen Gorge (OR-002-086F) Wilderness Study Areas 

are located along the east-central part of Steens 

Mountain in Harney County, Oreg., about 60 mi southsoutheast of Burns, Oreg. The 9,500-ft-high crest of 

Steens Mountain divides the combined study area into 

an eastern part characterized by a precipitous, eastfacing, 5,500-ft-high escarpment and a western 

part consisting of a gently west-dipping dissected 

plateau. The study area is underlain by a 

sequence of gently west-dipping Tertiary (see

Al
42°30' -

fj«nchglen BROTHERS FAULT ZONE SEGMENTS

HIGH STtENS 

WILDERNESS STUDY 

(OR-002-085F):

Figure 1. Index map showing location of the High Steens and Little Blitzen Gorge Wilderness Study Areas, 

Harney County, Oregon.

A2
Appendix 1 for geologic time chart) volcanic, 

pyroclastic, and minor sedimentary rocks. The oldest 

rocks, which are present only along the east 

escarpment, consist of rhyolitic extrusive rocks, 

subordinate tuffs, and sedimentary rocks; these are 

overlain by andesitic flows, breccias, and pyroclastic 

rocks. A younger thick sequence of basalt flows caps 

the east escarpment and forms the bedrock within the 

western part of the combined study area. Steens 

Mountain, which is a large, uplifted and mildly tilted 

fault block, is bounded along the base of its east 

escarpment by a concealed range-front normal fault 

zone. Other subsidiary faults and flexures exist within 

the Steens Mountain block. Spectacular deep, U-- 

shaped canyons located primarily on the west slope 

were formed by glaciers during Pleistocene time.

Prospecting, claim staking, and mining in the 

High Steens Wilderness Study Area has occurred 

intermittently since 1891. Harney County mining 

records show that about 450 lode and 50 placer claims 

were located within and adjacent to the High Steens 

Wilderness Study Area; presently (1985) 52 mining 

claims are considered active. Mercury and uranium 

were mined along the east escarpment just outside the 

southeastern part of the study area. Mercury 

production totaled approximately 55 flasks; uranium 

production is unrecorded. No prospects or workings 

were found in the Little Blitzen Gorge Wilderness 

Study Area.

Identified Resources

Inferred marginal reserves of perlite totaling 

about 400,000 tons are assigned to the Cinder Cone 

claims within the High Steens Wilderness Study Area 

(Appendix 2 and fig. 3, No. 1). The Little Blitzen 

Gorge Wilderness Study Area has no identified 

resources.

Mineral Resource Potential of the High Steens 

Wilderness Study Area

Areas having high, moderate, low, and unknown 

mineral potential for mercury and uranium resources 

are delineated for the High Steens Wilderness Study 

Area; areas having moderate, low, and unknown 

potential gold resources and low potential for 

resources of zeolite, perlite, oil and gas, and 

geothermal energy are also present (fig. 2).

The High Steens Wilderness Study Area overlaps 

the northern part of the Steens-Pueblo mining district, 

a 40-mi-long belt of epithermal, gold, copper, and 

mercury deposits located along the east edge of the 

Steens and Pueblo Mountains. Mercury- and uraniumbearing minerals are localized within fracture, shear, 

and breccia zones and along mafic dikes in veins and 

fracture coatings within the older rhyolitic extrusive 

and tuffaceous rocks along or just outside of the 

southeast part of the High Steens Wilderness Study 

Area; the metalliferous structures are likely related to 

the Steens Mountain range-front fault zone. 

Geochemical evidence and the distribution of mines

and prospects in and near the High Steens Wilderness 

Study Area indicate a zone of metal concentration 

surrounding the southeast boundary that contains the 

metalliferous structures. This zone contains 

anomalous concentrations of uranium as well as goldindicator elements (arsenic, barium, mercury, and 

molybdenum) in both rock and stream-sediment 

samples. The geologic environment within the zone, 

especially the alteration assemblages that 

accompanied the mercury-uranium mineralization, is 

favorable for undiscovered epithermal gold deposits. 

The metalliferous zone includes an area of high 

resource potential for mercury and uranium and a 

moderate potential for gold between Indian and Pike 

Creeks (extreme southeastern part of the study area, 

fig. 2). A high potential for uranium resources also 

exists in an area located just to the north in Little 

Alvord Creek canyon. A moderate resource potential 

for gold, mercury, and uranium is assigned to the 

remainder of the zone between Indian and Mosquito 

Creeks, and a low resource potential for these 

elements is designated for a narrow strip along the 

northeast edge of the High Steens Wilderness Study 

Area. The mineralized rocks exposed along the east 

escarpment may extend westward underneath the dip 

slope of Steens Mountain. Such rocks would be 

concealed by several thousand feet of basalt and 

andesite overburden, thus preventing an accurate 

evaluation of their mineral resource potential. An 

unknown resource potential for gold, mercury, and 

uranium is designated for the High Steens Wilderness 

Study Area west of the Steens Mountain crest.

A low resource potential for zeolites and perlite 

is assigned for that part of the High Steens Wilderness 

Study Area underlain by the rhyolitic extrusive rocks 

and tuffs (Pike Creek Formation, southeastern part of 

study area, fig. 2). Areas predominantly underlain by 

tuffaceous rocks (Alvord Creek Formation, fig. 2) 

along the southeast edge of the study area also have 

low potential for zeolite resources.

The potential for oil and gas resources in the 

High Steens Wilderness Study Area is considered to be 

low on the basis of unfavorable evidence regarding the 

presence of hydrocarbon source rocks. The 

easternmost part of the High Steens Wilderness Study 

Area has a low resource potential for undiscovered 

geothermal energy; active hot springs exist about 2 mi 

southeast of the study area (fig. 2).

Mineral Resource Potential of the Little Blitzen Gorge 

Wilderness Study Area

The Little Blitzen Gorge Wilderness Study Area, 

located on the structurally simple Steens Mountain dip 

slope and underlain by several thousand feet of basalt 

and andesite, has unknown mineral potential for gold, 

mercury, and uranium resources in concealed, possibly 

mineralized rocks similar to those of the Pike Creek 

and Alvord Creek Formations. The potential for oil 

and gas resources in the Little Blitzen Gorge 

Wilderness Study Area is considered to be low (fig. 2) 

on the basis of unfavorable evidence regarding the 

presence of hydrocarbon source rocks.

A3
LITTLE BLITZEN GORGE 

WILDERNESS STUDY AREA (OR-002-86F)

Figure 2. Mineral resource potential and geology of the High Steens and Little Blitzen Gorge Wilderness 

Study Areas, Harney County, Oregon.

A4
EXPLANATION

Area with high mineral resource potential

Area with moderate mineral resource potential 

Area with low mineral resource potential

Sec Appendix 1 for definition of levels of mineral resource and certainty of assessment

Commodities 

Au Gold

Hg Mercury

U Uranium

Geo Geothermal

Per Fertile

Zeo Zeolites

O,G Oil, Gas

Geologic map units

Alluvium (Quaternary) 

Landslide deposits (Quaternary and Tertiary) 

Steens Basalt {Tertiary)-Locally includes: 

Dikes

Steens Mountain Volcanics (Tertiary) 

Pike Creek Formation (Tertiary) 

Alvord Creek Formation (Tertiary)

 Contact Dashed where approximate

|__ _ _.. Fault-Dashed where approximate; dotted where concealed.

Ball and bar on downthrown block 

" ~~ y Upper monoclinal flexure axis

- -jr - Lower monoclinal flexure axis

Figure 2. Continued.

INTRODUCTION 

Location and Physiography

The High Steens (OR-002-085F) and Little 

Blitzen Gorge (OR-002-086F) Wilderness Study Areas 

are located in Harney County, Oreg., about 60 mi 

south-southeast of Burns, Oreg. (fig. 1). At the 

request of the U.S. Bureau of Land Management, 

35,930 and 6,430 acres of the High Steens and Little 

Blitzen Gorge Wilderness Study Areas, respectively, 

were studied. The two wilderness study areas are 

contiguous and are referred to either individually or as 

"the study area" throughout this report. The study 

area is situated along Steens Mountain, a prominent 

north-northeast-trending range more than 60 mi long. 

The approximately 9,700-ft-high crest of the range 

extends across the eastern part of the study area (fig. 

2). A steep escarpment with 5,500 ft of relief, which 

is dissected by numerous intermittent, eastwardflowing creeks, descends sharply from the mountain 

crest to the Alvord Desert basin along the east margin 

of the study area. The area west of the rangecrest is 

characterized by a gently west-tilted dip slope cut by 

deep (as great as 2,000 ft) glacially modified canyons 

of Little Blitzen River and Kiger, Big Indian, Little 

Indian, and Wildhorse Creeks (fig. 2). Three of these 

spectacular canyons drain onto Smith Flat, a plateau 

forming the base of a 2,000-ft-high, northwesttrending escarpment along the west boundary of the 

study area. Vegetation of the region is similar to that 

growing elsewhere in mountain ranges of the semiarid

northern Great Basin; sage, aspen, and juniper are 

most common. There is a tendency for a greater 

density of trees and grasses on the cooler, wetter dip 

slope of Steens Mountain.

Road access along the east escarpment consists 

of jeep trails that extend into a few prominent canyons 

from an improved gravel county road along the west 

edge of the Alvord Desert (fig. 1). The west slope is 

accessible during the summer months along Steens 

Mountain Loop Road via its junction with Oregon State 

Highway 205 at Frenchglen. Several jeep and hiking 

trails intersect this road and extend into remote parts 

of the study area.

Previous and Present Investigations

Previous geologic mapping in the study area 

includes Williams and Compton (1953), Walker and 

Repenning (1965), Wilkerson (1958), and Fryberger 

(1959). Geochemical and geophysical reconnaissance 

surveys were conducted for the U.S. Department of 

Energy's National Uranium Resource Evaluation 

(MURE) program to assess the radioactive mineral 

potential of the region (Erikson and Curry, 1977; 

Geodata International, Inc., 1980). A preliminary 

evaluation of the mineral resources of the High Steens 

and Little Blitzen Gorge Wilderness Study Areas was 

made by the Oregon Department of Geology and 

Mineral Industries (DOGAMI) (Gray and others, 1983).

