Mineral Resources of the

Home Creek Wilderness Study Area

Harney County, Oregon

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Chapter C

Mineral Resources of the

Home Creek Wilderness Study Area,

Harney County, Oregon

By DEAN B. VANDER MEULEN, ANDREW GRISCOM, 

HARLEY D. KING, and THOMAS L. VERCOUTERE 

U.S. Geological Survey

PHILLIP R. MOYLE 

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

Any use of trade names and trademarks 

in this publication is for descriptive 

purposes only and does not constitute 

endorsement by the U.S. Geological Survey

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1988

For sale by the

Books and Open-File Reports Section

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Library of Congress Cataloging-in-Publication Data

Mineral resources of the Home Creek Wilderness Study 

Area, Harney County, Oregon.

(Mineral resources of wilderness study areas Steens 

Mountain-Rincon region, Oregon ; ch. C) (U.S. 

Geological Survey bulletin ; 1740)

Bibliography: p.

Supt. of Docs, no.: I 19.3:1740-C

1. Mines and mineral resources Oregon Home Creek 

Wilderness. 2. Home Creek Wilderness (Or.) I. Vander 

Meulen, Dean B. II. Series. III. Series: U.S. Geological 

Survey bulletin ; 1740-C.

QE75.B9 no. 1740-C 557.3 s 88-600266 

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

Bureau of Land Management Study Area

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

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

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

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

of part of the Home Creek Wilderness Study Area (OR-002-085H), Harney County, Oregon.

CONTENTS

Summary Cl

Abstract Cl

Character and setting Cl

Identified resources Cl

Mineral resource potential Cl 

Introduction C3

Area description C3

Previous and present investigations C3 

Appraisal of identified resources C3

History and production C3

Mines, prospects, claims, and mineralized areas C5

Appraisal of mineral resources C5 

Assessment of mineral resource potential C5

Geology C5

Geochemical studies C6

Geophysical studies C7

Mineral resource assessment C7 

References cited C8 

Appendixes

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

Resource/reserve classification Cll

Geologic time chart C12

FIGURES

1. Index map showing location of Home Creek Wilderness Study Area, Harney County, Oregon C2

2. Map showing generalized geology and mineral resource potential of Home Creek Wilderness 

Study Area, Harney County, Oregon C4

Contents

Mineral Resources of the

Home Creek Wilderness Study Area,

Harney County, Oregon

By Dean B. Vander Meulen, Andrew Griscom, Harley D. King, and 

Thomas L. Vercoutere 

U.S. Geological Survey

Phillip R. Moyle 

U.S. Bureau of Mines

SUMMARY

Abstract

Mineral surveys of 22,015 acres of the Home Creek 

Wilderness Study Area (OR-002-085H) were conducted at 

the request of the Bureau of Land Management. In this 

report, the area studied is referred to as the "wilderness study 

area," or simply the "study area." The study area is adjacent 

to the Catlow Rim on the western slope of Steens Mountain 

in southeastern Oregon. Field work was conducted by the 

U.S. Geological Survey during 1986 and 1987 and by the 

U.S. Bureau of Mines during 1986 to evaluate the identified 

mineral resources (known) and the mineral resource potential 

(undiscovered) of the study area.

No mineral resources were identified in the study area. 

However, the study indicates low potential for silver resources in a small area near the central part of the study area, 

moderate potential for sand and gravel resources in lake 

shoreline deposits located within and adjacent to the western 

part of the study area, and low potential for geothermal 

energy throughout the study area. There is no resource 

potential for oil and gas in the study area.

Character and Setting

The Home Creek Wilderness Study Area (fig. 1) is 

located along the crest of the Catlow Rim, approximately 

65 mi south of Burns, Oreg. and 20 mi northwest of Fields, 

Oreg. The Catlow Rim is a composite fault scarp that rises

Manuscript approved for publication June 21, 1988.

1,000 to 1,900 ft above Catlow Valley and forms the entire 

length of the impressive 60-mi-long east valley wall. The 

scarp is the dominant geologic structure in the region and 

forms part of the west margin of the 30- by 90-mi, northtrending Steens Mountain-Pueblo Mountains fault block. 

Most of the study area is located on the Steens Mountain 

dip slope, a gentle west-tilted plateau. Several west-flowing creeks cut the plateau (fig. 1).

The oldest rocks exposed in the study area are basalt 

flows of middle Miocene age (5 to 24 million years before 

present, or Ma; see appendixes for geologic time chart). 

