Mineral Resources of the Green water 

Valley Wilderness Study Area, 

Inyo County, California

U.S. GEOLOGICAL SURVEY BULLETIN 1709-B

^#3**"

Chapter B

Mineral Resources of the

Greenwater Valley Wilderness Study Area,

Inyo County, California

By AUGUSTUS K. ARMSTRONG, MICHAEL T. GARRISON, 

JAMES G. FRISKEN, and ROBERT C. JACHENS 

U.S. Geological Survey

RICHARD L. RAINS 

U.S. Bureau of Mines

U.S. GEOLOGICAL SURVEY BULLETIN 1709

MINERAL RESOURCES OF WILDERNESS STUDY AREAS: 

NORTHEASTERN CALIFORNIA DESERT CONSERVATION AREA
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 Greenwater Valley Wilderness 

Study Area, Inyo County, California.

U.S. Geological Survey Bulletin 1709-B

Bibliography included.

Supt. of Docs. No.: I 19.3:1709-6

1. Mines and mineral resources California Greenwater

Valley Wilderness. 2. Geology California Greenwater

Valley Wilderness. 3. Greenwater Valley Wilderness

(Calif.) I. Armstrong, Augustus K. II. Series.

QE75.B9 No. 1709-B 557.3 s 86-600234

[TN24.C2] [553'.09794'87]
STUDIES RELATED TO WILDERNESS

Bureau of Land Management Wilderness Study Area

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

1976) requires the U.S. Geological Survey and the U.S. Bureau of Mines to conduct 

mineral surveys on certain areas to determine the mineral values, if any, that may be 

present. Results must be made available to the public and be submitted to the President 

and Congress. This report presents the results of a mineral survey of the Greenwater 

Valley Wilderness Study Area (CDCA-148), Inyo County, California.

CONTENTS

Summary Bl

Abstract 1

Character and setting 1

Identified resources 1

Mineral resource potential 1 

Introduction 3

Location and physiography 3

Sources of data 3

Acknowledgments 3 

Appraisal of identified resources 3

History and production 3

Mines and prospects 6

Conclusions 6 

Assessment of mineral resource potential 6

Geology 6

Geochemistry 7

Geophysics 7

Mineral and energy resources 7 

References cited 9 

Appendix 1. Definition of levels of mineral resource potential and certainty

of assessment 12 

Geologic time chart 13

FIGURES

1. Index map showing location of the Greenwater Valley Wilderness Study Area, 

Inyo County, California B2

2. Map showing geology and mineral resource potential of the Greenwater Valley 

Wilderness Study Area, Inyo County, California 4

3. Residual aeromagnetic map of the Greenwater Valley Wilderness Study Area and 

vicinity 8

4. Major elements of mineral resource potential/certainty classification 12

TABLE

1. Miscellaneous prospects in the Greenwater Valley Wilderness Study Area Bll

MINERAL RESOURCES OF WILDERNESS STUDY AREAS: 

NORTHEASTERN CALIFORNIA DESERT CONSERVATION AREA

Mineral Resources of the

Greenwater Valley Wilderness Study Area,

Inyo County, California

£y Augustus K. Armstrong, Michael T. Garrison, James G. Frisken, and Robert C. Jachens 

U.S. Geological Survey

Richard L. Rains 

U.S. Bureau of Mines

SUMMARY

Abstract

The Greenwater Valley Wilderness Study Area 

(CDCA-148) contains about 55,000 acres located at the 

southern end of the Black Mountains of southeastern 

California. Field work for this report was conducted 

from 1983 to 1985. The Quartz prospect, Graham Jem 

mine, and Jewell Quartz prospect within the study 

area have identified resources of gold and silver. The 

area west of Salsberry Peak has low resource potential 

for gold, silver, copper, lead, and zinc. An area south 

of Salsberry Peak in the southeast part of the study 

area has a low resource potential for zinc. The Calico 

Peaks locality northeast of Epaulet Peak in the north 

central part of the study area has a low resource 

potential for lead and copper. The locality northwest 

of Epaulet Peak has low potential for gold, lead, and 

zinc. An area of low potential for lead was delineated 

north of Epaulet Peak. The resource potential for 

nonmetallic boron-bearing minerals is low in the study 

area despite their presence 25 mi to the north in 

Greenwater Valley. The resource potential for oil, 

natural gas, and geothermal energy is also low in the 

study area.

Character and Setting

The Greenwater Valley Wilderness Study Area is 

located on the eastern flank of the southern end of the 

Black Mountains and includes part of the western side 

of Greenwater Valley. The study area is situated 

about 8 mi west of Shoshone, Calif, and 15 mi 

northwest of Tecopa (fig. 1). Relief is as great as 

2,600 ft, with several tall peaks cut by narrow, steepsided canyons and broad, sandy washes. The southern 

Black Mountains are composed of Proterozoic (570 to 

2,500 million years before present (Ma): see geologic 

time chart on last page of report) and Paleozoic (about 

240-570 Ma) metasedimentary and marine sedimentary 

rocks intruded by Tertiary (about 1.7-66 Ma) andesitic 

to rhyolitic intrusive and volcanic rocks, and overlain

by Pliocene (1.7-5 Ma) and Pleistocene (0.010-1.7 Ma) 

igneous (andesitic to basaltic) and sedimentary rocks. 

