UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall. Director

Bulletin 931-B

SOME QUICKSILVER PROSPECTS

IN ADJACENT PARTS OF 

NEVADA, CALIFORNIA, AND OREGON

BY

CLYDE P. ROSS

Strategic Minerals Investigations, 1941 

(Pages 23-37)

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1941

For sale by the Superintendent of Documents, Washington, D. C. ------ - Price 25 cents

CONTENTS

Page

Abstract................................................ 23

Introduction............................................ 23

Lone Pine district, Washoe County, Nev............. <,.... 24

General geologyo..................................... 25

Mineralized bodies.................................o 26

Outlook............................................. 27

Silvertown group near Cedarville, Calif.o............... 28

Red Hawk mine near Willow Ranch, Calif.................. 29

Currier mine near Paisley, Oreg............... 0 ......... 30

Glass Buttes prospect, northeastern Lake County, Dreg... 33

Conclusion.....»........................................ 36

Page

Plate 6. Index map of adjacent parts of Nevada, California, and Oregon, showing the location of 

the properties described.................... 26

7. Geologic and topographic map of the principal 

part of the Lone Pine district, Washoe 

County, Nev................................. 26

8. Topographic sketch map of the Glass Buttes

prospect, Lake County, Oreg.o............... 34

Figure 3. Geologic and topographic map of the Currier

mine, near Paisley, Lake County, Oreg.o.....' 31

III

SOME QUICKSILVER PROSPECTS IN ADJACENT PARTS OF 

NEVADA, CALIFORNIA, AND OREGON

By Clyde P. Ross

ABSTRACT

This report summarizes the results of reconnaissance study 

of quicksilver deposits in the northwestern corner of Nevada, 

the northeastern corner of California, and Lake County, Oreg. 

made in August 1940. The Lene Pine district, Nevada, the Silvertown and Red Hawk properties in California, and the Currier 

and Glass Butte properties in Oregon were included. The first 

two of these require further development before a definite opinion as to their value can be formed. The Red Hawk mine has 

yielded high-grade ore, but the ore bodies so far worked are 

very small and scattered. The small amount of development at 

the recently opened Currier mine has yielded encouraging results. The deposits in the Glass Buttes are large but of such 

low grade that thorough sampling would be needed to determine 

their value. In general the region appears to warrant more attention from quicksilver prospectors than it has yet received.

INTRODUCTION

A region, recently reconnoitered, that includes the general 

vicinity of the point at which Oregon, California, and Nevada 

join (pi. 6), contains many quicksilver prospects and a few 

mines. Little ore has been produced in this region, but the 

possibilities of developing a profitable mine or mines there are 

sufficient to justify more attention than the region appears to 

have received. To the north is the Ochoco region with its numerous quicksilver mines that include the Horse Heaven mine, one 

of the country's leading producers. To the east are the Steens 

and Pueblo Mountains, with many undeveloped quicksilver deposits, 

in some of which small amounts of exceptionally rich ore have 

been found. Near McDermitt, Oreg., only a short distance

23
24 STRATEGIC MINERALS INVESTIGATIONS, 1941

farther east, are the productive Opalite and Bretz mines« Among 

the nearest productive districts in northern Nevada are the Bottle Creek and National districts. The National contains the 

Buckskin Peak quicksilver mine (pi. 6).

Late in August 1940 the writer, ably assisted by Herman 

Zwang, made a trip from Denio, Oreg., through the northwest corner of Nevada to Cedarville, Calif., and thence north and east 

through Lakeview, Paisley, Bend, and Burns, Orego, with the object of visiting some of the principal quicksilver properties in 

that region. (See pl= 6.) The properties visited were those in 

the Lone Pine district, Nevada, the Silvertown group near Cedarville and the Red Hawk mine near Willow Ranch, Calif., and the 

Currier property near Paisley and prospects in the Glass Buttes 

between Bend and Burns, Orego Several other prospects said to 

exist in this region were not visited. These include prospects 

east of Pairport, Calif, one near Adel, Oreg., and rumored occurrences of quicksilver near Hart Mountain and elsewhere. Although the deposits described are all in Tertiary volcanic rocks, 

they differ in structure and mineral contento

All the samples collected during this investigation were 

taken by chipping narrow grooves across the mineralized bodies. 