The basalt flows underlie the entire study area and form the 

1,900-ft-high Catlow Rim escarpment (fig. 2). A Miocene 

rhyolite ash-flow tuff overlies the basalt flows in the northern and eastern parts of the study area. The west margin of 

the study area is located in Catlow Valley, a broad irregularly shaped basin. Pleistocene shoreline deposits and 

Holocene dunes are exposed in the valley.

Identified Resources

No mines, claims, prospects, or mineralized zones are 

present, and no mineral or energy resources or occurrences 

are identified within or adjacent to the study area.

Mineral Resource Potential

Part of a stream drainage and adjacent outcrops of ashflow tuff in the east-central part of the study area have low 

potential for silver resources (fig. 2). An anomalous

Mineral Resources of the Home Creek Wilderness Study Area, Harney County, Oregon C1
42°45' -

42°30' -

APPROXIMATE BOUNDARY

OF

HOME CREEK 

WILDERNESS 

STUDY AREA 

(OR-002-085H)

Figure 1. Index map showing location of Home Creek Wilderness Study Area, Harney County, Oregon. 

C2 Mineral Resources of Wilderness Study Areas: Steens Mountain-Rincon Region, Oregon
concentration of silver was recorded in a heavy-mineralconcentrate sample collected down-slope from the rhyolite 

ash-flow tuff. The tuff is part of the Devine Canyon Ashflow Tuff.

Shoreline gravel bar deposits located 12 mi south of 

the study area have been utilized for aggregate. Bar deposits of the same shorelines form extensive terraces along the 

base of Callow Rim within the western part of the study 

area (fig. 2). The bar deposits have moderate potential for 

sand and gravel resources.

Geothermal springs were not identified in or near the 

study area, although low-temperature geothermal springs 

that issue from fault zones 12 mi north of the study area do 

have potential for direct-heat application. Geologic structures such as recently active fault zones capable of producing geothermal energy may exist in the study area. The 

study area has low potential for geothermal energy. There 

is no oil and gas potential in the study area.

INTRODUCTION

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

of Land Management and is a joint effort by the U.S. 

Geological Survey and U.S. Bureau of Mines. An introduction to the wilderness review process, mineral survey 

methods, and agency responsibilities was provided by 

Beikman and others (1983). The U.S. Bureau of Mines 

evaluates identified resources at individual mines and 

known mineralized areas by collecting data on current and 

past mining activities and through field examination of 

mines, prospects, claims, and mineralized areas. Identified 

resources are classified according to a system that is a 

modification of that described by McKelvey (1972) and 

U.S. Bureau of Mines and U.S. Geological Survey (1980). 

Studies by the U.S. Geological Survey are designed to 

provide a reasonable scientific basis for assessing the potential for undiscovered mineral resources by determining 

geologic units and structures, possible environments of 

mineral deposition, presence of geochemical and geophysical anomalies, and applicable ore-deposit models. Mineral 

assessment methodology and terminology as they apply to 

these surveys were discussed by Goudarzi (1984). See 

appendixes for the definition of levels of mineral resource 

potential and certainty of assessment, and for the resource/ 

reserve classification.

Area Description

The Home Creek Wilderness Study Area (OR002-085H) encompasses 22,015 acres in the northern Basin 

and Range physiographic province of southeastern Oregon. 

The study area is located along the east side of Callow 

Valley approximately 14 mi south of Frenchglen, Oreg.

(fig. 1). The study area is accessible by an improved gravel 

road that parallels the west side of Callow Rim and several 

unimproved dirt roads and jeep trails thai approach ihe 

sludy area from ihe north and soulh. Maximum elevation 

in ihe sludy ara is approximately 6,500 ft above sea level 

al ihe southwesl edge, and minimum elevation is aboul 

4,600 ft along the base of Callow Rim. The climale is 

semiarid; Juniper groves are common along Callow Rim 

and in protected canyons, and sage brush and grasses are 

dominani al lower elevations. The sludy area is currenily 

used for cattle grazing.

Previous and Present Investigations

Previous geologic investigations lhat include the sludy 

area are a reconnaissance geologic map of ihe Adel 1° by 

2° quadrangle by Walker and Repenning (1965), an aerial 

radiometric and magnetic survey by the U.S. Departmeni of 

Energy (Geodala International, Inc., 1980), and an aeromagneiic survey by ihe U.S. Geological Survey (1972). 