The U.S. Geological Survey (USGS) mapped the 

geology of the study area in 1984 (Minor and others, 

1987). Rock samples were collected by the USGS in 

altered areas in the High Steens Wilderness Study Area 

for geochemical analysis and evaluation. Most of the 

geochemical data evaluated for this report are 

DOGAMI assay data initially presented by Gray and 

others (1983), which include 18 rock and 88 streamsediment samples from the study area. Heavy mineral 

concentrates of the DOGAMI stream-sediment samples 

were analyzed and evaluated by Barringer Resources, 

Inc. (Bukofski and others, 1984), and were also 

considered in this study. NURE reports by Erikson and 

Curry (1977) and Geodata International, Inc. (1980), 

were also used to help evaluate the radioactive 

mineral potential of the study area.

The U.S. Bureau of Mines (USBM) conducted 

surveys of the study area from late 1983 to 1985, 

focusing on investigations of mines, prospects, and 

mineralized areas and checking geochemical anomalies 

identified by Gray and others (1983). Studies included 

a review of Harney County and U.S. Bureau of Land 

Management (BLM) mining and mineral-lease records 

and USBM production records. Field studies involved 

searches for all mines, prospects, and claims within 

and adjacent to the study area; those found were 

mapped and sampled for geochemical analyses. 

Ground and aerial reconnaissance for unrecorded 

exploration and mine workings and rock alteration was 

done in areas judged favorable for mineral deposits. 

Twenty-seven properties sampled by the USBM are 

shown on fig. 3 and individual descriptions provided in 

Appendix 2. Details of the sampling procedures and 

results of the Little Blitzen Gorge Wilderness Study 

Area are presented in Peters and Esparza (1986). 

Detailed information on the High Steens Wilderness

A5
Study Area is available from the U.S. Bureau of Mines, 

Western Field Operations Center, E. 360 Third Avenue, 

Spokane, Washington, 99202.

Acknowledgments

The BLM in Burns, Oreg., kindly allowed USGS 

geologists access onto the higher part of the Steens 

Mountain Loop Road prior to public availability. They 

also generously permitted use of their fire guard 

station at Fields, Oreg., for lodging.

APPRAISAL OF IDENTIFIED RESOURCES

By Leon E. Esparza and Thomas J. Peters, 

U.S. Bureau of Mines

History and Production

The earliest recorded mining claim within the 

High Steens Wilderness Study Area was staked in late 

1891. Since then, 450 lode and 50 placer mining claims 

have been staked in the study area. There are 52 

active mining claims in and adjacent to the High 

Steens study area. No claims were filed for the Little 

Blitzen Gorge Wilderness Study Area.

There were four periods of intensive prospecting 

and claim staking in and near the High Steens 

Wilderness Study Area: 1891 to 1905, 1930 to 1942, 

1953 to 1956, and 1973 to 1977. The first period was 

for gold, the second for mercury, and the remaining 

two for uranium. Most of the gold exploration was 

limited to searches for placer deposits west of the 

Steens Mountain crest. Prospecting and mining for 

mercury and uranium was concentrated within and 

adjacent to the southeastern part of the High Steens 

Wilderness Study Area. During the late 1970's, several 

mining companies explored for precious metals in the 

southeastern part of the study area. The only recorded 

production consisted of approximately 55 flasks of 

mercury, primarily from the Steens Mountain and 

Weston mines (Appendix 2 and fig. 3, Nos. 6 and 8) 

(Ross, 1942; Williams and Compton, 1953; Brooks, 

1963; and Mike and John Weston, oral commun., 1984).

Mineral Deposits

Inferred marginal perlite reserves identified at 

one locality in the High Steens Wilderness Study Area 

are the only known resource. Gold, mercury, uranium, 

molybdenum, and zeolite minerals are present within 

and (or) adjacent to the High Steens Wilderness Study 

Area but are not of great enough significance to be 

considered resources. Despite minor occurrences of 

gold, the Little Blitzen Gorge Wilderness Study Area 

does not contain any identified resources.

Several small occurrences of perlite exist along 

the glassy margins of felsic flows and domes within the 

Pike Creek Formation in the southeastern part of the 

High Steens Wilderness Study Area (Fuller, 1931; Minor 

and others, 1987). One such occurrence at the Cinder

Cone claims (Appendix 2 and fig. 3, No. 1) is of 

sufficient extent (5 acres) and thickness (at least 25 ft) 

to be considered a resource. A marginal reserve of 

400,000 tons of perlite is estimated for the deposit.

Minor amounts of minute gold flakes were 

observed in alluvial samples collected from some of 

the major drainages of both the High Steens and Little 

Blitzen Gorge Wilderness Study Areas (Appendix 2 and 

fig. 3, Nos. 15, 16, and 18-20). The gold is not present 

in sufficient quantity to be considered a resource.

Mercury minerals were not observed within the 

study area, but eight known mercury occurrences lie 

within 1 mi of the southeast edge of the High Steens 

Wilderness Study Area (Appendix 2 and fig. 3, Nos. 6- 

11, 13, and 14). In general, the mercury occurs as 

cinnabar within altered, felsic volcanic rocks of the 

Pike Creek Formation and is associated with faults and 

fracture systems that dip away from the study area.

Uranium-bearing minerals, including autunite, 

torbernite, and uranophane(?) (Matthews, 1955 and 

1956), are present in and adjacent to the High Steens 

Wilderness Study Area along faults and related 

structures within altered parts of the Pike Creek 

Formation; several uranium prospects are located 

along narrow fracture zones containing uranium 

minerals in and adjacent to brecciated rhyolite 

(Appendix 2 and fig. 3, Nos. 2-5). However, the 

uranium is not present in sufficient quantity to be 

considered a resource.

Molybdenum-bearing ilsemannite is reported by 

Gray and others (1983) to exist at two uranium 

prospects within the High Steens Wilderness Study 

Area (Appendix 2 and fig. 3, Nos. 2 and 4). This 

molybdenum oxide is present within altered and 

fractured parts of the Pike Creek Formation in 

quantities too small to be considered a resource.

Tuffaceous rocks belonging to the Alvord 

Creek(?) Formation, exposed along the southeast

EXPLANATION

1 Cinder Cone Nos. 1-6 claims

2 Knight Hawk No. 1 claim

3 Alvord Uranium Cave claims

4 Timberbeast Nos. 1-7 claims

5 Pike Creek Carnotite claims

6 Steens Mountain mine

7 Red Rock No. 6 claim

8 Weston mine

9 Last Chance claims

10 Jack Pot Nos. 1-9 claims

11 Alex-Ladd claim

12 Steens Nos. 1-74 claims

13 Aile Rouge No. 1 claim

14 Sunshine No.3 claim

15 Big Indian mine

16 Buckhornmine

17 Daisy claims

18 Gold Crown claim

19 Gold Queen claim

20 Head Light mine

21 Homestretch lode

22 Jack Pot claim

23 Lady Washington claim

24 Miners Dream lode

25 Ole Olson lode

26 Snowbird claim

27 West End claim

Figure 3. Location of mines, prospects, and claims in 

and adjacent to the High Steens and Little Blitzen 

Gorge Wilderness Study Areas. Numbers refer to 

Appendix 2.

A6
42°37'30"-

APPROXIMATE BOUNDARY 

OF

LITTLE BLITZEN GORGE 

WILDERNESS STUDY AREA (OR-002-86F)

27 _ 

Xv X 19 

X15 X X

16

23

APPROXIMATE BOUNDARY

HIGH STEENS WILDERNESS 

STUDY AREA (OR-002-85F)

Figure 3. Continued.

A7
boundary of the High Steens Wilderness Study Area, 

are altered to the zeolite mineral clinoptilolite 

(Walker and Repenning, 1965). Sample results from 

the USBM indicate that locally the tuffaceous rocks 

are composed of about 40 percent clinoptilolite. Minor 

amounts of zeolites also occur within vesicles in some 

of the volcanic flows exposed in the study area. The 

zeolites do not form resources in the study area due to 

their relatively low concentrations, the sparsity of 

exposed tuffaceous rocks, and remoteness to a mill or 

market.

Building-stone resources are limited. Although 

over 75 percent of the study area is underlain by 

basalt, quarrying of the basalt would not be feasible, 

as it does not meet required aesthetic characteristics 

or bulk density. It is adequate for use as fill material 

in local road construction, but other sources are 

located closer to areas of specific need. Surficial sand 

and gravel are present within the study area, but are 

not located close enough to a market to be 

commercially significant.

ASSESSMENT OF MINERAL RESOURCE POTENTIAL

By Scott A. Minor and Donald Plouf f, 

U.S. Geological Survey

Geology

Steens Mountain, located in the northwestern 

part of the Basin and Range province, is a major northnortheast-striking and gently (5°) west-northwestdipping fault block. Its steep east escarpment 

developed along a range-front normal fault zone 

having as much as 10,800 ft of accumulative throw 

(Cleary and others, 1981). The range is primarily 

composed of a gently west-dipping sequence of 

Oligocene(?) and Miocene volcanic flows, pyroclastic 

rocks, and minor sedimentary rocks. Minor and others 

(1987) described in detail the geology of the study 

area.

The oldest rocks in the study area, exposed near 

the base of the east escarpment, consist of 

interstratified tuff and tuffaceous to volcaniclastic 

sedimentary rocks of the Alvord Creek Formation 

(Williams and Compton, 1953) (fig. 2). Possibly 

correlative rhyolitic ash-flow tuff and tuff breccia 

also crop out near the escarpment base. The Pike 

Creek Formation (Walker and Repenning, 1965) 

overlies the Alvord Creek Formation with slight 

angular discordance. It consists of several 

intercalated rhyolitic to dacitic flows and extrusive 

domes and minor associated tuff and tuffaceous 

sedimentary rocks. The Pike Creek is commonly 

silicified or argillized; near the base of the formation, 

two platy rhyolite flows are strongly silicified, 

argillized, and acid leached. The Pike Creek 

Formation is greater than 2,000 ft thick near the south 

end of the fault scarp, thins northward, and pinches 

out just north of Little Alvord Creek. The Steens 

Mountain Volcanics (Minor and others, 1987), which 

conformably onlaps the Pike Creek Formation from 

the north, is composed principally of interstratified

andesitic flows, flow breccia, and pyroclastic rocks. 

