DEPARTMENT OF THE INTERIOR

ALBERT B. FALL, Secretary

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, Director 

Bulletin 741

THESJARBIDGE MINING DISTRICT, NEVADA

WITH A NOTE ON THE

CHARLESTON DISTRICT

BY

FRANK C. SCHRADER

WASHINGTON

GOVERNMENT PRINTING OFFICE

1923
ADDITIONAL COPIES

Or THIS PUBLICATION MAT BE PROCURED FROM

THE SUPERINTENDENT OP DOCUMENTS

GOVERNMENT PRINTING OFFICE

WASHINGTON, D. C.

AT

20 CENTS PER COPY
CONTENTS.

Introduction 1

Scope of report 1

Location 1

Previous descriptions *

History and present conditions. _ 3

Production 5

Climate ______ __ - - 5

Vegetation ___ __ 5

Physical features __ __ 6

Great Basin province- 6

. Snake River valley 1 _ _ 6

Jarbidge Mountains _ 7

Geology 12

Sedimentary rocks 12

Paleozoic rocks _ 12

Tertiary (?) rocks_____________ _ 14

Miocene (?) _______________ _____ _ ___ 14

Pliocene (?)____________________ _ __ 15

Quaternary deposits 15

Igneous rocks _ _ _ 15

intrusive granitic rocks (Cretaceous?)- ___ __ ___ 15

Tertiary volcanic rocks________________c________ 16

General features _ _ _ _ _ __ 16

Old rhyolites (Miocene?) __ ___ ______ 17

Young rhyolites (Pliocene?) __ ___ _ ___ 20

Age of the volcanic rocks__-_________ _____ 23

Mineral deposits _________________________________ 24

Occurrence and distribution _______________________ 24

West vein system_______________________________ 25

East vein system _ _ _ ______ ______ 25

Cross vein system______________________________ 26

Structure and composition of the veins__________________ 26

Oxidized ore _______________________________ 26

Sulphide ore ____________________________:_ 32

Origin of the veins_____________________________^_ 34

Alteration of wall rock_________________:__________ 35

""* Mines and prospects on the west veins__________________ 36

Long Hike mine_____________________________ 36

North Star mine____________________________ 45

O. K. mine_______________________________ 46

Alpha mine _______________________________ 48

Starlight mine ______________________________ 51

Legitimate mine _____________________________ 57

Flaxie mine ________________________________ 58
IV CONTENTS.

Mineral deposits Continued.

Mines and prospects on the west veins Continued, Page.

Pavlak mine : 59

Pick and Shovel mine 60

Bluster mine_____ 6.1.

Big Vein prospect_________ --- 63

Success mine _ 63

Jarbidge Central prospect 65

Buckeye mine __ 65

Cold Spring mine_ __ 66

Norman mine- _ ; 66

Moore prospect __ _ _ ' 68

Mines and prospects on the east veins 69

Altitude mine____________ 69

Bullion prospect ' . 72

Ben Hur prospect _ 74

Ajax prospect__________________ _ '- 74

Candy prospect _ - 75

Red Dike prospect____________________ _~ 76

Morning Star mine__________________ _ 76

Baty prospect 76

Cougar Mountain prospect____:_________________ 77

Placers _ ______________________________ 77

Future of the district_________________________..__ 77

Charleston district_________________.._____________ 78

Location _ __ _________ 78

Topography _______________________________ 79

Geology _ ______________ 79

Metalliferous deposits _________________:______ 81

Lodes _ __ ___________ 81

Graham mine___________________ _______ 82

Prunty mine_________________________'__ 82

Prospects ___ __________________ 82

Placers _ __ ___________1________ 83

Nonmetalliferous deposits ________________________ 83

Index ____ 85

ILLUSTRATIONS.

Page.

PLATE I. Geologic reconnaissance map and section of the Jarbidge district, Elko County, Nev______________________ 4 

II. Topographic and mine map of a portion of the Jarbidge district_________________________________ 4

III. Crater Range, northern part of west slope, Jarbidge, and mines- 4

IV. A, First Crater; B, Head of Bonanza Gulch basin________ 4

V. A, Crater Range, east slope; B, Crater Range, east slope in

part _________________ 30

VI. A, Sixth Crater, head of East Fork of Jarbidge River;

B, Crest of Crater Range, middle part_____________

VII. Pinnacles and jointing in older rhyolite_____________
ILLUSTRATIONS. V

Page. 

PLATE VIII. A, Bonanza Gulch, Jarbidge Peak, and mines; B, Black Peak,

at head of Fourth Crater 21 

IX. A, Adularia, vein orthoclase (microscopic) ; B, Jointing and

weathering in young rhyolite 28 

X. Gold-silver ore with gangue of pseudomorphic quartz and

adularia after calcite: 28

XI. A, Adularia (microscopic) ; B, Gold-silver sulphide ore from

Alpha mine__ 28

XII. Photomicrograph of quartz and adularia pseudomorphic after

calcite _____ 28

XIII. Photomicrograph ef gold ore______ . 28

XIV. Gold ores_____ 28 

XV. A, B, Photomicrographs of gold-silver sulphide ore from

Alpha mine___ 28.

XVI. Map of part of surveyed and unsurveyed claims in the Jarbidge district_ 3(£

XVII. Plan and section of Legitimate mine_____ _ - 60-

XVIII. Legitimate mine ________________ 60'

XIX. A, North Mountain and Candy prospect; B, Bluster and Pick

and Shovel mines _________________ 61 

XX. Morning Star mine________________________ 76

FIGURE 1. Index map showing location of Jarbidge mining district_ 2

2. Diagram showing trend and relative position of principal veins

in Jarbidge district _____________ 27

3. Longitudinal section of Long Hike mine on plane of vein, 38

4. Diagram of enriched cross slips or faulting in Long Hike vein 41

5. Plan of Long Hike mine_______________________ 42

6. Plan and section of North Star mine____-___________ 45

7. Plan and vertical projection of O. K. mine___________ 47

8. Plan and projection of Alpha mine_______________

9. Topographic, claim, and level map of Starlight mine___-...'. 52.

10. Topographic, claim, and level map of Flaxie and Jarbidge Gold

mines __ _ ____ _______ 53

11. Longitudinal section of Starlight Hill group of mines______ 54

12. Plan and projection of Starlight mine_______________ 55

13. Plan of Pavlak mine_______________________ 59

14. Section of Bonanza Hill mines_________________ 61

15. Plan of Buckeye mine_______:____________~_~~ g5

16. Plan of No. 2 level of Norman mine____ .________" ~ 37

17. Map of First Crater and Jack Creek claims________ 70

18. Plan and section of Altitude mine___________ ~~ 7^

19. Sketch map of part of Charleston district______I~~~ 80

THE JARBIDGE MINING DISTRICT, NEVADA.

By FRANK C. SCHRADER.

INTRODUCTION.

SCOPE OF REPORT.

In 1910, soon after ore was discovered in the Jarbidge district, a 

reconnaissance examination of the district was made, and a report 

thereon was published in 1912.1 The present report is supplemental 

to the earlier report and aims to bring it as nearly as possible up to 

date. To this end two weeks was spent in the district in July, 1920. 

The material obtained was derived chiefly from underground examinations.

As time would.not permit complete revision of the geology, the 

geologic and topographic map of the earlier report is here reproduced as Plate I. Fortunately an excellent large-scale topographic 

map covering about 60 square miles of the most important part of 

the district, on the west slope of the Crater Range, had recently been 

made by the Elkoro Mines Co., a subsidiary of the Yukon Gold Co., 

and by the courtesy of that company this map, showing also the location of the mines, is included in the present report (PL II).

The report contains much new material on the geology and ore 

deposits of the district but only a brief summary of the material on 

those subjects given in the earlier report, to which the reader is 

referred for a fuller account.

Valuable information and aid were generously -given by the Elkoro 

Mines Co., the Jarbidge Buhl Mining Co., the Crater Mining Co., 

Benane Brothers, Claude C. Gillham, A. L. Rinearson, Patrick Donahue, William Van Alder, and other miners, prospectors, and citizens

of Jarbidge.

LOCATION.

The Jarbidge district lies in the northern part of Elko County, 

in northeastern Nevada, near the Idaho State line on the north and 

about 60 miles from the Utah State line on the east. (See PL I and 

fig. 1.) It is included within an area about 14 miles square, extending a few miles west of Jarbidge River and east of the East Fork, 

with its center near latitude 41° 51' north and longitude 15° 25' west.

1 Schrader,, F. C., A. reconnaisance of the Jarbidge, Contact, and Elk Mountain mining 

districts, Elko County, Nev.: U. S. Geol. Survey Bull. 497, pp. 1-98, 1912.

1
THE JARBIDGE MINING DISTRICT, NEVADA.

FIGURE 1. Index map showing location of Jarbidge mining district.
INTBODUCTION. 3

It lies in the northeastern part of the physiographic region known 

as the Nevada Plateau, between elevations of 5,500 and ll^OO feet, 

on the upper north slope of the high east-west range that forms the 

divide between the Great Basin on the south and the Snake River 

valley on the north. To this range, or portions of it, particularly to 

the southwest of the district, the name Bruneau Range or Bruneau 

Mountains has locally been applied. Jarbidge, the town or camp 

(Pis. II and III), is in the northwestern part of the district, on 

Jarbidge River, at an elevation of about 6,200 feet.

On the southwest the district is bordered by the less known 

Charleston district. It is 15 miles from Mountain City, 20 from 

Edgemont, 25 from Tuscarora, and 12 from Charleston, all four 

camps west or southwest from Jarbidge.

The nearest railway stations in an air line are Rogerson, Idaho, 

50 miles to the northeast, on a spur of the Minidoka & Southwestern 

branch of the Oregon Short Line, and Deeth and Elko, Nev., respectively 55 and 70 miles to the south, on the Southern Pacific and 

Western Pacific lines.

PREVIOUS DESCRIPTIONS.

Other than the report mentioned, the literature bearing on the 

district consists of some short papers, mostly by Winthrop W. Fiske, 

in mining journals that were current in the early years of the district. Most of the papers appeared in the publications named 

below, under some such heading as "Jarbidge, Nevada."

Salt Lake Mining Review: Jan. 30, Feb. 15 and 28, Mar. 30, June 15, July 30,

Sept. 30, Nov. 15 and 30, 1910; Feb. 15, 1911.

Mining and Scientific Press: Apr. 30, June 18 and 25, Sept. 3, Dec. 31, 1910. 

Mining World: Oct. 1 and 8, Dec. 24 and 31, 1910. 

Engineering and Mining Journal: Oct. 15, 1910. 

Reno Evening Gazette: June 2, 1913.

HISTORY AND PRESENT CONDITIONS.

A sketch of the district up to about 1912 appears in the earlier 

report. At that time most of the leading properties of to-day had 

been opened, many others had been prospected, and more than 

500 claims had been staked and filed for record by nearly as many 

men. The Pavlak mill was being built, machinery for the Buster 

and North Star mills was.on the way, and the problem of supplying 

the mines and mills with electric power was being considered.

At present the district contains about' 90,000 feet of underground 

workings, mostly in about 10 mines, and has 8 mills. Most of 

the larger mines are supplied with hydroelectric power by the Nevada Power Co. from its plant at Thousand Springs, Idaho. The 

power is transmitted at 44,000 volts over a 73-mile line built in 1917
4 THE JARSIDGE MINING DISTRICT, NEVADA.

by the Elkoro Mines Co. at a cost of nearly a quarter of a million 

dollars. This company not only opened up a new epoch in the 

life of the district by bringing in electric power but made also a 

most important contribution in determining the process most suitable 

for treating the Jarbidge ores. Some of the mills have not been 

successful, owing chiefly, it is said, to failure to employ the correct 

process for the ores treated or to mismanagement. The power is 

supplied to the mines at the Idaho State rate of 1^ cents a kilowatthour, which renders low-grade material that would otherwise be 

unworkable at once of commercial value.

The most important development made in the district during the 

last decade is that of the Elkoro Mines Co. in the Long Hike and 

neighboring mines. The company began operations in 1916, and 

soon afterward it built the electric-power line and the 100-ton 

Elkoro mill, which has been steadily in operation since early in 

1918.

Considerable development work has been done and is in progress 

by the Jarbidge-Buhl Mining Co., which, in addition to underground 

work, has extended the power line across the crest of the Crater 

Range and built a good wagon road up Jack Creek to its property. 

Much work has also been done in many other mines, among them 

the Starlight, Bluster, Pick and Shovel, Flaxie, Legitimate, 0. K., 

Alpha, and North Star (formerly Bourne). In July, 1920, the population of the district was 250. Nearly all the men were working in 

the mines.

The town site of Jarbidge, which extends along the river from 

Moore Gulch nearly to Bourne Gulch (PI. Ill), has been dedicated 

by the Government, and claimants now acquire deeds to their residence lots from the county judge at Elko.

The wage scale of the district in 1920 for miners was $5.50 and 

muckers and trammers $5 a shift. The Elkoro Mine Co., which 

employs 80 men, furnishes them with good board at $1.50 a day. 

The cost of mining and milling is about $7 to the ton of ore.

Supplies are brought in from Rogerson, on the north, by team 

and autotruck at a cost of If cents a pound. With county aid a 

new road has been built along the river through the rim-rock canyon 

belt below Jarbidge. It is of easy grade, avoids Jack Creek Mountain with its snow drifts and other steep hills crossed in the last 6 

miles of the old route, and is passable the year round. A triweekly 

mail and stage service is operated over this route. On the south 

the road from Elko and Deeth when in repair is suitable for passenger-automobile travel from the middle of June to October. As 

Deeth is a small place, without a hotel, most persons using the southern route start from Elko, the county seat, where living accommoda-
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE I

tpAHo STATK LINE j I

Topography by R. D. Pickett

.A

Geology by F. C. Schrader

JarbidgePk

DECLINATION 132?

GEOLOGIC RECONNAISSANCE MAP AND SECTION

OF THE JARBIDGE MINING DISTRICT, ELKO COUNTY, NEVADA

<, , _;L_ ocaJLe 121^00

1 go_________1_________2_________3________i_________5 MQ.US

ContoTiv interval4OO feet. 

EXPLANATION

TERTIARY CRETACEOUS (?) PALEOZOIC

Pliocene (.')

I

Younger or rim-rc 

rhyolite

 ck

K

Mine

___ \__

Intervolcanic 

rhyolite dikes

o

X

Prospect

Miocene (?)

 A ^

der (ore-bearin 

rhyolite

y

> ' 

i

->

g) Granodiorite dikes and Granodiorite and allied Principally Paleozoic sedimeneheets (granular in- granular intrusives. tary rocks (quartzites, limetrusives) principally stocks and stones, and shales) with 

dikes granitic intrusives, notably 

granodiorite

1 O

Section corner

^- ' \ *

Fault U. S. locution 

monument
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE II

Rock outcrops Mine Tunnel Shaft Prospect Location Tramway Aerial 

(Nettrly alLr+ydiULe) tramwa.

Telephone Surface contours 

line (Datumis meansea level)

TOPOGRAPHIC AND MINE MAP OF A PORTION OF THE JARBIDGE MINING DISTRICT, ELKO COUNTY, NEV.
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE III

CRATER RANGE, NORTHERN PART OF WEST SLOPE, JARBIDGE, AND MINES. 

Shows 3J miles of the west slope of the range, looking east from Bear Creek Ridge opposite Bourne Gulch. Phqtograph by Claude C. Gillham.
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE IV

A. FIRST CEATiili.

Looking south from south knoll of North Mountain, shown in Plate XIX, A. The "crater" is a huge cirque eroded in rhyolite. It measures H miles across its mouth from rim to rim. The walls are nearly 

vertical and in places about 800 feet high. To the right the Ben Hur vein or its footwall is exposed through a vertical range of 500 feet. Photograph by Claude C. Gillham, taken in August.

K. HEAD OF BONANZA GULCH BASIN. 

Looking northeast from Alforcus claim, above Bluster mine. The part of the basin here shown is semicircular and more than a mile wide. Photograph by Claude C. Gillham, taken in August.
INTRODUCTION. 5

tions and means of transportation are readily available. The biweekly automobile mail stage between Deeth and Charleston is used 

by some, who then proceed on horseback or afoot from Charleston 

over the remaining 24 miles of the route across the high mountains 

to Jarbidge. Charleston consists chiefly of a post office and a few 

stock ranches or farms.

PRODUCTION.

The reported production of the Jarbidge district at the end of 1921 

was about $1,500,000 in gold and silver, of which about $1,250,000 

was produced by the Elkoro Mines Co., mostly from the Long Hike 

mine. In 1919 Jarbidge produced more gold and in 1919, 1920, and 

1921 more gold from gold ores than any other camp in Nevada.

CLIMATE. 3

The climate at Jarbidge is similar to that of neighboring northwestern Utah and the Silver City region, Idaho, and in part to that of 

Great Basin on the south and the Snake Kiver valley on the north. 

The summers are long and dry and there is great daily range between day and night temperatures. The days are warm, with abundant sunshine, but owing to the dryness of the air the heat is not 

oppressive. The nights are cool to cold. Frosts occur every month 

of the year. The annual precipitation is about 13 inches. It falls 

mainly as snow in winter, which ranges from 12 to 100 inches in 

depth at higher levels, and in places some snow remains throughout 

the summer. Fresh snow begins to accumulate on the mountains 

early in October and in the valleys late in November. Springs feed 

perennial streams by which the district is well supplied with wholesome water. In winter the temperature rarely falls below 20°. At 

Jarbidge milling operations are conducted throughout the winter 

with little or no artificial heat. The first warm weather of the year 

occurs early in June, when waters from melting snow greatly increase the flow of Jarbidge River and the other streams.

VEGETATION.

The area lies in the Humboldt National Forest and contains considerable timber at the heads of the valleys, well up in the mountains, and along the larger streams (PL IV). The principal trees 

are limber pine and alpine fir, and the better stands are on the east 

and northeast slopes. Much of the timber is suitable for mining, but 

the pine is the only tree suitable for lumber. Sawmills have been in

s The notes on climate and vegetation are in part supplied by the United States Forest 

Service.
6 THE JARBIDGE MINING DISTRICT, NEVADA.

successful operation at several points, and a mill is now running 

near the head of Jarbidge River.

Mountain mahogany, juniper, and aspen, mostly bushy trees of 

stunted growth, are plentiful and widely distributed and extend 

high up the mountain slopes. Favorable slopes extending from the 

foothills nearly to the top of the mountains are clothed with a fair 

growth of good forage grass and form an excellent sheep range.

PHYSICAL FEATTJBES. 

GREAT BASIN PROVINCE.

The Jarbidge district lies on the boundary between two physiographic provinces the Great Basin on the south and the Snake 

River valley or Shoshone Basin on the north. It has a relief of more 

than 5,000 feet. The chief features of the Great Basin consist of 

minor mountain ranges trending in a north-northeasterly direction 

and intervening detritus-filled valleys. In northeastern Nevada the 

ranges largely give way to irregular groups of hills that, increasing 

in altitude from foothills on the south, merge into the Jarbidge 

Mountains, which here form the north rim of the Great Basin. This 

portion of the basin is drained mainly by the headwaters of Marys 

River, which flows into the Humboldt, on the south, at Deeth.

SNAKE RIVER VALLEY.

Toward the north the Jarbidge Mountains slope down to the Snake 

River valley or Shoshone Basin, a vast, nearly level dissected area, 

50 to 60 miles wide, surrounded by deeply sculptured mountains and 

extending in a curved course, concave to the north, entirely across 

southern Idaho.8 The master stream is Snake River, which flows 

in a westerly course through the plain, here and there in box canyons. 

The plain ranges in elevation from about 3,000 feet above sea level 

on the west to about 6,000 feet on the east. It is mainly of constructional origin and is underlain by Tertiary and Quaternary basaltic 

lava flows and lake beds. Some of the more recent lavas are probably 

not more than 100 years old.*

A good partial section of the lavas is exposed in the right or north 

wall of the Snake River canyon just below the celebrated Shoshone 

Falls, and a less full section at the Salmon River dam and crossing of 

the Jarbidge road about 30 miles south of Twin Falls.

The Jarbidge region is drained mainly by branches of Brimeau 

River, which from its source south of Charleston, Nev., flows in gen-

* Russell, I. C., Geology and water resources of the Snake River Plains of Idaho : U. S. 

Geol. Surrey Bull. 199, 1902.

* Russell, I. C., op. cit, p. 61.
PHYSICAL FEATURES. 7

eral north-northwestward about 80 miles to Snake River. It crosses 

the State lino at a point about 12 miles west of -Jarbidge River, 

which joins it 22 miles farther north. The next main tributary to the 

Snake on the east is Salmon River, which flows about parallel with 

the Bruneau and crosses the State line 50 miles east of it.

From the convex southern edge of the plain, at an elevation of 

about 4,000 feet, between Salmon and Bruneau rivers, the surface 

rises in a long, gerytle piedmont slope to the crest of the Jarbidge 

Mountains, the topography being on the whole in marked contrast 

with that of the rugged foothills on the Great Basin side, to the 

south. In the vicinity of the State line the elevation in general is 

about 6,000 feet; 6 miles farther south, at the foot of the high divide, 

it is about 7,000 feet. The highest ridges attain almost 11,000 feet. 

Near their headwaters the forks of Jarbidge River have cut deep 

trenches into the elevated volcanic plateau, which reaches its highest 

point south and east of Jarbidge.

The high ground extending northeastward from the Jarbidge district and mountains, usually mistaken for the Great Basin divide, 

is not the divide but a long spur ridge on the Snake River side.

JARBIDGE MOUNTAINS.

Of the mountains bounding the Snake River valley on the south, 

the Jarbidge Mountains are among the most conspicuous and lofty. 

The great watershed culminates in them at an elevation of nearly 

11,000 feet. They are about 12 miles wide and trend in an east-west 

direction across the heads of the northward-flowing Jarbidge River 

and its East Fork. The mountains consist largely of a huge pile of 

Tertiary volcanic rocks. The main ridges in the Jarbidge district 

trend with the drainage, at right angles to the axis of the divide, as 

shown in Plate I. The trend is not wholly due to consequent drainage 

on a sloping constructional surface, as would at first appear, but 

seems in general to harmonize with the trend of the Great Basin 

topography on the south and probably owes its origin to lines of 

fissuring or faulting produced in connection with the igneous flows 

and uplift.

The lavas were erupted in at least two distinct and extensive 

epochs, separated by a considerable time interval, during which 

subaerial erosion scored the surface and developed a drainage system 

similar to that of to-day. Those of the first epoch, the old rhyolites, 

were erupted through and rest on a surface of low relief, ascribed to 

erosion during Cretaceous, Eocene, and part of later Tertiary time.

The lavas of the later epoch were more fluidal and resistant than 

those of the first epoch. For convenience they are referred to collectively as the young or rim-rock lavas. They were freely poured
8 THE JARBIDGE MINING DISTRICT, NEVADA.

out, completely flooding the lower slopes of the region and burying 

a large part of the older lavas, in places to depths of nearly 2,000 

feet. This second epoch of eruption left the Jarbidge Mountain 

region roughly in the f6rm of a huge elongated east-west dome which 

rose perhaps 1,000 feet or more above the rocks that form the highest 

peaks of to-day and which, by reason of the fluidity of the later 

lavas, had a comparatively smooth surface. From the summit of 

the dome the surface declined in long, gentle slopes in nearly all 

directions, especially to the flat-lying Snake River Plains, about 20 

miles distant on the north, and to the base of Elk Mountain, about 

equally distant on the east.

On this new constructional domal surface, at the end of the second 

epoch of volcanism, subaerial erosion resumed its work of denudation, and the present drainage system, with its main courses approximately parallel to the lines of the intervolcanic epoch, was 

established. The higher part of the dome, where the extremes of 

precipitation and temperature were greatest and where there were 

lines of weakness due to volcanism, including perhaps crater openings of considerable depth, was the most deeply dissected.