It was impracticable to take samples weighing more than a few 

pounds each, although, as cinnabar is very irregularly distributed in most of the deposits, much larger samples would have 

been desirable. The tenor of some of the samples, therefore, 

may be far from representing accurately the grade of the deposits.

All the samples were assayed by J. J. Fahey, of the Uo S. 

Geological Survey.

LONE PINE DISTRICT, WASHOE COUNTY, NEV.

The Lone Pine district is in northwestern Washoe County, 

Nevada, just south of the Sheldon National Game Refuge (pi. 6).
QUICKSILVER IN PARTS OP NEVADA, CALIFORNIA, AND OREGON 25

There are some prospect holes within the refuge also, but that 

area is now closed to prospectors The early prospecting for 

gold disclosed very little of that metal. The more recent discovery of cinnabar led to the locating of a block of 18 claims 

by Curtis Mathews and W. S. Miller in December 1929.

The claims whose boundaries could be identified are plotted 

on the map (pi. 7). Antelope No. 1 and No. 2 claims are reported to lie north of No. 5 and No. 6, but no boundary posts 

for these claims were found by the writer. Antelope No<> 12 to 

No. 18 claims extend eastward from the side line of No. 11 to 

the streamway beyond the siliclfied rib near the east border of 

the area shown on plate 7. Shallow trenches and shafts have 

been dug at several places on the Antelope group, particularly 

in the northern part of Antelope No. 10 claim. In the winter of 

1939-40 the Colton Log & Lumber Co., of Portland, Oreg., took a 

bond on the property and made several bulldozer cuts. These are 

all shallow, most of them being barely deep enough to remove the 

surface soil.

Some claims that lie just west of the Antelope group and include part of the ground originally explored for gold have recently been staked by Harry Woods, but as yet he has put down 

only a few small pits. The approximate positions of two of his 

claims the Mary Lee and Margaret Dee--are shown on plate 7. 

Scattered holes and unmarked claim stakes indicate that the 

ground immediately to the north has been prospected to some extent.

Ralph Roberts and Arthur Granger, of the Geological Survey, 

paid a brief visit to the district in the fall.of 1939 and the 

writer and Herman Zwang spent 3 days in August 1940 in mapping 

and studying the area shown on plate 7.

General geology. The district is underlain by lava flows 

and associated tuffs that appear to belong to two units, both 

presumably of Tertiary age. (See pi. 7.) The lower unit
26 STRATEGIC MINERALS INVESTIGATIONS, 1941

consists of red to nearly black fine-grained andesite lava interbedded with and underlain by light-colored tuff with a few 

bands of conglomerate. These rocks in general dip gently east, 

but locally the lava has a platy structure that simulates bedding, and these partings dip northeastward at angles of 45° andmore. Along the southern border of the area mapped, the andesitic rocks are overlain unconformably by a basalt flow, 20 to 50 

feet thick, which dips gently south. The basalt contains numerous vesicles, in part filled with quartz. Near the middle of 

the eastern edge of the area mapped-there are exposures of a 

dark-colored rock that is somewhat similar to the basalt, though 

more pumiceous; this rock is mapped with the basalt, but it may 

perhaps belong stratigraphically with the andesite.