The Steens Mountain Volcanics crops out along the 

lower part of the east escarpment near the northeast 

margin of the study area (fig. 2) and has a maximum 

thickness of 3,000 ft. Both the Pike Creek Formation 

and Steens Mountain Volcanics are disconformably 

overlain by the 15.5-Ma (million years before present) 

Steens Basalt (Piper and others, 1939; Baksi and 

others, 1967), which consists of a 4,300-ft-thick 

homogeneous sequence of thin (20 ft average) basalt 

flows. This sequence forms the upper part of the 

Steens Mountain escarpment and, except for 

Quaternary surficial deposits, underlies the entire west 

dip slope within the study area. Numerous dikes and 

sills of the Steens Basalt intrude the underlying units 

and extend up into flows of the Steens Basalt primarily 

along the east escarpment. Most of the dikes strike N. 

15°-20° E. and dip 80°-90° ESE.

Several structures trend obliquely to the Steens 

Mountain fault block within and near the study area 

(fig. 2). Several north-northwest-trending normal 

faults are present along the base of the east 

escarpment. Also, some coherent landslide blocks 

present along the base of the escarpment may 

represent gravitationally remobilized fault blocks of 

the adjacent range-front fault zone. Uplift and tilting 

of the Steens Mountain block appears to have resulted 

from movement along both north-northeast- and northnorthwest-trending normal faults. The most 

conspicuous of the structures oblique to the Steens 

Mountain fault block is a northwest-trending faulted 

monocline that forms the prominent escarpment along 

the southwest border of the area. The monocline and 

associated normal faults are considered to be elements 

of a southern branch of the Brothers fault zone (fig. 1), 

a deep-seated, possibly right-lateral shear zone first 

described by Walker (1969). Lawrence (1976) viewed 

the Brothers fault zone as a major right-lateral tear 

fault that forms part of the northwest boundary of the 

Basin and Range province.

The earliest known deformation in the study area 

occurred after deposition of the Alvord Creek 

Formation and before eruption of the overlying flows 

of the Pike Creek Formation, as indicated by the slight 

angular unconformity between the two units. 

Extensional deformation in the area, defined in part by 

the range-front fault zone and subparallel fractures 

along the eastern escarpment, may have begun prior to 

emplacement of the N. 15°-20° E.-striking, 15.5-Ma 

dikes of the Steens Basalt (fig. 2). Steens Mountain 

underwent minor uplift and tilting shortly after the 

eruption of the Steens Basalt, but major block faulting 

and uplift occurred no earlier than 9.3 Ma (Rytuba and 

McKee, 1984) and has probably continued into the 

Holocene.

Pleistocene glaciation resulted in the formation 

of extensive glacial deposits and large U-shaped 

canyons on Steens Mountain. A large pluvial lake 

occupied the Alvord Desert basin during glacial times 

and was the site of lacustrine sedimentation near the 

southeast margin of the study area.

Geochemical Studies

A geochemical evaluation of the study area was 

undertaken by the USGS using assay data from streamA8
sediment and rock samples. Most of the data were 

acquired by DOG AMI, which collected 88 streamsediment samples and 18 rock samples from within and 

near the study area and analyzed them for 17 

elements. A description of the sampling and analytical 

techniques used by DOGAMI and the resulting data 

were reported by Gray and others (1983). Heavymineral concentrates of the stream-sediment samples 

were analyzed by Barringer Resources, Inc.; the 

analytical data from the magnetic and nonmagnetic 

fractions of the concentrates were presented in 

Bukofski and others (1984).

Mineralized and (or) altered rock samples were 

collected by the USGS and analyzed semiquantitatively 

for 31 elements using a direct-current arc emission 

spectrographic method (Meyers and others, 1961). 

These samples were also analyzed for antimony, 

arsenic, bismuth, cadmium, gold, mercury, and zinc by 

atomic absorption, using modifications of methods of 

Thompson and others (1968) or Koirtyohann and Khalil 

(1976), or by inductively coupled argon plasma-atomic 

emission spectroscopy, using a modification of the 

O'Leary and Viets (1986) method. The analytical 

results were entered into a USGS computer-based file 

(Rock Analysis Storage System) that is accessible to 

the public. (Inquires should be made to: Job No. 

RT29; U.S. Geological Survey, Branch of Analytical 

Chemistry, Lakewood, Colo., 80225.)

Anomalous values were determined primarily by 

considering the range, distribution, and mean of the 

elemental concentrations. The only heavy mineral 

concentrate data considered in the present study were 

those element values determined to be anomalous by 

Barringer Resources, Inc. (Bukofski and others, 1984).

Stream-sediment samples collected within the 

study area that appear to be derived from the 

widespread Steens Basalt contain anomalous 

concentrations of copper (as much as 156 parts per 

million (ppm)), nickel (as much as 120 ppm), and zinc 

(as much as 80 ppm). These relatively high 

concentrations probably reflect strong initial 

magmatic levels of these elements in the Steens Basalt 

and thus are not considered significant.

High concentrations of mercury and uranium are 

associated with somewhat weaker and sporadic 

anomalous concentrations of arsenic, barium, and 

molybdenum within the older silicic extrusive and 

tuffaceous rocks in the southeastern part of the High 

Steens Wilderness Study Area (Pike Creek and Alvord 

Creek Formations). The anomalies are primarily 

reflected in the rock, stream-sediment, and, with the 

exception of mercury and uranium, heavy-mineral 

concentrate samples analyzed by DOGAMI. The 

highest mercury concentrations (as much as 444 ppm) 

are in samples from the lower Pike, Dry, and Indian 

Creek drainage basins, whereas the highest uranium 

concentrations (as much as 354 ppm) are in those 

samples collected from the Pike and Little Alvord 

Creek drainages (fig. 2). Weak but anomalous 

concentrations of arsenic, barium, mercury, 

molybdenum, and uranium were detected throughout 

most of the remaining exposures of the Pike Creek 

Formation. Anomalous lead (as much as 72 ppm) and 

tungsten (as much as 100 ppm) concentrations are also 

present in a few of the heavy-mineral concentrate 

samples from the southeast margin of the study area.

Limonite and hematite grains also exist in some of 

these concentrates. These anomalies, and other 

geologic observations, indicate that epithermal 

mercury-uranium mineralization affected the area. 

Elsewhere Rytuba and Glanzman (1979) and Castor and 

others (1981) have found similar anomalous 

concentrations of arsenic, molybdenum, and, locally, 

tungsten associated with epithermal mercury-uranium 

mineralization; their anomalies are associated with 

mineralized silicic volcanic rocks of the McDermitt 

caldera complex located 50 mi southeast of the study 

area. Arsenic, barium, mercury, and molybdenum are 

also associated with disseminated epithermal gold 

mineralization (Lewis, 1982) and may reflect 

undiscovered gold deposits near the study-area 

anomalies.

One stream-sediment sample collected in the 

Little Blitzen Gorge Wilderness Study Area contains 

4.0 ppm mercury, and two others collected on the 

western dip-slope in the High Steens Wilderness Study 

Area contain slightly anomalous concentrations of 

mercury. Weak concentrations of gold (0.005 ppm), 

silver (as much as 0.13 ppm), or tin (as much as 32.3 

ppm) are also present in a few stream-sediment 

samples collected from major dip-«lope drainages. 

These concentrations may reflect high initial 

magmatic levels of the metals in the Steens Basalt; 

the tin concentrations also may be a result of 

contamination by human artifacts.

Geophysical Studies

An aerial gamma-ray survey conducted in the 

region as part of the U.S. Department of Energy's 

NURE program (Geodata International, Lie., 1980) 

maintained flightlines at altitudes of 350 to 1,200 ft 

above the ground. One north-«outh and four east-west 

composite flightlines spaced at intervals of 3 mi 

traversed the study area. Equivalent uranium 

determinations exceeded the background level over the 

exposure area of the Pike Creek Formation along an 

east-west flightline located 4 mi north of the south 

edge of the High Steens Wilderness Study Area, 

approximately coincident with Little Alvord Creek. 

Rapid changes of flight altitude in short distances 

along that flightline, however, diminished the 

reliability of the measurements.

A complete Bouguer gravity anomaly map was 

prepared using data acquired from National 

Geophysical Data Center, Boulder, Colo., 80303. 

Local features of the gravity map could not be 

interpreted because the data coverage included only 

two gravity stations in the study area and a few 

stations outside the southeast edge, which proved 

inadequate to correlate with the mapped geology. The 

coverage outside the southeast edge of the study area 

includes a closely spaced set of gravity stations along 

Indian Creek from Cleary and others (1981, p. 936). A 

steep gravity gradient of about 10 milligals (mGal)/mi 

with gravity values increasing westward along Indian 

Creek reflects the underlying range-front fault zone 

between Alvord Desert and Steens Mountain. Gravity 

gradients of similar amplitude separate Pueblo Valley 

from the upthrown, west-bounding southern SteensPueblo Mountains fault block (fig. 1) for a distance of

A9
about 40 mi south from the study area. The rangefront gravity gradient is terminated to the north by a 

poorly defined 10- by 20-mGal gravity low that has a 

gravity minimum centered near the north edge of the 

study area. The value of this gravity anomaly 

decreases about 27 mGal between the 9,733-ft summit 

of Steens Mountain and the south edge of the study 

area (fig. 1). Gettings and Blank (1974) interpreted 

their unpublished east-trending gravity profile across 

Steens Mountain to reflect a possible depression filled 

with the Pike Creek Formation underlying Steens 

Mountain at depth. However, we believe that the 

gravity low may be too extensive to support such an 

interpretation.

An aeromagnetic survey of the region was flown 

with an east-west flightline spacing of 2 mi and at a 

constant barometric elevation of 9,000 ft above sea 

level except over crestlines where the flight-path 

elevations were higher (U.S. Geological Survey, 

1972). The mapped magnetic anomaly pattern over the 

study area is dominated by a series of north-trending 

magnetic highs and lows with amplitudes that exceed 

200 nanotesla (nT), reflecting large contrasts in 

magnetization of the rocks.