The remainder of the study area is covered by 

Quaternary (1.7 Ma to the present) sand and gravel 

deposits.

Identified Resources

There has been very little production from mines 

in the study area. However, two of the five mines and 

prospects have had past production: the Salsberry 

prospect (fig. 2, No. 5) and the Graham Jem mine (fig. 

2, No. 2). Although no production figures were 

available for the Salsberry prospect, this property has 

estimated reserves of 20,000 tons of ore assayed at 

0.13 oz/ton gold, 0.26 oz/ton silver, 1 percent lead, 

and 2 percent zinc.

In 1908, the Graham Jem mine produced less 

than one ton of high-grade ore containing gold valued 

at $25,000 per ton. Recent work indicates that this 

mine contains reserves of about 9,000 tons of goldbearing vein quartz averaging 0.073 oz/ton gold.

Mineral Resource Potential

The resource potential for additional gold and 

silver in the area adjacent to the Salsberry prospect 

and Graham Jem mine is low. Gneissic country rock 

adjacent to the Graham Jem mine contains no gold or 

silver.

Scattered oxidized veins within the study area 

contain localized occurrences of gold, silver, copper, 

lead, and zinc, which have, at times, been mined on a 

small scale. However, geochemical analysis of 

samples collected from these veins contain low 

concentrations of these elements, which suggests that 

their resource potential is low. An area west of 

Epaulet Peak has a low resource potential for gold, 

lead, and zinc. West of Salsberry Peak is an area with a 

low resource potential for gold, silver, lead, zinc, and 

copper, and to the south is an area with low potential 

for zinc. One locality northeast of Epaulet Peak has a

Bl
116°45' 116°30' 1 16°00'

DEATH VALLEY

NATIONAL

MONUMENT

GREENWATER VALLEY

WILDERNESS STUDY

AREA (CDCA-148)

SAN BERNARDINO CO

DEATH VALLEY 

NATIONAL MONUMENT

35°45' 

35°30'

Figure 1. Index map showing location of the Greenwater Valley Wilderness Study Area, Inyo County, California.

B2
low potential for lead. A small area having low 

resource potential for copper and lead was delineated 

southwest of Calico Peaks.

The Furnace Creek Formation, which includes 

the sedimentary rocks that host boron-bearing mineral 

deposits that are extensively mined in the Ryan area 

(25 mi north of the study area), is exposed in the study 

area. However, boron-bearing minerals are not known 

to occur in these exposures, so the resource potential 

is low.

Extensive faulting and the lithologic 

characteristics of the rocks in the study area preclude 

the accumulation of oil and natural gas resources, so 

the potential for these resources is low.

There is no geological or geophysical evidence 

for the existence of geothermal resources within the 

study area, despite the fact that it is located only 5 mi 

west of warm springs at Shoshone and 14 mi northwest 

of Tecopa Hot Springs; therefore, the potential for 

geothermal resources is low.

INTRODUCTION 

Location and Physiography

The Greenwater Valley Wilderness Study Area 

(CDCA-148) comprises 55,044 acres located about 8 mi 

west of Shoshone, Calif., on the eastern flank of the 

southern end of the Black Mountains (fig. 1). It 

includes part of the west side of the Greenwater 

Valley, the Calico Peaks, and the northwest flanks of 

the Ibex Hills. The study area is accessible from a 

jeep trail leading up Rhodes Wash from Highway 178 

and from a jeep trail running southwest from 

Greenwater Valley Road. Elevations range from 4,766 

ft at Epaulet Peak to about 2,100 ft at the intersection 

of Highway 178 and Greenwater Valley Road. The 

study area is dominated by a line of steep-sided, 

deeply incised peaks composed of volcanic and 

sedimentary rocks of Tertiary age.

Sources of Data

The initial geologic studies of the region 

including the study area were unpublished geologic 

maps by L.A. Wright and B.E. Troxel, and maps and 

reports by Noble (1941), Drewes (1963), and Wright and 

Troxel (1984). U.S. Geological Survey personnel 

conducted geologic and geochemical investigations in 

the study area from 1983 to 1985.

The U.S. Bureau of Mines searched for 

information concerning mines and prospects within the 

study area; this information was obtained from U.S. 

Geological Survey publications, U.S. Bureau of Mines 

files, claim owners, and Inyo County and U.S. Bureau 

of Land Management claim records. In 1983, U.S. 

Bureau of Mines personnel collected 140 rock samples 

from 50 sites in the study area. These samples were 

analyzed by petrographic, fire-assay, colorimetric, 

atomic-absorption, radiometric, and x-rayfluorescence methods.