A notable and economically important feature of this process of 

denudation was the stripping off of the roof or cover of the dome, 

the great blanket of the younger lavas, which are now worn back to 

the east side of the East Fork valley on the east and beyond the 

Jack Creek valley on the north. The eroded edges of these lavas, 

rising nearly 1,000 feet above Jack Hole and Jarbidge River, form 

a steep inward-facing scarp or rim rock, which rests upon and encircles the slopes of the mountains on the north and rises to the 

10,000-foot contour where it crosses the divide on the east, (See 

PL L)

As soon as the young lava covering was worn through at or near 

the summit of the dome, erosion became concentrated along the contact of this covering with the underlying softer old lava, and it has 

been a controlling factor in determining the present dominant topographic features of the district.

Simultaneously and almost coextensively with the stripping back 

of the young lava covering, the main streams, in the process of down 

cutting along the contact and subsequently below it, shifted their 

channels laterally down the slope of the dome Jarbidge River to 

the west, East Fork to the east, and Jack Creek to the north. This 

migration of the channels has produced precipitous inward-facing 

cliffs bounding these streams on the outer side of the dome east of 

East Fork, north of Jack Creek, and west of Jarbidge River and 

contrasting strongly with the long and comparatively gentle slopes 

on the opposite or inner sides, across which the streams have migrated. It has also resulted in the present occupation by East Fork
PHYSICAL FEATURES. V

and the Jarbidge of practically the same drainage lines that existed 

in the intervolcanic epoch, before the rim-rock lavas were poured 

out.

The denudation and dissection of the old lavas that followed the 

removal of the young-lava covering has resulted in two distinct types 

of topography. One type, shown in Plate III, is adolescent. It appears in the old-lava area that occupies the heart of the district and 

extends from a line west of Jarbidge Elver to a line east of East 

Fork. The other type appears in the young-lava or piedmont portion of the field and is young.

The old-lava area contains the dominant features of the district 

the high, rugged north-south ridge between Jarbidge Eiver and East 

Fork and the deep valleys of these two streams, which are sunk to 

a point below the 6,000-foot contour, or about 5,000 feet below the 

tops of the neighboring mountains.

Of the seven culminating peaks, which, as shown on Plate II, are 

about a mile apart, the most northerly and highest is Jarbidge Peak. 

This and the four succeeding peaks to the south, which nearly equal 

it in height, are conspicuous to the traveler approaching the district 

from the Idaho side, being visible at a distance of 90 to 100 miles 

on a clear day. They are commonly known as the Crater Peaks, 

or collectively as the Crater Eange. 

The Crater Eange is the most striking feature of the district topographically, geologically, and economically. It exceeds in altitude 

the adjoining Great Basin divide. It is a huge mass of volcanic rocks 

and contains nearly all the mineral deposits of the district. It trends 

N. 20° W., as do also many of the veins, .a fact which suggests that 

the orogenic forces which produced the range or determined its strike 

probably also produced the fissures containing the N. 20° W. veins. 

The west slope declines more or less uniformly at an angle of about 

28° to Jarbidge Eiver; the east slope is rugged and breaks off 

abruptly, as shown in Plates IV, A ; V, A and B.

Near the middle of the area, from Jarbidge Eiver to the top of the 

north end of the Crater Eange, the surface rises about 4,300 feet in 

a horizontal distance of 1£ miles, or at the rate of nearly 3,000 feet 

to the mile.

The topography of the old-lava area is of the type produced mainly 

by water erosion in an° elevated country of horizontally deposited 

volcanic rocks. It is characterized by long, high, and in places narrow, though not usually sharp-crested ridges, with smooth or even 

contours, and correspondingly deep, mostly V-shaped valleys and 

gulches bounded by slopes that rise in many places for considerable 

distances at angles of nearly 45°. (See Pis. I and III.)

In portions of their courses even the main streams occupy steepwalled canyons, and locally, as back of the lower part of Jarbidge
10 THE JAKBIDGE MINING DISTRICT, NEVADA.

and west of Bear Creek, the uniformity of the mountain slopes is 

interrupted by vertical cliffs or scarps several hundred to a thousand 

feet in height, from whose bases long trains of talus or rock debris 

extend down toward the valleys. Some of the scarps are probably 

due to faulting.

On the east the Crater Range or, more exactly, its saddles, break 

off into steep-walled U-shaped cirques, amphitheaters, or basins, commonly known in this region as " craters," in which head most of the 

perennial tributaries of East Fork and Jack Creek. (See Pis. IV, A; 

V, A; VI, A.) There are six of these " craters." They are known 

in numerical order from north to south as First Crater, Second Crater, etc. Like the peaks with which they alternate, they are about a 

mile apart. They are separated by long sloping spur ridges, and 

some of them are confined by walls 1,000 to 1,200 feet high on the 

west. It is quite possible, to judge from tuff, breccia, and other volcanic debris observed in the walls, that some of them may really represent or be remnants of craters. In the main, however, they owe 

their general outline and probably their origin to former local or 

mountain glaciers that headed in them. They open toward the east 

or northeast, and in this direction their floors slope gently. The 

glaciated character of the valleys (U-shaped in cross section) into 

which they open is shown in Plate XIX, A. Since the disappearance 

of the glaciers the forms of the cirques have been modified by subaerial erosion, including that of snowslides or avalanches. Snow and 

ice now locally remain in some of them throughout the year, and the 

cliffs that confine them on all but the open side are flanked by belts 

of talus rising with steep slope usually about 200 feet above the floor.

The determination of the position of the cirques on the east slope 

of the range and their erosion by snow and ice have been peculiarly 

favored by the local climatic conditions. Throughout the winter, 

including the periods of snowfall, the prevailing winds come from 

the west. They are generally violent and sweep the upper west slope 

of the range bare of fine talus or rock debris and snow, which they 

carry over the crest and deposit as huge cumulative drifts in the 

heads of the "craters." (See PI. VI, B.) Here in glacial time the 

lower layers of snow under pressure of the superincumbent load congealed into ice. In the process of congealment the ice annexed on 

its under surface large angular blocks and lesser rock debris plucked 

from the cliffs and talus. This rock material held firmly in its 

grasp the glacier used as a powerful instrument of erosion as it 

slowly moved down the steep, rocky slope.

To this process of head erosion is due the steepness of the cliffs 

at the heads of the " craters." It captured some of the cols, as shown 

in the central foreground of Plate VI. B, and considerable portions
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE V

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X. CRATER RANGE, EAST SLOl'E. 

Looking west from a point east of East Fork, 1 miles distant. Photograph by Claude C. Gillham, taken in October. The name Third Crater, at the left of Sugarloaf, should be Fifth Crater.

X. CRATER RANGE, 1'AHT OF EAST SLOPE. 

Looking south from apex of Altitude vein on east ridge. Shows peaks, ridge, and gulch topography and flow bedding in lavas at left. Photograph by Claude C. Gillham.
U. 8. GEOLOGICAL SURVEY BULLETIN 741 PLATE VI

A. SIXTH CRATER, HEAD OF EAST FORK OF JARBIDGE RIVER. 

Looking south-southeast from south slope of Government Peak. Photograph by Claude C. Gillham, taken September j

B. CREST OF CRATER RANGE, MIDDLE PART.

Looking south from Jarbidge Peak. Rugged topography in old rhyolite at head of Jarbidge River in right background; heavy flow bedding in old rhyolite near head of East Fork in left background.

Dark lava caps old rhyolite in RIack Peak. Photograph by Claude C. Gillham, taken August 31.
PHYSICAL FEATURES. 11

of some of the most prominent peaks, as shown in Plate V, B. Head 

erosion in a much milder form than in glacial time is still in progress and will doubtless eventually destroy the picturesque crest of 

the entire range. The climate at the time the glaciers reached their 

zenith probably did not differ much from that of to-day.

The old-lava area on the whole is comparatively free from the 

impassable precipitous barriers that usually characterize a country 

of its scale of topography and class of rocks. It is mostly accessible 

to the pedestrian, and with slight detours a horse can be taken into 

almost any part of it.

The topography of the younger or rim-rock lava area contrasts 

strongly with that of the old-lava area. It resembles in its main 

features that of the adjoining Snake River Plains. The area consists in general of a gently sloping, rarely benched or scarped mesa 

or piedmont plain partly dissected by more or less parallel narrow, 

steep-walled box or V-shaped canyons. Its youthful character is due 

in some measure to the greater resistance of the rocks in which it 

is carved but mainly to the facts that its relatively dry climate essentially exempts it from the attacks of subaerial erosion and that 

the streams which rise in the moister mountain regions in crossing 

it erode only the bottoms of their channels, leaving the sides and 

upper edges of the valley walls intact.

Jarbidge River, the largest stream in the district, heads on the 

upper north slope of the Great Basin divide, in the angle formed 

by the junction of the divide with the Crater Range, at an elevation of about 9,000 feet. It flows in general nearly north through 

the western part of the district (PI. I). After receiving the East 

Fork a few miles beyond the Idaho State line, it joins the Bruneau 

about 20 miles farther north, of which it is seemingly the largest 

tributary. It is difficult to ford during the spring and early in 

summer.

In the upper part.of its course the Jarbidge receives numerous 

tributaries, the chief of which are Fox Creek and Pine Creek. In 

the remainder of the district its principal tributaries are Bear Creek 

and Deer Creek on the west and Bonanza Gulch, Bourne Gulch, and 

Jack Creek on the east. From Pine Creek nearly to Jack Creek, a 

distance of about 4 miles, it flows through a gravel-floored, locally 

terraced flat about 500 feet in width (PI. Ill) and has a fall of 

about 160 feet to the mile. After entering the young-lava area a 

short distance above Jack Creek its course is mostly in a canyon.

Jack Creek, a fine stream, heads in the First Crater and adjoining 

territory on the southeast. It occupies in a sense'a piedmont valley 

bounded by the old-lava mountains on the south and the young lavas 

forming the rim rock on the north.

13253 23 2
12 THE JARBIDGE MINING DISTRICT, NEVADA.

East Fork, which drains the eastern part of the district, is nearly 

as large as the Jarbidge, but its valley is more rugged. Its course 

through the young-lava area, which it enters in the northern part 

of the district, is mainly in a narrow canyon, whose walls have in 

places an almost sheer drop of 1,000 feet and can be crossed only 

by making a detour of several miles to the north by way of the 

Robinson Hole trail.

The extreme southeastern and south-central portions of the district, which are relatively unimportant so far as mining developments are concerned, drain, respectively, southeastward through 

Canyon, Cottonwood, and Camp creeks into Salmon River and 

southward through Marys River into the Humboldt.

GEOLOGY.

The Jarbidge district lies almost wholly in an area of Tertiary 

volcanic rocks resting on an eroded surface of folded and tilted sedimentary rocks, principally Paleozoic, which are cut by granitic intrusives. (See PL I.) The rock groups of the district, beginning 

with the oldest, are Paleozoic sedimentary rocks, post-Paleozoic 

intrusive rocks, early Tertiary lavas, late Tertiary lavas, Tertiary 

sedimentary rocks, and Quaternary deposits. The valuable mineral 

deposits occur in the early Tertiary lavas.

SEDIMENTARY ROCKS. 

PALEOZOIC ROCKS.

Sedimentary rocks regarded as Paleozoic occur at the western 

margin of the Jarbidge district and extend southward across the 

divide into the Great Basin. (See PL I.) In this vicinity they constitute in part the high north-south ridge between the Jarbidge 

drainage basin on the east and that of Bruneau River on the west, 

whence they extend westward into what is locally known as the 

Quartzite Range and also as the Copper Mountain Range.

These rocks consist, in order of deposition, of quartzite, limestone, 

and shale. They have been considerably disturbed, faulted, tilted, 

and folded. They dip steeply to the north at angles of 60° and 

apparently exhibit a general thickness of several thousand feet. 

They rest largely upon gray, coarsely crystalline hornblende granite, 

which seems to be intrusive, and they are locally overlain or capped 

by thin flows of rhyolite. The limestone is also cut by dikes of 

granodiorite of about the same age as the granite, or slightly 

younger.5 Some of these rocks on the southwest were casually observed by the writer along the Elko-Jarbidge road.

B Sweetser, N. W., Geology of tlie Jarbidge mining district: Min. and Sci. Press, vol. 

101, p. 871, 1910.
GEOLOGY. 13

Near the center of the Jarbidge district are outcrops thought to1 

belong to these old rocks, notably on the west slope of the Crater 

Range. Here, protruding boldly above the surface of the surrounding rhyolite, a reef of brecciated quartzite, commonly known as the 

" quartzite dike," extends interruptedly for about 2 miles in a northeasterly direction diagonally across the mountain side above the 

North Star and Buster mines and just below the 0. K. mine. It has 

an average width of about 200 feet. The quartzite is abundant in the 

Pavlak mine, and a short distance below the mine, at the foot of the 

bluff on the west side of Jarbidge River, occur large talus blocks of 

it, suggesting that the rock is probably in place in that vicinity also. 

These and similar data obtained elsewhere in the district indicate a 

thinning out of the overlying rhyolite toward the west and the presence of the underlying eroded surface of the Copper Mountain sediments sloping down eastward to a level probably not far below the 

bed of Jarbidge River.

On the northeast, where the quartzite reef crosses Bourne Gulch at 

an elevation of nearly 7,000 feet, it dips 80° NW. and shows on the 

hanging wall considerable fault breccia and a.little black slate or 

chloritic and graphitic schist containing needles and lath-shaped 

bodies of sericite and other metamorphic minerals. The rock seems 

in general to be altered to a relatively massive quartzite by silicification, but where not altered it consists of medium-grained whitish or 

light-gray, very hard quartzite. Except for a few layers of parallel 

sheeting it is structureless. A specimen of the rock from the Pavlak 

mine was examined microscopically and found to be very fine and 

irregularly grained, greatly shattered, and recemented by secondary 

white silica. It also contains about 3 per cent of interstitial sericite 

or white mica in the form of foils and shreds and a little chlorite. 

The margins of the constituent quartz grains are sharply etched and 

embayed by corrosion. Most of the grains are glassy, but some are 

milky. Many of them are elongated and, being longitudinally oriented, give to the rock a structure resmbling schistosity. In the 

larger grains the extinction is wavy, owing to the destruction of the 

optical continuity by pressure.

About half a mile southeast of the quartzite reef, to the north of 

the Bluster and the Pick and Shovel mines, chiefly on the south side 

of Bonanza Gulch, pale-greenish siliceous shale or sericitic quartzite 

and conglomerate crop out tlirough the rhyolite. The outcrops extend interruptedly westward down the gulch for about a quarter of 

a mile. These rocks appear younger than the quartzite reef, with 

which they are in marked unconformity and which has seemingly 

supplied much of the material in the conglomerate.

The conglomerate, of which about 80 feet is exposed, occurs toward 

the base or lower end of the croppings. It ranges from fine and
14 THE JARBIDGE MINING DISTRICT, NEVADA.

arkosic to coarse and bouldery. It consists mainly of boulders and 

pebbles of quartzite, black massive argillaceous rock freely traversed 

by quartz veinlets, and some old basalt or diabase. It is overlain by 

impure sandstone or graywacke, which seems to grade upward into 

the shale. Both the conglomerate and the shale are cut by rhyolite 

dikes, one of which is about 30 feet wide. The shale is more or less 

massive and in part banded, and the banding apparently represents 

lines of stratification. The rocks in general dip gently southeastward, 

into the mountain. Their deeply buried portions are probably the 

source of crushed small masses and fragments of shale and other sediments found in the veins and associated fault gouge higher up in the 

mountains. Their outcrops on Bonanza Gulch indicate a thickness 

of at least 500 feet. At the upper end of Jarbidge, in the west side 

of the valley, at less than than 100 feet above the river, occurs black 

slate which appears to be upf aulted in the rhyolite.

The sedimentary rocks above described are referred collectively to 

the Paleozoic on account of their resemblance to known Paleozoic 

rocks observed in the surrounding regions.

There seems to be. no doubt that the great pile of lava composing 

the Jarbidge Mountains rests upon an eroded surface that consists 

chiefly of these sedimentary rocks and is continuous beneath the 

lavas with that of the Great Basin on the south, Copper Mountain 

on the west, and Elk Mountain on the east.

The nearest locality at which the section of these Paleozoic rocks 

has been worked out in detail and their succession is well known is 

Eureka, Nev., 160 miles to the south. The section at that place appears in the earlier report.6 None of these rocks in the Jarbidge district seem to have suffered deep-seated metarnorphism.

TERTIARY (?) ROCKS. 

MIOCENE (?).

In the Starlight, Altitude, and other mines in the upper part of 

the Crater Kange and at the same general elevation at the surface 

near the heads of Bonanza and Bourne gulches occur small bodies 

of lignitic shale and dark slaty sandstone whose general similarity 

suggests that sedimentary rocks of this class may be locally interbedded in the old rhyolites. Wherever seen by the writer these 

rocks seem to have reached their present position by faulting or 

sliding as of talus. In the upper part of Bourne Gulch, however, 

on the Winner claim and adjoining ground, the rocks are reported to 

be in place, to crop out o\7 er a considerable area, to show a thickness 

of at least 20 feet, and to have a gentle dip.

 U. S. Geol. Survey Bull. 497, pp. 30-31, 1912.
GEOLOGY. 15

Because of the probability that these rocks are interbedded in the 

old rhyolites they are provisionally referred to the Miocene.

PLIOCENE (1).

According to A. L. Rinearson and others, there occur on the lower 

part of Jack Creek a few exposures of deposits of whitish to gray 

friable sandstone or waterlaid volcanic ash similar to that reported 

by prospectors on the south side of the Jarbidge Mountains,7 described in the present report in connection with the Charleston district (p. 81) and referred to the Humboldt formation, of middle 

Pliocene age. It is quite possible that some of these deposits may be 

interbedded in the rim-rock lavas.

QUATERNARY DEPOSITS.

The Quaternary rocks are relatively unimportant. They comprise 

glacial and snowslide deposits, talus, and alluvium.

In the " craters " and at the head of Jarbidge River occur deposits 

of bouldery clay which seems to have been formed by local glaciers.

The snowslide deposits occur mainly as crude fan-shaped accumulations at the mouths of some of the main gulches and craters, as at 

Snowslide Gulch. They consist of a heterogeneous mixture of angular rock debris, gulch-scour clay, and demolished timber, gathered 

and mixed pellmell by the avalanche. They reach 40 feet in thickness and a quarter of a mile in extent.

Trains or belts of talus, usually coarse, extend from the foot of 

the cliffs down toward the valleys, as in the head of Bonanza and 

Gorge gulches and in First Crater (PL IV, A).

Deposits of stream-laid gravel and sand floor the open portions 

of the main valleys, especially the Jarbidge Valley, from a point 

near Pine Creek nearly to Jack Creek, a distance of about 4 miles, 

with an average width of about 500 feet, as shown in Plate III. 

They consist mainly of old-lava pebbles that range from fine to 

coarse but are mostly above medium in size. Below Jarbidge, where 

they have been exploited, they have a thickness of more than 14 feet.

IGNEOUS ROCKS.

INTRUSIVE GRANITIC ROCKS (CRETACEOUS?).

The oldest igneous rocks consist of stocks and dikes of granular 

granitic rocks that intrude the Paleozoic sediments. The most 

abundant of them is a gray, coarsely crystalline hornblende granite 

that is extensively exposed underlying and intruded into the Paleozoic sedimentary rocks southwest and west of the district.8

7 U. S. Geol. Survey Bull. 497, p. 31, 1912.

8 Sweetser, N. W., op. cit., p. 871.
16 THE JAKBIDGE MINING DISTRICT, NEVADA.

After the intrusion both the granite and the Paleozoic rocks were 

further intruded and cut by dikes of granodiorite. A small body 

of this rock crops out through the sediments and their rhyolite covering in the upper part of Bonanza Gulch, north of the Bluster 

mine. It is a red medium-grained rock composed essentially of 

soda-lime and alkali feldspars in about equal amount, hornblende, 

and quartz. It contains numerous roughly equidimensional dark or 

dull-green crystals of hornblende, of which the largest are nearly 

a quarter of an inch in length.

The intrusive granitic rocks are regarded as probably of Cretaceous age and very likely belong to the same general period of intrusion as the batholiths of California and western Nevada. They 

are of economic importance, because ore deposits found in association 

with them in the Paleozoic sediments in the adjoining Charleston 

district seem to be genetically connected with their intrusion.

It is quite probable that deposits similar to those of Charleston or 

Copper Mountain and of the same age occur in the Jarbidge district, more or less deeply buried under the rhyolite.

TERTIARY VOLCANIC ROCKS. 

GENERAL FEATURES.

The intrusion, deformation, and erosion of the Paleozoic sediments were followed by the eruption of Tertiary lavas that more or 

less completely flooded the region. It was recognized by the Fortieth 

Parallel and other surveys that the Great Basin shows a variety of 

Tertiary lavas which are identical over wide areas and were erupted 

in somewhat the same succession. This succession in general is rhyolite, andesite, and basalt.

Among these rocks the most abundant and widely distributed are 

the rhyelites.9 The volcanic rocks in the Jarbidge district, as shown 

by a comparison with the studies of the Fortieth Parallel and other 

surveys, plainly belong to this family.

Ehyolites are glassy igneous rocks which form surface flows and 

have about the same chemical composition as granites. They are the 

volcanic equivalents of the granites, having been produced by the 

consolidation of a granite magma under volcanic conditions. They 

are highly acidic, most of them containing free silica in the form 

of quartz. In color they are generally white, pink, purple, or dark 

brown. The dense, pasty groundmass may contain phenocrysts of 

orthoclase, quartz, and plagioclase, with small amounts of biotite, 

augite, and hornblende.

The rhyolites of Jarbidge were erupted in at least two distinct 

epochs, separated by a considerable interval of erosion, and they are

9 U. S. Geol. Expl. 40th Par. Kept., vol. 1, 1878, p. 606.
GEOLOGY. 17

accordingly described as the earlier or old rhyolites and the later, 

rim-rock, or young rhyolites.

OLD RHYOLITES (MIOCENE 1). 

OCCUBRENCE AND DISTBIBUTION.

The economically most important and interesting of the volcanic 

rocks are the old rhyolites. On the eroded surface of the Paleozoic 

sediments they were poured out, mainly in successive broad flows, 

until they aggregated nearly 6,000 feet in thickness, measured from 

the floors of the old valleys to the tops of the neighboring mountains. They seem to have been erupted mainly along a fissure or 

series of fissures, inconspicuous craters or vents coinciding with the 

axis of the Crater Kange, whence they spread widely in all directions.

At or soon after the end of the eruptions the rocks were fissured, 

in part, perhaps, by contraction due to the cooling of the individual 

flows and heated mass, but mainly by crustal movement attended by 

faulting, which was mostly normal. .Most of the fissures thus produced are now occupied by the gold-bearing quartz veins of the 

district.

The erosive processes that followed eruption and gave the region 

its present surface relief are described on pages 7-11.

Except for a small area at the crest of the Crater Range, the 

present area of exposure of these rocks in the district, essentially as 

shown on Plate I, extends from the region beyond the Great Basin 

divide on the south to Jack Creek, Rimrock, and Robinson Hole on 

the north, a distance of 12 miles or more, and from the region west 

of the Jarbidge district to and beyond East Fork on the east, a distance of about 9 miles, thus occupying about 100 square miles. Beneath the young-lava covering they seem also to have a considerable 

extent to the southeast, where they are exposed mainly in the deeply 

cut valleys on the headwaters of 'Salmon and Marys rivers.

Measured vertically from the summit of the Crater Range to Jarbidge River, which is still sinking its bed into them, the old lavas, 

after having suffered two periods of erosion, still show a thickness of 

nearly 5,000 feet. On the west they have been largely removed by 

erosion and are represented only by thin outliers capping the Paleozoic rocks on the summits of the Copper Mountain Range. On the 

east and north they pass unconformably beneath and are buried by 

the younger lavas described on page 20.

As seen in the field, the rocks exhibit a great variety of colors, of 

which the prevailing is pinkish or reddish ash-gray. Greenish, 

reddish, and purple tints are also characteristic, and practically the 

whole northeastern part of the Crater Range is stained a bright 

brick-red by iron oxide.
18 THE JARIBIDGE MINING DISTRICT, NEVADA.