Mineralized bodies. The mineralized bodies in this area 

consist of lava and tuff that are fractured, kaolinized, locally 

silicified, and somewhat iron-stained. They contain some cinnabar and a little pyrite that is largely oxidized. The deposits have not been sufficiently explored to determine their 

size and shape. In most places the fractures are discontinuous 

and strike in various directions; but the more prominent fracture zones found so far, including the prominent silicified rib 

that crosses the northeast corner of Antelope No. 18 claim, the 

minor seam in a shallow shaft on Antelope No. 16, and the more 

conspicuous of the fracture zones revealed by the workings on 

Antelope No. 10, all trend northwestward. The first two are 

nearly vertical and the last dips 55° NEo

The silicified rib is 2 to 5 feet wide and is easily traceable for more than 800 feet. The intensely silicified fault 

breccia of which it is composed is reliably reported to contain 

a little cinnabar, but a sample chipped from it at one spot 

yielded no quicksilver on assay. The seam on Antelope No. 16 is 

said to contain a little gold. The workings on Antelope No. 10 

claim show considerable cinnabar along some fractures, much of
I'NITtD OTATia DEPARTMENT OF THE IS

so Miles

INDEX MAP OF ADJACENT PARTS OF NEVADA, CALIFORNIA, AND OREGON 

SHOWING THE LOCATION OF THE PROPERTIES DESCRIBED

U. S. GOVERNMENT PRINTING OFFICE : 1941 O-310491
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY BULLETIN 931 PLATE 7

EXPLANATION

M 1 uvi urn

+ + +*+ +

+ 4- f ^ +

Basalt f

^ ' ( ' ,O '-

Andesite

4 < V< -1

v <-.% L

^ >A,VTuff3? ^ \ >s° J2-

Mineralized f is- Vertical miner- Silicified rib Strikeand dip of Strike and dip 

sure,showing dip alized fissure fracture planes of bedding

500 9 i i i 2'°i°° Fee "t

Excavation Horizontal bedding

Contour interval 50 feet 

Datum assumed

GEOLOGIC AND TOPOGRAPHIC MAP OF THE PRINCIPAL PART OF THE LONE PINE DISTRICT, WASHOE COUNTY, NEVADA

AUGUST 1940
QUICKSILVER IN PARTS OF NEVADA, CALIFORNIA, AND OREGON 27

it in coatings of the pulverulent cinnabar commonly called 

"painto" Samples from the two shallow shafts or pits in the 

southeast part of the main group of workings, taken from channels cut across seams 48, 36, and 15 inches wide, yielded 0.29, 

0.07, and 0.18 percent of quicksilver, respectively. A sample 

chipped across an especially promising 10-inch seam was found 

to contain O a 70 percent (14 pounds to the ton) of quicksilver. 

This sample contained 0.12 percent of mercuric chloride, which 

was not looked for in the other samples. The possibility that 

chloride may be present in the ore represented by other samples 

should be taken into account in treating material from this district. Four samples cut by Walter Bentley, of the Colton Log & 

Lumber Coo, from a trench somewhat farther north contained 0.35, 

0.33, Oo075, and 0»075 percent of quicksilver. The workings 

west of the Antelope group, particularly on the Margaret Dee 

claim, are in partly opalized tuff with a little pyrite and cinnabar. No samples were cut there, because the rock now exposed 

obviously contains very little quicksilver. It is reported, 

however, that better material was found in one of the pits now 

caved.

Outlook.--Even though the district has not been thoroughly 

explored, some altered rocks that occur in it have been shown 

to contain fair percentages of quicksilver,, The deposits have 

been sampled by several people, and some of the samples have, 

yielded higher percentages than any of the samples collected for 

the Geological Survey. But the chance of mining quicksilver 

profitably depends on finding larger bodies of ore than were 

visible in 1940. In order to learn whether such bodies exist at 

readily accessible depths, it would be necessary to sink shafts 

or to drill. The first exploration should be undertaken in Antelope No. 10 claim, where the best showings now are, and should 

be guided by the fact that the principal fractures trend northwesto

310491 0 41 2
28 STRATEGIC MINERALS INVESTIGATIONS, 1941

The lava in this vicinity is underlain by tuff, and parts of 

the tuff may possibly have been replaced, like that exposed farther west, by opaline material containing cinnabar in minable 

quantities. None of this material is exposed here, and the 

search for it would necessarily be somewhat blind; but it seems 

most likely to be found in the vicinity of outcrops of fractured 

and mineralized lava. Such prospecting, however, would scarcely 

be justified unless prices became exceptionally high.