The U.S. Geological Survey conducted a combined geologic, geochemical, and geophysical survey of the wilderness sludy area during 1986 and 1987. Field investigations 

were focused on correlating geochemical and geophysical 

anomalies wilh rock uniis and geologic slruclures.

Investigations by ihe U.S. Bureau of Mines eniailed 

prefield, field and report-preparation phases during 1986. 

Prefield sludies included library research and perusal of 

Hamey Counly and U.S. Bureau of Land Managemeni 

mining and mineral lease records. Field sludies involved 

searches for mineralized zones wilhin ihe sludy area. 

Ground and aerial reconnaissance were conducted in an 

aliempl lo identify areas of alteration where mining aclivily 

mighi have taken place. Additional information is available from ihe U.S. Bureau of Mines, Western Field Operalions Center, E. 360 Third Avenue, Spokane, WA 99202.

APPRAISAL OF IDENTIFIED RESOURCES

By Phillip R. Moyle 

U.S. Bureau of Mines

History and Production

The Home Creek Wilderness Sludy Area is aboul 10 

mi wesl of the Steens-Pucblo mining district, which lies 

along the east escarpment of the Sleens Mouniain-Pueblo 

Mounlains faull block (Bradley, 1982). Small quantities of 

mercury were produced from ihe district (Ross, 1942; 

Williams and Compton, 1953). A small marginal perlite 

reserve and occurrences of gold, mercury, uranium, molybdenum, and zeolite minerals were noted in or near the High 

Sleens Wilderness Sludy Area (Minor and others, 1987), 

aboul 10 mi easl of ihe Home Creek Wilderness Sludy

Mineral Resources of the Home Creek Wilderness Study Area, Harney County, Oregon C3
119°00'00" 

 I 

118°57'30" 

 I 

118°55'0al 

 \ 

118°52130" 118°50'0a'

42° 

37'30"

42° 

35'00"

42° 

32'30"

42° 

30'00"

'MIC S, G

Qls

APPROXIMATE BOUNDARY

OF

HOME CREEK

WILDERNESS STUDY AREA

(OR-002-085H)

Ag

Geo

S.G

Qls 

Tdt 

Ts

L/B Geo 

(entire study area)

EXPLANATION

Area having moderate resource 

potential (M)

Area having low resource 

potential (L)

Levels of certainty of assessment 

Data only suggest level of

potential 

Data give good indication of

level of potential

Commodities

Silver

Geothermal energy 

Sand and gravel

Geologic map units

Lake shoreline deposits and sand 

dunes (Quaternary)

Devine Canyon Ash-flow Tuff 

(upper Miocene)

Steens Basalt (middle Miocene) 

Contact

Fault-Dashed where approximate; dotted 

where concealed. Bar and ball on 

downthrown side

M/C S, G

2 MILES 

J

Figure 2. Generalized geologic map and mineral resource potential of Home Creek Wilderness Study Area, Harney County, 

Oregon.

C4 Mineral Resources of Wilderness Study Areas: Steens Mountain-Rincon Region, Oregon
Area. Within the past 5 years, a company exploring for 

epithermal gold deposits has conducted reconnaissance 

sampling on the western flank of Steens Mountain (George 

Brown, written commun., 1986). However, no claims have 

been located, no mineral production has been recorded, and 

no workings were in evidence in or adjacent to the study 

area.

Mines, Prospects, Claims, and Mineralized 

Areas

No mine or prospect workings are present, and no 

mineralized areas were found within or near the study area. 

Furthermore, no gold was recovered from eight 

reconnaissance placer samples taken by the U. S. Bureau of 

Mines from drainages within and adjacent to the study area. 

Stream-sediment samples, partially concentrated in the 

field, were further concentrated on a laboratory-sized 

Wilfley table to separate heavy minerals, such as gold, 

from a lower density gangue. The concentrates were 

scanned with a binocular microscope to determine heavymineral content. Concentrates were also checked for 

radioactivity and fluorescence.

In the nearby Steens-Pueblo mining district, Erikson 

and Curry (1977) examined uranium prospects and observed that concentrations of oxidized uranium occur in 

narrow zones in and adjacent to rhyolite breccias and rhyolite dikes in the Pike Creek Formation (Walker and Repenning, 1965). These occurrences are possibly associated 

with high-angle fracture zones. Although Erikson and 

Curry (1977) noted that uranium surface shows are "* * * 

weak, small, and sporadic," they also concluded that significant uranium mobilization had taken place. Uraniumbearing formations are not known to crop out, and no 

anomalous radioactive emissions were detected in the vicinity of high-angle faults in or near the Home Creek 

Wilderness Study Area.