The rocks occur in successive flows, probably a hundred or more 

in number, resting unconformably one upon another and ranging 

apparently from 30 to 40 feet to several hundred feet in thickness. 

The flows are thinner in the upper part of the section, toward the 

top of the mountains. (See PI. VI, B.) In general they are ill defined, particularly in the vicinity of the veins and mines where rock 

alteration has taken place. Locally vegetation is helpful in differentiating them. They are best exposed on East Fork (see PI. VI, 2?, 

left background), where at one point twelve or more successive flows 

can be differentiated.

The best exposure of these flows on Jarbidge River is near its head 

on the west side, downstream from the Ozark lode. Here the flows 

dip gently southwest, but on East Fork they dip gently to the 

southeast, the difference in direction of dip of the two localities 

being due to their position in diverging sectors of the domical uplift.

In some localities, as shown in the cliffs back of Jarbidge and 

along Bear Creek, the flows exhibit crude columnar structure caused 

in places by cooling of the heated lava flows individually and elsewhere by jointing. In places the columns weather into pinnacled 

forms (PI. VII). Some of the flows are also cavernous, with grottoes 

as large as 7 feet in diameter, examples of which are conspicuous 

in the high cliffs on Bear Creek. Three-quarters of a mile above 

Jarbidge one of these openings, known as the Cave, having a floor 

width of about 20 feet and a height of 16 feet, extends some 60 feet 

into the mountain. The caverns were formed mainly by uneven congealment of the lava while yet in motion, and in some of them, as 

in the Cave, their forms have been determined largely by faulting 

and dissolving of the rock mass by circulating acidic solutions. 

Similar features on a smaller scale occur in hand specimens as druses, 

many of them lined with hyalite or opaline chalcedony.

The flows are in the main nearly horizontal. They include locally 

intercalated sheets of black and brown obsidian or glass and also, 

particularly in the upper part of the section, the usual coarser volcanic ejecta, such as ash, tuffs, breccias, agglomerates, nodules, bombs, 

and lapilli, more or less widely distributed. Nodular and bomb 

phases occur on and near the Ozark ground, near the head of Jarbidge River.

STBUCTUBE.

The rocks show gentle folding and fault dislocations, particularly 

along the vein fissures, as on Bear Creek, in the Long Hike mine, and 

along the quartzite reef. The fault along the quartzite reef is probably one of the major faults of the district and is older than the veins.

The faults, including the vein-fissure faults, seem to be mostly normal. In general they strike about north-northwest, nearly parallel
GEOLOGY. 19

with the Crater Range. They occur roughly in two groups the 

west group, mainly in the west slope of the Crater Range and along 

Jarbidge River, and the east or Crater group, mainly in the upper 

east slope of the range. Those of the west group mostly dip to the 

east, into the range; those of the east group strike more nearly north 

than those of the west group and dip steeply to the west, into the 

range and against the dip of the west group.

The faults probably represent in part prevolcanic deformation 

lines in the underlying rocks that extend horizontally far beyond the 

Jarbidge district, and they were subsequently extended upward 

through the lavas by widespread postvolcanic disturbances.

The prevalence of normal faulting, however, and the convergent 

dips of the two groups or systems from opposite sides of the axis of 

the range indicate that some of the fissures are probably also in part 

due to the subsidence of the axis of the Crater Range and the adjustment that followed the outpouring of the lavas. In places fissuring 

may have been aided by contraction of the heated lava mass or part 

of it in cooling.

The rocks are cut by rhyolite dikes, which are similar in character 

to the extruded rocks and were probably derived from the same 

general magma. Examples may be seen in Bonanza Gulch below 

the Pick and Shovel property.

The rocks normally consist of a fine-grained dense or aphanitic 

groundmass with equidimensional phenocrysts of quartz and feldspar 0.2 inch or less in diameter that give to the rock a porphyritic 

aspect. The quartz is the more abundant mineral. In places the 

phenocrysts are so plentiful as to give to the rock the appearance of 

a medium-grained granite, but in general the groundmass much 

exceeds the phenocrysts in volume. Banding or flow structure is 

locally present but not usually pronounced. The rocks in general 

are considerably altered. In some areas, particularly in the vicinity 

of veins and fissures, they are highly altered by metasomatic replacement, the chief changes being devitrification and silicification of the 

rocks almost as a whole, attended by the development of certain new 

or secondary minerals.

The feldspars, which are mostly orthoclase, are usually much 

weathered, kaolinized, or reduced to chalky spots of crystalline 

chlorite, sericite, and other minerals and where corroded out at the 

surface give to the pebbles in the river gravels and to long-exposed 

talus a pitted or pock-marked appearance.

CHEMICAL COMPOSITION.

The chemical composition of a normal specimen of the old rhyolite 

from the South Hill Top tunnel at the upper end of Jarbidge is 

shown in column 1 of the accompanying table of analyses.
20 THE JABBIDGE MINING DISTRICT, NEVADA. 

Analyses of Nevada rhyolites.

SiOi..... ......................................................

Al|03 .... ......................................................

FesOj.. ........................................................

FeO..... ......................................................

MgO...........................................................

CaO.. ...... ....................................................

NajO..........................................................

K8 0..... ......................................................

HjO...... ....................................................

HS 0+..... ....................................................

TiO*.. ........... ..............................................

PS 06 ... ........................................................

1

76.77

12.63

1.13

.27

.07

.21

.30

6.43

.49

1.55

.18

.04

100. 07

2

76.80

11.64

.66

.50

Tr.

.43

2.53

6.69

3

75.29

.71

2.90

5.34

4

71.00

1. Specimen No. 33, old rhyolite, Jarbidge district. George Steiger, analyst.

2. Specimen No. 166, Fortieth, Parallel Survey, typical rhyolite, Mopung Hills, Humboldt County, Nev.

3. 4. Specimens Nos. 1 and 57, young rhyolite, Jarbidge district. George Steiger, analyst.

The specimen represented by analysis 1 is a fine-grained purplegray, slightly porphyritic rock with a glassy felsitic to microcrystalline spherulitic groundmass and contains small, irregular phenocrysts of reddish or pale wine-colored glassy quartz and dull, inconspicuous weathered kaolinized and sericitized orthoclase. It is 

closely banded with fluidal structure and contains a few small elongated macroscopic and microscopic druses and parallel veinlets or 

stringers of apparently secondary quartz, in association with which 

is developed considerable pyrite. Pyrite in small macroscopic and 

microscopic cubes and grains is likewise disseminated throughout 

the groundmass, as is also considerable fine hematite or ferritic material. Magnetite and apatite are present as accessories.

Comparison with analyses tabulated by H. S. Washington 10 shows 

that the Jarbidge rock is remarkably low in sodium and is classified 

in the quantitative system as bisbose (1.3.1.1"). It is evident, however, that in spite of the fresh appearance of the rock it has undergone much alteration, which would have a tendency to increase the 

percentage of silica and potassium and to reduce that of sodium.

Analysis 2 represents the most siliceous of the typical rhyolites 

whose analyses are given in the report of the Fortieth Parallel 

Survey and is here quoted for comparison. The specimen analyzed 

came from the Mopung Hills, jn western Humboldt County, Nev., and, 

to judge from the description given, is very similar to the Jarbidge 

rock of analysis 1. The analyses show a very close agreement between 

these two rocks in their most abundant constituents, silica and potash.

YOUNG RHYOLITES (PLIOCENE?). 

OCCURRENCE AND DISTRIBUTION.

After a considerable interval of volcanic quiescence and vigorous 

subaerial erosion the young rhyolitic lavas were poured out from

10 U. S. Geol. Survey Prof. Paper 99, 1917, p. 55.
V. 8. GEOLOGICAL SURVEY BULLETIN 741 PLATE VII

PINNACLES AND JOINTING IN OLDER RHYOLITK.

Showing pinnacles carved and characteristic pseudo-columnar vertical jointing exposed by erosion 

and weathering on Jarbidge River below Jarhidge, near mouth of Moore Gulch. Compare 

with PI. IX, B, Photograph by E. C. Weyle.
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE VIII

A. BONANZA GULCH, JARBIDGK PEAK, AND MINES.

Looking cast from Elko road, on opposite side of Jarbidge Valley. Photograph by 

Claude C. Gillham.

HLACK PEAK, AT HEAD OF FOURTH CHATEK.

Looking southwest from south slope of Round Peak. Shows horizontal contact of vertical 

columnar dark young rhyolite with the underlying old rhyolite. Photograph by Claude C. 

Gillham, taken September 1.
GEOLOGY. 21

 essentially the same vents as the old lavas and covered their deeply 

eroded surface. The marked unconformity between the two formations is plainly seen in the northern and western parts of the district. (See PI. I.) Here the young rhyelites form a gently outwardsloping piedmont plain, which, extending beyond the district, merges 

into the flat-lying Snake River Plains on the north arid reaches the 

foot of Elk Mountain, 10 miles distant, on the east. They seem also 

to have a wide extent to the southeast and south, on the headwaters 

of Salmon and Marys rivers, respectively.

They were poured out at greater elevations than the old lavas; 

they were also more liquid, and, being erupted in successive flows 

conformably one upon another, they spread widely and reflooded 

the entire district more extensively than the old lavas, though not so 

deeply, and gave to the Jarbidge Mountains roughly the form of a 

huge east-west dome. On the outskirts of the district they rest in 

places upon the old eroded floor of Paleozoic rocks. Within the 

district they are best exposed on the north and east, where the eroded 

edges of their flows that terminate the surrounding plain form the 

inward-facing scarp or rim rock bounding Jack Creek valley on the 

north and East Fork on the east. Remnants of them seem also to 

occur in the crest of the Crater Range for instance, capping Jarbidge and Black peaks (PL VIII).

In the valleys and low places the lavas attained a probable thickness of 2,000 feet, as may be inferred in the vicinity of the junction 

of Jack Creek with Jarbidge River, where they still show a thickness of more than 1,000 feet. At ihe summit of the dome and the 

rim of the " crater," however, by reason of their fluidity and the 

steeper slopes, their thickness probably did not much exceed a few 

hundred feet.

Owing to the unevenness of the floor on which the lavas rest and 

to later erosion, their contact with the underlying old lavas is very 

irregular, as shown in the northern part of the district from Jack 

Hole westward (PL I). After crossing Jack Mountain near the 

0.1 d wagon road the contact line descends into Jarbidge Valley to a 

point near the forest station and about 400 feet above the river; 

this figure approximately expresses the depth to which the river 

has at this point sunk its channel into the old underlying lavas 

during the present period of erosion. Here the contact line is sharply 

deflected to the north and crosses the river at a sharp angle about a 

mile farther downstream, near the 5,800-foot contour, whence it bends 

back on the opposite side and crosses Telegraph Ridge at a point 2 

miles to the southwest, at an elevation of about 7,500 feet, between 

the old Elko wagon-road pass and the wireless-telegraph station, 

which stands upon the young lavas to the north of the contact.
22 THE JAEBIDGE MINING DISTRICT, NEVADA.

STBUCTUKE.

The young rhyolites occur mainly in homogeneous fine-grained 

flows conformably superimposed one upon another and dipping 

gently away from the mountains in quaquaversal manner. They 

are prevailingly dull reddish purple and reddish brown. They are 

as a rule closely though in places dimly banded by fluxion structure parallel with the flows and are comparatively free from volcanic ejecta. Locally, however, they contain intercalated sheets of 

finely tuffaceous and vesicular material which are drab, dull greenish, and black.

In places they are gently folded, slightly faulted, and vertically 

jointed and weather into castellated badland forms (PI. IX, 5), but 

compared with the old underlying lavas they have been on the whole 

not much disturbed or deformed. So far as observed, none of the 

dikes, veins, or fissures so freely traversing the old lavas occur in 

these rocks. From this it is inferred that the jointing and faulting 

in these young rhyolites are probably contemporaneous with the 

postvein faulting in the old rhyolites.

These rocks are lithoidal. They contrast strongly with the old 

rhyolites above described, having a much more basic appearance, 

and are locally known as basalt. In a few places they are medium 

grained or moderately porphyritic. They consist almost wholly of 

a dark-reddish or brownish-purple aphanitic groundmass, which 

usually is more or less closely banded by flow structure and grained 

and streaked by drawn vesicles. Macroscopic minerals are usually 

absent and if present are so few and small as to form a negligible 

percentage of the rock. The rocks have a more or less conchoidal 

fracture and weather purplish or dark reddish brown, owing mainly 

to oxidation of the iron content. They show none of the metasomatic or propylitic alteration occurring in the old rhyolite.

In column 3 of the table on page 20 is given a partial chemical 

analysis of a characteristic specimen of the young rhyolites. The 

specimen is a purple or dark reddish-brown aphanitic vesicular 

lithoidal rock, with small macroscopic drawn vesicles forming part 

of the generally closely banded fluidal structure, and contains very 

little quartz. It was collected from Telegraph Ridge, about a mile 

northwest of Jarbidge. The analysis shows a remarkably high percentage of silica for a rock of so basic an appearance, the silica being 

less than 1.5 per cent lower than that in the analysis of the old rhyolite, which is rich in quartz. It also shows that the silica must 

be contained almost wholly in the groundmas, either as tridymite 

or in some other form. In lime, soda, and potash content it stands 

close to analyses 1 and 2 and shows that in composition the rock on 

the whole is normal rhyolite.
GEOLOGY. 23

Analysis 4 represents a specimen from the northeastern part of the 

district at a point about a mile southeast of Robinson Hole, where the 

trail in leading up out of the Robinson Creek canyon reaches the top 

of the rim rock and the edge of the plain on the east. The specimen 

is a medium-grained black rock of vitreous luster resembling pitchstone. It consists essentially of dark-gray glass, charged with feldspathic and augitic (?) microlites, the whole showing very perfect 

fluidal banding, with subordinate areas of spherulitic structure.

AGE OF THE VOLCANIC HOCKS.

Formations of known age fixing closely the age of the rhyolites 

above described do not occur in the Jarbidge district. Throughout 

eastern Nevada and western Utah rhyolites and tuffs developed on a 

grand scale are regarded as Pliocene by King u and Hague.12 Also 

from evidence such as rhyolitic ejecta contained in lake beds furnished by detailed work in the area to the southwest, Emmons 13 concludes that the rhyolitic eruptions in this part of Nevada probably 

began in early Miocene time and continued through the Pliocene. 

The rhyolites that deeply flooded the Owyhee Mountains in the region 

about Silver City, Idaho, are referred by Lindgren 14 to the Miocene 

epoch and regarded as being erupted simultaneously with part of 

the great flows of the Columbia River basalt. Their deformational 

features, faulting, fissures, and ore deposits are similar to those of the 

older lavas in the Jarbidge district.

As the Mount Bennett rhyolite of Russell in the region near Mountain Home, Idaho, bears similar relations to the lavas of Snake 

River to those borne by the rhyolites of the Silver City region, and 

as it resembles and is correlated by Russell with the rhyolite underlying the Snake River Plains, as exposed at Shoshone Falls, which 

King 15 under the name trachyte refers to the Miocene, it seems probable that the rhyolites of Mount Bennett and Shoshone Falls are of 

the same age as those of the Silver City region and are probably 

Miocene. Therefore, to judge from the rhyolites in the surrounding 

regions, it seems probable that the rhyolites of the Jarbidge district 

range from the Miocene well into the Pliocene. The old rhyolites 

are regarded as probably late Miocene and the young rhyolites as 

middle Pliocene, or possibly later.

" King, Clarence, U. S. Geol. Expl. 40th Par. Kept., vol. 1, p. 694, 1878. 

11 Hague, Arnold, Geology of the Eureka district, Nev.: U. S. Geol. Survey MOD. 20, p. 

232, 1892.

13 Emmons, W. H., U. S. Geol. Survey Bull. 408, p. 35, 1910.

14 Lindgren, Waldemar, U. S. Geol. Survey Twentieth Ann. Rept., pt. 3, p. 116, 1900.

15 King, Clarence, U. S. Geol. Expl. 40th Par. Rept.. vol. 1, pp. 192-193, 1878.
24 THE JARBIDGE MINING DISTRICT, NEVADA.

MINERAL DEPOSITS.

OCCURRENCE AND DISTRIBUTION.

The mineral deposits that led to the discovery of the Jarbidge district in 1910 occur as tabular gold-bearing quartz fissure veins or 

lodes in the old rhyolites, with which, so far as this district is concerned, they are roughly coextensive. They are in general well defined, being more or less sharply separated from the country rock, 

and contain angular inclusions of rhyolite, sedimentary rocks, and 

seams of clay or gouge. Many of them have 1 to 8 inches of gouge 

on either wall. They seem obviously to belong to the group of propylitic veins, most of which were formed since the Miocene epoch. 

Among their characteristics is a peculiar alteration of the adjoining 

wall rock and a tendency to contain both gold and silver.

The veins are about 40 in number. They are in or associated with 

the Crater Range, the seat of volcanic eruption. They lie mainly 

between Jarbidge River and East Fork at various elevations between 

about 6,000 and 10,500 feet, or, in other words, they occur interruptedly through a vertical range of nearly 4,500 feet. Most of the veins 

lie within a belt about 4 miles wide, extending from a point near 

the mouth of Jack Creek on the north to and beyond the Great Basin 

divide and the head of Jarbidge River, 10 miles distant, on the south. 

Most of them are on the lower and middle west slope and the upper 

east slope of the Crater Range, and in general they have a northnorthwesterly strike and a nearly vertical dip, as shown in figure 2.

They range from 1 to 30 feet or more in width and from less than 

1,000 feet to several miles in length. Their outcrops, some of which 

are bold, prominent reefs rising in places 50 feet above the surface, 

extend interruptedly from an elevation of 6,000 feet to 10.800 feet, 

and some individual veins show a vertical range of nearly 2,000 feet. 

It seems probable that some of the veins may penetrate the underlying sedimentary and granitic rocks.

The veins in general consist of two main systems or groups, which, 

starting at the head of Jarbidge River on the south, gradually diverge northward into the western or Jarbidge River system and the 

eastern or Crater system; the two systems, however, are not everywhere sharply differentiated.

The veins of both systems occupy chiefly normal fault fissures, 

which seem to have been produced mainly by regional disturbances 

and in part by a sinking or parallel down faulting of the axial portion of the range that followed the first epoch of eruption, in consequence of which the fissures on either side dip in part steeply in 

opposite directions into the range those of the east system to the 

west and those of the west system to the east. Some veins of the two 

systems accordingly converge downward, and it is probable that
MINEBAL DEPOSITS. 25

some of the fissures meet or intersect in the deeply buried axial portion of the range.

In the fissures produced by extensive regional faulting more or 

less regularity in strike, dip, and vein content is to be expected, but 

in those due to local postvolcanic sinking and adjustment of the 

range there should naturally be more variations, including probably 

in most fissures change in dip at the contact of the lavas with the 

underlying older rocks.

WEST VEIN SYSTEM.

The western part of the mineral belt, comprising the veins of the 

west system, crosses Jarbidge River obliquely near the mouth of 

Bonanza Gulch and the Pavlak mine, whence it continues northnorthwestward across the lower part of Bear Creek nearly to Telegraph Pass. «

This system comprises the wider veins and more valuable deposits, 

such as those of the North Star, Pick and Shovel, and Bluster, and 

the more recently discovered deposits of the Starlight and Long 

Hike mines, on which the most extensive development work has been 

done. These veins lie mostly between elevations of 6,000 and 8,000 

feet. They are at a considerably lower geologic horizon than the 

veins of the Crater system. They also contain the most prominent 

croppings and are locally associated with conspicuous reefs of silicified wall rock. They are nearly all easily reached by wagon road 

or trail from the Jarbidge River valley. As shown in figure 2, 

they strike in general north-northwest and dip eastward into the 

mountains at angles of about 80°. They contain more brecciated 

material, and their walls are more irregular, less sharply defined, 

and show more extensive propylitic alteration than the veins of the 

east system.

The largest of these veins occur in a belt about 1 mile wide and 

3 miles long, bounded on the west by Jarbidge River and extending 

from Moore Gulch on the north to Gorge Gulch on the south.

EAST VEIN SYSTEM.

The east or Crater system of veins, represented mainly by the Altitude, Windy, Ben Hur, and Ajax, occurs mainly on the upper east 

slope of the Crater Range, between elevations of 9,000 and 10,800 

feet. From points on Jack Creek and Jenny Creek, a mile or more 

north of First Crater, they extend southward through the series of 

i; craters " and their intervening ridges to and beyond the Great 

Basin divide, a distance of about 10 miles (PI. V, A). They are 

reached by way of the Jack Creek and East Fork valleys or by 

trail from the upper part of Jarbidge River.
26 THE JARBIDGE MINING DISTRICT, NEVADA.

These veins in most respects contrast strongly with those of the 

west system. As shown in figure 2, they have a more northerly strike 

than the western veins, and some of them dip about 80° W., into the 

mountain. Their outcrops, which are usually inconspicuous, collectively show a vertical range of more than 4,000 feet. Their present 

exposures occur mostly at geologic horizons nearly 2,000 feet higher 

than the western veins, and accordingly they may be younger. They 

are narrower than the western veins, being usually from 1 to 4 feet 

in width, and are more persistent horizontally, some being said to 

have a length of 3 miles and to extend interruptedly for 6 or 7 miles. 

They are more sharply defined, with clean-cut walls that are free, 

and the footwall generally carries from 1 to 8 inches of clayey " talcose" gouge. The veins are closely banded, and some of the bands 

are separated by thin seams of gouge. These veins occupy mainly 

normal fissures produced in part by subsidence or down faulting of 

the axial mass of the range, with which they are nearly parallel.

CROSS VEIN SYSTEM.

Besides the two main systems above described there is a third or 

subordinate system whose veins strike northeast, almost at right 

angles to those of the other two. This third system, which for convenience may be referred to as the cross system, is represented along 

Jarbidge River by the Buster and Amazon veins; on the north by the 

so-called cross veins of Jack Creek, including the Moore vein; and 

on the south, toward the head of Jarbidge River, by the Jasper, Wonder, High Up, and Little Mud veins (fig. 2).

STRUCTURE AND COMPOSITION OF THE VEINS. 

OXIDIZED ORE.

The economic metals of the deposits are gold and silver. They 

occur in the form of native gold, gold-silver alloy, or electrum, and 

the silver-bearing minerals argentite, cerargyrite, and naumannite. 

The primary metallization produced mainly sulphides, chiefly 

argentite and pyrite, but from the oxidized portions of the veins 

pyrite has practically disappeared.

The chief gangue minerals are quartz and adularia, and a common 

feature is their macrocrystalline to cryptocrystalline character. The 

quartz is the more important, as its dominance or abundance favors 

the occurrence of the ore minerals, especially gold. Other gangue 

minerals and associated minerals are apatite, barite, calcite, chalcedony, chlorite, epidote, fluorite, hematite, hyalite, kaolin, halloysite, leverrierite, limonite, psilomelane, pyrolusite, marcasite, 

muscovite, opaline silica, orthoclase, pyrite, sericite, and talc. Four 

of these minerals barite, naumannite, halloysite, and leverrierite 

were first recognized in this camp in the present work.
MINERAL DEPOSITS. 27

0 IMO 3000 <MO MOO 75QQ Feet

Denotes general slr^e and dip of system

FKJUUH 2. Diagram sho-ving trend and relative position of principal veins in

Jarbldge district. 

13253 23 3
28 THE JABBIDGE MINING DISTRICT, NEVADA.

The veins are composed mainly of a characteristically laminated 

pseudomorphic milk-white quartz-adularia gangue (PI. X), which 

in the croppings and surface workings is usually stained reddish brown 

to blackish and yellowish by iron and manganese oxidation products. 

Some of them, as the Pavlak and the Pick and Shovel, also contain 

considerable fault breccia or fragments of silicified rhyolite country 

rock, fragments and seams of the underlying shale, slate, or quartzite, 

and seams or stringers of halloysite and leverrierite resembling talc, 

from all of which it is inferred that more or less faulting or movement accompanied and followed the fissuring and subsequent veining. 