Ackno w Ledgm ents

B. E. Troxel of the U.S. Geological Survey 

provided unpublished geologic maps of the Calico 

Peaks area by L. A. Wright and himself. T. R. 

Neumann and M.S. Miller of the U.S. Bureau of Mines 

Western Field Operations Center helped with 

fieldwork. F. C. Johnson, a geologist with the 

American Borate Company, provided valuable 

information concerning access to the study area and 

local geology.

APPRAISAL OF IDENTIFIED RESOURCES 

By Richard L. Rains, U.S. Bureau of Mines

History and Production

Greenwater Valley was the site of the most 

spectacular of the assorted booms in Death Valley 

mining history. In May of 1886, A.G. Rhodes reported 

silver shows in deposits about 2 mi northwest of 

Rhodes Spring (2 mi southwest of the study area); 

1,200 Ib of silver ore produced from one mine was 

valued at $800 (Latschar, 1981). However, when 

Rhodes and his partners perished in the desert, most 

information concerning the property and its mine was 

lost with them (Latschar, 1981).

In 1905, three prospectors relocated the mine at 

Rhodes Spring, and by the end of 1906, several new 

mines were opened nearby. By December of 1906, 

there were five working mines around the original site, 

the largest of which was owned by the Bonanza 

Greenwater Copper Company. While there were shows 

of gold, silver, copper, and lead, none of the mines 

reported any production (Latschar, 1981). According 

to Latschar (1981), surface evidence of copper 

mineralization was found in 1905 about 13 mi north of 

the study area. By 1907, four towns in the Greenwater 

district were home to 2,000 inhabitants, and 73 

incorporated mining companies had invested $140 

million in mining capital. However, most exploration 

(including shafts sunk more than 1,499 ft deep) failed 

to reveal sufficient ore. Within three years, the 

district: was virtually abandoned after producing only a 

few tons of ore. Smaller rushes in and around the 

study area for gold, silver, copper, lead, and zinc 

accompanied the Greenwater boom, but activity had 

ceased by the end of 1910.

The Bonanza Greenwater Copper Company 

announced in May of 1907 that one of its mines at 

Rhodes Spring had estimated reserves valued at 

$100,000. The gold-bearing rock being stripped from 

the edge of an intrusive dike was assayed at $90 to 

$100 per ton. By June, 20 tons of ore had netted 

$1,400 profit, which resulted in a rash of claims being 

filed all around the site. By the end of 1907, the 

Bonanza Greenwater Copper Company operations had 

ceased because most of the easily recoverable ore had 

been removed.

In March of 1908, gold was discovered at the

B3
Mines and prospects

1. Quartz prospect

2. Graham Jem mine

3. Inyo Zinc prospect

4. Jewell Quartz prospect

5. Salsberry prospect

DEATH L/CAu,Pb,Zn VALLEY

APPROXIMATE BOUNDARY 

OF

GREENWATER VALLEY

WILDERNESS STUDY AREA

(CDCA-148)

Figure 2. Map showing geology and mineral resource potential of the Greenwater Valley Wilderness Study Area, 

Inyo County, California.

B4
EXPLANATION

Area with low mineral or geothermal resource potential, certainty level C. 

See appendix 1 and figure 4 for definition of levels of mineral 

resource potential and certainty of assessment

COMMODITIES

Au Gold 

Ag Silver

Boron

Copper

Lead

Zinc

B

Cu 

Pb 

Zn

CORRELATION OF MAP UNITS 

-Holocene

Pleistocene!?)

and 

Pliocene

Miocene

-QUATERNARY

TERTIARY

PALEOZOIC

AND 

LATE PROTEROZOIC

T PROTEROZOIC

GEOLOGIC MAP UNITS

Qg Gravel deposits (Holocene and Pleistocene)

FUNERAL FORMATION (Pleistocene and Pliocene) divided into:

QTfs 

QTfa

Sedimentary rocks unit 

Andesitic-basaltic rocks unit

Tr Rhodes Tuff (Miocene)

Ti Andesitic and rhyolitic intrusive rocks (Tertiary)

PzXs Sedimentary rocks (Paleozoic and Late Proterozoic)

Em Metasedimentary rocks (Proterozoic)

MAP SYMBOLS

 CONTACT

 JEEP TRAIL

X MINE-Number refers to list of mines and prospects

X PROSPECT-Number refers to list of mines and prospects

Figure 2. Continued.

B5
Graham Jem mine (fig. 2, No. 2; table 1). However, 

this occurrence turned out to be only an isolated 

pocket of high-grade ore valued at $25,000 per ton 

(Latschar, 1981). The rush ended by June of that year. 

There has been little mining activity in the study 

area since the early 1900's. Despite there being 14 

lode-mining claims and one millsite claim active 

within the study area at the time fieldwork for this 

report was done, there has been only minor recorded 

production as described above.