A prominent magnetic high and an adjacent 

magnetic low along the crestline of Steens Mountain 

reflect normally and reversely magnetized sections, 

respectively, of the Steens Basalt (Mankinen and 

others, 1985). These anomalies, however, are absent 

along a flightline located near Mosquito Creek and the 

headwaters of Little Blitzen River (fig. 1). A pair of 

elongated magnetic lows along each side of Kiger 

Creek probably reflect exposures of reversely 

magnetized parts of the Steens Basalt, where magnetic 

effects of the exposures are not cancelled by overlying 

normally magnetized rocks. The sources of elongated 

magnetic anomalies farther west are unclear. 

Inasmuch as dikes exposed near the crestline of Steens 

Mountain have northerly trends, the anomalies farther 

west may reflect concealed thick feeder dikes or dike 

swarms emplaced during more than one geomagnetic 

polarity epoch.

The intense magnetic anomalies that overlie the 

study area are superimposed on a broad magnetic high 

over Steens Mountain. A prominent magnetic gradient 

expressing a total amplitude that exceeds 100 nT 

upward to the west generally follows the west edge or 

center of the Alvord Desert and Pueblo Valley (fig. 1) 

south for about 40 mi. Like the range-front gravity 

gradient, the magnetic gradient is interrupted on the 

north by a relative magnetic low between Big Alvord 

and Mosquito Creeks. The source of the magnetic low 

is uncertain because the position of the anomaly 

probably is displaced by the magnetic effects of nearsurface sources with large contrasts of 

magnetization. Perhaps the coincidence of the 

magnetic low and the poorly defined regional gravity 

low reflects the location of a cupola of an underlying 

felsic intrusive body. Alternatively, the location of 

the geophysical lows may reflect uplifted pre-Tertiary 

basement rocks with low magnetization and density.

Magnetic-intensity contours are nearly parallel 

to the northeast-trending, normal-fault trace that 

crosses Indian Creek just southeast of the study area 

(fig. 2). The fact that the associated magnetic 

gradient extends for nearly 3 mi and magnetic

contours cross the trend of topographic contours 

farther to the south suggests that the fault penetrates 

to great depth.

Mineral and Energy Resources of the High Steens 

Wilderness Study Area

The Steens-Pueblo mining district, a 40-mi-long, 

2- to 3-mi-wide, epithermal base- and precious-metal 

(gold, copper, and mercury) mineralized belt, lies along 

the steep east escarpment of the Steens-Pueblo 

Mountains fault block (Ross, 1942; Williams and 

Compton, 1953; Bradley, 1982) and overlaps the 

southeastern part of the High Steens Wilderness Study 

Area. The localization of the mineralized belt along 

the range-front fault zone and the common presence 

of ore and gangue minerals as veins and fracture 

coatings indicate that the mineralization was 

structurally controlled.

Gold, Mercury, and Uranium

Reported mining activity, geologic 

investigations, the study of mines and prospects, and 

geochemical anomalies indicate mercury and uranium 

mineralization has affected the southeastern part of 

the High Steens Wilderness Study Area (fig. 2). 

Anomalous concentrations of uranium as well as the 

gold-indicator elements arsenic, barium, and 

molybdenum are spatially associated with mercury. 

Most of the mineralization was confined to northwestto northeast-trending fracture, shear, gouge, and 

breccia zones and dikes within the older rhyolitic 

extrusive and tuffaceous rocks of the Pike Creek and 

Alvord Creek Formations (Williams and Compton, 

1953; Wilkerson, 1958; Peterson, 1969). The structural 

zones are likely related to the concealed Steens 

Mountain range-front fault zone located along the base 

of the east escarpment. Veins, fracture coatings, and 

disseminations within these zones are the most 

common modes of occurrence of the metallic 

minerals. Wall rocks near the mineralized veins and 

fractures are typically silicified and argillized and 

locally have undergone kaolinization. Platy rhyolite 

flows near the base of the Pike Creek Formation also 

show effects of acid leaching.

Mercury commonly is present as cinnabar and is 

accompanied by quartz, chalcedony, opal, limonite, 

and (or) clay gangue (Ross, 1942; Williams and 

Compton, 1953; Wilkerson, 1958). Uranium generally 

exists as autunite or torbernite and is accompanied by 

the molybdenum-bearing mineral ilsemannite (minor) 

and iron-manganese oxides in a clay and (or) silica 

gangue (Matthews, 1955 and 1956; Gray and others, 

1983).

The anomalous suite of gold-indicator elements, 

sporadic gold values (see sample data, Appendix 2), 

mercury deposits, and alteration types present in the 

Pike Creek Formation strongly suggest that 

undiscovered epithermal gold deposits may exist in or 

beneath the southeasternmost part of the High Steens 

Wilderness Study Area. The lack of observed free gold 

other than minute grains in a few stream-sediment 

samples suggests that any undiscovered gold is

A10
disseminated and (or) below the surface.

Some dikes belonging to the Steens Basalt that 

intrude mineralized rocks of the Pike Creek Formation 

are altered or mineralized (Williams and Compton, 

1953), indicating that mineralization occurred after 

the eruption of the 15.5-Ma Steens Basalt. 

Mineralized zones located along north-trending faults 

and related structures that displace the Steens Basalt 

suggest that some mineralization occurred during or 

after major block faulting, possibly as late as 9.3 Ma.

A mineral-deposit model is suggested for the 

southeastern part of the High Steens Wilderness Study 

Area in which epithermal solutions containing 

mercury, uranium, arsenic, barium, molybdenum, 

tungsten, and probably gold permeated range-front 

fault- and dike-related structures, preferentially 

depositing the metals primarily in the Pike Creek 

Formation. The metals could have come from a deep 

source that was penetrated by some of the major 

faults (expressed by large geophysical gradients). Gold 

is inferred to have precipitated mainly below the 

present erosional surface, and disseminated gold 

deposits may exist there.

Sporadic, weak concentrations of mercury, tin, 

silver, and gold were detected by geochemical analysis 

of stream-sediment samples collected on the west 

slope of Steens Mountain. Minor amounts of free gold 

were also seen in some of these samples. No 

mineralized or altered rocks were seen west of the 

Steens Mountain crest within the study area, 

suggesting that the metal concentrations may have 

been derived from now-eroded leakage haloes 

associated with mineralized rocks lying beneath the 

Steens Basalt. Leakage may have occurred along 

north-northeast-trending normal faults, fractures, and 

basalt dikes (fig. 2) from concealed, hydrothermally 

mineralized rocks similar to those of the Pike Creek 

Formation. Alternatively, the metal concentrations 

may reflect high background levels within the Steens 

Basalt and (or) residual anomalies from rocks overlying 

the Steens Basalt that are now eroded.

A high potential, certainty level C, for mercury 

and uranium resources is assigned to an area between 

and including Pike and Indian Creek canyons along the 

margin of the High Steens Wilderness Study Area (fig. 

2). See Appendix 1 for levels of mineral resource 

potential and certainty of assessment. The area is 

characterized by ore mineral concentrations and 

pronounced metalliferous anomalies detected within a 

highly fractured, brecciated, and hydrothermally 

altered zone of the Pike Creek Formation. An 

additional area that has a high potential for uranium 

resources, certainty level C, is present along Little 

Alvord Creek canyon within a fractured and altered 

part of the Pike Creek Formation that contains 

uraniferous minerals and geochemical anomalies; the 

NURE aerial gamma-ray survey (Geodata 

International, 1980) also suggests the presence of 

uranium in this area. A moderate potential, certainty 

level C, for mercury and uranium resources is assigned 

to an area located along most of the east margin of 

the study area south of Mosquito Creek within faulted 

and fractured felsic flows and tuffaceous rocks 

(including some of the large landslide blocks). Weaker 

geochemical anomalies and alteration, and a lack of

mineral occurrences, distinguish this area from those 

with high potential. The U.S. Department of Energy 

(1980, p. 86) considered the entire Pike Creek 

Formation to have "speculative potential" for uranium 

oxide.

Both the areas of high and moderate mercury and 

uranium resource potential described above have 

moderate resource potential, certainty level C, for 

gold, primarily on the basis of minor detrital gold and 

anomalous concentrations of gold-indicator elements 

(mercury, arsenic, molybdenum, and barium). The 

geologic environment there, including the 

forementioned alteration assemblages, is favorable for 

epithermal gold, and epithermal gold deposits exist 

elsewhere in the southern part of the Steens-Pueblo 

mining district (Gray and others, 1983). Anomalous 

elements detected at the sample sites include silver, 

arsenic, barium, and molybdenum and indicate that 

undiscovered gold or mercury deposits might contain 

these commodities as byproducts. The northeasternmost part of the study area is characterized by only 

weak metallic anomalies despite the likely presence of 

fractured rocks of the Steens Mountain range-front 

fault zone underneath and within landslide blocks 

there. A low potential, certainty level B, for mercury, 

uranium, and gold resources is assigned to this area. 

Some samples collected in the High Steens Wilderness 

Study Area west of the range crest contain weak 

concentrations of gold, silver, and mercury. These 

metal values may reflect the presence of mineralized 

silicic volcanic rocks at depth similar to those exposed 

along the southeastern part of the range-front 

escarpment. This part of the High Steens Wilderness 

Study Area has unknown potential, certainty level A, 

for gold, mercury, and uranium resources; any possible 

mineralized zones there are concealed by a 

considerable thickness (2,000-4,000 ft) of the Steens 

Mountain Volcanics and Steens Basalt, preventing 

meaningful mineral resource potential evaluations.

Zeolites

The occurrence of clinoptilolite, a zeolite 

mineral having numerous agricultural and industrial 

uses, within tuffaceous rocks of the Alvord Creek 

Formation (Walker and Repenning, 1965; USBM, 

unpublished data) indicates that favorable geologic 

conditions existed for the formation of zeolites in the 

southeastern part of the High Steens Wilderness Study 

Area. Under such conditions, other silicic volcanic 

glass and tuffaceous rocks of the Alvord Creek and 

Pike Creek Formations presumably would be 

susceptible to zeolitic alteration. However, samples 

collected from the Alvord Creek Formation contain 

relatively low concentrations of clinoptilolite, and 

exposed rocks of both the Alvord Creek and Pike 

Creek Formations typically have undergone 

silicification and (or) argillization rather than 

zeolitization. There is thus little likelihood for 

undiscovered zeolite resources in the areas underlain 

by the Pike Creek and Alvord Creek Formations. Most 

of the southeastern part of the High Steens Wilderness 

Study Area has a low resource potential, certainty 

level C, for zeolite resources (fig. 2).