The ore occurs mostly in crushed and brecciated portions of the veins, 

and the veins to the north of Bourne Gulch are softer and more sugarlike than those to the south.

So far as present workings extend, to depths of about 800 feet, the 

veins are about all oxidized. Exceptions occur in the Alpha, Norman, 

Starlight, and Bullion mines, where, as described on page 32, a 

small amount of sulphide ore has been found. Extension of development work well into the sulphide zone on a few of the veins would be 

of material aid in rendering a forecast for the future of the district.

In the gangue quartz is on the whole the dominant mineral, but it 

is more or less profusely intergrown with adularia, and in some veins 

the adularia, although not visible to the naked eye, greatly exceeds 

the quartz and constitutes the bulk of the vein. Specimens from the 

west system show from 10 to 60 per cent of adularia, and some from 

the Crater system as high as 90 per cent. Adularia or vein feldspar 

is a variety of orthoclase free from sodium. It is semitranslucent and 

has characteristic crystal form (PL IX, A). It has a hardness of 6 

and an index of refraction of about 1.524. It is mostly fine grained 

and is best studied under the microscope (PI. XI, A). Its abundance 

in the Jarbidge veins is of unusual interest, especially as quartz is the 

almost universal gangue mineral of auriferous veins. Its presence 

and abundance indicate that the Jarbidge veins were formed at fairly 

high temperature and at depths of probably less than 2,000 feet.

Only under the microscope does the proportion of quartz to adularia 

become apparent. The adularia occurs in individual crystals and 

grains intergrown with the quartz and only rarely shows cleavage. 

The crystals occur in several forms, of which the most plentiful and 

characteristic are small, thin tabular rhombic plates.

The following is a partial analysis of a normal specimen of ore 

from the North Star mine:

Partial analysis of ore from the North Star mine.

[George Steiger, analyst.]

SiO2 ____________________________________ 72. 28 

Na2O___________________________________ . 20 

KaO____________________________________ 11. 84
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE IX

A. ADULARIA, OR VEIN ORTHOCLASE.

Incrusting joint planes and fissure walls in rhyolilc horse in the 17-foot Bullion vein, in 

First Crater. The adularia forms a layer 0.1 inch thick. The areas that appear 

aphani tic consist also of adularia, but it is too tine grained to show its crystalline form 

on the scale of this photograph. Magnified 2 diameters.

B. JOINTING AND WEATHERING IN YOUNG RHYOLITE.

Shows characteristic vertical jointing and castellated badland forms of polygonal cross section 

produced by weathering. View on Jarbidge River near mouth of Deer Creek and Idaho State 

line, looking north. (Compare with PL VII.) Photograph by E. C. Weyle.
IT. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE X

GOLD-SILVER ORE WITH GANGUE OF PSEUDOMORPHIC QUARTZ AND ADULARIA

AFTER CALCITE.

From North Star (formerly Rourne) mine. Characteristic of the veins and ores of the Jarbidge

district.
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE'XI

-t. ADULVIUA 1\ SILVER-GOLD ORE IN RHYOLITE.

Showing normal occurrence, crystallization, and habit. The smooth light-colored areas are quartz; 

the black areas are argentite and pyrite. Ordinary light; magnified 380 diameters.

B. (JOLD-SILVER SULPHIDE ORE FROM ALPHA MINE.

Showing banding and relations of argeutite and pyrite in quartz-adularia-calcite gangue. The 

specimen contains a little native gold, which is not visible on this scale. Photograph of polished 

surface, magnified 3 diameters.
TJ. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE XII

PHOTOMICROGRAPH OF QUARTZ AND ADULARIA PSEUDOMORPHIC AFTER CALCITE.

From Pick and Shovel mine, 100-foot level. Example of the cellular, drusy, radial, and hladed 

structure characteristic of the Jarbidge veins. Magnified 40 diameters.
U. S. GEOLOGICAL SURVEY BULLKTIN 741 PLATE XIII

M

PilOXOMICHOGKAI'II OF GOLD ORE FROM NOKTH .STAR MINK

Shows character and manner of distribution of thegold in the quartz-adulariagangue 

(gray) and its association with urgcntite (.bluck), cliaracteristic of the Jarbiage 

district. The light area represents a hole in the thin section. Magnified 105 

diameters.
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE XIV

GOLD OiiES.

At "Blistery" phase, from Bluster mine.

B, Nodular or kidney phase, from Pick and Shovel mine.

Characteristic of certain ores in the veins of the West system. The gold occurs 

mostly along the dark lines and seams crudely encircling the nodular nuclei of 

rhyolite. The nodule marked a is rhyolite which jieripherally has been corroded and luetasomatically altered by the gangue solutions.
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE XV

PHOTOMICROGRAPHS OF GOLD-SILVER SULPHIDE ORE FROM ALPHA MINE.

A shows lamellar fibrous calcite being replaced by quartz, adularia, chalcedony, pyrite, and argentite. 

B shows argentite replacing calcitc along its lamellar partings. Roth magnified 40 diameters.
MINERAL DEPOSITS. 29

From this analysis it is calculated that the amount of adularia 

present in the specimen is 70.65 per cent. The rest of the specimen 

consists o'f 13.67 per cent of free silica and 15.68 per cent of undetermined constituents, presumably for the most part alumina and other 

impurities. Except that it shows about twice the amount of potash 

the analysis compares favorably with that of the country-rock rhyolite given on page 20 (analysis 3). Comparison of microscopic sections of this ore with sections from the Crater veins indicates that 

much of the Crater ore probably contains more than 90 per cent of 

adularia and about 15 per cent of potash.

A striking feature of the Jarbidge gangue is its laminated or platy 

and bladed structure, in which innumerable contiguous or connecting 

laminae or plates and blades are variously arranged. This material 

is aptly termed by the miner " fish-scale quartz," from the plates 

partly overlapping one another. (See PI. X.) Much of the pseudomorphic platy and cellular structure seems to be due to silicification 

and replacement of calcite along the parting and cleavage planes of 

the primary mineral. The plates range from those of minute size up 

to some nearly an inch in diameter and from the thickness of a knife 

blade to that of ordinary pasteboard. (See PI. XII.)

As seen in thin section the dominant structure is the disposition 

of the minerals in sectors or long fan-shaped areas, each area composed of a number of similar subareas. There is much sericite, and 

veins of the west system contain also considerable flubrite.

Two of the most abundant minerals occurring both as gangue 

minerals and as gouge are halloysite and leverrierite, white hydrous 

silicates of aluminum that resemble talc and kaolin and are commonly so called by the miners. They are both secondary products 

derived from devitrification of the rhyolite and decomposition of 

feldspar or other aluminous minerals. Both have many of the properties of ordinary clay gouge and absorb much water. Halloysite 

is amorphous and contains considerable water.

Leverrierite 16 is a; white micaceous hydrous silicate of aluminum. 

It is similar to halloysite and is closely related to kaolin, but it differs 

from halloysite in being crystalline and from kaolin in the ratio 

and combination of its constituents. It contains more silica, less 

alumina, and less water than kaolin and retains only 7 per cent of 

its water at 110°, whereas kaolin retains nearly all of its 14 per cent 

of water up to 400°. Leverrierite is easily fusible; kaolin is not 

fusible. In physical and optical properties leverrierite resembles 

muscovite, but its cleavage is less prominent. It is brittle when dry 

and very plastic when wet. Its index of refraction is approximately 1.58.

18 Larsen, E. S., and Wherry, B. T., Leverrierite from Colorado : Washington Acad. Scl. 

Jour., vol. 3, pp. 208-217, 1917.
30 THE JAKBIDGE MINING DISTBICT, NEVADA.

A specimen of the white gangue from the 6,400-foot level of the 

Long Hike mine, collected by the writer in the present work, was 

determined through chemical analysis by J. G. Fairchild to be halloysite. The loss of water at 110° C. was 1.12 per cent, and at the 

point of ignition 10.76 per cent. The specimen, though whitish, has 

a pale bluish to greenish hue and is in part stained pinkish or reddish with hematite and physically resembles alunite. As material 

similar to this specimen occurs in practically all the mines, it is 

inferred that halloysite and leverrierite are probably general 

throughout the district.

A specimen of fault gouge collected in the .present work from the 

Starlight mine and examined by W. T. Schaller corresponds closely 

with the characteristics of leverrierite as originally described by 

Larsen and Wherry.

Manganese oxide, chiefly psilomelane and wad, occurs as black 

and dark-brown dustlike forms, small bodies or masses, and dendritic growths in the veins and on country rock, and locally it coats 

quartz druses and cements fine-grained quartz breccia.

A black mineral with metallic luster resembling argentite from the 

deep workings of the Long Hike mine, examined by Mr. Schaller, 

was found to carry plentiful selenium and is regarded as naumannite, a selenide of silver, Ag2Se. As the mineral occurs in a normal 

specimen of ore, it is inferred that naumannite probably occurs also 

in other mines in the district. A good description of naumannite 

from Idaho is given by Shannon.17

Thin sections of ore from the oxidized zone show also considerable hematite disseminated as grains and dust and derived from 

the oxidation of pyrite. Owing to the generally porous character 

of the gangue and the plentiful supply of the percolating surface 

waters, this oxidation probably extends to considerable depths. The 

gangue contains also, mainly as filling^ considerable gold and silver, 

the metals of the camp, described in detail farther on.

The gangue ranges from fine to coarse and from soft and friable 

to hard and siliceous, but owing to the prevalence of the pseudomorphic cellular structure the ore of the district on the whole is 

fragile and can be easily crushed and milled. It is of coarser texture 

and harder in the veins of the west system, where silicification has 

been more extensive. Here the veins are as a rule only coarsely and 

crudely banded to massive, and the laminated gangue occurs largely 

in bouldery bunches, the largest several feet in diameter. These 

veins also contain in places considerable fault breccia or fragments 

of silicified rhyolite country rock, from which it is inferred that 

more or less faulting accompanied and followed the fissuring and

" Shannon, E. V., Am. Jour. Sci., 4th ser., vol. 50, pp. 390-391, 1920.
MINERAL DEPOSITS. 31

subsequent vein formation. From the association of the silicified 

rhyolite the veins are often called " dikes."

Some veins, of which the Pick and Shovel is a good example, 

contain also fragments and seams of siliceous pale-greenish and 

blackish shale or slate supposed to be derived from the underlying 

sedimentary rocks.

In places the walls of the western veins are irregular and ragged 

or less sharply defined than those of the eastern veins and show the 

most extensive propylitic alteration found in the district. Here 

also occur the bold croppings. Some of the croppings are prominent 

reefs of the characteristically laminated quartz-adularia gangue and 

silicified rhyolite. They are commonly stained yellowish to reddish 

brown and blackish by iron and manganese.

In the eastern veins the gangue is composed of the same dominant 

minerals as that in the western veins, but in reverse ratio, the adularia 

constituting in the specimens examined 80 to 90 per cent of the vein. 

Though these veins show the same pseudomorphic structure as those 

of the west group, it is less pronounced and the texture is relatively 

fine. The veins are in large part closely and definitely banded and 

comby, and the bands are in places separated by thin slate-colored 

partings.

Both the croppings and the subsurface parts of the veins show 

free gold (PI. XIII), which may be obtained by panning the crushed 

material. Good ground usually yields a long string of fine bright 

colors of gold in the pan.

With the gold in the veins is associated also silver, which occurs 

chiefly as argentite, as naumannite, as an alloy with the gold, and 

probably also in other forms. In many places there is black, sooty 

silver sulphide, which is characteristic of leached argentite. The 

quantity of silver is usually small, amounting to only about 2 ounces 

to the ton of ore, but in some ore as much as 90 ounces is reported. 

Tellurides of gold and silver have been reported with the richer ore, 

but the report is not known to have been verified.

In its widest distribution the gold shows as small bodies or specks, 

but parallel faces or slabs of the gangue, some larger than a man's 

hand, are plated with gold as thick as a knife blade. In other places 

large areas are incrusted with blebs of iron-stained quartz, freely 

sprinkled with specks of gold. (See PI. XIV.) Most of the gold, 

however, is finely divided and not visible to the naked eye. It ranges 

from particles the size of a pinhead down to minute specks, which 

are usually associated with dark patches or specks of argentite, other 

silver-bearing minerals, and hematite (PI. XIII). In most of the 

veins it is concentrated in streaks or pay shoots associated with fine 

dark streaks of silver sulphide and iron oxides. The gold content 

shows a wide range, the shipping ore of some veins being worth $600
32 THE JAKBIDGE MINING DISTRICT, NEVADA.

to $1,000 a ton. The Bluster vein, 5 feet in width near the surface, 

was said to average $60 to the ton.

Another common form of occurrence of the gold is in nodules or 

reniform lumps formed by more or less finely banded concretionary 

growths of gangue, usually around an inclosed fragment of rhyolite 

which is generally corroded and metasomatically altered, or around 

a fragment of slate, as illustrated in part in Plate XIV, B. In these 

forms, which usually constitute rich ore, the gold occurs mostly along 

the dark lines associated with the circular banding above described.

The gold in the western veins is mostly of high grade; that of the 

Bluster mine, which has a deep-yellow color, seems to be among the 

best and is said to run about $20 or more to the ounce. In the eastern 

veins, however, the gold is mostly light colored, contains much 

silver in alloy or is electrum, and runs abqpfc $12 to the ounce.

SULPHIDE ORE.

Of the meager amount, of sulphide ore which has been found, that 

in the Alpha mine is probably the most nearly characteristic of the 

district. A specimen of it from the 400-foot level is described below.

The ore in general is gray. It is crudely banded with alternate 

dark and light bands and streaks as much as an inch or more in 

width (PI. XI, B). It is medium to fine grained and is slightly 

brecciated. -It contains a few lustrous whitish spots of remnantal 

lamellar calcite and a few small round inclusions of reddish-brown 

oxidized rhyolite (PI. XI, 5), each kind 0.2 inch in diameter. 

The inclusions occur on either side of the rich ore shoot in the vein. 

Argentite occurs near or partly surrounds the largest rock inclusion 

but only slightly touches or penetrates it, if at all, being generally 

separated from it by a shell of the quartz-adularia gangue. There 

are also isolated beadlike bodies of quartz which seem to represent 

primary quartz phenocrysts derived from the replaced rock. The 

richest part of the ore is that of the dark bands, which in places 

consist chiefly of argentite and pyrite. In s^ome ore, however, the 

richest part is in dark streaks and bodies irregularly distributed.

Microscopically the ore is seen to consist mainly of a microcrystalline gangue of quartz, adularia, and calcite in which is contained 

much sulphide, consisting of pyrite, argentite, and a little chalcopyrite, also some cerargyrite, pyrargyrite, and a little chlorite. 

Argentite, the black metallic ore mineral, though variously mingled 

with the pyrite, tends to be scattered as small bodies around larger 

bodies of pyrite. The ore also contains a little sericite, zircon, apatite, and barite. Portions of the gangue are cryptocrystalline and 

present a salt and pepper appearance.

Except the rock inclusions the calcite is the oldest mineral and is 

replaced by all or nearly all the later minerals, especially quartz,
MINERAL DEPOSITS. 33

adularia, and the various sulphides. The dominant gangue mineral 

is quartz, which occurs mostly in small interlocking irregular anhedral forms associated with similar forms of adularia. The quartz 

is generally disposed in lamellar, radial, divergent, fan-shaped, and 

other anomalous forms pseudomorphic after calcite, which it has replaced. Some is marginally feathered, and some is flamboyant.

Most of the adularia occurs in small, well-developed, more or less 

definite rhombohedral crystals and allied forms and is plentifully 

distributed almost throughout the ore (PI. XI, A). It is best seen in 

plain light when magnified about 200 diameters. In places it is very 

plentiful, and here and there it is the dominant mineral as along 

the edges and lamellar partings or blades of the calcite areas last 

replaced or not yet wholly replaced and separating wider belts of 

calcite and quartz, suggesting that some of the adularia is later than 

the quartz or most of the quartz-adularia gangue. This suggestion 

is corroborated by the occurrence of later veinlets of adularia 

traversing areas of the general quartz-adularia gangue; also by the 

fact that adularia was the last to be deposited in most of the bipartite 

comb-structure veinlets. Some of the adularia crystals show welldeveloped cleavage.

The calcite occurs largely in lamellar form in plates of considerable size and to a small extent in fibrous form (PI. XV, A). All 

these forms in part show more or less of the fan-shaped structure 

with radial relief lines, etc., generally characteristic of ores of this 

class. The calcite now present is a mere remnant of that which 

formerly constituted the vein.

The replacement of the calcite by the other minerals has in large 

part occurred along the lamellar partings of platy habit in the calcite parallel to the basal pinacoid, as described by Adams,18 and has 

given rise to the platy structure so characteristic in replacement 

quartz. (See PI. XV, B.) Some of the oblique cleavage lines, however, were followed by replacement offshoots, branches, or bodies 

almost independent of the lamellar partings. (See PI. XV, A.)

As seen under the metallographic microscope much of the ore shows 

a well-developed finely fibrous to felty texture, seemingly due to a 

very intricate intergrowth of quartz and adularia in the lamellar 

calcite along the cleavage and other planes as well as along the 

partings.

The ore is slightly cellular or vuggy, as is characteristic of pseudomorphic replacement ores, and the vugs are mostly irregular and 

lined with inward-projecting crystals of quartz and adularia (PL 

XII). The adularia is less plentiful in the inner or later growths 

than in the outer or earlier growths of the lining. In one vu<*, how18 Adams, S. F., A microscopic study of vein quartz : Econ. Geology, vol. 25, p. 645, 1920.
34 THE JAEBIDGE MINING DISTRICT, NEVADA.

ever, the lining shows two successive concentric bands of adularia 

alternating with those of quartz near the inner part.

OKIGIN OF THE VEINS.

From the universal occurrence of the laminated and other pseudomorphic structures of the quartz and adularia that practically constitute the veins it seems certain that the vein fissures have been 

mineralized during at least two distinct periods. After the eruption 

and fissuring of the old rhyolites there followed a period of mineralization in which the fissures were filled with material totally 

different from that which now occupies them. Just what minerals composed this'first filling or what metals it may have contained is not definitely known, for so far as present developments 

in the district extend no trace or clue to them remains save the 

casts and forms shown in the pseudomorphic quartz-adularia gangue 

above described, remnants of calcite in the meager sulphide ore thus 

far found, and a little calcite which occurs here and there, seemingly as secondary filling, in some thin sections of the altered 

rhyolite.

From a study of these forms in connection with cabinet specimens 

of calcite and barite and similar deposits in other fields it seems 

certain that the first gangue mineral in the Jarbidge veins must have 

been calcite. The replacement of the primary calcite by the present 

gangue minerals seems to have been accomplished through the agency 

of ascending hydrothermal solutions. These solutions brought in 

the gold and silver content and probably contained several other 

minerals, but they were particularly charged with silica, potassium, 

and aluminum, and as they dissolved out the calcite of the original 

gangue silica was precipitated and quartz intergrown with adularia 

was deposited in its place, largely pseudomorphic after the structural forms or casts of the preexisting calcite, thus forming the present gangue.

In connection with the hydrothermal origin of the veins it may 

be also noted that the nearest hot spring is the Wilkins Hot Spring, 

about 10 miles northeast of Jarbidge. This spring doubtless owes its 

temperature to heated but gradually cooling volcanic rocks through 

which its water flows in depth.

Below ground-water level the ore may be expected to become sulphide ore, with probably a very material increase in silver and with 

the gold content held mainly in the sulphides, but little if any of it 

being free.

The depth at which the Jarbidge veins were formed is difficult to 

state, o It seems probable, however, that the veins now exposed in 

the district were formed at a depth of not more than 2,000 feet below
MINERAL DEPOSITS. 35

the surface, and the other deposits at a correspondingly greater 

depth.

It is not likely that many of the veins will be found to carry ore 

in the underlying sedimentary rocks. In the mines situated well up 

toward the crest of the range, however, the thickness of the orebearing rhyolite above the sediments is estimated to be from 1,000 to 

3,000 feet. Of the sedimentary rocks limestone will probably be 

found to be the most favorable.

It is held by certain engineers that the workable deposits of the 

district are restricted to one or at most two flows of the rhyolite 500 

to 800 feet in thickness, that to these flows alone are due the ore 

shoots found in the district, and that outside of these flows it is useless to search for ore. This view is not tenable, however, in the light 

of the fact that workable deposits have already been found interruptedly through a vertical range of more than 4,000 feet, a figure 

which approximately expresses the thickness of the rhyolites contained in the zone of mineralization. Doubtless some flows, owing 

to fissures, fractures, and certain soluble and replaceable constituents 

which they may contain to a greater degree than others, are more 

favorable for ore deposition. In the second place, not all and probably relatively few flows or eruptions of the rhyolite were accompanied or followed by ore-depositing solutions. It is wholly reasonable, however, to look for workable ore in any of the underlying or 

older flows and sedimentary rocks through which any ore-producing 

flow or its associated ore-bearing solutions passed in coming to the 

surface.

ALTERATION OF WALL ROCK.

In the walls adjacent to the veins and extending back from them 

100 feet or more, particularly in the west vein system, the country 

rock has suffered more or less extensive alteration, in which the chief 

results have been devitrification and silicification of the rhyolite 

and in places the development of sericite in the feldspar, as well as 

of much pyrite throughout the rock. This process of alteration has 

left the texture and constituent minerals in an almost perfect state 

of preservation and given to the silicified rock a fresh and unaltered 

appearance. Elsewhere the rock is completely replaced or changed 

into massive quartz or veinlike gangue, in which all trace of the 

feldspars and other rock minerals has disappeared except the quartz 

phenocrysts, which by their wine color and other characteristics 

can be distinctly traced from the relatively little altered rock over 

into the gangue, where they apparently occupy the same relative 

position to one another which they held in the original rock. The 

rhyolite contains veinlets of quartz and adularia, which seem to be 

of the same age and to have been formed by the same solutions as 

the replacing gangue of the veins.
36 THE JARBIDGE MINING DISTRICT, NEVADA.

In the east vein system, where the veins are composed chiefly of 

adularia, denoting that the solutions that formed them were poor in 

silica, there is little if any alteration of the wall rock. On the 

whole, the degree of alteration of the wall rock seems in general to 

bear a more or less direct ratio to the acidity of the adjacent vein.

MINES AND PROSPECTS ON THE WEST VEINS.

The mining properties of the Jarbidge district, about 30 in number, consist chiefly of claim groups and mines located on the veins 

that have been described. On a score or more of them considerable 

development work has been done. A description of most of them 

follows. Their relative location is indicated on Plate XVI, which 

shows about 800 claims.

The properties on which the most development work has been done 

are on the veins of the west system. They number about fifteen 

and include the Long Hike, Starlight, O.-K., Flaxie, Alpha, Legitimate, North Star, Pavlak, and Bluster mines. Their distribution is 

shown in Plates II and III.

Nearly all the maps and sections of the workings in the mines, as 

well as the topographic map forming Plate II, have been kindly 

supplied by the Elkoro Mines Co., whose engineering work seems to 

be very precise but whose elevations are based on an assumed elevation at Jarbidge, near the mouth of Bear Creek, of 6,100 feet, or 

about 100 feet lower than that of the map printed in the earlier report 

and here reproduced as Plate I. As the original elevations on the 

company's maps and sections are in current use and will render the 

maps and sections reproduced in the present report more readily 

useful in the field, they are retained throughout. Their retention 

accounts for a difference of about 100 feet in elevation shown between 

the two maps.

LONG HIKE MINE.

Location. The Long Hike mine is a little to the northwest of 

the center of the district and east of Jarbidge, in the northwest slope 

of the Crater Kange (Pis. II and III). Properties near or adjoining the mine are the North Star, 0. K., Alpha, Legitimate, Starlight, 

Flaxie, Jarbidge Gold, and Elmore. The camp and main opening, 

which are on what is known as the 68 level, are at an elevation of 

about 6,800 feet, about 700 feet above the town of Jarbidge, at the 

mouth of Bear Creek. The property comprises a group of twentyfour claims. (See PI. XVI.) It extends through a horizontal distance of 3,800 feet and a vertical distance of about 1,YOO feet.