Mines and Prospects

At the Graham Jem mine (fig. 2, No. 2), four 

quartz veins are exposed intermittently for at least 

1,000 ft in undifferentiated augen gneiss and granitic 

rock. The veins generally strike N. 30° to 35° W.; in 

most places, they dip nearly vertically and are as 

much as 5 ft thick, but average about 2.5 ft. Vein 

segments have been offset about 50 ft by faults. The 

quartz veins are massive and milky; iron-oxide staining 

ranges from sparse to heavy. Malachite, azurite, and 

other secondary copper minerals lightly stain the 

quartz veins. The veins are fractured and sheared and, 

in one place, are healed with magnetite. No primary 

sulfides were observed. Three adits (totaling 290 ft), 4 

shafts, 2 trenches, and 12 prospect pits are located on 

the property. About 9,000 tons of ore (quartz and 

sheared gneiss) averaging 0.073 oz per ton gold were 

identified.

At the Salsberry prospect (fig. 2, No. 5), a shear 

zone in and along a rhyolite dike cutting gneissic and 

granitic rocks is exposed for about 600 ft and averages 

2.2 ft thick. The shear zone strikes N. 60° W. and dips 

65° to 80° NE. It is offset more than 5 ft inside the 

adit where the zone cannot be traced beyond 95 ft 

from the portal. The offsetting fault was not observed 

on the surface. Sheared material consists mostly of 

fine, rounded particles and clasts of rhyolite, augen 

gneiss, pods of argentiferous galena, and secondary 

copper minerals. Workings consist of one adit 115 ft 

long, 2 shafts, and 8 prospect pits. About 20,000 tons 

of ore with an average grade of 0.13 oz per ton gold, 

0.26 oz per ton silver, 1 percent lead, and 2 percent 

zinc was identified.

Conclusions

The identified mineralized bodies at the Graham 

Jem mine and the Salsberry prospect are not 

considered resources because they are too small to 

mine. Considerable planning and development would 

be needed to produce ore from either of these mines 

because of poor access, rugged terrain, and harsh 

climate. Transportation and power costs would be 

very high because of the remote location.

The gold concentrations at the Graham Jem mine 

and the Salsberry prospect are high enough to be 

amenable to large-tonnage heap-leaching recovery 

methods. Additional mapping, sampling, and drilling 

programs may identify sufficient tonnage to classify 

these concentrations as mineral resources.

ASSESSMENT OF MINERAL RESOURCE POTENTIAL

By Augustus K. Armstrong, Michael T. Garrison 

James G. Friskin, and Robert C. Jachens 

U.S. Geological Survey

Geology

The Greenwater Valley Wilderness Study Area is 

underlain by an Early Proterozoic metamorphic 

complex of sedimentary and igneous origin and a thick 

sequence of Late Proterozoic and lower Paleozoic 

marine sedimentary rocks. These are overlain by 

volcanic and sedimentary rocks of Cenozoic age; 

Mesozoic rocks are absent in the study area. This 

entire sequence of rocks has been distorted and 

displaced by several episodes of faulting and folding, 

most extensively during the Mesozoic and Cenozoic 

eras. This deformation makes it impossible to 

interpret the composite cross section of all the 

stratigraphic units present in the Black Mountains.

Early Proterozoic rocks in the study area (fig. 2) 

are predominantly quartz-feldspar augen gneiss and 

grade into poorly defined bodies of quartz-feldsparmica schist. Quartz veins are found within the gneiss 

terrane.

The most conspicuous units of the 10,500-ft thick 

Late Proterozoic and lower Paleozoic sedimentary 

succession are the Noonday Dolomite and the Johnnie 

Formation, which are exposed locally in the study area 

west of the Calico Peaks (fig. 2). In the study area, 

this sequence also includes limestone, shale, and 

quartzite of early Paleozoic age.

The Tertiary stratigraphy of the study area is 

composed of andesitic to rhyolitic intrusive rocks, the 

Rhodes Tuff of Wright and others (1984), and andesitic, 

basaltic, and sedimentary rocks of the Funeral 

Formation. The andesitic to rhyolitic intrusive rocks 

crop out in scattered exposures about 3 mi north and 

east of Epaulet Peak. Andesitic and rhyolitic dikes 

and irregularly shaped bodies locally include rhyolitic 

flows and were probably emplaced at various times 

during Tertiary volcanism.

The Rhodes Tuff is composed of Miocene 

rhyolitic and rhyodacitic volcanic flows and 

agglomerates, sedimentary rocks, and intrusive 

bodies. These rocks cover less than half of the study 

area, but are the thickest of the rock units within its 

boundaries. The rocks are cut by numerous shear 

zones.

The nearest reported outcrops of the Furnace 

Creek Formation are 15 mi north of the study area. 

The formation may be covered by alluvium in 

Greenwater Valley. The Furnace Creek Formation is 

composed of tuffaceous clastic rocks with subordinate 

evaporite and borate deposits (Drewes, 1963).

The andesitic to basaltic rocks of the 

Pleistocene(?) Funeral Formation occur as flows, 

dikes, and agglomerates. They crop out along the 

northeast flank of Epaulet Peak and on the slopes east 

and southeast of Calico Peaks. The sedimentary rocks 

of the Funeral Formation, composed of sandstone, 

conglomerate, and a siltstone breccia containing 

coarse conglomerate, crop out over a small area in the 

westernmost part of the study area.