All
Perlite

Perlite, a hydrated silicic volcanic glass having several 

industrial and agricultural applications, occurs within 

the thin (30 ft average) vitrophyric margins of some of 

the flows within the Pike Creek Formation (Fuller, 

1931; Minor and others, 1986). The perlite resource 

identified along Little Alvord Creek (Appendix 2 and 

fig. 3, No. 1) is contained within the glassy margin of a 

rhyolite dome at the base of the formation; perlitic 

glass may be extensive just a few tens of meters below 

the surface along the dome margin. Nonetheless, the 

area underlain by the Pike Creek Formation 

(southeastern part of the study area) has a low 

potential, certainty level B, for additional 

undiscovered perlite resources (fig. 2). Although there 

are several isolated perlite occurrences in the 

southeastern part of the High Steens Wilderness Study 

Area, they are most likely not voluminous due to the 

generally thin nature of the vitrophyres.

Geothermal Fjiergy

Alvord Hot Springs, a group of springs with an 

average surface temperature of 169° F and flow rate 

of 132 gal/min (White and Williams, 1975), is located 

about 2 mi southeast of the High Steens Wilderness 

Study Area along the base of the Steens Mountain 

range-front escarpment (fig. 2). The source reservoir 

for the hot springs has a mean calculated temperature 

of about 356° F, a calculated volume of about 1.2 mi , 

and can generate 49 megawatts of electrical energy 

over a 30 year period (Muffler, 1979). The presence of 

these and other hot springs and high temperatures 

detected in wells of the Alvord Desert basin indicate 

that the basin is geothermally active, with a potential 

for direct heat utilization and possibly electrical 

power production (Peterson and Brown, 1980). Cleary 

and others (1981) indicated that meteoric waters in the 

region probably have circulated and been heated at 

great depth along some of the major range-bounding 

faults. Geothermal fluids could also conceivably 

percolate upward to shallow depths along branching 

segments of the Steens Mountain range-front fault 

zone at the east edge of the study area. However, no 

hot springs or other indications of recent or active 

geothermal activity exist within the study area. The 

geo thermal energy resource potential of the 

easternmost part of the High Steens study area is 

considered to be low, certainty level B (fig. 2).

Oil and Gas

Available geologic data do not indicate the 

presence of oil and gas resources in or near the High 

Steens Wilderness Study Area. The Tertiary volcanic 

rocks underlying most of the High Steens Wilderness 

Study Area are not sources of hydrocarbons, and the 

basal Alvord Creek Formation, a predominantly 

sedimentary unit exposed adjacent to the east 

boundary, contains only minor and local accumulations 

of carbonaceous (fossil plant) material. There are no 

surficial tar or oil seeps, black shales, or other

evidence of hydrocarbon source beds in exposed parts 

of the formation. The existence of favorable source 

beds in unexposed, stratigraphically lower parts of the 

Alvord Creek Formation is highly speculative. 

Synvolcanic sedimentary strata of similar age exposed 

elsewhere in southeast Oregon that locally contain 

favorable hydrocarbon source rocks (Fouch, 1983; 

Warner, 1980) were likely deposited in basins isolated 

from that of the Alvord Creek Formation. The nearest 

exposed pre-Teriary basement rocks, located about 30 

mi south of the High Steens Wilderness Study Area, 

consist of Mesozoic metamorphic and intrusive rocks 

(Walker and Repenning, 1965), which are unlikely 

sources for hydrocarbons.

In assessing the petroleum potential of 

wilderness lands in Oregon, Fouch (1983) determined 

the High Steens Wilderness Study Area to have "low 

potential" for yielding oil or gas. Wilderness lands 

located in the Alvord Desert basin directly to the east, 

however, were assessed as having "medium 

potential." At present, there are no active oil and gas 

leases nor producing wells in the High Steens 

Wilderness Study Area and surrounding areas.

In consideration of the unfavorable, although 

somewhat limited, geologic evidence regarding the 

presence of hydrocarbon source rocks and the lack of 

oil and gas leases, exploration, and production, the 

High Steens Wilderness Study Area is judged to have 

low potential, certainty level B, for oil and gas 

resources (fig. 2).

Mineral Resources of the Little Blitzen Gorge 

Wilderness Study Area

Gold, Mercury, and Uranium

Sporadic anomalous concentrations of silver and 

mercury were detected in stream-sediment samples 

collected along the Little Blitzen River. Very minor 

detrital gold was also seen in some of these samples. 

No mineralized or altered rocks were observed within 

the study area, suggesting that the metal 

concentrations may have been derived from noweroded leakage haloes associated with mineralized 

rocks underlying the Steens Basalt. Leakage may have 

occurred along north-trending normal faults, fractures, 

and dikes (fig. 2) from concealed, hydrothermally 

mineralized rocks similar to those of the Pike Creek 

Formation. Alternatively, the metal concentrations 

may reflect high background levels within the Steens 

Basalt. The study area has unknown potential, 

certainty level A, for resources of gold, mercury, and 

uranium in epithermal-related deposits; any possible 

mineralized rocks are concealed by approximately 

2,000 to 4,000 ft of rocks of the Steens Basalt and 

Steens Mountain Volcanics, preventing accurate 

mineral resource potential assessments.

Oil and Gas

Available geologic data do not indicate the 

presence of oil and gas resources in or near the Little

A12
Blitzen Gorge Wilderness Study Area. Basalt flows of 

the Steens Basalt underlying most of the Little Blitzen 

Gorge Wilderness Study Area are not sources of 

hydrocarbons. The Alvord Creek Formation, a 

predominantly sedimentary unit exposed along the 

Steens Mountain range-front escarpment that possibly 

extends underneath the Little Blitzen Gorge 

Wilderness Study Area, contains only minor and local 

accumulations of carbonaceous (fossil plant) 

material. There are no surficial tar or oil seeps, black 

shales, or other evidence of hydrocarbon source beds in 

exposed parts of the formation; the existence of 

favorable source beds in unexposed parts of the 

formation is highly speculative. Synvolcanic 

sedimentary strata of similar age exposed elsewhere in 

southeast Oregon that locally contain favorable 

hydrocarbon source rocks (Fouch, 1983; Warner, 1980) 

were likely deposited in basins isolated from that of 

the Alvord Creek Formation. The nearest exposed 

pre-Tertiary basement rocks, located about 35 mi 

south of the study area, consist of Mesozoic 

metamorphic and intrusive rocks (Walker and 

Repenning, 1965) unlikely sources for hydrocarbons.

In assessing the petroleum potential of 

wilderness lands in Oregon, Fouch (1983) determined 

the Little Blitzen Gorge Wilderness Study Area to have 

"low potential" for yielding oil or gas. At present, 

there are no active oil and gas leases nor producing 

wells in the Little Blitzen Gorge Wilderness Study 

Area and surrounding areas.

In consideration of the unfavorable, although 

somewhat limited, geologic evidence regarding the 

presence of hydrocarbon source rocks and the lack of 

oil and gas leases, exploration, and production, the 

Little Blitzen Gorge Wilderness Study Area is judged 

to have low potential, certainty level B, for oil and gas 

resources (fig. 2).

REFERENCES CITED

Baksi, A.K., York, D., and. Watkins, N.D., 1967, Age of 

Steens Mountain geomagnetic polarity 

transition: Journal of Geophysical Research, v. 

72, p. 6299-6308.

Brooks, H.C., 1963, Quicksilver in Oregon: Oregon 

Department of Geology and Mineral Industries 

Bulletin 55, 223 p.

Bradley, Robin, 1982, Mining districts and mineral 

deposits of the Basin and Range Province of 

Oregon: U.S. Geological Survey Open-File 

Report 82-58, 14 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., 94 p., 

Barringer Resources, Inc. available from U.S. 

Bureau of Land Management, Oregon State 

Office, 825 N.E. Multnomah, Portland, Oreg. 

97208 .

Castor, S.B., Mitchell, T.P., and Quade, J.G., 1981, 

Uranium resource evaluation, Vya quadrangle, 

Nevada, Oregon, and California: U.S. 

Department of Energy Open-File Report PGJ135(81), 36 p.

Cleary, John, Lange, I.M., Qamar, A.I., and Krouse, 

H.R., 1981, Gravity, isotope, and geochemical 

study of the Alvord Valley geothermal area, 

Oregon: Summary: Geological Society of 

America Bulletin, v. 92, no. 6, p. 319-322, p. 934- 

962.

Erickson, E.G., and Albee, H.F., 1958, Final report - 

Timber Beast property: Defense Minerals 

Exploration Administration, Final Report DMEA4760, 10 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), p. 23, available through U.S. 

Geological Survey, Branch of Open-File Services, 

Denver, Colo. .

Fouch, T.D., 1983, Petroleum potential of wilderness 

lands in Oregon: U.S. Geological Survey Circular 

902-J, 9 p.

Fryberger, J.S., 1959, The geology of the Steens 

Mountain, Oregon: Eugene, University of 

Oregon, M.S. thesis, 65 p.

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

sequence of Steens Mountain in southeastern 

Oregon: Univeristy of Washington Press, 

University of Washington Publications in 

Geology, v. 3, no. 1, p. 1-130.

Geodata International, Inc., 1980, Aerial radiometric 

and magnetic survey, National Topographic Map, 

Adel, Oregon: U.S. Department of Energy OpenFile Report GJBX-104(80), 149 p.

Gettings, M.E., and Blank, H.R., 1974, Structural 

interpretation of aeromagnetic and gravity data 

from Steens Mountains, Oregon abs. : 

Transactions of the American Geophysical Union, 

EOS, v. 55, no. 5, p. 557.

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.

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

in the determination of mercury by cold vapor 

atomic absorption: Analytical Chemistry, v. 48, 

no. 1, p. 136-139.

Lawrence, R.D., 1976, Strike-slip faulting terminates 

the Basin and Range Province in Oregon: 

Geological Society of America Bulletin, v. 87, 

no. 6, p. 846-850.

Lewis, Alvin, 1982, Gold geochemistry: Engineering 

and Mining Journal, v. 183, no. 12, p. 56-60.

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

1985, The Steens Mountain (Oregon) geomagnetic 

polarity transition 1. Directional history, 

duration of episodes, and rock magnetism: 

Journal of Geophysical Research, v. 90, no. B12, 

p. 10,393-10,416.