History and production. Concerning the discovery and early history of the Long Hike mine, data are very meager. Some of the
U. S. GEOLOGICAL SURVEY R.58E. BULLETIN 741 PLATE XVI

MAP OF PART OF 

SURVEYED AND UNSURVEYED CLAIMS

IN THE

JARBIDGE MINING DISTEICT 

JAKBIDGE, NEVADA

R.58E
MINES AND PROSPECTS ON THE WEST VEINS. 37

ground now known as the Long Hike claims was staked under that 

name in 1910, as shown by the claim map of that date.19

In 1915 George J. Shoup, of San Francisco, enlisted capital and 

took an option on the property, and in 1915-16 he opened up a new 

ore body on it. In 1916, while the property was still in the prospect 

stage, the present owner, the Elkoro Mines Co., of Jarbidge, became 

interested in it, pushed development work, and soon began designing 

a treatment plant, which during the summer and winter of 1917-18 

; resulted in the building of the Elkoro mill. The company also 

simultaneously built the 73-mile electric-power line from Buhl, 

Idaho. The mill began operation in March, 1918, and has been 

running almost steadily ever since, treating daily about 100 tons of 

ore that averaged about $10 to the ton, and had produced by the end 

of 1921 nearly $1,250,000 worth of gold and silver. In June, 1919, 

the mine was the largest producer of gold in Nevada, and in 1920 

it was the second largest, the mine of the Nevada Consolidated Copper Co. at Ely being the largest. In April, 1920, the company was 

said to have 40,000 tons of $10 ore developed in the mine. In July, 

1920, it was roughly estimated that sufficient ore was in sight to 

keep the mill running for about five years, and in January, 1921, 

the company was estimated to have a reserve of at least 100,000 tons 

in die Long Hike, Starlight, and Flaxie mines. During the second 

quarter of 1922 the net operating profit of the company was nearly 

$58,000.19a

The company has also acquired or leased the neighboring Starlight, Flaxie, Legitimate, O. K., and Buster properties as prospective sources of ore. It employs 80 men and uses yearly more than 

40,000 pounds of supplies, which are brought in from Rogerson. The 

mine timber is logged from Deer Creek, west of Jarbidge, and is 

sawed at the mine.

Development. The mine is opened to a depth of 900 feet by about 

8,000 feet of workings, including five adit tunnels, winzes, drifts, 

,' crosscuts, and stopes, as indicated in part in figures 3 and 5, which 

/ show approximately the stage of development attained by July, 1920. 

It is opened on 10 or more levels, which, contrary to the customary 

mode of designating mine levels, are enumerated in ascending order 

and are known respectively by the consecutive numbers 63 to 74 (70 

and 73 omitted), denoting approximately the elevation, No. 63 standing for 6,300± feet, and so on. Thus, as shown in figure 3, the actual 

elevation of the 68 level, for example, is 6,825 feet. Most of the levels 

are spaced about 100 feet apart vertically.

19 U. S. Geol. Survey Bull. 497, -pis. 12 and 13, 1912.

ie» Eng. and Min. Jour. Press, vol. 114, No. 10, p. 431, Sept. 2, 1922.
38 THE JARBIDGE MINING DISTRICT, NEVADA.

Equipment. The mine is well equipped with tram tracks, hoists, 

buildings, and electric power and light and has a sawmill at the 

portal. A 1,700-foot inclined tram connects the camp with the mill 

at the river side and Jarbidge, and the ore is delivered from the 

mine to the mill in aerial-tram buckets holding one-third of a ton 

each. (See PL III.)

The mill, which employs the cyanidation and counter-current decantation process, is a combination of the Marcy and Hardinge mills 

with Blake crusher and Dorr classifiers. It has a rated capacity of 

100 tons in 24 hours but generally handles 120 tons with ease, as 

most of the ore is soft. A little ore that is mostly hard, refractory

Ssl5623.il. /

If Vein feathers out to 

63 ££K«J[(i_.talcose stringers and 

15 leached and barren

1,000 Feet

Ruled areas indicate stopc

FIGURE 3. Longitudinal section of Long Hike mine on plane of vein.

quartz, tending to cause undue wear in the steel lining of the ball 

mill, is crushed in a 5-stamp adjunct.

Since commencing, in March, 1918, the mill has operated almost 

continuously and has made exceptionally good recoveries, the average extraction being about 98 per cent in gold and 40 per cent in 

silver. At the time of visit the extraction in silver was about 50 

per cent. Considerable difficulty was being experienced in the recovery of the silver, as the quantity of silver mineral is comparatively 

small, the metal content of the ore being approximately 1 ounce of 

silver to 1 ounce of gold. However, the company reported that much 

of the silver is reprecipitated in the process of treatment and that 

the recovery was improving. In 1922 the recovery was reported to 

be 99.5 per cent of the gold and 75 per cent of the silver.

The cost of mining and milling is from $4.50 to $7 a ton of ore, but 

$4.50 ore, though it yields no profit, can be handled without loss, and
MINES AND PBOSPECTS ON THE WEST VEINS. 39

even $4 ore if broken is milled. The ore milled in 1919 averaged $12 

to the ton; that which was being milled in the summer of 1920 ran 

only about $10. As the Long Hike dumps contain considerable goodlooking quartz and mineralized rock they will probably all finally be 

treated for their metal content.

Geology. The country rock is the old rhyolite, most of which is 

highly oxidized, with the feldspars kaolinized, sericitized, and leverrieritized, giving to the rock in general a light-gray color. In this 

light-gray groundmass phenocrysts and blebs of relatively dark or 

wine-colored quartz are conspicuous. In the lower levels the rock is 

typically the old rhyolite with wine-colored quartz phenocrysts and 

is more uniform in character than the rocks in the upper levels, which 

are of diverse character and in general of finer texture.

Variations of the rock occur from place to place on the different 

levels, as described below. In general, little or no differentiation of 

flows or beds is possible. The rock has been considerably faulted and 

crushed, and locally it contains inclusions of black shale or slate and 

dark sandstone. The sedimentary inclusions, which range from comminuted bits to masses several feet in thickness and 10 feet or more 

in extent, have reached their present position by faulting. A large 

fault, known as the main fault, extends almost longitudinally through 

the mine (fig. 3). It strikes about northwest and dips 75° SW. It 

is older than the vein.

Ore deposits. The deposits are contained chiefly in the Long Hike 

vein and are valuable mainly for their gold content. The vein strikes 

N. 55° W. and dips about 75° SW. It ranges from 1 to 30 feet or 

more in width and has a known horizontal extent of about 3,000 feet 

in the Long Hike mine and a vertical range of 1,200 feet. As it narrows horizontally from the principal workings southeastward into 

the mountain and downward through the lower levels, where with 

increase in depth the rocks become tighter and accordingly less favorable for penetration by circulating mineral solutions, it does not seem 

to hold much promise beyond the limits of the present workings.

The deposits now worked are in large part the result of surficial 

enrichment caused chiefly by chloride solutions, iron sulphides, manganese compounds, and alkaline waters, much as described by Emmons 20 and others for other districts, the transportation agency being 

chiefly descending meteoric water. The deposits were probably also 

enriched in part by solution of the calcite and by solution and redeposition of the gold.

However, as the present workings are all in the oxidized zone, if 

the vein or its fissure continues downward it would be reasonable to 

expect to find primary sulphide ore in depth similar to that in the

80 Emmons, W. H., The enrichment of ore deposits: U. S. Geol. Survey Bull. 625, pp. 

305-324, 1917.
40 THE JAKBIDGE MINING DISTRICT, NEVADA.

Alpha mine (p. 32), though such ore at moderate depth will probably 

be of too low grade to work unless it occurs in considerable quantity. 

With one or possibly two exceptions the croppings are inconspicuous, 

so that in general cross trenching or underground work was required 

to determine the position of the vein. Approximately on the projected course of the vein to the southeast, on the neighboring Jarbidge Gold ground, near the Elmore mine, at an elevation of 7,800 

feet, occur croppings which may represent in part the apex of the 

Long Hike vein. These croppings, which are rugged and rise 10 to 

30 feet above the surface, consist mainly of more or less silicified 

rhyolite and quartz replacing rhyolite. However, present indications are that the vein or the silicified root of the cropping does not 

descend to the 68 level, or that if it does it dips more steeply than the 

neighboring fault.

The Long Hike vein, like most other veins of the district, is composed chiefly of a gangue of quartz, adularia, and altered rhyolite. 

In general it is so extensively oxidized that much of it presents a 

whitish limelike or chalky appearance, is relatively soft, and accordingly is easily mined and milled. The vein also contains, however, 

bodies of the relatively hard greenish replacement quartz and adularia characteristic of veins of this class found in the Oatman and 

other districts of the West. In places the vein is heavily stained 

reddish brown and blackish with oxides of iron and manganese.

The quartz-adularia gangue largely replaces the calcite, after which 

it is pseudomorphic, as shown by its lamellar and bladed structure. 

It has replaced also much of the included rhyolite and of the adjacent 

wall rock. Though much of the vein appears to be limy or chalky, it 

is noncalcareous, the limy properties of the calcite having been completely removed in the replacement or subsequently changed in the 

process of oxidation.

The vein contains considerable leverrierite, which occurs as a constituent of the gangue and as gouge in the fractures and on the vein 

walls. It seems to have been derived from the decomposition of the 

glassy groundmass or vitreous constituents of the rhyolite and the 

alteration of its feldspars. There is present also a little barite, some 

of which incrueting altered rhyolite was collected in the present work 

on the 69 level. The barite occurs in small macroscopic crystals 

and was probably formed contemporaneously with the quartz and 

adularia. Fluorite is present in small amount, and with it is associated considerable related sericite.

Except for considerable faulting denoted by slickensides, gouge, 

and sheeting, both within the vein and on the walls, the vein is mostly 

structureless or massive and shows but little banding or crustification. 

In places it is traversed obliquely by narrow, inconspicuous fault zones 

or seams resembling planes of movement. These zones are commonly
MINES AND PROSPECTS ON THE WEST VEINS. 41

known as cross slips and generally are accompanie d by smaller stringers or bands of good ore, and some are filled with quartz and other 

gangue minerals. The ore of any one seam or streak is said to be 

generally continuous and to maintain its tenor entirely across the vein 

from wall to wall. Similarly, a lean streak is lean throughout.

The cross slips on the 68 and 69 levels generally continue without 

interruption from the vein through the contact into the wall rock, but 

at the contact they are deflected, as shown by the presence of quartz, 

slickensiding, shearing, and fault-drag material (fig. 4), indicating 

movement between the wall and the vein in approximately a horizontal direction between the 

seams were

time the 

formed

and the time of their 

filling by the quartz 

and ore. Slight 

movement has also 

taken place since the 

quartz was deposited. 

The differential of 

movement has been 

to the northwest on 

the footwall side and 

to the southeast on 

the hanging-wall 

side. The continuation of the seams 

from the vein into 

.the wall rock is generally less difficult 

to determine on the

footwall side than on the hanging-wall side. Faulting in the dip 

plane of the fault seems to be normal.

The vein walls in general are ill defined. Some workable replacement deposits extend for a considerable distance laterally into the 

country rock.

The gold occurs disseminated in the quartz-adularia gangue and 

associated altered and replaced rhyolite. It is so finely divided that 

it is not visible to the naked eye and must be recovered by the cyaniding process. It is not uniformly distributed in the vein longitudinally, vertically, or laterally. Considerable portions of the vein are 

barren. The better ore is on the hanging-wall side of the vein. Of 

the replacement deposits in the wall rock, however, those.in the footwall are much the better, as would be expected in deposits that are 

largely supergene.

FiauRB 4. Diagram of enriched cross slips or faulting in 

Long Hike vein. The heavy lines denote streaks or bands 

of good ore in the fault zone. Faulting in the dip plane 

of the fault zone seems to be normal.
42 THE JAKBIDGE MINING DISTRICT, NEVADA.

The vein is opened to a depth of 900 feet on the 10 or more levels 

above noted.

On the 68 level, which has a length of about 2,000 feet and extends 

to the side line of the adjoining Jarbidge Gold ground, the vein is
MINES AND PROSPECTS ON THE WEST VEINS. 43

from 5 to 10 feet wide and has produced about 4,300 tons of $12 ore, 

a larger tonnage than any other level in the mine. The good yield 

in ore is probably largely attributable to the fact that this part of 

the vein contains considerable of the hard lamellar replacement 

quartz. The quartz contains inclusions of altered and in part brecciated and mineralized rhyolite. The most productive stopes were 

G-7, 8, and 9 (fig. 3).

The deepest deposits of any importance were found at about 400 

feet back from the face of the tunnel, in or near stopes G-16 and IT. 

They produced 800 tons of $20 ore. Beyond this point no ore of any 

consequence was found. At its face the level meets a fault, at and 

near which the ground is so intensely broken as to be of no promise. 

The fault strikes N. 20° W. and dips 45° W. In August, 1922, it was 

said that the main tunnel of this level was being extended to connect 

with the deep shaft of the Starlight mine, largely for the purpose of 

exploring at depth the block of intervening ground.

In the ground between stopes G-ll and G-14 and extending upward nearly to the top of the 69 level the ore was of low value, 

averaging only about $2 to the ton, and was confined essentially to a 

vein width of about 3 feet. Here the so-called north-south cross 

slips, which elsewhere almost invariably enriched the vein, contributed little or no value, although they contained quartz stringers.

The country rock, as shown in the hanging wall of stope G-7, is 

coarse grained or porphyritic, with dark phenocrysts, and its flow 

structure dips gently toward the vein. It is seamy and is largely 

altered by kaolinization and stained reddish or lavender and dark 

by iron and manganese oxides, which permeate it. Elsewhere it 

contains inclusions of dark slate, which apparently have not been 

altered by heat and are in part pyritic.

At stope G-6 the hanging wall consists of a sort of bluish-drab 

clay or mud-rock gouge containing small black carbonaceous or 

graphitic inclusions regarded as of sedimentary origin. Elsewhere 

the walls or gouge contain small lenticular bodies and streaks of black 

and white speckled quartz and quartz breccia firmly cemented by 

psilomelane.

On the 69 level, which is opened for a length of 1,250 feet, the vein 

is 4 to 9 feet in width and narrows as it extends southeastward into 

the mountain. It has produced 30,000 tons of $12 ore. The country 

rock at stope E-12, on the hanging-wall side, consists of lead-gray 

medium-grained highly altered rhyolite with a more or less platy 

or thin bedlike structure dipping toward the vein at angles of about 

12°. The microscope shows it to be pressed, to be more or less schistose, and to contain rounded and subangular grains of primary quartz 

and much secondary muscovite or sericite, some of which has a

' 13253 23 4
44 THE JAKBIDGE MINING DISTRICT, NEVADA.

divergent arrangement and radiates from feldspar and quartz crystals as nuclei. At about 500 feet farther in the mountain, in block 

E-16, the rock is similarly highly altered, lighter colored, and more 

highly mineralized and has a growth of barite crystals deposited on 

its joint planes and fracture surfaces.

The 71 level has a length of 875 feet, of which the inner 800 feet 

is on the vein, which extends to the N. 20° W. fault. From this level 

to the surface the vein has produced 3,400 tons of $15 ore and at the 

time of visit still contained 2,000 tons. The vein averages 3£ feet in 

width and consists chiefly of typical lamellar pseudomorphic replacement quartz and adularia with small inclusions of brecciated, altered, 

and mineralized rhyolite. It is thoroughly oxidized and is mostly 

stained pink or reddish by iron; where not thus stained it is whitish. 

It is microscopically drusy and in places shows specks and small 

bodies of argentite. The quartz-adularia gangue shows at least two 

generations or periods of growth. The phenocrysts in the rhyolite, 

especially those of quartz, are encircled by zones of secondary chalcedonic or metacolloidal silica, and locally the width .of the zone 

equals the radius of the crystal. Around the feldspars the zonary 

growth is not so wide but is more crystalline. Slight stains of malachite and azurite suggest that before oxidation the vein probably 

contained a little chalcopyrite or that some of the pyrite now altered 

to hematite may have been cupriferous.

The 72 level is opened by a 350-foot adit tunnel. It contains the 

supposed apex of the Long Hike vein, which here is 3 feet in width 

and is exposed for 150 feet.

The 74 level, which is in ground adjoining the Long Hike No. 3 

claim, is opened by a 150-foot tunnel, which does not show any mineralization.

The 67 level, opened for a length of 500 feet immediately beneath 

the productive part of the 68 level, has produced 18,000 tons of $12 

ore.

' The 66 level, which at the time of visit was opened by a 1,300-foot 

adit tunnel, has produced 550 tons of $8 ore. During the spring of 

1921 the tunnel was extended 500 feet farther but without finding 

any ore. At the face this tunnel is the deepest working in the mine 

and has-a nearly vertical depth of 900 feet on the dip of the vein.

The 64 level is developed mainly by a 250-foot drift at a depth of 

about 700 feet below the surface. The vein consists largely of thoroughly oxidized and mineralized rhyolite. From this level upward 

to the 67 level it is about 5 feet wide, and the portion extending up 

to the 66 level has produced 500 tons of $7 ore.

The 63 level, the lowest level of the mine, lies at a depth of about 

700 feet. It is developed by a 200-foot drift. A pump stationed here 

drained the mine at the time of visit. In descending from the 64
MINES AND PROSPECTS ON THE WEST VEINS. 45

level the vein narrows and locally feathers out, and on the 63 level 

it consists chiefly of a narrow leached and barren zone containing 

stringers of leverrierite, kaolin, or " talc." The country rock is only 

partly oxidized and for a distance of 20 to 90 feet from the vein contains considerable finely disseminated pyrite and psilomelane, apparently indicating nearness of the workings to the sulphide zone. The 

pyrite, however, is in part secondary; some of it fills cracks or small 

cavities in the feldspar and quartz phenocrysts, whence smaller 

stringers or veinlets extend into connecting fractures. A striking 

feature of the rock is the shattered condition of the quartz phenocrysts and the pyrite filling and cementing the cracks.

r « LEVEL 

"l n which no work3 able ore was found.

.,.., .

PROJECTION ON PLANE OF VEIN 

FIGURE 0. i'lan and section of North Star mine on Bourne vein.

NORTH STAR MINE.

The North Star mine is about 2,000 feet above the mouth of Bourne 

Gulch, in the steep south slope at about 350 feet above its floor. (See 

PI. Ill and fig. 6.) It has produced $5,000 in gold ore. Its deposits were the first discovered in the district. They were found by 

D. A. Bourne and are described in the earlier report, at the time of 

which more than 1,000 feet of underground work had been done, 

chiefly by the owner, the North Star Mining & Milling Co. The
46 THE JAKBIDGE MINING DISTRICT, NEVADA.

company subsequently built a large Hardinge mill at the mine with a 

rock crusher and automatic gold separator and later added a 5-stamp 

mill and cyanidation plant but was able, it is said, to save only about 

38 per cent of the metallic content of the ore. The principal period 

of operation was from August, 1911, to February, 1912, during which 

the company treated 4,000 tons of $12 ore.

The company is a stock company and since 1918 has been mostly 

owned and controlled by the Elkoro Mines Co. The Elkoro Co. 

recently drove the lower 450-foot tunnel on level No. 4, 240 feet 

vertically below the main workings, for exploratory purposes, but 

found only traces of ore in a few places. The mine has about 3,000 

feet of workings, all in the oxidized zone (fig. 6), the maximum depth 

of development being about 250 feet. It is opened mainly by adit 

tunnels on levels 1, 2, and 3. It contains two veins, the Bourne 

vein and the North Star vein, both in the old rhyolite. The more 

productive one is the Bourne vein; it is the higher up and the more 

westerly of the two. It strikes N. 40° W. and dips 60° NE., into 

the mountain. It is 3 feet or more in width. The best ore has a 

gangue of reddish or light-brownish soft fine-grained pseudomorphic 

replacement quartz.

Considerable work was also done in the early days on the North 

Star vein, but it did not produce much ore. After sampling this 

vein, however, the Elkoro Co. has decided to do further work on it.

o. K. MINE.

The 0. K. mine is in the upper south slope of Bourne Gulch, about 

three-quarters of a mile from its mouth (Pis. II and III), No. 1 

level (fig. 7) being at an elevation of 7,540 feet. It was discovered 

in 1914 by Add Rickard, of Jarbidge. In 1915, through the agency 

of George S. Shoup, it was bonded to Louis Greenbaum, of San 

Francisco, and in 1916 it was purchased by the Elkoro Mines Co., 

the present owner. Greenbaum developed No. 1 tunnel as far as 

shaft A-B (fig. 7). The remainder of the development work was 

done by the Elkoro Mines Co., which in 1920 built an aerial tramway to the mine to take out the ore that it had blocked out a few 

years earlier. The production up to July, 1920, was small, but late 

in 1921 the company was said to be working the mine with excellent 

results. In January, 1922, the company reported that it had mined 

practically all the ore above the Zero level; that it found the ore to 

decrease in value from the surface down; and that it would probably 

finish the mine in the summer of that year. In March it was reported that a good ore body had recently been found beyond the 

main fault. The ore above the Zero level averaged about $30 to the 

ton, and that below it ranged from about $15 down to material of 

nonworkable grade.
MINES AND PROSPECTS ON THE WEST VEINS. 47

The vein lies in the old rhyolite, which is mostly firm, coarse to 

medium grained, and in part pyritic. It dips steeply to the northwest. It does not crop out' but was discovered by the posthole, 

trench, and pan method of prospecting under 8 feet of talus, where 

it was found to be well developed. About all the surficial material 

at and near the mine is said to pan well. The vein ranges from 6 

inches to 4 feet in width and averages about 2| feet. It is opened 

to a depth of 400 feet and horizontally for about 1,400 feet and is 

reported to extend for a considerable distance farther to the southeast. It is crossed by several faults, of which the most important 

are-"fault A," at about 350 feet in from the mouth of tunnel No. 1,

Vein narrow; 

consists of hard 

barren quartz

FIGURE 7. Plan and vertical projection of O. K. mine.

and the " Big fault," at 1,050 feet in. Fault A strikes N. 60° E. 

and dips 80° SE. It has flexed or offset the vein several feet on 

both the No. 1 and Zero levels. The Big fault dips 65° NW.

Most of the ore in the vein as blocked out by the Elkoro Mines Co. 

up to July, 1920, is indicated in figure 7. The ore averages about 

$20 and ranges from $5 to $30 to the ton in gold and silver, with 

the silver content relatively high. The reddish phase of the ore is 

said to have the highest metal content.

From recent work it is inferred that the ore lies mostly near the 

surface and does not extend to any great depth. It occurs mostly 

against or in association with the fault on its northwest or hangingwall side.

On the first 300 feet of level No. 1, from the portal to fault A, 

the vein is only about 1 foot in width and consists chiefly of hardr
48 THE JAKBIDGE MINING DISTRICT, NEVADA.

barren quartz. Beyond the fault it remains narrow but becomes of 

fair tenor and continues so for the distance of 500 feet to the shaft. 

It is in hard rhyolite and consists mostly of hard quartz, which is in 

part blocky, but in places the ore is soft, with the quartz showing 

the replacement pseudomorphic structure. Locally the vein consists 

of a few stringers and incloses a small horse. On level No. 2 it is 

broken and pinched and has little or no ore other than $5 to $6 

ore occurring between the shaft and the Big fault. In prospect 

tunnel No. 2 no vein or mineralization was found.

ALPHA MINE.

The Alpha mine is in the upper south side of Bourne Gulch, adjoining the O. K. mine on the east (Pis. II and III). The property 

consists of five claims. The Alpha and neighboring mines are 

reached by a good wagon road ascending Bourne Gulch. The Alpha 

deposit was discovered in 1910 by Judge Hughes, of Jarbidge, and 

soon afterward workable ore was found by Add Rickard. The total 

production is $165,000.

In 1912 the mine was purchased, it is said, for $25,000 by the Elko 

Mines Co., of Chicago, which in 1913 put in a 50-ton 5-stamp and 

rod mill and operated it continuously for two years following, with 

the result that 6,400 tons of ore was mined and milled. -A concentrator was also used during the last two months of this period. The 

extraction of gold obtained was 74 per cent. An aerial tram connects 

the mill with the mine at the 400-foot level.