B6
Geochemistry Geophysics

The reconnaissance geochemical study was based 

on analysis and evaluation of stream-sediment 

samples, heavy-mineral concentrates from stream 

sediments, and rock samples. Stream-sediment and 

concentrate samples contain material derived from 

major rock units of the drainage basin being studied. 

Sampled drainage basins range in area from less than 

one to several square miles.

All samples were analyzed for 31 elements by a 

six-step semiquantitative emission-spectrographic 

method (Grimes and Marranzino, 1968). These 

analyses were used to identify drainages containing 

anomalous concentrations of metallic and metalrelated elements. Anomalous values were determined 

by inspection of histograms, percentiles, and 

enrichment relative to crustal abundance. These 

anomalies usually reflect known mining activity, but in 

some instances they indicate areas of undiscovered or 

previously unrecognized mineralization.

All rock and heavy-mineral concentrate samples 

containing anomalous concentrations of metals were 

collected at three mines or prospects and from nearby 

drainage basins. Mineralized rock samples from the 

Salsberry prospect (fig. 2, No. 5) contain a maximum of 

200 parts per million (ppm) silver, 3,000 ppm copper, 

7,000 ppm zinc, and 1 percent lead. A concentrate 

sample collected about 1 mi downslope to the 

southwest contains 700 ppm arsenic, more than 10,000 

ppm barium, 10,000 ppm lead, and 5,000 ppm zinc. 

Another concentrate, collected downslope 1.5 mi west 

of another Salsberry adit, contains 1,000 ppm lead. 

Two concentrates from streams draining the southwest 

side of the ridge from Salsberry Peak to Salsberry Pass 

contain 100 and 300 ppm lead, indicating that some 

related mineralized rocks are present along the ridge 

southeast of the Salsberry prospect. A concentrate 

sample collected outside the study area (0.75 mi southsoutheast of Rhodes Hill) contains 1,000 ppm zinc and 

more than 10,000 ppm barium, indicating the presence 

of mineralized rock from either Rhodes Hill or the 

ridge near the Salsberry prospect.

About 3 mi northwest of the Salsberry prospect 

on the southwest side of the Calico Peaks is another 

prospect (fig. 2, No. 4) that contains minor copper 

mineralization. A concentrate sample collected 

downstream and to the north of this prospect contains 

2,000 ppm lead and more than 10,000 ppm barium. A 

concentrate sample collected 2.5 mi south and 

downstream of the prospect contains 500 ppm lead and 

more than 10,000 ppm barium. Two concentrates from 

tributaries draining the south and east flanks of the 

hill 0.5 mi east of the prospect contain more than 

10,000 ppm barium and 100 ppm lead, respectively.

The remaining anomalous concentrate samples 

are associated with the Graham Jem mine (fig. 2, No. 

2). A concentrate sample collected 0.5 mi south of the 

mine contains 1,500 ppm lead, 1,000 ppm zinc, and 

more than 10,000 ppm barium. A concentrate sample 

collected from a tributary east of the Graham Jem 

mine that contains more than 1,500 ppm lead and more 

than 10,000 ppm barium indicates that the mineralized 

rocks may extend to the east.

An aeromagnetic survey of an area including the 

study area (fig. 3) was flown in 1981 and compiled 

under contract to the U.S. Geological Survey (U.S. 

Geological Survey, 1983). Total-field magnetic data 

were collected along east-west flight lines spaced 

approximately 0.5 mi apart and at a height of 1,000 ft 

above terrain. Because of the rugged topography in 

the survey area, actual terrain clearance varied about 

300 to 3,000 ft. Corrections applied to the data 

compensated for diurnal variations of the Earth's 

magnetic field, and subtraction of the International 

Geomagnetic Reference Field (the update of the 

month the data were collected) yielded a residual 

magnetic field.

The study area lies on the flank of a large 

northwest-trending magnetic high that is located over 

the Black Mountains and occupies most of the 

southwest half of the map (fig. 3). The main source of 

this anomaly is the crystalline basement of the Black 

Mountains and, where the basement is exposed, the 

anomaly correlates with Proterozoic metadiorite, 

Mesozoic(?) diorite, and Tertiary granitic rocks of 

Smith Mountain (7 mi northwest of Epaulet Peak) 

(Drewes, 1963; Wright and Troxel, 1984). The anomaly 

is bounded on the northeast and southwest by linear, 

northwest-trending zones of steep magnetic gradients 

that parallel major fault zones in the region (the Death 

Valley, Furnace Creek, and Sheephead fault zones) 

(Stewart, 1983).