Matthews, T.C., 1955, Oregon radioactive discoveries 

in 1954 and 1955: Ore Bin, v. 17, no. 12, p. 87- 

92.

____1956, Radioactive occurrences in Oregon, 1956:

A13
Ore Bin, v. 18, no. 12, p. 105-107.

Meyers, A.T., Haven, R.G., and Dunton, P.J., 1961, A 

spectrochemical method for the semiquantitative 

analysis of rocks, minerals, and ores: U.S. 

Geological Survey Bulletin 1084-1, p. 207-229.

Minor, S.A., Rytuba, J.J., Grubensky, M.J., Vander 

Meulen, D.B., Goeldner, C.A., and Tegtmeyer, 

K.J., 1987, Geologic map of the High Steens and 

Little Blitzen Gorge Wilderness Study Areas, 

Harney County, Oregon: U.S. Geological Survey 

Miscellaneous field Studies Map MF-1876, scale 

1:24,000.

Muffler, L.J.P., ed., 1979, Assessment of geothermal 

resources of the United States 1978: U.S. 

Geological Survey Circular 790, 163 p.

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

antimony, arsenic, bismuth, cadmium, copper, 

lead, molybdenum, silver, and zinc in geological 

materials by atomic absorption spectrometry 

using a hydrochloric acid-hydrogen peroxide 

digestion: Atomic Spectroscopy, v. 7, no. 1, 

p. 4-8.

Peters, T.J., and Esparza, L.E., 1986, Mineral 

investigation of the Little Blitzen Gorge Study 

Area, Harney County, Oregon: U.S. Bureau of 

Mines Mineral Land Assessment Open-File 

Report MLA-32-86.

Peterson, N.V., 1969, Uranium, in Mineral and water 

resources of Oregon: Oregon Department of 

Geology and Mineral Industries Bulletin 64, p. 

180-185.

Peterson, N.V., and Brown, D.E., 1980, Preliminary 

geology and geothermal resource potential of the 

Alvord Desert area: Oregon Department of 

Geology and Mineral Industries Open-File Report 

0-80-10, 57 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.

Ross, C.P., 1942, Quicksilver deposits in the Steens 

and Pueblo Mountains, southern Oregon: U.S. 

Geological Survey Bulletin 931-J, p. 227-258.

Rytuba, J.J., and Glanzman, R.K., 1979, Relation of 

mercury, uranium, and lithium deposits to the

McDermitt caldera complex, Nevada-Oregon: 

Nevada Bureau of Mines Report 33, p. 109-117.

Rytuba, J.J., and McKee, E.H., 1984, Peralkaline ashflow tuffs and calderas of the McDermitt 

volcanic field, southeast Oregon and northcentral Nevada: Journal of Geophysical 

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

Thompson, C.E., Nakagawa, H.M., and Van Sickle, 

G.H., 1968, Rapid analysis for gold in geologic 

materials, in Geological Survey Research 1968: 

U.S. Geological Survey Professional Paper 600-B, 

p. B130-B132.

U.S. Department of Energy, 1980, An assessment 

report on uranium in the United States of 

America: U.S. Department of Energy Open-File 

Report GJO-11K80), 150 p.

U.S. Geological Survey, 1972, Aeromagnetic map of 

the Adel and parts of the Burns, Boise, and 

Jordan Valley 1 by 2° quadrangles, Oregon: U.S. 

Geological Survey Open-File Report, scale 

1:250,000.

Walker, G.W., 1969, Geology of the High Lava Plains 

province, in Mineral and water resources of 

Oregon: Oregon Department of Geology and 

Mineral Industries Bulletin 64, p. 77-79.

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.

Warner, M.M., 1980, S. Idaho, N. Nevada, southeastern 

Oregon prime exploration target: Oil and Gas 

Journal, v. 78, no. 18, p. 325-341 (not inclusive).

White, D.E., and Williams, D.L., 1975, Assessment of 

geothermal resources of the United States, 

1975: U.S. Geological Survey Circular 726, 155

P.

Wilkerson, William, 1958, The geology of a portion of 

the southern Steens Mountain, Oregon: Eugene, 

University of Oregon, M.S. thesis, 89 p.

Williams, Howell, and Compton, R.R., 1953, 

Quicksilver deposits of Steens Mountain and 

Pueblo Mountains, southeast Oregon: U.S. 

Geological Survey Bulletin 995-B, p. 19-77.

A14
APPENDIX 1. Definition of levels of mineral resource potential and 

certainty of assessment

Definitions of Mineral Resource Potential

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 unlikely. This broad 

category embraces areas with dispersed but insignificantly mineralized rock as well as areas with few 

or no indications of having been mineralized.

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 a reasonable likelihood of resource accumulation, and (or) where an application of 

mineral-deposit models indicates favorable ground for the specified type(s) of deposits.

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.

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

moderate, or high levels of resource potential.

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

area.

Levels of Certainty

U/A

UNKNOWN

POTENTIAL

H/B

HIGH POTENTIAL

M/B

MODERATE POTENTIAL

L/B

LOW

POTENTIAL

H/C

HIGH POTENTIAL

M/C 

MODERATE POTENTIAL

L/C

LOW

POTENTIAL

H/D

HIGH POTENTIAL

M/D 

MODERATE POTENTIAL

L/D

LOW POTENTIAL

N/D

NO POTENTIAL

o

Q.

B C 

LEVEL OF CERTAINTY

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

B. Available information 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.

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.

A15
GEOLOGIC TIME CHART 

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

EON

-"" y

Phanerozoic

Proterozoic

Archean 

pre-Arc

ERA

Cenozoic

Mesozoic

Paleozoic

Late Proterozoic

Middle Proterozoic

Early Proterozoic

Late Archean

Middle Archean

Early Archean 

;hean 2

PERIOD

Quaternary

Tertiary

Neogene 

Subperiod

Paleogene 

Subperiod

Cretaceous

Jurassic

Triassic

Permian

Carboniferous 

Periods

Pennsylvanian

Mississippian

Devonian

Silurian

Ordovician

Cambrian

 -(3800?)- -

EPOCH

Holocene

Pleistocene

Pliocene

Miocene

Oligocene

Eocene

Pafeocene

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

_ _

AGE ESTIMATES 

OF BOUNDARIES 

(in Ma)

- 0.010 

- 1.7

1 A

oo

_ cc

cc

- 96

 1*3P

one

*> m f\ - ~240

^.*J\J 

****f\ - ~330 

 *?Rn

- 410

- 435

- 500

_ o^CTSYI ~o/u 

_ onn

_ ifinn

 OKnn ZOUU

OlA/U

O"H/U

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

informal time term without specific rank.

A16
Append i 2. Mines, prospects, and claims in and adjacent to the High Steens Wilderness Study Area, Harney County, Oregon 

[* indicates outside the study area; color classification scheme by Munsell Color Co.]

Map No, 

(fig. 3)

Name 

( commodity) Geology Workings and production Sample data

Cinder Cone 

Nos. 1-6 

claims 

(perlite)

Knight Hawk 

No. 1 claim 

(claim No. 6 and 

Rhoads prospect) 

(uranium)

Alvord Uraniun 

Cave claims 

(uranium)

Timberbeast 

Nos. 1-7 cU 

(uranium)

Pike Creek

Carnotite claims 

(uranium)

A perlite flow at least 25 tt thick crops 

out in vicinity of Little Alvord Creek. 

Surrounding flow are outcrops o£ moderatepink (5R 7/4) rhyolite and pale-red (5R 6/2) 

biotite-dacite . Perlite is moderate brown 

(SYR 3/4) to dark gray (N3), moderately 

friable, and contains sporadic silica 

concretions. Perlite flow covers area of 

about 5.0 acres. Located by Lester Rhoads 

on April 1, 1966. Unpublished records of 

BLM (1984) indicate the claims are active.

Iron and manganese oxide-stained, vesicular 

flow-banded, silicitied, white (N9) rhyolite 

cut by fault that strikes N. 30° E., and 

dips 65° W., and has a rake of 58° SW. 

Outcrop appears to be a small extrusive body 

that extends for about 40 ft and is about 24 

ft thick. Lester Rhoads located claim on 

April 4, 1960. Prior to this date, the 

claim was apparently known as Claim No. 6. 

Claim also referred to as Rhoads prospect.

Pale-red (5R b/2) biotite dacite crops out 

along resistent scarp. Isolated, small, 

podlike beds of dark-gray (N3) perlite crop 

out at and near base of the scarp. Dacite 

is slightly kaolinized and manganese and 

iron oxide stained. Joints strike N. 70° W. 

and dip vertically; another set strikes N. 

3° W. and dips 45° E. Two faults were 

identified: the first fault strikes N. 15° 

E. and dips vertically; the second fault 

strikes N. 14° E. and dips 25° E. Claims 

were located by Dewey M. Quier and others on 

August 6, 1955.

Country rock is composed ot moderate-orangepink (19R 7/4) silicified rhyolite; duskyyellow-green (5GY 5/2) silicified dacite; 

and white (N9) to very light gray (N8) 

rhyodacite, which has been intruded by darkgray (N3) to grayish-black (N2) lamprophyre 

dikes. Alteration consists of kaolinization 

and manganese and iron oxide staining. 

Fractures are commonly vertical and strike 

N. 55° E., N. 72° E., N. 30° E., N. 60° W., 

and N. 2U° W. A local fault strikes N. 30° 

W. and dips 75° SE. to vertical. Ceorge 

Slack and others located claims for uranium 

on September 2, 1956. Raymond E. Dick and 

Nell Stockbrand relocated the claims on 

August 20, 1979.

Iron and manganese oxide stains along a 

fault associated with fractures in 

silicified, platy, pale-red-purple (5RP 6/2) 

rhyolite. Silicification exists as 

chalcedony and quartz veinlets that commonly 

parallel flow banding. Fractures also 

locally silicified. Four faults, all 

apparently normal, were recongized: one 

strikes N. 88° W., dips 85° N., and has a 

rake of 80° E.; another strikes N. 25° W. 

and dips 55° W.; a third strikes N. 12° W. 

and dips 72° E.; the fourth strikes N. 3° E. 

and dips 6° b. Uranium minerals not seen. 