Three low-temperature geothermal springs that lie 

along the flanks of the Blitzen Valley, about 12 mi north of 

the study area, range in temperature from 78 to 89 °F and 

produce from 100 to 1,800 gallons of water per minute that 

is used for livestock and irrigation (Waring, 1965). The 

Oregon Department of Geology and Mineral Industries 

(1982) classified the area around the springs as "* * * 

known or inferred to be underlain at shallow depth (less 

than 350 ft) by thermal water of sufficient temperature for 

direct heat applications." No geothermal springs are 

known to emanate from structures in or near the study area.

Oil and gas leases issued in 1982-83 for most of the 

study area were terminated in 1984-85. Lands in wilderness study areas of the Steens Mountain region were 

assessed by Fouch (1983) as having low potential for petroleum resources; however, no geologic structures favorable 

for oil and gas are known to underlie this study area.

Appraisal of Mineral Resources

There are no identified mineral or energy resources or 

occurrences in the Home Creek Wilderness Study Area, 

and the host formations and depositional environment of 

the metallic and industrial minerals of the High Steens 

Wilderness Study Area (Minor and others, 1987) are not 

known to be present within or adjacent to this study area 

(Moyle, 1987).

ASSESSMENT OF MINERAL RESOURCE 

POTENTIAL

By Dean B. Vander Meulen, Andrew Griscom, 

Harley D. King, and Thomas L. Vercoutere 

U.S. Geological Survey

Geology

The Home Creek Wilderness Study Area is located 

along the west slope of Steens Mountain. Most of the 

slope, including the study area, is underlain by middle 

Miocene Steens Basalt (Piper and others, 1939; Baksi and 

others, 1967). Strata within the study area consistently dip 

2° to 6° to the west, although direction and angle of dip 

vary greatly near the larger fault zones. In the study area, 

the Steens Basalt is made up of a thick, chemically homogeneous sequence of basalt flows that are typically 20 to 30 

ft thick. Near the southern part of the study area along the 

Callow Rim escarpment (fig. 2), the Steens Basalt has a 

minimum thickness of 1,900 ft; the base of the basalt unit 

is not exposed in the study area.

Along the north boundary of the study area in the 

canyon of Roaring Springs Creek (fig. 2), exposures of the 

Steens Basalt are unconformably overlain by an ash-flow 

tuff. Whole-rock and trace-element data (Hildreth, 1981) 

indicate that the tuff is probably correlative with part of the 

Devine Canyon Ash-flow Tuff, dated at 9.2 Ma (Walker, 

1979). In this study area the tuff has a maximum thickness 

of about 50 ft. Isolated exposures of the Devine Canyon 

Ash-flow Tuff are also present in the southeast and central 

parts of the study area. Near the southeast boundary, 

exposures of the welded tuff typically form a pattern of low 

flat-topped ridges that probably reflect an inversion of 

paleotopography; that is, the welded tuff filled paleo-stream 

channels or depressions and was later exposed by preferential erosion of the surrounding rock. Exposures of the tuff 

in the study area represent distal facies of a caldera-forming 

ash-flow tuff eruption. Walker (1970) and Greene (1973) 

indicate that the Devine Canyon Ash-flow Tuff erupted 

from a caldera located within the Harney Basin, 50 mi 

north of the study area.

West of the Callow Rim is the Callow Valley, a large 

irregular-shaped graben formed by basin and range

Mineral Resources of the Home Creek Wilderness Study Area, Harney County, Oregon C5
extensional tectonism. During the Pleistocene, the valley 

was filled by Callow Lake. Along the west boundary of the 

study area, wave-cut benches and shoreline deposits formed 

on Callow Rim at various lake levels. The highest 

shoreline deposil is 4,795 ft above sea level, about 250 ft 

above the present valley floor. At least five major 

shorelines are exposed along the western part of the rim. 

The shorelines consist of beach and bar deposits and wavecut benches. Delta deposits form part of the shoreline 

where larger streams entered Callow Lake. Shoreline 

deposits consist of partly sorted to sorted sand and gravel.