The linearity of the zones of steep magnetic 

gradients on the northeast side of the Black Mountains 

anomaly, their parallelism with fault zones in the 

region, and the inferred steep attitude of the contacts 

indicate that the magnetic source in the Black 

Mountains is bounded on the northeast by a major fault 

(or fault zone) concealed beneath sedimentary and 

volcanic rocks. The inferred location of the boundary 

passes beneath the northeastern part of the study 

area. Although this structural boundary is only 

associated with two known mineralized zones 

(Salsberry and Inyo zinc prospects) within the study 

area, many occurrences of copper minerals and barite 

(a barium mineral) to the northwest (Drewes, 1963) 

cluster around the structural boundary, indicating that 

they may have been deposited by hydrothermal fluids 

migrating along the fault zone. Similar mineralized 

zones may be present beneath the study area.

Mineral and Energy Resources

Geologic, geochemical, and geophysical data 

indicate that the Greenwater Valley Wilderness Study 

Area contains mineral resource potential for 

epithermal base- and precious-metal deposits and 

boron-bearing sediments (fig. 2). See appendix 1 and 

figure 4 for definitions of mineral resource potential 

and certainty of assessment. The gold, silver, zinc, 

lead, and copper-bearing deposits in the Black 

Mountains west of the study area typically occur in 

veins, stockworks, or bedding-replacement bodies 

along faults, usually in Proterozoic or Paleozoic

B7
36° 15 -

EXPLANATION

Approximate boundary of 

wilderness study area

Location of copper and(or) 

barlte mineralization

Inferred location of magnetic boundary 

Magnetic contour line

Figure 3. Residual aeromagnetic map of the Greenwater Valley Wilderness Study Area and vicinity. Contour 

interval is 20 nanoteslas. Hachures indicate direction of decreasing magnetic intensity. Black dots indicate 

area of copper and (or) barite mineralization.

B8
carbonate rocks (Norman and Stewart, 1951). 

However, only scattered low-grade occurrences of 

these metals are present in the study area.

Gold and silver, along with minor lead, copper, 

and zinc, are found in Tertiary volcanic rocks at the 

Salsberry prospect, and gold with minor copper is 

present in shear zones in granite at the Graham Jem 

mine. Berger (1983) reported that similar epithermal 

precious- and base-metal deposits are located near 

centers of volcanism, and that through-going 

anastomosing fracture systems are the ore controls. 

These deposits are characterized by the presence of 

pyrite, arsenopyrite, galena, sphalerite, and 

chalcopyrite, and by anomalous concentrations of gold, 

silver, lead, zinc, and copper. Salsberry prospect, 

along with small prospects (table 1) such as the Inyo 

Zinc, Quartz, and Jewell Quartz, belong to this type of 

deposit. Three areas on the west side of the Calico 

Peaks (fig. 2) have anomalous concentrations of metals 

in panned-concentrate samples that indicate the 

Tertiary volcanic rocks have low resource potential for 

gold, silver, lead, copper, and zinc deposits in 

polymetallic epithermal-vein deposits. A small area 

south of the Calico Peaks has low mineral resource 

potential for lead and copper with a certainty level of 

C. An area west of Salsberry Peak has a low mineral 

resource potential for gold, silver, copper, lead, and 

zinc with a certainty level C. An area south of 

Salsberry Peak has low resource potential for zinc with 

a certainty level of C.

An anomalous metal suite similar to that found 

in the previously noted volcanic terrane is found north 

of Epaulet Peak in the northwest part of the study 

area; there are indications of low resource potential 

for lead with a certainty level of C.

The Graham Jem mine and the Quartz prospect 

west of Epaulet Peak explore gold-bearing quartz veins 

in a sheared gneissic terrane with anomalous 

concentrations of gold, lead, and zinc. Little 

mineralization was observed immediately adjacent to 

these deposits. This part of the study area has a low 

resource potential for gold, lead, and zinc with a 

certainty level of C.

The geophysical, geochemical, and geologic data 

indicate that the mineralized areas shown on figure 2 

are part of a northwest-trending magnetic high (fig. 3) 

associated with Precambrian igneous rocks along a 

possible fault zone. The mineralizaton is located on 

the northeast side of this magnetic anomaly.

Boron-bearing deposits in the subsurface may 

extend from the Ryan area into the northern part of 

Greenwater Valley, north of the study area. However, 

boron minerals have not been found in the study area. 

Exploration drilling would be needed to prove the 

existence of boron in the subsurface of the study 

area. With the data available, the resource potential 

for boron minerals is low with a B certainty level.

The study area lies within a part of the Great 

Basin that has a low potential for oil and natural gas 

(Scott, 1983). The absence of source rocks and the 

structural complexity of this region preclude the 

accumulation of oil and natural gas resources in the 

study area; therefore, the resource potential of oil and 

natural gas is low with a C certainty level.

Although the study area lies only 5 mi west of 

the warm springs of Shoshone and 14 mi northwest of

Tecopa Hot Springs where water temperatures range 

from 80° to 118°F (Sammel, 1979; Brook and others, 

1979), there is no evidence of geothermal activity in 

the study area. The warm springs of Shoshone and 

Tecopa Hot Springs are associated with the deep 

range-front fault systems that provide migration paths 

for the geothermal (source) waters. As distance 

increases from the fault systems, geothermal resource 

potential should decrease rapidly. Within the study 

area, the geothermal resources potential is low with a 

C certainty level.