SILVERTOWN GROUP NEAR CEDARVILLE, CALIF.

The Silvertown group, in the north-central part of T. 42 N-, 

R. 15 E., in the Warner Mountains, Modoc County, Calif, (pi. 6), 

consists of 5 claims held by Roy Stanley, of Cedarville, Calif. 

The claima extend across the mountains from a point near North 

Deep Creek to South Deep Creek, a distance of nearly a mile, and 

the lode is said to have been explored, in places, even farther 

south.

The country rock of the prospects is thick-bedded agglomerate, conglomerate, lava, and tuffaceous sandstone that belong to 

what has been called the Lower Cedarville formation, of Miocene 

age. This unit is reported to comprise "from 2,000 to 3,500 

feet of andesitic agglomerates, tuffs, conglomerates, intercalated flows, and sediments." The great mass of Tertiary strata 

that make up the Warner Mountains is reported to have a maximum 

aggregate thickness of about 5,000 feet. In the vicinity of the 

Silvertown group the beds trend east of north and dip 10° W.

The lode is a silicified fracture zone that trends N. 20° W. 

and has a steep northeast dip. The rock is more or less silicified over a width of fully 100 feet, but the more intensely

I/ Russell, R. J., Basin range structure and stratigraphy of the Warner 

Range, northeastern California: California Univ., Dept. Geol. Sci., Bull., 

vol. 17, No. 11, pp. l*02-1406, 1928. LaMotte, R. S., The Upper Cedarville 

flora of northwestern Nevada and adjacent California: Carnegie Inst. Washington Pub. 1*55, P. 61, 1936.
QUICKSILVER IN PARTS OF NEVADA, CALIFORNIA, AND OREGON 29

mineralized material appears to range in width from a few inches 

to 20 feet. The workings include shallow cuts and caved tunnels 

distributed along the length of a claim on the north side of the 

valley of South Deep Creek and scattered holes farther north.

The lode contains films and specks of cinnabar and disseminated grains of pyrite, malachite, and azurite, in altered rock 

that is in places almost completely, replaced by jasper and sericite. As the mineralized fracture zone traverses the beds obliquely, its country rock is different in different places; much 

of the zone is in agglomerate, but some of it appears to be in 

lava. The more thoroughly mineralized portions are reported to 

contain 0.55 pound of quicksilver with local richer streaks. 

The two samples cut by the writer contain 0.04 and 0.01 percent 

of quicksilver, but these samples were too small to be representative; it seems entirely probable that selective mining 

would yield ore of higher tenor. The scanty workings accessible 

at the time of visit suffice only to show that there is a large 

amount of cinnabar-bearing material. Additional exploration is 

necessary in order to obtain a satisfactory idea of the commercial possibilities of the area.

RED HAWK MINE NEAR WILLOW RANCH, CALIF.

The Red Hawk quicksilver mine, formerly known as the

2/ Modoc, is in T. 4 N., R. 14 E., about 3 miles from the post

office of Willow Ranch, Calif, (pi. 6). It lies in the southern part of the High Grade district, where gold was formerly

5/ mined. The property comprises three claims. Some work was

done at the Red Hawk mine in 1917 or 1918 by A. H. Dixon and 

Charles Kirkpatrick, of Lakeview, Oreg. A ruined furnace is on 

the property but no record of the amount of quicksilver produced

2/ Bradley, ff. ff., Quicksilver resources of California: California 

State Min. Bur. Bull. 78, p. 72, 1918.