After suspension of operations by the company in 1915 some work 

was done by lessees with fair results. At the time of the writer's 

visit the property had been bonded for a year to the Jarbidge Gold 

Mining Co. 'Commencing in September, 1920, the mine was being 

exploited and developed with a small crew of men by the Legitimate 

Mines of Jarbidge Co., which in February, 1921, claimed to have 

blocked out ore enough to keep the mill running for two years. Two 

good ore shoots, one of which is on No. 4 level (fig. 8), had been 

opened. By April the mine had been leased and bonded to the Jarbidge Nevada Mining Co., of Tacoma, Wash., the present owner. 

This company now owns 10| adjoining patented claims, including 

the Guarantee, Legitimate, and Alpha groups.

Early in June, 1921, a third ore shoot, for which the company had 

been crosscutting for some time through 70 feet of very hard rock, 

was opened on the 362-foot level, which is that of the Snowbrush 

tunnel, a crosscut from the surface. It proved to be about 5 feet in 

width and was said to pan about $35 to the ton in gold and to assay 

$43 to the ton in gold and silver. Some of the gold is visibly free. 

The ore at this place is said to be similar to the ore on the 172-foot
MINES AND PEOSPECTS ON THE WEST VEINS. 49

level, but the ore shoot seems to be a new one, as it rakes to the north, 

whereas the ore shoots in general rake to the south. The discovery 

was regarded as an important one, as it was made in hitherto unexplored ground and was thought to add to the resources of the 

mine 200 feet of stoping ground on the dip of the vein extending 

upward to the 172-foot level. But subsequent drifts and upraise 

at a point 50 feet southeast of the shaft failed to find the continuation 

of the ore body, which seems to be cut off by a fault, apparently the 

same fault that cuts off the ore in the O. K. mine. The fault dips 

35° NW. and crosses the 362 level near the tunnel entrance. In 

December, however, the raise on the 362 level was said to be encouraging, and in March, 1922, it was reported that considerable good ore 

had been blocked out in connection with it, some averaging $35 to the 

ton, and that ore was being produced. In April a winze that was 

being sunk from the 362-foot level at a point 30 feet southeast of the 

shaft and had attained a depth of 18 feet was said to show the vein 

to be 3| feet wide and to contain in the footwall side an 8-inch shoot 

of sulphide ore that averaged $176 to the ton, and it was reported 

that the rest of the vein averaged $12 to the ton, with the value in 

silver about four times that in gold. A sample taken from the bottom 

of the winze is said to have run $450 to the ton. The high-grade 

assays of sulphide ore are said to average about 4 ounces of gold and 

300 ounces of silver to the ton. The company plans to extend the 

winze to a depth of 100 feet during the winter of 1922-23.

A specimen of the ore from this place received May 12, 1922, 

is considerably more oxidized than the sulphide ore at the shaft described on pages 32-34. However, from the wide dissemination 

of pyrite and silver sulphide in the specimen it is inferred that the 

workings are probably nearing the sulphide zone. The metallic contents are chiefly contained in or associated with specks and aggregates of blackish argentite and naumannite, the dominant silverbearing minerals. Eeddish-brown and pinkish material staining 

small spots of the ore seems to be proustite or pyrargyrite. In May 

the mine was said to have $30,000 in ore blocked out. In August it 

was reported that further work in the raise had disclosed a 7-inch 

streak of very rich ore at a point about 35 feet above the 362 level 

and 6 inches from the hanging wall, a sample of which, it is said, 

assayed 90 ounces in go)d and 87 ounces in silver, or about $2,700 to 

the ton. Specimens of this ore kindly supplied by the superintendent 

of the mine and examined by the writer show the ore to be oxidized 

a,nd stained pale to dark rusty brown by iron oxide on joint and 

fracture surfaces. It is closely banded or crustified, is medium 

grained, consists mainly of a laminated gangue of fine-grained quartz 

and adularia pseudomorphic after calcite and of remnantal calcite, 

and is highly calcareous. A little pale pyrite is present, mostly
50 THE JAKBIDGE MINING DISTRICT, NEVADA.

irregularly distributed along the contact of siliceous bands with the 

less siliceous bands. In places some pyrite is associated with argentit'e. The visible ore minerals so far as recognized are argentite, 

native gold, native silver, and electrum. The argentite is present in 

considerable quantity as dark or blackish irregular bodies. With it 

is associated most of the native gold. The native silver and electrum, 

which in places are abundant and are more or less associated, occur 

chiefly as specks, flakes, films, and wirelike forms, mostly along the 

darker bands of the ore. The native silver and the silver contained 

in the electrum were probably derived from argentite by oxidation.

\

^> Probab le course of vein 

on 40Oftlevel unexplored

Area of unexplored vein 

above.the 40Oft. level

Crosscut ,.- '' Sulphide

Country roc

much broken

FIQDRB 8. Plan and projection of Alpha mine.

The deposits occur in the Alpha vein. The vein dips about 80° 

SW. in drab coarse country-rock rhyolite similar to that in the 

0. K. mine. It averages about 3 feet in width and looks well, but 

both vein and ore shoots occur in lenses or pinch and widen. The 

vein consists mostly of laminated replacement pseudomorphic quartz 

and adularia. As shown in branches or offshoots in the sulphide (?) 

zone, the vein is solidly frozen to the wall rock.

It is opened to a depth of about 300 feet by 2,000 feet of workings, 

chiefly by three adit tunnels or drifts and a shaft, as shown in 

figure 8. Each drift is about 500 feet in length. On the 400-foot 

level at about 300 feet in from the portal the vein is crossed by a 

fault known as the main fault, which has thrown its fore part 15 

feet to the northeast. The fault dips about 60° NW. In this part
MINES AND PROSPECTS ON THE WEST VEINS. 51

of the mine the country rock is much broken. On the southeast or 

footwall side of the fault it has been crushed and altered to a soft 

medium-grained ash-gray mass and is pyritiferous. The vein is 

narrow but relatively rich, the small stope shown in figure 8 having 

produced $30,000 in ore said to have averaged $90 to the ton. In the 

winze about 30 feet beyond the fault the vein is said to contain 2 feet 

of $200 ore. Also the stope on the 172-foot level has produced well. 

In May, 1922, the showings on this level were said to be so encouraging that the company contemplated driving it well into the mountain.

The ore consists chiefly of thoroughly oxidized laminated pseudomorphic quartz and adularia. It is for the most part deeply 

stained reddish brown and blackish with iron and manganese oxides 

and apparently is an ideal milling ore. It is said to contain 1 ounce 

of gold and 2 ounces of silver to the ton. Some of it is very rich. 

Some contains considerable epidote, and some is coated with coppercolored blist'ery or microbotryoidal forms of iridescent hematite 

which might readily be mistaken for copper ore.

What is probably the beginning of the sulphide zone was reached 

in the vicinity of the shaft by the deepest workings on the 362-foot 

and 400-foot levels, in consequence of which the mill had recently 

been equipped with large tanks and facilities for an improved 

cyanide process for handling both oxide and sulphide ores. In 

August, 1922, however, it was said that arrangements had been made 

to have the ore treated in the Elkoro mill, to which it is taken by 

aerial tram by way of the Starlight head house, after being crushed 

in the Alpha mill. At that time 600 tons of broken ore was available.

The ore on the 400-foot level is chiefly sulphide ore with much 

black silver sulphide (argentite) and naumannite in a sparry quartzadularia-calcite gangue. It is described on pages 32-34 and illustrated in Plates XI, B; XV, A and B. Two inches of the vein is 

said to average nearly $700 to the ton. Associated with the argentite 

are some native gold and a little cerargyrite and pyrargyrite.

STARLIGHT MINE.

The Starlight mine is one o.f a group that includes also the Legitimate, Flaxie, and Jarbidge Gold mines, located in Starlight Hill, in 

the upper north side of Bourne Gulch opposite the Alpha mine 

(figs. 9 and 10). The slope is steep but not rugged (PI. II and

fig- 11).

The veins in these mines are similar to the Long Hike vein and 

are characteristic of the leading productive veins north of Bourne 

Gulch. They all strike N. 50°-60° W. and, except the Starlight and 

Legitimate veins, dip 70°-SO'° SW. They consist chiefly of the 

lamellar replacement pseudomorphic quartz-adularia gangue. The
52 THE JAKBIDGE MINING DISTRICT, NEVADA.

gangue and ore are more or less sugary, but much of the gangue, 

though good looking, has either no metallic content or not nearly so 

much as the replacement deposits in the wall rock. The veins lie in 

the old rhyolite, which, however, is at a considerably higher horizon 

than that of the Long Hike mine, is not so typical of that rock, and 

contains more associated sedimentary rock.

The Starlight property includes the Starlight, Sunset, and Mahogany claims. It adjoins the Legitimate propertj' on the southeast and the Flaxie on the northeast (fig. 9).

History. The Starlight deposit was discovered in 1915 by William 

Holland and Charles and William Martin, all of Jarbidge. The disFIGCBH 9. Topographic, claim, and level map of Starlight mine. A-A, Line of section in

figure 11.

^overy was made by trenching and panning, as the vein does not crop 

out. The discoverers early developed it essentially as it is now developed in tunnel No. 1. Soon afterward Albert Hanford took a 

three months' option on the property and opened tunnel No. 2 in 

part. Then the Elkoro Mines Co., the present owner, took an option 

on and developed the property in general, except tunnels Nos. 4, 5, and 

 6. Later it purchased the property for $165,000 and brought the developments up nearly to the present stage, and recently it has continued development work by driving No. 2 tunnel eastward and stoping out ore. By September, 1922, this work was extended almost to 

the Guarantee ground,0 which it was expected to penetrate soon.
MINES AND PROSPECTS ON THE WEST VEINS. 53
54 THE JARBIDGE MINING DISTRICT, NEVADA.

The' production, figures of which are not available, has been considerable. The ore reserves seem to be moderate.

Development and equipment. The mine is opened through a vertical range of 900 feet between the elevations of 6,900 and 7,800 feet. 

It is opened on seven levels, mainly by five adit tunnels, a shaft, driftsr 

winzes, and crosscuts, aggregating about 4,000 feet of workings. The 

levels are nearly all spaced about 100 feet apart vertically. They are 

numbered in descending order, No. 1 being the 100-foot level, No. 2 

the 200-foot level, and so on, except that the one next below No. 2 is 

known as the sublevel. (See fig. 12.) The upper workings are mostly 

in very broken and soft ground beneath a ravine. The lowest workings are sufficiently high above Bourne Gulch to afford the mine good 

drainage.

NW. SE.

FIGURE 11. Longitudinal section of Starlight Hill group of mines, on line A-A, figure 9, 

with Flaxie and Jarbidge Gold wordings projected thereon.

The equipment consists chiefly of an electric-power line, electric 

compressors and drill sharpeners, tram tracks on about all levels, 

electric light, and buildings adequate for housing 50 men. The mine 

has more than 1,000 feet of tmbering. The lower 450 feet of the shaft 

is all timbered. The ore is treated in the Elkoro mill, where it is delivered by means of aerial tram, first by a 3,300-foot line to the 

Long Hike ore bin, then by a 1,250-foot line to the mill.

Ore deposits. The deposits occur in or are associated with the 

Starlight vein. The vein has a known extent horizontally of about 

1,400 feet and vertically of 700 feet. It is not regular but forks and 

branches. It strikes N. 60° W. and dips to the north. In the upper 

part of the mine the dip is 70°, but in depth it flattens to 50°.

The opposition in direction of the dip of the vein to that of the 

Flaxie vein and its parallelism in strike with that vein suggest that
MINES AND PROSPECTS ON THE WEST VEINS. 55

the Starlight vein may possibly be the northwestward continuation 

of the Flaxie vein tilted over to the south by a fault. Its position is 

more nearly diagonal than opposite to the Flaxie, and its apex is less 

than 1,000 feet from the Flaxie, measured across the strike. In case 

it is not the Flaxie vein, as the two veins converge in dip they should 

meet at no great depth, especially as the dip of the Starlight flattens 

with descent. It seems more probable, however, that the Legitimate 

vein, lying opposite to and parallel with the Flaxie vein, may prove 

to be the eastward continuation of the Starlight vein.

FIGURE 12. Plan and projection of Starlight mine.

The Starlight vein is 7 feet or more in maximum width, and much 

of it is from 2 to 4 feet wide. A considerable part of it consists 

of good-looking soft sugary quartz or quartz-adularia-halloysite 

gangue but is of only small or no value. A little sulphide ore in 

which the ore mineral is chiefly argentite occurs in the deeper part 

of the mine west of the face of No. 3 level.

The mine is traversed by two faults, appearing notably on levels 

1 and 3, both of which, as shown by recent work, delimit the vein 

and locally form its hanging wall. From these conditions the company concludes, apparently correctly, that the mineralization was 

effected by ascending solutions that came up under the faults, by
56 THE JAKBIDGE MINING DISTRICT, NEVADA.

which they were dammed back, presumably by impervious fault 

gouge.

The tunnel of No. 1 level, about 400 feet in length, owing to a 

cave-in was only in part enterable at the time of visit, but the large 

dump at the mouth shows that the vein material and ore are typical 

of the district. The dump consists of highly oxidized, mostly reddish and brownish gangue. It contains also considerable impure 

slate rock with black carbonaceous material. In its farther part the 

level exposes a 5-foot section of sedimentary rocks consisting in 

descending order of 4 feet of gray arenaceous slate or slaty sandstone and 1 foot of black impure slate dipping 30° NE. The rocks 

are carbonaceous and pyritic and are unconformable with the structure in the associated fault zone. The stope on this level is said to 

have contained 4£ feet of $25 ore. The fault exposed on this level 

appears also at a point 150 feet below the level, where the vein is in 

contact with it and extends along underneath it.

No. 2 level, about 100 feet vertically below No. 1, is about 550 feet 

in length. Its dump also consists mostly of oxidized material which 

is more or less fine and relatively soft. A crosscut to the northeast 

recently exposed a narrow branch vein containing good ore, which 

also is terminated by the faults above described.

The sublevel, 100 feet below No. 2, is southeast of the main fault 

zone. It is without an adit tunnel and is worked through No. 2 level. 

It is opened mainly by a drift about 600 feet long, which cuts three 

ore bodies about as indicated in figure 12. The face of the drift is 

nearly all in good-looking quartz.

No. 3 level, about 200 feet below No. 2 and 100 feet below the intervening sublevel, is opened by an adit tunnel 1,300 feet in length and 

has considerable ore in its middle part at and near the shaft. Near 

its face it is crossed by a fault that cuts off the vein. By drifting 

from a stope about 150 feet above this level the fault was again found 

forming the hanging wall of the vein, which, however, contained no 

ore at that place. The vein was followed to the southwest directly 

under the fault and apparently gradually pinches out in that direction.

On No. 4 level, which is 125 feet below No. 3, the vein, 4 feet in 

width, is crossed by stringers and shows only a small metallic content, $2 or less to the ton. Development work done in driving the 

drift toward its face and in raising to No. 3 level indicates that the 

ore extends but a short distance below No. 3 level.

No. 5 level is mostly in firm, tight, coarse rhyolite. The projected 

course of the vein is on what seems to be a fault in altered rhyolite 

only, though there is a good footwall, and the dip is flattened to 55°. 

No ore has been found here.
MINES AND PBOSPBCTS ON THE WEST VEINS. 57

No. 6 level is the lowest adit crosscut. It is 1,650 feet in length and 

runs N. 80° E. It was driven to drain the mine, and incidentally it is 

said to drain also the Legitimate mine, through the Legitimate fault, 

which it cuts. A strong .stream of water flows from its mouth. It is 

nearly all in rhyolite, but the face is in the interbedded slate-sandstone series, which here dips about 30° NE. The 100-foot crosscut, 

turned at about 100 feet back from the face, is in gray sandstone or 

graywacke, the more or less extensive occurrence of which suggests 

probable bottoming of the rhyolite in this locality.

In March, 1921, it was reported that the ore then being mined on 

No. 3 level, at a depth of 350 feet, and on the sublevel, above No. 3, 

contained more or less silver, especially on the footwall side of the 

vein. In some of the ore the silver was said to be worth more than 

the gold. Some of the ore was reported to assay 34 ounces in silver 

and to show considerable free gold, and some of it was said to average from $700 to $1,000 to the ton. The ore is thoroughly oxidized; 

some of it has a light lavender color, due to iron and manganese 

stain, and the gangue is in large part altered and mineralized rhyolite. Other ore is of light color, resembles kaolin or chalk in appearance, and seems to consist chiefly of halloysite and quartz. The ore 

i$ so " talcky " that in the process of panning the " talc " forms hindrance balls and lumps which retain the gold until they are reduced 

by trituration to solution or slime.

LEGITIMATE MINE.

Location. The Legitimate mine is in the southwest base of Starlight Hill and the northeast side slope of Bourne Gulch (PI. XVIII). 

It joins the Starlight mine on the southeast (fig. 9). The underground workings of the Starlight on the Sunset ground are said to be 

within 160 feet of the Legitimate main tunnel (No. 3), which is about 

30 feet higher than the Starlight No. 2 level (PI. XVII).

The property consists of eight patented claims, including three in 

the Legitimate group, four in the Guarantee group, and the Tacoma 

fraction (PL XVI).

History, The Legitimate vein was discovered through trenching 

and panning by Add Rickard; who also prospected it. Subsequently 

Dave Marquardson, Steve Benan, and their associates became owners 

of the property and sold it to persons who organized the Jarbidge 

Nevada Mines Co., of Tacoma, Wash. This company did nearly all 

the development work, beginning in 1915, and worked the mine for 

nearly four years. It drove the adit tunnel (No. 3) into the vein 

and found an ore body 50 feet long by 150 feet high, on which it sank 

a short distance. It mined and milled 1,000 tons of $25 ore and 

ran a 5-stamp mill (the Alpha mill) for two months on its best ore
58 THE JAEBIDGE MINING DISTRICT, NEVADA.

but did not obtain a good extraction of the metals and is said to 

have recovered only $2,500 in bullion for an expenditure of $25,000. 

It tried the flotation process on the ore, but without success, and 

finally ceased work in October, 1919. In 1920 the mine was said to 

be about worked out, but in November, 1921, it was reported to have 

been taken over by the Elkoro Mines Co., which began to develop it 

through the No. 3 level of the Starlight mine and in March, 1922, 

was reported to be finding ore. The mine was not examined in the 

present work.

Development. The mine is opened by about 2,000 feet of workings, including mainly three adit tunnels, of which one (No. 3) is 600 

feet long, drifts, and a 300-foot raise (PI. XVII). The work is 

about all on the Legitimate claim, but the vein is said to extend 

eastward through the Guarantee ground (PI. XVI).

Ore deposits. The vein strikes about N. 60° W. and dips 75° N. 

It is from 3 to 4 feet in width. The gangue is mostly halloysite 

and altered rhyolite, with a little associated quartz, which occurs 

mostly in cross slips. As the strike and dip are about the same as 

those of the Starlight vein and as the two veins are approximately 

in alinement the Legitimate vein is probably in general the continuation of the Starlight vein. a

At a depth of 500 feet, or 160 feet below tunnel No. 3, the vein 

is cut off by a fault that approximately parallels it in strike but 

dips to the northeast. In 1920 what little ore was known to occur 

in the mine was said to lie against the fault.

FLAXIE MINE.

The Flaxie mine is just northeast of the Starlight and Legitimate 

mines, higher up the north slope of Bourne Gulch (fig. 10). It is 

owned by the Flaxie Mine Co., of which Hodge Brothers, of Bruneau, 

Idaho, are leading members. The property includes two patented 

claims. The production is $1,000, mostly in high-grade gold ore. 

The ore was milled on the ground in a small 3-stamp mill about 1916.

In 1921 it was reported that the Elkoro Mines Co. had taken a 

lease and bond on the property and was improving the equipment 

throughout for immediate mining. The mine is opened to a depth 

of 350 feet, mainly by a 500-foot crosscut tunnel and drifts (fig. 10).

The vein dips to the southwest in old rhyolite, which is said to be 

considerably broken, especially on the hanging-wall side. It is 

faulted at several places and in 1920 was known to contain a moderate 

amount of $9 to $10 ore, but it is of more than ordinary interest, 

as it is on the projected strike of the neighboring Long Hike vein, 

and more than 1,000 feet higher than the apex of that vein, which 

it resembles and of which it may be a continuation and therefore 

may attain considerable depth in the rhyolite. In March, 1922, it was
MINES AND PROSPECTS ON THE WEST VEINS. 59

reported that a new ore shoot 2 feet wide and averaging $20 to the 

ton had recently been found. In May, 1922, it was said that the 

mine had been equipped with an aerial tram and that the company 

was taking out ore. In August it was raising and sinking on ore of 

very good grade. The development work, it is said, shows the 

ground to be much faulted.2011

PAVLAK MINE.

The Pavlak mine is on Jarbidge River about a mile above Jarbidge 

and is easily accessible (PI. II and fig. 13). It is owned chiefly by 

Henry McCormick, of 'Salt Lake City. It is described in the earlier 

report. 21 At that time the deposits had been opened mainly by the

100 50 0 100 200 JOOFCCT

FIGURE 13. Plan of Pavlak mine.

owner, the Jarbidge Pavlak Mining Co., by about 1,000 feet of workings. Several thousand dollars' worth of shipping gold ore, some of 

high grade, and considerable milling ore had been produced, and a 

mill was being built. The production to date is about $13,000.

The deposit was one of the first to be discovered, by Messrs. Pavlak 

and Truro, pioneers, in the fall of 1909. In 1910 or 1911 Messrs. 

Brown, of Salt Lake City, and Kinney, from the East, purchased 

the property from the Pavlak Co. for $125,000, according to reports, 

and worked it. The mill was started in August, 1911, and ran intermittently for four months or more, but owing to financial difficulties 

it was closed in February, 1912. During the period of operation it 

treated 3,000 tons of good-grade ore, but the extraction was so low 

that the total output was only about $10,000,

Mn By November, 1922, the southeast drift had been extended to a point 100 feet Inside 

the Guarantee ground, with encouraging results. The ore at that point, which Is at a 

vertical depth of 700 feet, is said to be similar to the high-grade ore of the Legitimate 

mine, fouud in tunnel No. 2 at a depth of 60 feet, and the managers infer that it probably extends to a much greater depth and that the principal deposits of the mine may be 

found considerably below the 700-foot level.

21 U. S. Geol. Survey Bull. 497, pp. 67-72, 1912.

13253 23 5
60 THE JAKBIDGE MINING DISTRICT, NEVADA.

The mill is a 50-ton cyanide plant with a Chilean crusher and high 

tower head Burke filters and uses a combination leaching and amalgamation process. Much of the failure to make suitable extraction of 

the metallic contents in the ore is said to be due to lack of adequate 

crushing and grinding facilities. The Chilean crusher was put in 

only toward the end of the operating period, and about the same 

time a Trent agitator was added but not used.

The mine has about 2,000 feet of development work consisting 

mainly of tunnels, drifts, and stopes, mostly on the mill-tunnel level 

(fig. 13). The long crosscut tunnel is more than TOO feet in length, 

of which the last 80 feet is in the Paleozoic quartzite. The quartzite, 

which is described more fully on page 13, is so shattered and brecciated as to suggest its being on a fault zone. A strong stream of water 

that flows from the mouth of the tunnel practically drains the mine 

and also a considerable portion of the surrounding ground, apparently through the fault zone.

The mine is said to contain a moderate quantity of ore, mostly in 

the Pavlak vein. Most of the output came from this vein, chiefly 

from the upper workings. At the face of the workings the vein is 

said to be cut off by a fault, but it can probably be recovered to the 

south. The vein is 3 feet or more in width and contains good ore 

where it is exposed for several hundred feet in the mine.

PICK AND SHOVEL MINE.

The Pick and Shovel mine is about 2£ miles southeast of Jarbidge, 

900 feet above Jarbidge River (Pis., II and XIX, B). With the 

neighboring Bluster and Success mines, it forms the Bonanza Hill 

group (fig. 14). These mines are described in the earlier report. 