Claims were located by Dewey h. Quier and 

others on June 22, 1955.

A narrow, unmaintained, 

road leads to within 1,OOU 

ft of the deposit, which is 

undeveloped.

One adit 24 ft long with a 

20-ft crosscut that extends 

to northwest lies along 

road parallel to Little 

Alvord Creek. Road 

terminates about 300 ft 

beyond adit at a shallow 

bulldozer cut about 50 ft 

in diameter. No record of 

product ion.

A bulldozer-cut road leads 

to within 200 ft of an 

arcuate open cut. Open cut 

spans a distance of 30 ft, 

and averages less than 3 ft 

in depth. No recorded 

production.

Two collapsed adits and 

three bulldozer cuts, two 

of which may serve as part 

of the road system. Lower 

adit has at least 296 ft ot 

crosscuts and drifts; upper 

adit has at least 7U ft of 

workings according to 

Erickson and Albee (1958). 

No recorded production.

Two adits, one of which is 

collapsed, and about 1,000 

ft of bulldozer cuts and 

roads. Open adit has a 

drift 95 ft long with a 

crosscut 30 ft long leading 

to vertical winze and 

manway. Winze and manway 

are at least 75 ft deep, 

lined with and separated by 

cribwork, and presumably 

intersect workings of now 

collapsed adit. No 

recorded production.

All but one of nine random chip 

samples have refractive indices 

of 1.49610.001; the other has an 

index of 1.494±0.001. Average 

analyses from additional 

physical testing: 93 percent 

glass, b.5 percent impurities, 

18.8 lb/tt 3 expanded density, 

90.6 percent furnace yield, and 

60 wt percent nonexpansibles. 

An estimated 400,000 tons of 

perlite classified as marginal 

reserves on property.

One chip sample of rhyolite 

collected. Analysis shows no 

significant metal values. Three 

random chip samples of iron 

oxide stained rhyolite 

average: no detectable gold or

silver, 83 ppm arsenic, 4.3 ppm 

uranium oxide, 40 ppm thoriuir

oxide.

oxide, 40 ppm thorium 

nd 3 percent potassium

Five grab samples of biotite 

dacite contain an average of 3.0 

ppm uranium oxide and 3.7 

percent potassium oxide. One of 

five samples has 45 ppm thorium 

oxide; remaining four samples 

have no thorium above detection 

limit. Radioactivity near the 

claims averages about 30 counts 

per second (cps), with no 

readings 6 reater than two times 

background.

Four grab samples of rhyolite 

average 6.73 ppm uranium oxide, 

29.9 ppm thorium oxide, and 3.88 

percent potassium oxide. Five 

grab samples of dacite average 

20.9 ppm uranium oxide, 26.2 ppm 

thorium oxide, and 4.16 percent 

potassium oxide. Three chip 

samples of dacite average 6.29 

ppm uranium oxide, 86.3 ppm 

thorium oxide, and 4.05 percent 

potassium oxide. A 

scintillometer survey indicated 

an average background count of 

50 cps, with a 90 eps count rate 

at the contact between country 

rock and lamprophyre. Other 

zones of anomalous radioactivity 

are spotty and discontinuous and 

average about 50 cps.

Eighteen chip samples of 

rhyolite, one chip sample of 

quartz, and two chip samples of 

gouge collected. Three rhyolite 

samples average 0.015 ppm gold, 

four average 58 ppm mercury, one 

225 ppm thorium oxide, and three 

average 134 ppm uranium oxide. 

Quartz sample contains 63 ppm 

mercury and 350 ppm 

molybdenum. One 6 ouge sample 

contains 373 ppm uranium 

oxide. Remaining samples 

contained no significant metal 

values.

A17
Appendix 2. Mines, prospects, and claims in and adjacent to the High Steens Wilderness Study Area, Harney County, Oregon Continued

tlap No. 

(fig. 3)

Name 

(commodity) Geology Workings and production Sample data

8*

Steens Mountain Country rock consists of fractured and 

mine (Horse silicified, light-brownish-gray (5YK 6/1) 

Heaven mine) and pale-red (5R 6/2) platy, flow-banded 

(mercury) rhyolite; and light-greenish-gray (5GY 8/1) 

and light-bownish-gray (5YT 6/1) hornblendebiotite rhyodacite. Silicification confined 

to rhyolite and is present as veinlets of 

chalcedony, opal, and drusy, sucrosic 

quartz. Flow bands strike N. 25- 35° W. and 

dip 65° NE. to vertical. Fractures in 

rhyolite strike N. 20° E. and dip 75° SE. 

One of the fractures in largest adit is 

silicified across a zone 3.0 ft wide. 

Fractures in rhyodacite strike about N. 50° 

W. and dip about 80° NW. to vertical. A 

fault in rhyodacite strikes N. 2° E. and 

dips 55° SE. and has a rake of about 80° 

NW. Iron oxide stains fractures in 

rhyolite. Cinnabar exists as coatings in 

fractured rhyolite and in gouge seams along 

fault. Deposit was discovered by Bert Roark 

and Glenn Stephenson in October IVJB 

(Brooks, 1963, p. 193). Most of development 

work was done by Horse Heaven Mines, Inc., 

in 1939-1940.

Red Rock No. 6 Silicified grayish-orange-pink (10R 8/2) to 

claim (mercury) moderate-pink (5R 7/4), platy, flow-banded, 

rhyolite country rock. Fault zone exposed 

in an open cut strikes N. 80° E. and dips 

83° SE. Silicified zones consist of drusy 

and sucrosic quartz veinlets in fault 

breccia and fractures. Three sets of 

fractures: one set strikes N. 65° W. and 

dips steeply southwest; second strikes N. 

50° E. and is vertical; third set strikes N. 

75°-55° E. and dips 50° SE. to vertical. 

Fault zone exposed in one open cut strikes 

N. 80° E. and dips 83° SE. Flow banding 

strikes N. 10°-15° E. and dips 65° SE. to 

80° NU. Cinnabar forms disseminations in 

some quartz, the latter of which is also 

rarely manganese oxide stained. Iron oxide 

stains are absent. Claim notice found near 

workings indicates claim located by Willard 

R. White for Norman C. Wood, on July 11, 

1970. However, workings appear to be much 

older.

Weston mine Country rock moderate-pink (5R 7/4) rhyolite 

(Alexander mine, cut by grayish-black (N2) lamprophyre dike, 

Juniper Mercury both oi which are locally breccia ted and 

mine) silicified. Silicified zones consist of 

(mercury) 0.5- to 2.0-in.-thick calcedony and quartz 

veinlets. Brecciation contined to two sets 

of fractures: one strikes N. 25° E. and 

dips 80° SE., other strikes N. 10° E. and 

dip 70°NW. A sinuous normal fault strikes 

about N. 10° E. to N. 10° W. and dips 

85° W. Quartz commonly present on hanging 

wall. Gouge along fault consists of clay 

mineral beidellite (Williams and Compton, 

1953, p. 72). Cinnabar associated with clay, 

coats rhyolite, and disseminated in 

quartz. Iron oxide stains are localized, 

and form locally botryoidal goethite. Jim 

and Hike Weston acquired the mine and 

surrounding claims from Harry and Don 

Alexander in 1958, who originally located 

the mining claim June 25, 1941, under the 

name Juniper Cinnabar Quartz claim.

Two adits, one open cut, 

and two trenches. One adit 

has 270 ft of drifts and 

crosscuts, one underhand 

stope, and two shallow 

winzes. Other adit is less 

than 10 ft long, but is 

entered through a 20-ftlong open cut. The two 

trenches are about 20 and 

30 ft long. Ruins of two 

small retorts lie about 300 

ft south of the workings. 

Incomplete production 

records indicate that about 

45 flasks of mercury were 

produced through 1961 

(Ross, 1942; Williams and 

Compton, 1953; and Brooks, 

1963).

Two open cuts: one is 10 

ft long and 5 ft wide; 

other is 20 ft long and 4 

ft wide. No recorded 

production.

One adit, two inclined 

shafts, and open cut about 

60 ft long. Adit has about 

250 ft of workings and 

partially parallels 

fault. The two inclined 

shafts are 30 and 50 ft 

deep. The Westons have 

constructed a 1 ton/day 

retort and small jaw 

crusher, which were being 

repaired at time of the 

field work. Records are 

incomplete, but since 1941, 

at least 10 flasks of 

mercury were produced 

(Williams and Compton, 

1953, and Jim and Mike 

Weston, oral commun., 

1984).

Fourteen samples of rhyolite 

collected; seven chip and seven 

grab. Mercury in three chip 

samples ranges between 57 and 75 

ppm and another contains 6,650 

ppm. Gold in six chip samples 

ranged from 0.010 to 0.025 ppm; 

remaining chip sample contains 

0.124 ppm.

Four chips samples of silicified 

rhyolite contain no significant 

metal concentrations. One chip 

sample of silicified fault 

breccia contains 426 ppm 

mercury.

Four chip samples of quartz have 

a weighted average of 58 ppm 

mercury and 0.51 ppm silver. 

One chip sample of rhyolite 

contains 24 ppm mercury and 0.46 

ppm silver. One sample of fault 

gouge contains 170 ppm 

mercury.

A18
Appendix 2. Mines, prospects, and claims in and adjacent to the High Steens Wilderness Study Area, Harney County, Oregon Continued

Map No. 

(fig. 3)

Name 

(commodity) Geology Workings and production Sample data

Last Chance claims 

(mercury)

Jack Pot Nos. 1-9 

claims (No-Hole 

Nos. 1 and 2) 

(mercury)

Alex-Ladd claim 

(uranium)

Steens Nos. 

1-74 claiir 

(uranium)

13* Aile Rouge [sic] 

No. 1 claim 

(mercury)

Sunshine No. 3 

claim (Red Rock 

No. b claim) 

(mercury)

Host rock is silicified, platy, moderatepink (5R 7/4) rhyolite and moderate-orangepink (10R 7/4) to grayish-orange-pink (10R 

8/2) biotite rhyodacite. Host rocks are 

locally brecciated along fractures that 

strike N. 80° W. and dip 85° to 90° N. 

Chalcedony and quartz fill fractures and 

cement breccia. Ironoxide locally stains 

fractures. Mercury minerals not seen. Mike 

T. Weston located the claims on August 29, 

1951.