3/ Hill, J. M., Some mining districts in northeastern California and 

northwestern Nevada: U. S. Oeol. Survey Bull. 59^, pp. 38-Ug, 1915. .
30 STRATEGIC MINERALS INVESTIGATIONS, 1941

in it has been found, and it probably was operated only a short 

time.. In August 1940, when the mine wea visited, the property 

was held by Eo D. McGilroy and R. S. Hall, who had done some development work and planned to do more. No work was then in pro-- 

gress. Several short tunnels, irregular cuts, and a shallow 

shaft, scattered over the hillside, explore several separate 

steep mineralized fractures that trend about N. 20° W. The

north and dips 30° E. The ore, which is erratically distributed 

along the fractures, consists of silicified tuff with cinnabar, 

hematite, and nontronite (hydrous silicate of iron)» Locally 

mossllke radiating groups of cinnabar and hematite grains lie in 

a groundmass of fine-grained quartz. Beryllium is reported to 

be present in the nontronite-bearing rock, but it was not detected in specimens tested at the Geological Survey. Pockets of 

high-grade cinnabar ore have been found in the past, but apparently all were small. As cinnabar is visible at several places 

in the shallow workings, further exploration seems justified; 

but the mineralized zones appear to be so discontinuous that it 

would be unwise to spend much money until larger and more persistent ore bodies are found.

CURRIER MINE NEAR PAISLEY, OREG.

The Currier mine is in sec. 36, T. 32 So, R. 16 E., about 12 

miles northwest of Paisley, Lake County, Oreg., near the Premont 

Highway (pi. 6). It lies close to the base of Winter Ridge and 

just above the flats that border Summer Lake. Cinnabar, it is 

said, has long been known to occur here, but the present activity dates from May 1940, when Ao M. Seits and Dr. E. W« Howard 

took a bond on the property« In August, development in the 

shallow open cuts shown in figure 3 was being pushed. No work 

was being done in the old tunnel, though it had been extended 

earlier in the year to the point shown on the map. A Lacey
QUICKSILVER IN PARTS OF NEVADA, CALIFORNIA, AND OREGON. 31

Alluvium Basalt

5,O , , , ,9

Andesite Mineralized fractures 

showing dip

i so Feet

Contour interval, 10feet. Datum, mean sea level (approximate). 

Aug. 22,1940.

Figure 3. Geologic and topographic map of the Currier mine, near Paisley,

Lake County, Oreg.
32 STRATEGIC MINERALS INVESTIGATIONS, 1941

furnace of some 35 to 40 tons rated capacity, equipped with a 

special condensing system designed by Mr. Seits, was on the 

property and had been in operation, but it was shut down and under repair.

The workings are in a flow of andesite that is nearly black 

where fresh and is overlain by a basaltic flow; both are essentially horizontal. These lavas are stratigraphically low in the 

Tertiary volcanic series from which Winter Ridge has been carved. 

The andesite is irregularly bleached and altered and is cut by 

several shear and breccia zones, which trend nearly north and 

stand vertical or dip east at moderate to high angles. These

minor fractures are presumably related to the fault that was bei/ lieved by Russell ~^ to border this part of Winter Ridge 

The recognizable fracture zones in and close to the present 

workings are shown in figure 3. Scattered exposures are said to 

indicate that the persistent fracture zone which passes through 

the main pit extends for considerable distances both north and 

south of the area mapped. The rock in these zones is brecciated, 

silicified, and replaced by the clay mineral dickite. It is 

lighter-colored than the unaltered andesite and has in most 

places a distinctly purple cast, presumably due to finely divided hematite. The breccia fragments are cemented by quartz, and 

some of them are coated with cinnabar, which also lines the 

walls of fissures in the altered rock. ' A little calclte is associated with the cinnabar, and barite and a little native 

quicksilver are locally present. There is some pyrite, notably 

in the shallow winze in the tunnel.

Samples cut in the short crosscut extending southward from 

the tunnel contain only 0.02 and 0.03 percent of quicksilver, 

but high-grade material is reliably reported to have been found 

in the tunnel workings, particularly in the winze. A sample

U/ Russell, I. C., A geological reconnaissance in southern Oregon: U. 