The veins lie in the rhyolit'e and strike north-northwest with nearly 

vertical dips.

The Pick and Shovel property is owned and worked by John 

Escalon, the discoverer. In 1916 it produced $5,000 in gold' ore. 

The ore was treated by the amalgamation process in a 3-stamp mill 

down near the river and the-mouth of Bonanza Gulch. It camo 

from a branch of the Pick and Shovel vein on the northwest, known 

as the Fleming or Arizona Fraction vein.

The mine is developed by 1,000 feet of workings, distributed interruptedly through the length of the claim and consisting mainly of 

several crosscut tunnels, one of which is 300 feet long, a 60-foot 

shaft, and several short drifts.

The vein is from 5 to 20 feet wide. It dips steeply eastward, into 

the mountain side, or is vertical. It is mostly quartz, much of it 

pseudomorphic after spar. It is relatively very sound and is firmer
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE XVII

of vein

VeinTfbulted off 

at/surface. (?)

PLAN AND SECTION OF LEGITIMATE MINE. 

By A. L. Rincarson.
U. S. GEOLOGICAL SURVEY BULLETIN 741 PLATE XVIII

LEGITIMATE MINE.

Looking northwest across Bourne Gulch. Part of Starlight mine at left. The timber 

on the slope is mostly mountain mahogany.
U. S. GEOLOGICAL SURVEY BULLETIN" 741 PLATE XIX

A. NORTH MOUNTAIN AND CANDY PROSPECT.

On northerly extension of Altitude vein. Looking northeast from rim of First Crater 

and intersection of Ben Hur vein (shown in PI. IV, A). Photograph by Claude C. 

Gillham, taken in August.

B. BLUSTER AND PICK AND SHOVEL MINES. 

Looking east from west slope of Jarbidge Valley. Photograph by Claude C. Gillham.
MINES AND PROSPECTS ON THE WEST VEINS. 61

and harder than the 

neighboring Bluster 

and Success veins. It 

carries good ore 

shoots, some of which 

are rich, and generally the ore shows 

much free gold associated with bluishblack argentine. 

Brownish areas several inches in diameter of surfaces of 

the ore are heavily 

frosted with fine 

spongy porous gold 

or electrum. A considerable portion of 

the ore averages about 

$3.50 to the pound. 

The gold runs about 

$12 to the ounce. In 

the fall of 1920 a 

southeast branch of 

the vein opened by a 

95-foot crosscut was 

found to be 4 feet 

wide and to pan 

about $40 in gold to 

the ton.

BLUSTER .MINE.

Location. The 

Bluster and Success 

mines are 2| miles 

southeast of Jarbidge, east of the Pick 

and Shovel mine 

(Pis. II and XIX, 

B; fig. 14). They 

are adjoining properties and are on the 

same vein, the Bluster 

or Bluster-Success 

vein. The vein approximately parallels
62 THE JARBIDGE MINING DISTRICT, NEVADA.

the Pick and Shovel vein but is 800 feet distant from it horizontally to the east and 500 feet higher up the mountain slope, its 

apex having an elevation of about 8,600 feet. It strikes N. 30° W. 

and dips 60° E., into the mountain side. It is said to have^a known 

extent of 1 mile, from Bonanza Gulch on the north to Gorge Gulch 

on the south. It ranges from a few feet to 45 feet in width, and 

though parts of it are barren the greater portion, so far as it has been 

exploited, is workable. The ore is mostly of the soft sugary quartz 

variety and is thoroughly oxidized. The best ore is found about 6 to 8 

inches from the footwall side. The widest ore .shoot is 26 feet in 

width and is best developed on No. 2 level of the Success mine. The 

ratio of gold to silver contained in the ore ranges from 15:1 in the 

Success to 3:1 in the Bluster. The Bluster mine is at an elevation 

of about 8,000 feet, or 1,300 feet above Jarbidge Kiver.

History. The Bluster vein was discovered early in the history of 

the district. Almost from the time of discovery the Bluster mine 

has been owned by the Bluster Consolidated Mines Co., of Jarbidge. 

About 1911 George Wingfield took a bond on the Bluster and Success mines jointly, but he soon discontinued the bond for want of an 

extension of time. Then the Bluster Co. opened up the veins, put in a 

10-stamp straight amalgation mill below the mine near the river, and 

built a 3,400-foot aerial tramway with |-ton buckets to connect the 

mine and mill. The company operated the mine and mill for six 

months in 1914 and produced $70,000 in gold bullion, but as the 

process of treatment was not suited to the ore the extraction was 

only about 35 per cent, with the result that nearly two-thirds of the 

metallic content of the ore treated, or about $140,000 in gold and 

silver, lies in the tailings pond. Since then only assessment work 

has been done on the property.

In September, 1921, it was reported that the property had been 

purchased by the Bonanza Gold Mining Co., of Los Angeles, and that 

operations would soon be resumed.22 Later it was reported that the 

Bluster and Success mines had been examined by Chicago interests,23 

and in August, 1922, that negotiations were still pending. In November the company was said to be cutting much saw timber and 

excavating ground for a cyanide plant.

Development and equipment. The mine is opened to a depth of 

about 300 feet by 3,000 feet of workings, chiefly drifts and adit 

crosscuts (fig. 14). There are two principal levels, the lower, or 

level No. 3, at an elevation of about 8,400 feet and the upper, or 

level No. 2, at an elevation of about 8,500 feet. On the lower level, 

which is the more extensive, the approach to-the vein is a 400-foot 

crosscut tunnel leading from the head house of the aerial tramway.

=2 Eng. and Min. Jour., Sept. 17, 1921, p. 473. 

23 Salt Lake Min. Rev., Nov. 30, 1921.
MINES AND PROSPECTS 'ON THE WEST VEINS. - 63

The equipment includes chiefly the 70-ton stamp mill and 3,400-foot 

aerial tramway above described and buildings sufficient to house 35 

men. Good water and timber occur near by.

Ore deposits. The deposits are contained chiefly in the Bluster vein, 

which is from 3 to 45 feet wide. The walls in general are well defined 

and are accompanied by a sheet of kaolin-like gouge. Together with 

several branches the vein has an extent of nearly 2,000 feet on the 

property. It is opened to a depth of about 300 feet and contains large 

and valuable ore bodies. A considerable tonnage of milling ore has 

been blocked out. The ore occurs mostly in the footwall side of the 

vein and as metasomastic replacement deposits in the adjacent rhyolite. It is soft and breaks easily, and holes for blasting are often 

bored with an auger. The ore shoots are nearly parallel with the vein. 

They range from thin tabular sheets to flattish lenticular bodies 

nearly 20 feet in width and 200 to 300 feet in length. The ratio of 

the value of the gold to that of the silver contained in the ore is 3:1. 

The gold occurs free and alloyed with silver, or as electrum.

On the lower level northward for 380 feet from the crosscut tunnel 

the vein is locally 45 feet in width and in places contained good ore 

shoots, of which one of the best had a width of 8 feet and averaged 

$21 to the ton.

For 380 feet southward from the crosscut tunnel the vein for the 

most part has good walls and shows ore in places. A considerable 

percentage of the ore is said to have averaged $40 to the ton. The 

ore shoot is said to have an extent of 250 feet. The drift at the time 

of visit was entering good-looking quartz ore. At an intervening 

point a short crosscut to the north shows 2 feet of black shale or slate 

underlying a similar thickness of gray sandstone.

BIG VEIN PROSPECT.

On the Bluster ground between the south ends of the Pick and 

Shovel and Bluster mines and approximately paralleling the veins 

of these mines in strike and dip is the north end of the so-called Big 

or 80-foot vein. From the Bluster ground this vein extends southward across the Single Jack claim and is said to continue at least to 

Gorge Gulch, three-fourths of a mile distant, where the Indian Camp 

and Oregon groups are staked on it and other veins thought to be 

related to the Bluster vein. Where it has been prospected near the 

Bluster mine it is said to carry from $5 to $10 in gold to the ton.

SUCCESS MINE.

Location. The Success mine adjoins the Bluster mine and is on 

the northward continuation of the Bluster vein, in the upper south-
64 THE JABBIDGE MINING DISTRICT, NEVADA.

side slope of Bonanza Gulch (PI. II, fig. 14). It is owned by the 

Success Mining & Milling Co., of Jarbidge.

History. The deposit was discovered by Charles Nelson and associates in 1910, but at that time they did little more than assessment work and did not know that the dep°osit was on the Bluster 

vein. Eich pannings were found in the outcrop at the portal of No. 

2 tunnel. The mine has not yet been worked for production. In 

1911 George Wingfield took a bond on the property and did most 

of the work which has been done to date, but he relinquished the 

property late in that year for want of an extension of time. The 

owner then began work and developed the ore. In 1917 Mr. Hanford, of the Elko Mines Co., of Chicago, took a bond on the mine 

and drove the last 400 feet of No.' 4 tunnel, but seemingly he did not 

find much ore and relinquished it late in that year. Since then both 

the Success and the Bluster mines have been inactive, it is said for 

want of funds to build plants having a treatment process suited to 

the ore.

Development. The mine is developed through a vertical range of 

500 feet by about 3,500 feet of workings, consisting mainly of adit 

tunnels driven from the north (fig. 14). Of these the longest are 

tunnels Nos. 2 and 4, 160 feet apart vertically. Tunnel No. 2, which 

is but a few feet above level No. 3 of the Bluster mine, has a length 

of 450 feet. Tunnel No. 4 extends 1,000 feet from the portal. The 

lowest tunnel (No. 5), 300 feet long, with the portal near Bonanza 

Gulch at an elevation of approximately 8,100 feet, 140 feet lower 

than tunnel No. 4, has not yet reached the vein.

Ore deposits. The mine is reported to have more than $300,000 

worth of ore blocked out, and some good ore lies on the dump. The 

ore is mostly of the soft, sugary quartz-adularia kind and is said 

to average about $16 to the ton. The ratio of the metals contained 

in the ore is said to be about 1 ounce of gold to 1 ounce of silver. 

The proportion of silver increases toward the southerly part of the 

mine, where the vein is 30 to 40 feet wide.

On level No. 2, at 50 feet from the portal, the vein looks well and 

has an ore shoot 6 feet wide extending for a considerable distance. 

From the 150-foot point inward another ore shoot 9 feet wide looks 

well. It is banded, has well-defined walls, and is said to average $15 

to the ton.

In the Discovery cut, 140 feet above the portal of level No. 2, is a 

6-foot ore shoot said to average $35 to the ton.

On level No. 4 the face of the drift on the vein shows 3 feet of 

good quartz ore. The first 100 feet or more of drift on this level is 

on a smaller parallel vein that lies 40 feet east of the main vein.
MINES AND PROSPECTS ON THE WEST VEINS. 65 

JARBIDGE CENTRAL PROSPECT.

The Jarbidge Central prospect, just north of the Success mine, 

on the opposite side of Bonanza Gulch, is said to show good ore in 

its 50-foot shaft and several cuts.

BUCKEYE MINE.

The Buckeye mine is nearly 1^ miles southeast of Jarbidge, at an 

elevation of about 6,000 feet, or 1,800 feet above the river (Pis. II 

and III). The property comprises two claims the Stray Dog and

RA/SC

FIGURE 15. Plan of Buckeye mine.

the Buckeye and adjoins the patented ground of the Elkoro Mines 

Co. on the northeast. The deposit was discovered in 1910 by A. 

Dufrens and S. G. Hull, of Jarbidge, who with others later formed 

the Buckeye Mining Co., the present owner, which has been steadily 

developing the property and has opened about 1,000 feet of workings 

and blocked out about $75,000 worth of ore (fig. 15). It is estimated 

that about $3,000 in gold was recovered with an arrastre by early-day 

lessees. The ore is said to average $20 to the ton. Some of it is 

very rich.
66 THE JARBIDGE MINING DISTRICT,. NEVADA.

COLD SPRING MINE.

The Cold Spring or Alice May mine, owned by the Cold Spring 

Mining Co., of Jarbidge, is north of Bonanza G.ulch, between the 

Buckeye mine and the Jarbidge Central prospect, at an elevation of 

about 8,000 feet (Pis. II and III). The deposit was discovered in 

1910 by Messrs. Dufrens and Hull. The property comprises five 

claims and is on three veins, all of which are said to have been 

opened to the north and to' the south of the property with good 

results. The mine is developed by about 700 feet of workings similar 

to those of the Buckeye mine but not so extensive.

1 NORMAN MINE.

The Norman mine is about 8 miles south-southeast of Jarbidge, at 

the head of Jarbidge River, in the upper west slope of the Crater 

Range, about half a mile from the Marys River divide, at an elevation of about 9,100 feet (PI. I). It is owned and worked by Olaf 

Norman, of Jarbidge, who discovered the deposit in July, 1910, by 

panning float on the mountain side. The property comprises a 

group of seven claims (PI. XVI).

The country rock is old rhyolite, relatively coarse grained and in 

part porphyritic. It is profusely speckled by wine-colored quartz, 

much of which, owing to the abundance of iron oxide, resembles on 

casual observation reddish-brown garnet. The rock in general contains considerable iron oxide in grains and some in disseminated 

small cubes after pyrite. Much of it is stained yellowish brown with 

limonite and on joint faces and seams is more or less coated with 

yyrite.

The Norman vein strikes N, 25° W. and dips 80° W. In the present

workings it has a maximum width of about 50 feet and apparently lies 

in a strong fissure. The mine is worked for gold but contains also 

silver and shows indications of copper. It is developed by about 

1,600 feet of workings, consisting chiefly of three crosscut tunnels 

and drifts distributed through a vertical range of nearly 300 feet 

between elevations of 9,000 and 9,300 feet. Most of the workings 

are timbered and equipped with tram tracks. Water and timber are 

plentiful. A strong stream of excellent water flows from tunnel 

No. 2.

At the time of visit the vein was best exposed in tunnel No. 2. 

This tunnel, which is on the Lake claim at an elevation of 9,170 feet, 

cuts the vein at a depth of 60 feet at 100 feet from the portal (fig. 

16). Here the vein walls are about vertical, are smooth, and look 

well. In the drifts on either side of the tunnel the first 2 feet of 

the hanging-wall side of the vein is ore averaging $23 in gold to the 

ton. The gangue is chiefly quartz, with more or less brecciated and
MINES AND PROSPECTS ON THE WEST VEINS. 67

mineralized rhyolite, all thoroughly oxidized. At about 25 feet from 

the tunnel, on each side, however, the ore and in part the vein cease, 

as if cut off by faulting, but in the muddy condition of the ground 

at the time of visit this point could hot be satisfactorily determined. 

At the south end of the ore shoot the sheeting in the wall rock dips 

50° NW. Another 'sheeting dips 50° NE., and in the roof of the 

drift slickensided surfaces in brown clay dip gently north-northwest. 

Near the middle of the vein occurs another ore shoot about 4 feet 

wide that averages $8 to the ton. About 40 feet north of the tunnel 

the hanging-wall drift cuts an oblique 3-foot shoot of iron-gray 

copper-silver sulphide ore in which chalcopyrite is the dominant 

ore mineral (fig. 16). It is reported that later development shows 

that a width of 9 feet of the vein 

carries chalcopyrite and that the

chalcopyrite tends to occur in 

boulder-like masses. The gangue 

consists of a microcrystalline 

mass of orthoclase and quartz, in 

which are numerous fragments 

of freshly broken feldspar crystals, giving the ore much the appearance of a breccia. Sericiteis 

abundant, and much of it occurs 

in bodies of considerable size 

composed of small elongated 

foils and fiber-like bits. The 

chalcopyrite is widely disseminated in grains or crystals and 

in aggregates or bodies and 

masses as much as a quarter of 

an inch in diameter, but it does 

not seem to replace phenocrysts 

or other minerals. Some of the 

chalcopyrite on its surface is altered to secondary chalcocite and 

black copper oxide. Associated with the chalcopyrite is a little pyrite, 

and weathered joint planes are stained reddish brown by hematite 

derived from the pyrite. The oblique position of the copper-bearing 

, ore shoot suggests that it is younger than the vein. Mr.' Norman 

reports iron-stained or gossan-like croppings at several points along 

the course of the vein to the north of the mine, which he regards as 

fair indications of copper.

In tunnel No. 3, which is also on the Lake claim at an elevation of 

9,180 feet and is 65 feet long, the vein shows 20 feet of sugary barren 

quartz. The dump of a 14-foot shaft sunk on the vein at an elevation 

of 9.300 feet contains considerable good-looking quartz.

FIGUKE 16. Plan of No. 2 level of Norman 

mine. Scale, 1 inch equals 100 feet. 

a, 2 feet of $23 gold ore; 6, 4 feet of $8 

gold ore; c, kaolin-like gouge; d, dark 

quartz-gangue ore containing copper and 

silver sulphide minerals.
68 * THE JARBIDGE MINING DISTRICT, NEVADA.

Tunnel No. 1, on the Yellow Jacket claim, has a length of 364 

feet. It reached the vein at a depth of 125 feet at a point 250 feet 

to the north of and 50 feet higher than tunnel No. 2. The cross 

section of the vein at this point, beginning on the hanging-wall side, 

is said to be as follows:

Section of Norman vein in tunnel No. 1.

Feet.

Oxidized zone of quartz and ore_____________ _ 15 

Sulphide zone of quartz and ore__________ _ 12 

Light-brown quartz (probably oxidized)_____________ 6

33

The best ore is said to occur in the hanging-wall side of the sulphide zone, on which a 24-foot drift has been driven to the north.

That the vein is probably strong to the north of the Norman mine 

is indicated by the presence of large boulders of good-looking replacement quartz in the talus and float along the Jarbidge River trail 

in that vicinity. The vein is regarded by William Van Alder 24 as 

the southerly extension of the Altitude vein, and this view is probably correct, as it seems to be in the same fissure as that vein. But 

the vein itself is not known to have been carefully traced between the 

Altitude mine and the Norman mine. The intervening 4$ miles of 

country is mostly very rugged.

To the south of the Norman mine the vein is not so strong, but it 

continues through the low pass across the Marys River divide, on 

both sides of which it has been prospected by Al Knight and associates on the Summit and adjoining claims. The cut on the north 

side of the divide shows fairly good looking quartz, but being near 

the surface it is highly oxidized and leached.

MOORE PROSPECT.

The Moore prospect is two-thirds of a mile northeast of Jarbidge, 

in Moore Gulch half a mile above its mouth. It is on the south end 

of the Bluetop claim, which joins the Long Hike property (PI. 

XVI). It is owned by Mr. Moore, of Buhl, Idaho. It consists principally of a fairly good looking 2|-foot vein, which at the cabin 

strikes N. 40° E. and dips 65° SE. The vein also shows in a near-by 

20-foot shaft and 50-foot tunnel, where it is in part split up into 

several stringers. It lies in brownish-gray medium-grained rhyolite, 

which is hydrothermally altered, and contains considerable secondary quartz and other minerals.

84 Oral communication.
THE JARBIDGE MINING DISTRICT, NEVADA. 69 

MINES AND PROSPECTS ON THE EAST VEINS.

The properties on veins of the east system are in the upper east 

slope of the Crater Range or near its crest on the west slope.

ALTITUDE MINE.

Location. The Altitude mine is one of a group of six or more 

properties which might well be called the First Crater group, from 

their location in or near the First Crater (PI. IV, A; fig. 17). They 

include the Altitude, Bullion, Ben Hur, Candy, New Star, New 

Hope, Red Dike, and others.

The Altitude mine, described as the Howard-McCoy mine in the 

earlier report, is 3£ miles southeast of Jarbidge, in the upper east 

side of the Crater Range, at the head of Jack Creek, in the First 

Crater. It is in the steep south wall of the " crater," between elevations of 9,700 and 10,300 feet. It adjoins the Bullion property, described below, on the north.

The property comprises a group of six claims (fig. 18). It is 

owned and worked by the Jarbidge-Buhl Mining Co., of Buhl, 

Idaho, and Jarbidge. The camp is in the " crater " about one-third 

of a mile north of the mine. The production has been small, and it 

seemed doubtful whether the showings at the time of visit justified 

the large expense of building the electric-power line and wagon road 

to the mine. It was said, however, that the company planned to use 

the power line in developing the mine and finding ore before considering the project of building a mill, and later it was reported 

that considerable ore had been blocked out. During the open season 

of 1921 the mine and camp were fully equipped with a hoist and 

other apparatus for operating throughout the winter. Underground 

work with compressors supplied with electric power was started in 

November and continued till late in the spring of 1922, when operations were suspended, it is said for lack of funds,

Development and equipment. The mine is opened to a depth of 

500 feet by about 2,000 feet of workings, consisting mainly of an adit 

crosscut tunnel, drifts, and crosscuts (fig. 18). The tunnel starts on 

the Altitude claim.

The equipment consists chiefly of about 3 miles of electric-power 

line, which was built across the range from the Starlight mine in 

1920; about 7 miles of good wagon road, built from Hot Springs up 

Jack Creek on the east; and buildings for housing a considerable 

force of men. Water and timber are plentiful on the ground or 

near by. The power line and a trail from Jarbidge enter the 

" crater" on the northwest (PI. IV, J., and fig. 17).

Geology. The country rock is the old rhyolite, which here, however, is near the upper part of the section of that rock and consists
70 THE JARBIDGE MINING DISTRICT, NEVADA. 

R. 58 E.

T.47N. 

36

EXPLANATION 

Vein

Strike and dip

> 

Spring

IZOO 2400

FIGUHB 17. Map of First Crater and Jack Creek claims, showing outline of the " crater, 

Jack Hole rim rock, and new road to Bullion and Altitude mines. By A. L. Rinearson.
MINES AND PROSPECTS ON THE EAST VEINS. 71

of flows that are 'greatly varied in color and texture and are apparently considerably younger than the rocks occurring down near the 

river and the base of the section, as at the North Star and Pavlak 

mines. The color is mostly drab-gray or bluish gray of various

PLAN

0 50 100 200 300 FEET

ALTITUDE TUNNEL

'£LEV. 970O' TOO 7

SECTION

FIGURE 18. Plan and section of Altitude mine. Scale of claim map, 1 inch=2,000 feet.

shades, and the texture is fine to medium grained. Flow structure 

and flow breccia are common. Associated .with the rhyolite is considerable lignitic and other sedimentary material.

Ore deposit?. The mine is on two veins, the Altitude vein and the 

Windy vein (fig. 17), which in the first report were described respec-
72. THE JARBIDGE MINING DISTRICT, NEVADA.

tively as the Howard-McCoy vein and the Van Alder or East vein. 

The present main opening is near the foot of the " crater " wall, 192 

feet below the openings made on these veins in 1910. The veins strike 

about parallel and converge in dip. In the upper or old workings 

they are 140 feet apart, and in the present workings only 50 to 60 

feet apart. The Altitude vein, which seems to be the richer, dips 

steeply to the east. It is opened to a point 800 feet from the portal 

of the tunnel and 620 feet vertically below the top of East Ridge. 

The Windy vein is opened to a point about 600 feet from the portal.

The veins are from 3 to 16 feet wide and are more or less banded. 

For a length of 140 feet the opened portion of the Windy vein is said 

to have carried $14 ore and locally ore that averaged more than $100 

to the ton. There are barren places, however, in both veins.

The ore in both veins is gold ore, and the gangue is mainly replacement pseudomorphic quartz and adularia, as described in the earlier 

report.

At about 670 feet from the portal the Altitude vein is crossed by 

an east-west fault zone about 40 feet wide. It consists mostly of soft 

altered iron-stained rhyolite and contains numerous seams of talclike material, most of which lie parallel with the fault. At 24 feet 

back of the fault the vein contains a 5-foot ore shoot with welldefined walls. A short distance back of the fault the company in 

February, 1922, began driving a crosscut eastward to intersect the 

Windy vein at a point about 100 feet beyond the face of its present 

workings.

To the south of .the Altitude mine the veins are said to have been 

traced interruptedly for several miles through the " craters " and

intervening ridges (PL ^ XVI). Northward from the mine, down

the Jack Creek valley, they have been traced for 1£ miles to a point 

where they seem to unite, as beyond that point only one vein, the 

Altitude, continues for a considerable distance.