REFERENCES CITED

Berger, B.R., Cox, D.P., ed., 1983, Epithermal gold, 

silver: model 5:4 in U.S. Geological SurveyIngeominas Mineral Resource Assessment of 

Colombia: Ore Deposit Models: U.S. 

Geological Survey Open-File Report 83-423, 

p. 39.

Brook, C.A., Mariner, R.H., Mabey, D.R., Swanson, 

J.R., Guffanti, M.C., and Muffler, L.J.P., 1979, 

Hydrothermal convection systems with 

reservoir temperatures less than 90 , in 

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

resources of the United States: U.S. Geological 

Survey Circular 790, p. 18-85.

Drewes, H.D., 1963, Geology of the Funeral Peak 

quadrangle, California, on the east flank of 

Death Valley: U.S. Geological Survey 

Professional Paper 413, 78p.

Grimes, D.J., and Marranzino, A.P., 1968, Directcurrent arc and alternating-current spark 

emission spectrographic field methods for the 

semiquantitative analysis of geological 

materials: U.S. Geological Survey Circular 591, 

6 p.

Latschar, J.A., 1981, Historic Resource Study: A 

history of mining in Death Valley National 

Monument, Volume II: History Preservation 

Branch, Pacific Northwest/Western Team, 

Denver Service Center, National Parks Service, 

p. 634-653.

Noble, L.F., 1941, Structural features of the Virgin 

Spring area, Death Valley, California: 

Geological Society of America Bulletin, v. 52, 

p. 941-1000.

Norman, L.A., and Stewart, R.M., 1951, Mines and 

mineral resources of Inyo County: California 

Journal of Mines and Geology, v. 47, p. 17-223.

Sammei, E.A., 1979, Occurrence of low temperature 

geothermal waters in the United States, in 

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

resources of the United States: U.S. Geological 

Survey Circular 790, p. 86-131.

Scott, E.W., 1983, Petroleum potential of wilderness 

land in California, in Miller, B.M., ed., 

Petroleum potential of wilderness lands in the 

western United States: U.S. Geological Survey 

Circular 902-D, 12p.

Stewart, J.H., 1983, Extensional tectonics in the Death 

Valley area, California: Transport of the 

Panamint Range structural block 80 km 

northwestward: Geology, v. 11, p. 153-157.

U.S. Geological Survey, 1983, Aeromagnetic map of

B9
the Kingman-Trona area, California: U.S. Wright, L.A., Kramer, J.H., Thornton, C.P., and

Geological Survey Open-File Report 83-663, Troxel, B.W., Appendix I Type sections of two

scale 1:250,000. newly-named volcanic units of the central

Wright, L.A., and Troxel, B.E., 1984, Geological map Death Valley volcanic field, eastern

and section of the north 1/2 Confidence Hills California: California Division of Mines and

15' quadrangle, Inyo County, California: Geology Map Sheet 34, text-map separate, p.

California Division of Mines and Geology, Map 21-24. 

Sheet 34, scale 1:24,000, 31 p.

BIO
Table 1. Miscellaneous prospects in the Greenwater Valley Wilderness Study Area

Map Number Name Geology Workings Sample/Resource Data

Quartz prospect

Graham Jem mine

Inyo Zinc 

prospect

Jewell Quartz 

prospect

Salsberry 

prospect

Quartz veins 230 ft 

long strike N. 70 W., 

dip 40° NE-60 0 SW in 

gneiss and granite. 

Copper staining 

locally heavy.

Four quartz veins 

<1,000 ft long in 

gneiss and granite. 

Veins strike N. 30- 

35° W. ; average 2.5 

ft thick. Veins are 

iron and copper 

stained, with no 

primary sulfides.

Shear zones with 

iron minerals trend 

NW and are stained 

with copper minerals.

Siliceous, argillized 

rhyolite is iron and 

copper stained.

Shear zone in rhyolite 

dike cutting gneiss and 

granite is exposed for 

about 600 ft and 

averages 2.2 ft in 

thickness. Shear zone 

strikes N.60°W., dips 

65°-80° NE. Sheared 

material includes 

rhyolite, gneiss, pods 

of argentiferous 

galena, and secondary 

copper minerals.

Five pits. Of 6 chip samples of 

quartz, 2 contained 

0.0002 and 0.0005 oz/ 

ton gold, 3 contained 

0.01-0.04oz/ton silver. 

One select sample of 

granite contained 0.24 

oz/ton silver, 2.9 percent copper.

Three One concentrate sample 

adits, 2 collected O.Smi south 

trenches, of the mine contained 

and 12 1, 500 ppm lead, 1,000 ppm 

pits. zinc , and >10,000 ppm

barium. One sample from 

west of the mine 

contained >1, 500 ppm 

lead and 10,000 ppm 

barium. Prospect as a 

whole contains reserves 

of about 9,000 tons of 

vein quartz averaging 

0.073 oz/ton gold.