Country rock consists of grayish-orange-pink 

(10R 8/2) biotite dacite, which is locally 

iron oxide stained and kaolinized(?). Mine 

workings exposed a fracture zone and 

fault. Fracture zone strikes about N. 37° 

W. and dips steeply northeast to vertical. 

Fault strikes N. 20° E. and dips 75° E. to 

vertical. Jack Pot Nos. 1-9 were located by 

Glen Stephenson in March 1955. Z.L. Cook 

relocated two of claims under name No-Hole 

Nos. 1 and 2 on April 24, 1965.

Silicified and iron oxide stained, grayishorange-pink (10R 8/2) to moderate-red (5R 

5/4) brecciated rhyolite. Rock cut by a 

fracture zone that strikes N. 60° E. and 

dips 65° E. Silicification consists mostly 

of chalcedony. Harry Alexander located 

claims on September 25, 1955.

Grayish-orange-pink (10R 8/2) flow-banded 

rhyolite and moderate-orange-pink (10R 7/4) 

flow-banded rhyodacite. Rocks are slightly 

iron oxide stained, partially kaolinized and 

intermittently silicified. Quartz veinlets 

generally are less than 0.10 in. thick, 

rarely vuggy, and translucent. Joints are 

oriented as follows: strike N. 67° W., dip 

79° NE.; strike N. 89° E., dip 72° NW.; 

strike N. 15° E., vertical; and strike N. 

55° W., dip 65° HE. Vertical fault near 

eastern edge(?) of claim group strikes N. 

63° E. Wyoming Minerals located claims on 

April 22, 1977. Recent records indicate 

claims are no longer active.

Grayish-orange-pink (10R 8/2) to moderatepink (5R 7/4), silicified and brecciated 

rhyolite. Breccia associated with two 

faults, one with a strike of N. 35° W., a 

dip of 83° E., and a rake of 17° S., and 

appears to have right lateral separation. 

Other fault appears to be normal, strikes N. 

28° E., dips 64° S., and has a rake parallel 

to dip. Iron oxide staining present along 

northwest-trend ing fault. Claim located by 

W.B. Stewart on August 26, 1942.

Country rock is medium-light-gray (Mb) and 

moderate-orange-pink (10R 7/4), silicified, 

iron oxide stained, flow-banded rhyolite. 

Silicification expressed by quartz-filled 

veinletb. fault adjacent to workings 

strikes N. 83° E., dips b5° SE., and has a 

rake of about 45° E. This mining claim was 

originally located by Rosco A. Officer as 

the Red Rock No. 6 claim in March 1961. 

William R. White relocated claim for 

I.orman C. Wood on July 10, 1970 as Sunshine 

No. 3.

One collapsed adit and 

pit. No recorded 

production.

One open cut 27 ft long by 

3 ft wide and one adit 84 

ft long preceded by a 20- 

ft-long, 4-ft-wide open 

cut . No recorded 

production.

No workings were found. 

Production unknown.

No workings or record of 

production.

No workings or production

Inclined shaft about 15 ft 

deep and about 6 ft wide. 

No recorded production.

One chip sample and one grab 

sample of rhyodacite contain no 

significant metal 

concentrations; three grab 

samples of rhyolite contain as 

much as 5.8 ppm silver, 0.059 

ppm gold, 20 ppm mercury, and 40 

ppm tin.

Two chip samples of biotite 

dacite and one chip sample of 

gouge contain no significant 

metal concentrations.

One grab sample of silicified, 

brecciated rhyolite contains no 

significant metal values and no 

radioactivity greater than a 

background of about 30 cps.

Average background for 

radioactivity is about 30 cps; 

no readings greater than two 

times background were 

observed. Three grab samples of 

rhyolite and two grab samples of 

rhyodacite collected contain no 

significant metal values.

One chip sample of breccia from 

northwest-striking fault 

contains 0.36 ppm silver, 22 ppm 

mercury, and 2.3 ppm uranium 

oxide .

One chip sample of silicified 

rhyolite has 0.014 ppm gold and 

one grab sample of rhyolite has 

65 ppm mercury.

A19
Appendix 2. Mines, prospects, and claims in and adjacent to the High Steens Wilderness Study Area, Harney County, Oregon Continued

Map No. 

(fig. 3)

Name 

immodity) Geology Workings and production Sample data

19

Big Indian mine 

(placer gold)

Buckhorn mine 

(placer gold)

22

Daisy claims 

(gold)

Gold Crown claim 

(placer gold)

Gold Queen claim 

(placer gold)

Head Light mine 

(placer gold)

Homestretch lode 

(placer gold)

Jack Pot claim 

(placer gold)

Shallow gravel veneer along Big Indian Creek 

composed of fine to coarse sand, pebbles, 

and cobbles of andesite and basalt. Claim 

located by John Munch on August 17, 1901.

Big Indian Creek here flows through mediumdark-gray (N4) and brownish-gray (5YR 4/1) 

basalt and brownish-gray (5RY 4/1) andesite 

of the Miocene Steens Mountain Volcanics. 

Claim is in middle of a group of placer 

claims that continue up creek for about 1/2 

mi. T.C. Wright located this claim on 

August 17, 1901.

Moderate-reddish-brown (10R 4/6) to 

moderate-red (5R 4/6) volcanic cinder and 

dark-gray (N3) scoraceous andesite. Cinder 

crops out over an area of less than one 

acre. W.R. Gray and S. Alberson located 

claims on January 22, 1908.

Alluvium composed of sand and gravel derived 

from basalt and andesite. Gus Monroe 

located claim on September 17, 1901.

Small point bar deposit composed of sand and 

gravel derived from basalt and andesites 

that overlie medium-dark-gray (N2) basalt 

bedrock. John X. Williams located claim on 

September 16, 1901.

Gravel bar with volume less than 2 yd 

surrounded by large boulders of vesicular 

basalt. Claim located by Homer Rambo on 

October 10, 1901.

Point bar deposit composed of silt- to 

boulder-sized clasts of basalt and 

andesite. Charles Stacey located claim on 

October 16, 1901.

Small point bar deposits with less than 0.5 

yd of sand and gravel derived from basalt 

and andesite. frank V. Armstrong located 

claim on August 20, 1901.

No workings or record of 

production.

No workings or record of 

production.

According to claim location 

notice, there is a 10 ftdeep shaft; however, it was 

not found during the field 

work in 1984. No record of 

production.

No workings or record of 

production.

No workings or record of 

production.

No workings or record of 

production.

No workings or record of 

production.

No workings or record of 

production.

One placer sample, consisting of 

three level 14-in.-diameter 

pans, contains 0.021 mg gold, a 

trace of garnet, and 2 percent 

black sand.

One placer sample, consisting of 

three level 14-in. pans, 

contains 0.009 mg of fine 

angular gold and 2 percent black 

sand.

One random chip sample of 

volcanic cinder contains no 

significant metal values.

One placer sample, consisting of 

three level 14-in.-diameter 

pans, contains 0.004 mg gold and 

a trace of black sand.

One placer sample, consisting of 

three level 14 in.-diameter 

pans, contains 0.044 mg gold, a 

trace of garnet and scheelite, 

and 2 percent black sand.

One placer sample, consisting of 

three level 14-in.-diameter 

pans, contains 0.002 mg gold, 

trace garnet, and 2 percent 

black sand.

One placer sample consisting of 

two level 14 in. pans contains 2 

percent black sand.

Two placer samples, each 

consisting of three level 14- 

in .-diameter pans, contain a 

trace of garnet and 2 percent 

black sand. One sample has a 

trace of scheelite.

Lady Washington 

claim (placer 

gold)

Miners Dream lode 

(gold)

Small gravel deposit, with a volume of less 

than one cubic yard, overlying bedrock 

(Steens Basalt). George L. Davidson located 

claim on September 17, 1901.

Vesicular, platy, medium-dark-gray (N4) 

basalt cut by an iron oxide stained, darkgray (N3) to grayish-black (N2) lamprophyre 

dike. Dike strikes N. 25° E., is vertical, 

and is adjacent to another vertical dike of 

medium-dark-gray (N4) brecciated basalt that 

strikes N. 5° E. Dikes can be traced 

spordically for at least 1,000 ft. Iron 

oxide staining exists as a coating on 

weathered surface of the dikes. Fractures 

in platy basalt either strike N. 5° W. and 

are vertical, or strike N. 80° E. and dip 

45° NW.; latter are parallel to flow banding 

in basalt. fractures in dikes predominantly 

strike in westerly direction and are 

vertical. Nearby fracture zone that strikes 

N. 37° W. and dips 50° NE cuts palagonite. 

Claim was located by James W. Griffin on 

October 14, 1901.

No workings or record of 

production.

No workings or records of 

production.

One placer sample, consisting of 

three level 14-in.-diameter 

pans, contains a trace of black 

sand.

One chip sample of brecciated 

basalt has no significant metal 

values. A grab sample of 

palagonite has 0.042 ppm gold.

A20
Appendix 2. Mines, prospects, and claims in and adjacent to the High Steens Wilderness Study Area, Harney County, Oregon Continued

Map No. Name 

(fig. 3) (commodity) Geology Workings and production Sample data

25 Ole Olson lode Very pale green (10G 8/2) palagonite(?) tuff No workings or record of A chip sample of dike has no

(gold) with moderate-reddish-brown (10R 4/6) to production. significant metal values. One 

moderate-red (5R 4/6) cinder and volcanic of two grab samples of tuff had 

bombs 1 ft in diameter. Tuff cut by a dark- 0.012 ppm gold and 0.370 ppm 

gray (N3) to grayish-black (N2) vertical silver; other had no significant 

latnprophyre dike that is about 25 ft thick metal values, 

and strikes N. 65° W. Claim was located by 

L.A. Borgstrum on October 16, 1901.

26 Snowbird claim Alluvium consisting of silt- to boulder- No workings or record of Three level 14 in. pans

(placer gold) sized clasts derived from basalt and production. collected along edge of creek 

andesite. Charlie Holtz located claim on has a trace of black sand. 

August 14, 1902.

27 West End claim Alluvium derived from basalt and andesite. No workings or records of Three level 14 in. pans

(placer gold) Harry Brown located the claim on August 17, production. collected from point bar have 2

1901. percent black sand.

A21
GPO 785-048/48033