Patterned ground features, common in colluvium east 

of Callow Rim, are probably Ihe result of a combination of 

joinl cracking, frost heave, mass wasting, and wind erosion 

(Ritter, 1978, p. 447). In the western part of Ihe sludy area 

Holocene talus deposils locally cover large parts of the 

lower Catlow Rim escarpment. Along ihe base of Ihe 

escarpmeni, lake shorelines are partly concealed by these 

deposits. Streams draining the western part of the study 

area have breached and eroded some of the shoreline bars, 

and in other locations alluvial stream deposits have buried 

the shorelines. South of the sludy area, dunes are common 

along the valley floor. Dunes 8 mi soulh of the study area 

show several episodes of migration during the Holocene. 

Ancient artifacts are preserved in these dunes along with al 

leasl iwo major air-fall luffs from Mounl Mazama, dated at 

0.007 Ma (Mehringer and Wigand, 1984).

Three separate fault-set directions are recognized in the 

Home Creek Wilderness Study Area. The oldest and most 

conspicuous set is the northwest-trending range-front fauli 

zone and parallel faults located along the base of the Catlow Rim escarpment (fig. 2). A second set of normal faulls 

bounds a small north-trending graben in the northern part 

of the sludy area. The ihird and youngesl sel of normal 

faults strikes N. 60°-70° W. and parallels fauli-conlrolled 

drainage canyons in the west-ceniral part of ihe sludy area.

The youngest faults truncate the norlh-lrending graben 

(fig. 2) located in the northern part of the study area and are 

subparallel to a large fault-disrupted monocline thai forms 

the western escarpment of the High Steens fault block 9 mi 

northeast of the study area. The monocline and associated 

normal faults are considered to be part of the southern 

section of the Brothers fault zone, a deep-seated regional 

shear zone (Walker, 1969; Minor and others, 1987).

Geochemical Studies

In 1986-87, the U.S. Geological Survey conducted a 

reconnaissance geochemical study of the Home Creek 

Wilderness Study Area. The study included the collection 

and analysis of 15 rock samples, 27 stream-sediment 

samples, and 27 nonmagnetic heavy-mineral-concentrale 

samples from stream sediment. Stream-sediment samples 

and stream sediments from which the concentrates are

derived were collected from active alluvium in stream 

channels.

Stream sediments represent a composite of rock and 

soil eroded upstream from the sample-collection sites. 

Nonmagnetic heavy-mineral concentrate samples provide 

information aboul the chemistry of rock material eroded 

from the drainage basin upstream from the sample-collection siles. The nonmagnetic fraction of heavy-mineral 

concentrates may contain many ore-forming or ore-related 

minerals. Selective concentration of minerals permits determination of some elements thai are nol easily detected in 

bulk stream-sedimenl samples. Most rock samples appeared fresh and unaltered and were collected to provide 

information on geochemical background concentrations. A 

few of the rock samples appeared altered and possibly 

mineralized; ihese were collected to determine the suite of 

elements associated with the observed alteration or mineralization.

All of the stream-sedimenl samples and heavy-mineral 

concentrates and four of the rock samples were analyzed 

semiquantitalively for 31 elements by using the direclcurrenl arc emission speclrographic melhod (Grimes and 

Marranzino, 1968). Eighi of the rock samples were analyzed for 43 elements by using a similar melhod. Slreamsedimenl samples and four of the rock samples were also 

analyzed by inductively coupled argon plasma alomicemission speclroscopy (ICAP-AES) for antimony, arsenic, 

bismulh, cadmium, and zinc and by atomic absorption for 

gold and mercury (Crock and others, 1987). Analytical 

data are by M.S. Erickson (written commun., 1987).

An anomalous concentration of silver (20 parts per 

million, or ppm) was detected in a nonmagnetic heavymineral-concentrale sample collected down slope from ihe 

Devine Canyon Ash-flow Tuff in ihe easl-central part of 

the study area. The anomalous concentration may indicate 

silver mineralization associated wilh Ihe ash-flow tuff or 

with faults and fractures within the luff. An association 

belween silver anomalies in siream-sedimenl samples and 

Ihe ash-flow luff is recorded in ihe Rincon Wilderness 

Sludy Area, 14 mi soulh of the study area (Vander Meulen 

and others, 1988). No additional silver anomalies were 

detected in the study area.

Silver and silver-bearing minerals were not observed in 

the concentrate during microscopic examination. The 

sample contained iron oxide, a possible source of the silver. 

Iron oxides may become enriched in various melals, including silver, by adsorption or coprecipiiation. Faults or fracture zones are possible avenues along which fluids may 

have migrated upward and precipitated mineral grains 

containing silver. Locations and trends of faults mapped in 

the region (fig. 2) suggest that a buried fault may be present.