One shaft, Two samples from shear 

2 trenches, zones contained 0.0008 

and 9 pits, and 0.0018 oz/ton gold. 

Six samples ranged from 

0.015 to 0.17 oz/ton 

silver. One sample contained 21.4 percent 

copper. None contained 

more than 49 ppm zinc.

Two shafts, One sample of rhyolite

1 pit. contained 0.0091 oz/ton 

gold and 0.057 oz/ton 

silver.

One adit, Samples contain 200 ppm

2 shafts, silver, 3,000 ppm 

and 8 pits, copper, 7,000 ppm zinc, 

and 1 percent lead. 

Prospect as a whole 

contains about 20,000 

tons of ore averaging 

0.13 oz/ton silver, 1 

percent lead, and 2 

percent zinc.

Bll
APPENDIX 1. Definition of levels of mineral resource 

potential and certainty assessment.

Mineral resource potential is defined as the 

likelihood of the presence of mineral resources in a 

defined area; it is not a measure of the amount of 

resources or their profitability.

Mineral resources are concentrations of naturally 

occurring solid, liquid, or gaseous materials in such 

form and amount that economic extraction of a commodity from the concentration is currently or potentially feasible.

Low mineral resource potential is assigned to 

areas where geologic, geochemical, and geophysical 

characteristics indicate a geologic environment where 

the existence of resources is unlikely. This level of 

potential embraces areas of dispersed mineralized rock 

as well as areas having few or no indications of 

mineralization. Assignment of low potential requires 

specific positive knowledge; it is not used as a catchall 

for areas where adequate data are lacking.

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 chance for resource 

accumulation, and where an application of genetic and 

(or) occurrence models indicates favorable ground.

High mineral resource potential is assigned to 

areas where geologic, geochemical, and geophysical 

characteristics indicate a geologic environment 

favorable for resources, where interpretations of data 

indicate a high likelihood for resource accumulation, 

where data support occurrence and (or) genetic models 

indicating presence of resources, and where evidence 

indicates that mineral concentration has taken place. 

Assignment of high resource potential requires positive 

knowledge that resource-forming processes have been 

active in at least part of the area; it does not require 

that occurrences or deposits be identified.

Unknown mineral resource potential is assigned 

to areas where the level of knowledge is so inadequate 

that classification of the area as high, moderate, or

type in a well-defined area. This phrase is not used if 

there is the slightest possibility of resource 

occurrence; it is not appropriate as the summary 

rating for any area.

Expression of the certainty of the mineral 

resource assessment incorporates a consideration of (1) 

the adequacy of the geologic, geochemical, geophysical, and resource data base available at the time of 

the assessment, (2) the adequacy of the occurrence or 

the genetic model used as the basis for a specific 

evaluation, and (3) an evaluation of the likelihood that 

the expected mineral endowment of the area is, or 

could be, economically extractable.

Levels of certainty of assessment are denoted oy 

letters, A-D (fig. 4).

A. The available data are not adequate to 

determine the level of mineral resource potential. 

Level A is used with an assignment of unknown mineral 

resource potential.

B. The available data are adequate to suggest 

the geologic environment and the level of mineral 

resource potential, but either evidence is insufficient 

to establish precisely the likelihood of resource occurrence, or occurrence and (or) genetic models are not 

known well enough for predictive resource assessment.

C. The available data give a good indication of 

the geologic environment and the level of mineral 

resource potential, but additional evidence is needed 

to establish precisely the likelihood of resource occurrence, the activity of resource-forming processes, or 

available occurrence and (or) genetic models are 

minimal for predictive applications.

D. The available data clearly define the geologic 

environment and the level of mineral resource 

potential, and indicate the activity of resourceforming processes. Key evidence to interpret the 

presence or absence of specified types of resources is 

available, and occurrence and (or) genetic models are 

adequate for predictive resource assessment.

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

LEVEL OF CERTAINTY

Figure 4. Major elements of mineral resource potential/certainty classification.

B12
GEOLOGIC TIME CHART 

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

EON

Phanerozoic

Proterozoic

Archean 

pre Ar

ERA

Cenozoic

Mesozoic

Paleozoic

Late Proterozoic

Middle Proterozoic

Early Proterozoic

Late Archean

Middle Archean

Early Archean 

:hean 2

PERIOD

Quaternary

Neogene 

Subpenod

Tertiary 

Paleogene 

Subpenod

Cretaceous

Jurassic

Triassic

Permian

Pennsylvaman 

Carboniferous

Mississippian

Devonian

Si urian

Ordovician

Cambrian

 - (3800?) - -

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 Ma)

- 0.010 

- 1.7

- 66

- 96

OfiC

- 9Qfi

 ^f\C\

- 410

, Crtrt

*J / \J

- 1600

- 3000

 AKKO 

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

Informal time term without specific rank.

B13
GPO 785-048/48036