S. Geol. Survey Uth Ann. Kept., pp. UU5-1A9, pi. gU,
QUICKSILVER IN PARTS OF NEVADA, CALIFORNIA, AND OREGON 33

from the shear zone at the southeast edge of the scraped surface 

above the furnace yielded 0.09 percent of quicksilver, and one 

from the shear zone at the north end of the main pit contained 

Oo08 percent. Two from the south end of that pit, the first 

from a cut across a highly silicified seam a foot wide and the 

second from a cut 5s feet long across the entire lode, contained 

0.65 and 0.69 percent respectively. A pocket of high-grade cinnabar ore had been removed from this part of the pit the day before the samples were taken. If any material from this pocket 

had been included In the samples, the tenor would have been much 

higher.

The work done thus far, though not a sufficient basis for 

estimating reserves, has had some distinctly encouraging results. 

The andesite is cut by discontinuous mineralized fractures distributed over a width of roughly 50 feet. The length of the 

mapped area is only about 200 feet, but further exploration is 

expected to show that the mineralized zone extends much farther 

than this. The vertical range thus far explored is about 65 

feet, and in order to exceed this range materially, it would be 

necessary to sink. Sinking would necessitate pumping, for the 

ground at the east edge of the area shown In figure 3 was marshy 

as late as August, after the weather had long been dry.

Further development and sampling will be required in order 

to reveal the grade of ore to be expected. It seems probable, 

however, that ore shoots 5 feet or more in width and containing 

fully 10 pounds of quicksilver to the ton will be found and that 

there will be pockets containing more than 20 pounds to the ton. 

Mr. Seits thinks that a large part of the mineralized ground 

averages 5 pounds to the ton.

GLASS BUTTES PROSPECT, NORTHEASTERN LAKE COUNTY, OREG.

The Glass Buttes prospect is on the isolated hills of that 

name in the northeast part of Lake County, Oreg. It is about
34 STRATEGIC MINERALS INVESTIGATIONS, 1941

3.5 miles by road south of the highway between Bend and Burns,

in Tps. 23 and 24 S., R. 23 E. (pi. 6). The property is owned

by Charles E. Miller, of Bend, Oreg., and comprises 48 claims,

as shown on plate 8. Quicksilver has been known for several

5/

years to occur here. Test pits and short tunnels are scattered

over the property, but so far there has been no production. The 

part of the Miller property from No. 1 tunnel to about 2,000

feet to the north was visited by the writer August 23, 1940<>

6/ According to Waters,- the buttes are composed of three

groups of lava flows. The highest and lowest of these groups 

are basaltic. The intermediate group, which is more than 400 

feet thick and forms the greater part of the Glass Buttes, includes dacite and several other kinds of andesite, as well as 

perlite, obsidian, and vitrophyre. Only these glassy lavas are 

exposed at the quicksilver prospects. According to Waters, the

a

volcanic rocks of the Glass Buttes form a broad anticline broken 

by many normal faults of diverse trends and magnitudes.

The property, which has an area of about 1.5 square miles, 

is underlain by lava that originally consisted almost exclusively of flow-banded glass. This lava has been extensively opalized along broad zones of northwesterly trend that extend beyond 

the limits of the area shown on plate 8. Halloyslte, a clay 

mineral, is mixed with the opal, locally in some abundance. 

Cracks and holes in the opaline material are lined with finegrained quartz. Other and presumably later cracks are lined 

with cinnabar grains. The opaline material locally has horizontal bands that may represent the flow bands of the lava which 

it has replaced. Most of the pits and other excavations seen by 

the writer show cinnabar but generally in very small amounts. 

The cinnabar darkens on exposure, and it can therefore be detected only by chipping the surface of the opaline material.

]5/ Schuette, C. N., Quicksilver in Oregon: Bull. U, State of Oregon, 

Dept. Geology and Min. Industries, p. l6S, 1938.

6/ Waters, Aaron, A structural and petrographic study of the Glass Buttes, 

Lake County, Oreg.: Jour. Geology, vol. 35, No. 5, pp. UU1-U52, 1927.
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY BULLETIN 931 PLATE !

Samples designated 6.0.2,6,7 

collected by C.P. Ross ; other 

assays furnished by Charles E. 