On the basis of the size of the silver anomaly (20 

ppm), ihe absence of detected silver in other samples in the

C6 Mineral Resources of Wilderness Study Areas: Steens Mountain-Rincon Region, Oregon
area, and the absence of detected anomalous concentrations 

of elements commonly associated with silver, we believe 

that the anomaly does not reflect a deposit of silver occurring at the surface in the Home Creek Wilderness Study 

Area. The silver anomaly could, however, reflect more 

mineralized rock at depth.

An anomalous concentration of lead in a nonmagnetic 

heavy-mineral-concentrate sample is probably due to a lead 

artifact, such as a bullet fragment. No other elements were 

detected in anomalous concentrations in these or other 

concentrate samples. No notably anomalous concentrations 

of ore-related elements were detected in stream-sediment 

samples collected in the Home Creek Wilderness Study 

Area.

Geophysical Studies

Geophysical investigation of the Home Creek Wilderness Study Area consisted of three kinds of geophysical 

surveys: aeromagnetic, gravity, and aerial gamma-ray spectrometer.

A regional aeromagnetic survey was flown over the 

study area (U.S. Geological Survey, 1972). Data were 

collected along parallel east-west flightlines spaced at 2-mi 

intervals and flown at a constant barometric elevation of 

9,000 ft above sea level. Additional aeromagnetic data are 

available in the atlas on the Adel 1° by 2° quadrangle 

published for the Department of Energy (Geodata International, Inc., 1980). These data consist of east-west profiles 

spaced at 3-mi intervals and flown at an average height of 

400 ft above the ground surface. Five of these profiles cross 

the wilderness study area.

Magnetic minerals, where locally concentrated or absent, may cause a high or low magnetic anomaly that can 

be a guide to mineral occurrences or deposits. Boundaries 

between magnetic and less magnetic rock units are located 

approximately at the steepest gradient on the flanks of the 

magnetic anomaly. The majority of the anomalies in the 

study area are probably caused by the preponderance of 

lava flows and other volcanic rocks because these rocks 

characteristically have high magnetic susceptibility. The 

major magnetic feature in the study area is a linear low 

extending over, and parallel to, the Callow Rim. This 

magnetic anomaly is likely caused by the topographic effect of the 1,900-ft scarp at the valley rim. The low may 

also reflect a reversely magnetized section of Steens Basalt 

(Mankinen and others, 1985).

A gravity survey of the general area was conducted by 

the U.S. Geological Survey in 1986 to supplement available 

data from the National Geophysical Data Center, Boulder, 

Colo., 80303. Station spacing ranged from about 3 to 5 mi, 

and nine stations are situated within or on the border of the 

study area. The data display a poorly defined gravity 

gradient that slopes down into a gravity low associated with 

Callow Valley, probably caused by low-density sedimentary deposits filling the valley. The steepest part of the 

gradient is located over the range-front fault zone at the 

base of the Callow Rim escarpment.

Radiometric data were collected and compiled by 

Geodata International, Inc. (1980) for the National Uranium Resource Evaluation (NUKE) program of the Department of Energy. Aerial gamma-ray spectrometer measurements were made along east-west flight lines spaced at 3- 

mi intervals. The recorded flight altitudes generally range 

from 200 to 400 ft above the ground. Recordings were 

made of gamma-ray flux from radioactive isotopes of uranium, thorium, and potassium or their decay products. 

Abrupt shifts of recorded flux level occur over geologic 

contacts. Results indicate that statistically significant 

anomalies of uranium, potassium, and thorium are not 

present within the study area.

Mineral Resource Assessment

Part of a stream drainage and adjacent outcrops of ashflow tuff in the east-central part of the study area have low 

potential for silver resources, certainty level B (fig. 2). A 

heavy-mineral-concentrate sample collected from the drainage contains anomalous concentrations of silver. The 

Devine Canyon Ash-flow Tuff is exposed on a ridge 400 ft 

west of, and up-slope from, the sample site. An association 

between silver anomalies in stream-sediment samples and 

anomalous concentrations of silver in the same ash-flow 

tuff is observed in the Rincon Wilderness Study Area, 10 

mi south of this study area.

Pleistocene lake shoreline deposits located within and 

adjacent to the western part of the study area have moderate 

potential for sand and gravel resources, certainty level C 

(fig. 2). Similar deposits along the same shoreline 12 mi 

south of the study area constitute gravel resources.

Geothermal hot springs issue from north- and northwest-trending fault zones 12 mi north of the study area. 

Similar faults zones are located in the western and central 

parts of the study area and east of the study area. The fault 

zones and areas surrounding them include most of the 

study area; therefore, the entire study area has low potential, certainty level B, for geothermal energy.

Tertiary volcanic rocks underlying the Home Creek 

Wilderness Study Area are not sources of hydrocarbons. 

Furthermore, geologic structures favorable for the production of oil and gas are not known to underlie the study area. 

Pre-Tertiary basement rocks exposed about 25 mi south of 

the study area are Mesozoic metamorphic and intrusive 

rocks (Walker and Repenning, 1965; Roback and others, 

1987) and are unlikely sources for hydrocarbons. The 

absence of rocks capable of producing hydrocarbons and 

the minimal probability that such rocks exist at depth indicate that the study area has no potential for oil and gas, 

certainty level D.

Mineral Resources of the Home Creek Wilderness Study Area, Harney County, Oregon C7
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. 6,299-6,308.

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

Edward, J.R., 1983, Mineral surveys by the Geological Survey and the Bureau of Mines of Bureau of Land Management 

Wilderness Study Areas: U.S. Geological Survey Circular 

901, 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.

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

Analytical methods for the analysis of stream sediments and 

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

Open-File Report 87-84, 35 p.

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

uranium favorability of Tertiary rocks, southeastern Oregon; 

eastern Klamath, southern Lake, Harney, and western 

Malheur Counties: Grand Junction, Colo., Bendix Field Engineering Corp. report for U.S. Energy Research and Development Administration under contract No. EY-76-C13-1664, 

issued as U.S. Department of Energy Open-File Report 

GJBX-92(77), 18 p.

Fouch, T.D., 1983, Petroleum potential of wilderness lands, Oregon: U.S. Geological Survey Miscellaneous Investigations 

Series Map 1-1544, scale 1:1,000,000.

Geodata International, Inc., 1980, Aerial radiometric and magnetic survey, National Topographic Map, Adel, Oregon [1° by 

2° sheet; National Uranium Resource Evaluation Program]: 

U.S. Department of Energy Open-File Report GJBX-104 

(80), v. 2, 145 p.

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

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

Report 84-787, 51 p.

Greene, R.C., 1973, Petrology of the welded tuff of Devine 

Canyon, southeastern Oregon: U.S. Geological Survey Professional Paper 797, 26 p.

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

alternating-current spark emission spectrographic field methods for the semiquantitive analysis of geologic materials: U.S. 

Geological Survey Circular 591, 6 p.

Hildreth, Wes, 1981, Gradients in silicic chambers; implications 

for lithospheric magmatism: Journal of Geophysical Research, 

v. 86, no. Bll, p. 10,153-10,192.

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.

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

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

Mehringer, P.J., Jr., and Wigand, P.E., 1984, Holocene history of 

Skull Creek dunes, Catlow Valley, southeastern Oregon, 

U.S.A.: Journal of Arid Environments, 11, 117-138.

Minor, S.A., Plouff, Donald, Esparza, L.E., and Peters, T.J., 1987,

Mineral resources of the High Steens and Little Blitzen Gorge 

Wilderness Study Areas, Harney County, Oregon: U.S. Geological Survey Bulletin 1740-A, 21 p.

Moyle, P.R., 1987, Mineral resources of the Home Creek Wilderness Study Area, Harney County, Oregon: U.S. Bureau of 

Mines Open-File Report MLA 58-87, 13 p..

Myers, 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.

Oregon Department of Geology and Mineral Industries, 1982, 

Geothermal resources of Oregon: National Oceanic and 

Atmospheric Administration, National Geophysical Data 

Center map, produced for U.S. Department of Energy, scale 

1:500,000.

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

Geology and ground-water resources of the Harney Basin, 

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

189 p.

Ritter, D.F., 1978, Process geomorphology: Dubuque, Iowa, Wm. 

C. Brown Co., 603 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.

Roback, R.C., Vander Meulen, D.B., King, H.D., Plouff, Donald, 

Munts, S.R., and Willett, S.L., 1987, Mineral resources of the 

Pueblo Mountains Wilderness Study Area, Harney County, 

Oregon and Humboldt County, Nevada: U.S. Geological 

Survey Bulletin 1740-B, 30 p., scale 1:48,000.