Miller

Large rectangles represent 

mining claims

Adapted from a ma.p.furnished by Charles £.Miller 

with minor additions

TOPOGRAPHIC SKETCH MAP OF GLASS BUTTES PROSPECT,

LAKE COUNTY, OREGON

i ;ooo o 2,ooo Feet 

Contour interval 5O feet^datum mea.n sea level (approximate) 

AUGUST 1940
QUICKSILVER IN PARTS OP NEVADA, CALIFORNIA, AND OREGON 35"

In several places the opaline material is broken by fractures and breccia zones that are. comparatively rich in cinnabar* 

These trend N. 55°-65° W. and most of them dip rather steeply 

northeastward, though a few dip toward the southwesto The largest ones thus far exposed in No. 1 tunnel and in the bottom of 

a 43-foot shaft 850 feet northeast of the portal of that tunnel are 2 to 5 feet, wide and have been followed only short distances along the strike.

The quicksilver content of a few representative samples is 

shown on plate 8. The samples designated by G. 0. and a number 

were taken by the writer; the others were furnished by Mr. 

Miller, who also reports two samples not recorded on plate 8. 

One of these, from a "broken zone" 1 foot wide, contained 0.675 

percent of quicksilver; the other, from a "brecciated seam," 

contained 0.550 percent of quicksilver. Sample G.0.2, from the 

bottom of the 44-foot shaft, contained 0.10 percent of mercuric 

chlorideo As the total amount of quicksilver in this sample was 

only 0.22 percent, a large proportion of the metal was present 

as chloride, and this may be true of other parts of the deposit. 

This possibility should be taken into account in planning the 

reduction plant, and other samples should be tested for chloride, 

On the other hand, sample G»0.7, which is from a comparatively 

rich band 2 feet wide in No. 1 tunnel, yielded only 0.05 percent 

of mercuric chloride. This sample contained 0.68 percent of 

quicksilver,.

The assays, together with observations on the ground, indicate that the quicksilver content of the opalized material 

ranges from a trace to about 15 pounds to the ton. Most of the 

samples recorded on plate 8 are from the richer parts of the deposit, so that the assays probably do not fairly represent the 

average tenor. It seems improbable that more than a small part 

of the deposit could be mined profitably at the prices that prevail under normal circumstances, but as the deposit is very
36 STRATEGIC MINERALS INVESTIGATIONS, 1941

large and certainly contains some fairly rich ore, further work 

may show that it could serve as a source of quicksilver under 

emergency conditions»

CONCLUSION

The deposits described in this paper include only the principal ones revealed by prospects along the route of the reconnaissance (pi. 6), but they probably are representative of others scattered over this region. Other deposits are known to occur in the region, and .it is probable that still others would be 

revealed by careful prospecting. The region has, in the past, 

contributed little to quicksilver production, partly because 

many of the deposits are not rich enough to be profitable when 

quicksilver prices are normal and partly because many prospectors are unfamiliar with quicksilver lodes; but the recent abnormally high prices have aroused interest in quicksilver deposits of all kinds and have induced many prospectors to learn 

how to look for them. The scanty available information is inadequate but suggests that, on the whole, the deposits within 

the limits of the present reconnaissance will be mainly of low 

grade and profitable only during periods when the price of 

quicksilver is high.

Each of the deposits described above-differs from the others, 

and it is to be expected that distinctly different types will be 

found in other parts of the region. As cinnabar deposits rarely 

contain abundant sulphides of other metals, their outcrops are 

less deeply colored, in general, than those of other metalliferous deposits; they tend, rather, to be paler than the surrounding rocks. This is not an Invariable rule, but it applies to 

many of the deposits in and near the region here considered. 

Any area of conspicuously light-colored rocks should therefore 

be examined, especially if opal and other fine-grained forms of 

silica are abundant in them; and it should be remembered that
QUICKSILVER IN PARTS OF NEVADA, CALIFORNIA, AND OREGON 37

cinnabar darkens so readily as rarely to be recognizable on the 

surface of an outcrop. Rock that seems likely to contain cinnabar should therefore be examined on freshly chipped surfaces.

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