U.S. Bureau of Mines and U.S. Geological Survey, 1980, Principles of a resource/reserve classification for minerals: U.S. 

Geological Survey Circular 831, 5 p.

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

parts of the Bums, Boise, and Jordan Valley 1° by 2° quadrangles, Oregon: U.S. Geological Survey open-file report, 

scale 1:250,000.

Vander Meulen, D.B., Plouff, Donald, King, H.D., and Mayerle, 

R.T., 1988, Mineral Resources of the Rincon Wilderness 

Study Area, Harney County, Oregon: U.S. Geological Survey 

Bulletin 1740-E, 26 p.

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.

 1970, Cenozoic ash-flow tuffs of Oregon: The Ore Bin, v. 

32, no. 6, p. 97-115.

-1979, Revisions to the Cenozoic stratigraphy of Harney

Basin, southeastern Oregon: U.S. Geological Survey Bulletin 

1475, 35 p.

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.

Waring, G.A., 1965, Thermal springs of the United States and 

other countries of the world, a summary: U.S. Geological 

Survey Professional Paper 492, 383 p.

Williams, Howel, 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.

C8 Mineral Resources of Wilderness Study Areas: Steens Mountain-Rincon Region, Oregon
APPENDIXES
DEFINITION OF LEVELS OF MINERAL RESOURCE POTENTIAL 

AND CERTAINTY OF ASSESSMENT

LEVELS OF RESOURCE POTENTIAL

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

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

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

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

have been active in at least part of the area.

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

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

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

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

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

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

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

been mineralized.

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

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

moderate, or high level of resource potential.

LEVELS OF CERTAINTY

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

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

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

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

hZ

UJ

o

Q_

UJ

U

u_

o

A

U/A

UNKNOWN POTENTIAL

B

H/B

HIGH POTENTIAL

M/B

MODERATE POTENTIAL

L/B

LOW POTENTIAL

C

H/C

HIGH POTENTIAL

M/C

MODERATE POTENTIAL

L/C

LOW POTENTIAL

D

H/D

HIGH POTENTIAL

M/D

MODERATE POTENTIAL

L/D

LOW POTENTIAL

N/D

NO POTENTIAL

LEVEL OF CERTAINTY

Abstracted with minor modifications from:

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

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

Geological Survey Bulletin 1638, p. 40-42. 

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

C10 Mineral Resources of Wilderness Study Areas: Steens Mountain-Rincon Region, Oregon
RESOURCE/RESERVE CLASSIFICATION

ECONOMIC

MARGINALLY 

ECONOMIC

SUBECONOMIC

IDENTIFIED RESOURCES

Demonstrated

Measured

Rese

Indicated

jrves

Marginal 

Reserves

Demonstrated 

Subeconomic 

Resources

Inferred

Inferred 

Reserves

Inferred 

Marginal 

Reserves

Inferred 

Subeconomic 

Resources

UNDISCOVERED RESOURCES

Probability Range

Hypothetical Speculative

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

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

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

Mineral Resources of the Home Creek Wilderness Study Area, Harney County, Oregon C11
GEOLOGIC TIME CHART

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

EON

Phanerozoic

Proterozoic

pre-Archean2

ERA

Cenozoic

Mesozoic

Paleozoic

Late Proterozoic

Middle Proterozoic

Early Proterozoic

Late Archean

Middle Archean

Early Archean

PERIOD

Neogene

Subperiod

Tertiary

Paleogene 

Subperiod

Jurassic

Triassic

Permian

Pennsylvanian 

Carboniferous

Periods ...,_..._...

Mississippian

Devonian

Silurian

Ordovician

Cambrian

/T or\f\7\

EPOCH

Holocene

Pleistocene

Pliocene

Miocene

Oligocene

Eocene

Paleocene

Late

Early

Late 

Middle 

Early

Late 

Middle 

Early

Late 

Early

Late 

Middle 

Early

Late 

Early

Late 

Middle 

Early

Late 

Middle 

Early

Late 

Middle 

Early

Late 

Middle 

Early

AGE ESTIMATES OF 

BOUNDARIES IN 

MILLION YEARS (Ma)

 0.010

 1.7

 5

T A

OO

55

 66

 96 

1 in

205

 290 

-330

 .. - irn

 410

 435

~ J/ U

1 bUU

 3400

 jiccn 

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

informal time term without specific rank.

C12 Mineral Resources of Wilderness Study Areas: Steens Mountain-Rincon Region, Oregon

GPO 585-045/9763
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