BULLION PROSPECT.

The Bullion property lies in the floor of the First Crater at an 

elevation of about 9,500 feet and adjoins the Altitude mine on the 

north. It comprises a group of 17 claims known as the Bullion 

group (fig. 17). It is owned by the Crater Mining Co., of New 

York, which is said to be interested also in the neighboring New Star, 

New Hope, National, and Ajax groups; a total of 36 claims.

The Bullion claims are on what seems to be mostly the northward continuation of the Altitude and Windy veins, but they include 

other veins, which lie approximately parallel with these veins. The 

veins as a whole stand nearly vertical, pearly all of them show 

replacement pseudomorphic quartz-adularia gangue and mineralized
MINES AND PROSPECTS ON THE EAST VEINS. 73

replaced rhyolite, and several of the openings show sulphide ore, or 

at least pyrite very finely disseminated through the veins. This is 

notably true of the Victoria No. 5 vein in the 65-foot tunnelon 

Bullion claim No. 3 and the 17-foot vein on the Bullion claim in the 

southwestern part of the property.

The general presence of sulphide at or near the surface is probably due to a locally high ground-water level being maintained in 

the " crater " by the abundant supply of water constantly issuing 

from springs and the melting of huge snowbanks that skirt the, foot 

of its surrounding wall.

The veins are mostly narrow, being 2£ to 3 feet wide, though one 

recently opened is reported to be more than 20 feet in width. The 

Victoria No. 5 vein has a width of 4 feet. At the time of visit only 

shallow openings had been made on the veins, but in most of them 

the showings were good.

Since the writer's visit a 60-foot drift and crosscuts have been 

driven on the so-called 17-foot vein, which according to notes and 

specimens kindly furnished by Mr. A. L. Rinearson may be described 

essentially as follows: The vein lies in gray rhyolite about 700 feet 

west of the Altitude vein or it's projected course, with which it is 

approximately parallel. It dips about 85° E. or is vertical and is 2Q| 

feet wide. The footwall is regular and the hanging wall more or 

less irregular. The vein consists mostly of mineralized and replaced 

or bluish-gray rhyolite, which is similar to the country rock but 

which by the invading quartz-adularia (?) hydrothermal solutions 

has been largely changed to a gray sulphide ore, through which finegrained pyrite and a little chalcopyrite are widely disseminated. Besides the minerals above mentioned, the vein also contains considerable secondary quartz-adularia gangue, sericite, and some chlorite.

The vein contains several parallel layers or zones composed essentially of relatively pure adularia or quartz-adularia gangue, of which 

the two thickest are a 2-foot layer at about 6 feet from the hangingwall side and a 2£-inch layer at 11£ feet from the hanging wall or 9 

feet from the footwall. The 60-foot drift is mostly driven on the 

2-foot layer.

The adularia bands are stained brown or reddish brown with hematite and limonite and are sharply in contrast with the gray sulphide 

bands. They are fine grained and are free from pyrite and chalcopyrite, which have apparently been oxidized and in part leached out 

of them by descending percolating waters. Locally in open seams 

along the contact of the sulphide ore with the adularia ore the face 

of the sulphide wall is coated with adularia crystals 0.2 inch in maximum dimensions (PI. IX, A). The crystals are mostly stained yellowish brown by limonite.
74 THE JARBIDGE MINING DISTRICT, NEVADA.

Near the foot of the west crosscut the vein is traversed by a small 

normal longitudinal fault which dips 60° W. The rhyolite above the 

fault is similar to the adularia layers in that it contains no pyrite, the 

pyrite seemingly having been oxidized and leached out. On claim 

No. 11 a 14-inch quartz vein which occurs on the footwall of a dike 

is opened by a 36-foot tunnel.

BEN'HUR PROSPECT. I 

The Ben Hur prospect, formerly owned by the Vukovich Brothers, of Jarbidge, and now said to be owned by the Crater Mining 

Co., of New York, is in and near the west wall and adjoining rim 

of the First Crater (PL IV, A). It is about 2£ miles southeast 

of Jarbidge and half a mile west of the Bullion group. The property comprises three claims (fig. IT) and contains several veins, 

of which apparently the most valuable is the Ben Hur vein, which 

extends through the length of two claims on the property. The 

Ben Hur vein strikes about1 N. 20° W. and dips steeply to the east 

or is nearly vertical. It is best exposed on the north. Here on the 

north end of the Ben Hur No. 1 claim and adjoining New Sjtar and 

New Hope ground* the vein is gashed or broken through by erosion 

in the northwest corner of the "crater." The gash extends about 

1,000 feet horizontally at the top or rim of the " crater" and 500 

feet or more in depth to the floor. Through this nearly vertical 

distance the vein, especially its footwall, is more or less exposed 

in cross section on either side of the gash.

The vein is 2£ to 3 feet in average width, but on No. 2 claim it 

is 14 feet wide. It is composed mainly of the usual lamellar pseudomorphic quartz-adularia gangue and appears to be all oxidized. It 

is mostly banded and shows a fiber-like cross growth or structure, 

which becomes conspicuous by oxidation and weathering.

In general the vein is tight walled and relatively hard. In its 

exposed descent of 500 feet from the top to the bottom of the 

" crater " it shows no sign of pinching or weakening, and openings 

made in it on the New Star ground in the bottom of the " crater " 

are said to be encouraging.

Southward from the rim of the " crater " the vein or its branches 

have been opened at several points on Nos. 1 and 2 claims with moderately fair results, as have also other veins west of it on the No. 3 

claim and on the Reward, Ajax, and other claims a little lower down 

the mountain slope to the west.

AJAX PROSPECT.

The Ajax prospect adjoins the Ben Hur on the south and the 

Altitude on the west (fig. 17). It is 3 miles southeast of Jarbidge,
^ MINES AND PROSPECTS ON THE EAST VEINS. 75

in the steep head slope of Bonanza Gulch, at an elevation of about 

9,600 feet (PI. VIII, A). The last mile of the approach is covered 

by a good trail. The property comprises 10 or more claims, known 

chiefly as the Aja-x group. It is owned and worked by Pat Donahue, 

of Jarbidge. There are several veins in the vicinity, of which a 

total length of 3,600 fee); is said to lie within the Ajax property. 

They probably include <". southerly extension of the Ben Hur vein 

or a branch of it. They have been prospected at several points,, 

chiefly by cuts and adit tunnels or drifts, some of which present 

fair showings. One of them,.the Ajax vein, where opened by the 

Ajax tunnel at an elevation of about 9,800 feet, is 4 to 5 feet in 

width and dips 80° W. The face of the tunnel, which is 400 feet 

long, is 250 feet below the surface and contains 2$ feet of fairly 

good looking banded ore. The gangue includes, besides quartz and 

adularia. considerable altered rhyolite and clay.

CANDY PROSPECT.

The Candy prospect, which was not visited in this work, is about 

2 miles east of Jarbidge and half a mile north of the First Crater, 

on the east slope of North Mountain between the heads of Jenny 

Creek and Jack Creek (PI. XIX, A; fig. 17). It is owned and 

worked by Mark Leffler, of Jarbidge, who discovered the deposit 

in 1919.

It is said to be on the northward continuation of the Altitude 

vein, which is here from 5 to 15 feet wide, is banded, and containsa 10-inch shoot of high-grade ore that shows and pans much free 

gold. In a specimen of the ore received from the owner the gangue 

in which the gold is embedded is chiefly adularia. The specimen is 

highly oxidized. It is noncalcareous or contains no calcite and 

shows a very finely- laminated and honeycombed pseudomorphic 

structure. A panning made of it shows the gold to consist of particles scarcely visible to the unaided eye. They are rough or sharply 

angular, even more so than those shown in Plate XIII, and nearly 

all are elongated or wiry. Some of the longer ones are longitudinally striated or filiform, the striations probably being due to twinning. Most of the gold is of a pale brass color, but some is a deep,, 

rich yellow.

Associated with the gold concentrates in the pan is considerable 

fine-grained magnetite and a little zircon and apatite. Besides several small openings, a 270-foot crosscut, which now has a length of 

110 feet, is being driven to tap the vein at a depth of 100 feet.

The property contains also several small yellowish gold-bearingveins lying in or near a rhyolite dike, with which they are parallel.

13253 23 6
76 THE JARBIDGE MINING DISTEICT, NEVADA.

RED DIKE PROSPECT.

The Ked Dike prospect, also called the Red Vein, concerning 

which the following data were kindly furnished by Mr. Pat Donahue, is on East Ridge, on the southeast side of Jack Creek and tha 

First Crater (PL IV, A; fig. IT). The vein was discovered by Mr. 

Donaliue in 1916 and is owned by Finch & 'Sons, of Alazon, Nev. It 

extends from an elevation of about 8,000 feet southward up the 

ridge for about 2,000 feet. It is from 2 to 12 feet wide and dips 

35° E., into the ridge. It consists chiefly of a quartz-adularia ganguo 

which is more or less greenish and similar to that of the Pick and 

Shovel mine. The value is chiefly in gold and ranges from $1 to 

$40 to the ton.

MORNING STAR MINE.

The Morning Star mine, formerly known as the Arkansas property and so described in the earlier report, is in the head of the 

Third Crater, 4 miles southeast of Jarbidge (PL XX). It is reached 

by way of the Bonanza-Bluster or Crater trail. The deposit was 

discovered in 1910 by Ralph F. Harder and Bishop Norman, of 

Jarbidge, who in the next five years did considerable development 

work on it. It is owned by Harder & Gillham. The property comprises 10 claims and contains 4,500 feet of the Morning Star vein, 

formerly called the Harder-Norman, supposed to be the southward 

continuation of the Windy vein. This vein is intersected by the 

Altitude vein, of which about 3,000 feet lies on the property (PL 

XVI).

The Morning Star vein, which is about 7 feet wide, strikes about 

N. 20° E. and dips 80° W., and the Altitude vein, which is 5 feet 

wide, strikes N. 20° W. and dips 80° E. The Morning Star vein 

is opened by an upper 103-foot drift, a lower 300-foot crosscut, from 

which 80 feet of drift extends northward to the junction of the two 

veins, and several open cuts, all of which are said to yield good 

returns. It contains 1 foot of $12 ore in the footwall side, and its 

remaining 6 feet averages about $3.50 to the ton.

BATY PROSPECT.

The Baty prospect is in the Fourth Crater, 4£ miles southeast of 

Jarbidge (PL V, A). It is owned by Mrs. Etta Baty, of Jarbidge. 

The vein, which strikes about north through the length of two 

claims, lies about one-third of a mile east of the Altitude vein (PL 

XVI). It seems to be a compound vein or lode. It is said to be 50 

feet in width and to contain numerous parallel high-grade ore shoots 

from 3 to 6 feet in width, which appear to be exceptionally encouraging.
U. S. GEOLOGICAL SURVEY 

MORNING STAR MINE. 

In head of Third Crater. Looking west. Photograph by Claude C. Gill
FUTURE OF THE DISTRICT. 77 

COUGAR MOUNTAIN PROSPECT.

The Cougar Mountain prospect is 7 miles southeast of Jarbidge, 

on Cougar Mountain, between the Fifth and Sixth craters (PI. 

V, #). It contains several openings. It is owned by Knight & 

Blakely, who have done considerable development work on it in the 

last five years. The veins, of which there are several, are said to 

be promising.

PLACERS.

The only placer deposits in the district are the so-called Park 

placers, on Jarbidge River below Jarbidge, and a few similar deposits on the East Fork, none of which, however, seem to have any 

Aralue.

The eroded portions of the Jarbidge veins doubtless yielded 

detrital gold enough to form Avorkable placers of considerable'extent, 

but OAving to the character of the gold, the fineness and the porous 

or fluffy structure of its particles, it is so buoyant in water that it 

is easily carried out of the district by the streams. This is indicated by the string of fine gold particles often found floating on the 

surface of the water in panning, and by observations made by Mr. 

Donald Steel 20 on gold washed ou^ of thawing Jarbidge dumps, the 

irold being concentrated only at the termini of the streams without

O tJ ^

a trace being deposited in the intervening riffle-like fractures, crevices, and rock cavities over which it passed.

Deposits of the Jarbidge class are probably an important source 

of the Avell-knoAvn placer gold which is so abundant in many places 

along Snake River but which, owing to its extreme fineness and 

buoyancy, has baffled repeated attempts to recover it.

FUTURE OF THE DISTRICT.

i 

As practically no work,has yet been done in the sulphide, zone that

would afford data for forming an opinion concerning the probable 

continuation and character of the deposits in depth, the follovving 

forecast is based largely on experience and results with similar deposits in other districts.

Nearly all the ore thus far mined in*the district has come from the 

oxidized zone and o\ves its metallic content largely to enrichment. 

The enrichment was accomplished mainly through the agency of descending meteoric waters, which leached the metallic contents from 

the higher parts of the veins before they were eroded aAvay and concentrated them in the loAver parts, which are noAv being mined. Some 

of these oxidized deposits, as shoAvn in a few of the mines, extend to 

maximum depths of about 700 feet. They apparently decrease in 

depth with nearness to the axis of the Crater Range, where the sur18 Oral communication.
78 THE JARBIDGE MINING DISTKICT, NEVADA.

face slopes that shed the meteoric water steepen. In some of the 

veins there still remains a fair reserve of this class of ore.

As the veins with increase in depth extend into the sulphide zone 

they must be expected to become more regular in tenor, but narrower 

and leaner than they are in the oxidized zone. Many of them probably extend to considerable depths, and some of these are probably 

workable. Most of them, however, are likely to become too narrow 

or too lean to be workable in depth, their silver and gold minerals 

giving way to practically barren pyrite. The outlook for deep mining 

in the district is therefore not regarded as encouraging.

Although active mining in the Jarbidge district will continue for 

several years, the fate of certain valuable unworked deposits in other 

remote districts of the West, from which after a prosperous period 

of activity expensive power lines were removed and the districts 

abandoned, should suggest to the Jarbidge owner the advisability 

of working his mine while power and transportation are so readily 

available as now.

CHARLESTON DISTRICT.

LOCATION.

The Charleston district, also called the Copper Mountain district, 

adjoins the Jarbidge district on the southwest. It was not examined 

in this work other than by meager observations made from the autostage on the Elko-Jarbidge road. The present description is based 

largely on information gathered from prospectors and engineers who 

have visited different parts of the district and accordingly is general 

in character.

The district is a somewhat indefinite area contained mostly in a 

north-south belt about 5 miles wide by 20 miles long, extending from 

about the latitude of the north edge of the Jarbidge district southward to Charleston, where it includes the Charleston district of early 

days. The natural boundary between the two districts is the high 

mountain ridge southwest of Jarbidge separating the Jarbidge 

River drainage, represented by Bear Creek and Pine Creek, on the 

east from the Bruneau River drainage, represented by Coon Creek 

and Copper Creek, on the west (PI. I). The country east of the 

ridge is more accessible from the northeast or Idaho side, and that 

west of it from the south or Elko side.

The discovery of mineral deposits in the district must have at 

least preceded the rise of Charleston as an early-day camp, which is 

said to have been in 1885 but may have been in 1876, the }-ear from 

which 76 Creek is said to take its name. At any rate, Charleston 

came into existence through gold-placer mining at a site 4 miles to 

the north, on 76 Creek, near the southwest base of Copper Mountain. 

It soon became a lively camp, with three schools, several stores, a
CHARLESTON DISTRICT. 79

hotel, ice house, saloon, and other buildings, some of which still remain. The site is in the midst of a wide hilly sagebrush basin, 

largely surrounded by mountains, which are mostly low and in part 

bare and which on the northeast slope up into the main range.

TOPOGRAPHY.

The district is strongly mountainous. It lies in the westward continuation of the Jarbidge Mountains and their west foothills, which 

slope down nearly to Bruneau River at an elevation of about 6,000 

feet northwest of Charleston. It is drained chiefly by Coon Creek 

on the north and Copper Creek and 76 Creek on the south, all of 

which flow into Bruneau River. The most prominent topographic 

feature is Copper Mountain, near the center of the area. It rises to 

an elevation of about 10,000 feet and is separated from the main mass 

of the Jarbidge Mountains by the deep valley of Coon Creek and 

the Charleston saddle or pass, which has an elevation of about 8,500 

feet and is traversed by the Elko-Jarbidge road.

Copper Mountain is a relatively compact domical mass about 4 

miles long by 2 miles broad and trends a little west of north. On 

the east and north it is largely encircled by Coon Creek; on the south 

its surface slopes off rapidly into Copper Basin, a deep depression 

several miles in diameter drained by Copper Creek and its tributaries. On the west the surface declines 4,000 feet nearly to Bruneau 

River. Copper Basin is separated from 76 Creek on the southeast 

by a long sloping ridge, which the Elko-Jarbidge road ascends.

Beyond Coon Creek the axial uplift of Copper Mountain seems 

to be continued northward by a lower range locally known as the 

Buck Creek Mountains. This range is said by Mr. A. L. Rinearson 

to lie mainly in Tps. 40 and 47 N., R. 57 E., and to extend nearly 

to the Idaho State line.

GEOLOGY.

The country rocks of the district are principally the Paleozoic 

sedimentary series already described in connection with, the Jarbidge 

district. They consist, in ascending order, of schist, quartzite, limestone, and shale. These beds have been considerably faulted and 

folded. They mostly dip to the north and exhibit a general thickness of several thousand feet. They rest upon gray, coarsely crystalline hornblende granite, which seems to be intrusive, and are cut by 

dikes of slightly younger granodiorite. Locally they are overlain 

or capped by thin flows of the Jarbidge old rhyolite.

The accompanying sketch map (fig. 19), by Mr. Frank Erno, of 

Jarbidge, is introduced to show the relative position of the principal rock formations and places of metallization, in the belief that 

it will be helpful to the prospector visiting the district in the near 

future. On the map have been added a few notes from other sources.
80 THE JABBIDGE MINING DISTBICT, NEVADA.

KKUIRB 19. Sketch map of part of Charleston district, showing relative position of principal rock formations and areas of mineralization. By Frank Erno.
CHARLESTON DISTRICT. 81

In the Buck Creek Mountains the rocks are said to be block faulted 

on a large scale. Near the head of Buck Creek they dip to the 

soutliAvest, and at the north end of the mountains they dip to the 

northwest.

Some of the quartzite, as seen in the gravels of 76 Creek, a few 

miles above Charleston, and in place at the head of Copper Basin, 

is a hard gray to brownish-gray rock and seems to be relatively 

very old. A specimen collected by Mr. Erno at Bear Paw Mountain, 

in the northern part of the district, is a black fine-grained rock that 

somewhat resembles slate but is hard, siliceous, heavy, and slightly 

laminated or cleaved.

As exposed on 76 Creek along the Elko-Jarbidge road, 3 to 6 miles 

above Charleston, where limestone and black or dark shale form the 

mountains that rise 600 to 1,000 feet on either side, the limestone is 

mostly bluish lead-gray to buff and is in part heavy bedded. It 

extends northwestward, seemingly into Copper Mountain.

The gravels of 76 Creek, which are mostly rhyolite, contain also 

several varieties of limestone fine-grained noncrystalline, blue semicrystalline, blackish medium-grained crystalline, and white crystalline calcite or marble. The different degrees of crystallinity probably represent different phases of contact metamorphism due to the 

intrusion of the igneous rocks rather than large bodies of these several varieties of limestone.

The upper parts of Copper Basin and 76 Creek valley contain a 

considerable deposit of whitish volcanic ash, locally called " limestone." In the northeastern part of the basin the deposit is eroded 

into low rounded hills and mounds of fairly regular shape and uniform slope. It seems to have a thickness of several hundred feet 

and to rest mainly on the sedimentary rocks, but on the north above 

the road, at an elevation of 8,100 feet, it locally extends up onto the 

rhyolite.

The intrusion of the limestone and other sedimentary strata by 

granite and allied igneous rocks renders conditions in the district 

peculiarly favorable for the occurrence of mineral deposits. The 

useful minerals known or reported to occur there are gold, silver, 

<?opper, lead, antimony, manganese, nitrates, and oil shale. They 

.are about all in or near Copper Mountain (fig. 19).

METALLIFEROUS DEPOSITS. 

J/3DES.

The metalliferous lode deposits occur in the sedimentary Paleozoic 

rocks and their associated granitic intrusives. They occur chiefly 

fis tabular fissure veins having a quartz gangue, but they may include
82 THE JAKBIDGE MINING DISTRICT, NEVADA.

also contact-metamorphic and replacement deposits in the limestone,, 

such as occur in the Contact and other neighboring districts. Fromo 

their association with the granitic intrusive rocks the deposits are regarded as probably of Cretaceous age. A few of them are credited 

with a small production.

GRAHAM MINE.

The Graham mine, owned by Charles and Edgar Graham, of 

Charleston, is on a quartz lode in limestone in the hillside a few 

hundred feet west of 76 Creek, in the same general vicinity as the 

gold placers above noted, 4 miles north of Charleston. It is said to 

contain 1,600 feet of underground workings, most of which have 

been opened in recent years. The tunnel drift, 900 feet long, is on a 

good vein, which in 1914, when examined by Mr. Emo, is said to 

have contained an 18-inch ore shoot of $16 ore. The ore when hand 

sorted ran 24 per cent in copper and $6 in gold to the ton.

PRUNTY MINE.

The Prunty mine, owned by the Messrs. Prunty, of Charleston, is 

on 76 Creek about one-third of a mile above the Graham mine. It 

has been worked intermittently since 1905, and the ore was treated 

in a hydraulic 5-stamp mill, water being brought to the mill in a 

ditch around the side of the mountain. The production has been 

small. The metals produced are silver, gold, copper, and antimony. 

Antimony seems to be present in the ore in considerable quantity, as 

it alone is said to be nearly sufficient to pay for operating the mine.

PROSPECTS.

Prospects of one or more of the metals above listed occur at 

various places in the district, most of which are indicated on. 

figure 19.

A lead-silver prospect in the northeast rim of Copper Basin along 

the wagon road is in limestone and quartzite, which crops out 

through the Jarbidge old rhyolite at or near its western margin. A 

little work has been done on this prospect.

At several points 1 to 2 miles northwest of this prospect, in the 

east slope of Copper Mountain, there are showings of copper and 

silver, and in the northeast slope of the mountain showings of gold.

On the upper west slope of the mountain copper and gold have 

been found, and at about the middle of the west slope is an old 

tunnel, the Carlton tunnel, 700 feet long, driven on copper deposits 

which are said to average about 2 per cent in copper but which 

were of too low grade to be workable at the early-day time of 

exploitation.
CHARLESTON DISTRICT. 83

At about the middle of the northwest slope of the mountain are 

traces of manganese. A specimen of the mineralized rock at this 

place received by the writer from Mr. Vukovich, of Jarbidge, was 

found to contain considerable rhodonite (manganous silicate).

In the limestone area to the north of Copper Mountain and north 

of Coon Creek are said to occur good showings of lead, silver, and 

copper.

In the Buck Creek Mountains small quartz veins containing free 

coarse gold are said to occur in the slate and dark quartzite.

PLACERS.

The placer diggings, the first mineral deposits found in the district, were chiefly on the west side of 76 Creek about 4 miles above 

Charleston. Of the two ditches visible from the Elko road that 

lead the water from the creek around the steep mountain side, the 

lower one was used for placer mining and the upper one supplies 

power to the Prunty quartz mill, above described. The placers were 

doubtless derived from lode deposits, probably from lodes that now 

occur near by, as above described. But they may have been derived 

from lodes that have since been eroded away. Their occurrence and 

origin are of more than passing interest, as the adjoining Jarbidge 

district, with its numerous gold veins, has not yielded any placers.

NONMETALLIFEROUS DEPOSITS.

Down the west slope of Copper Mountain froin the Carlton tunnel 

occur small croppings of sedimentary rocks that are said to contain 

nitrates.

Oil shale in float or talus is reported to have been found a few 

miles southeast of Charleston. As the formations of that locality 

apparently continue northward into the mountains on 76 Creek, it 

is probable that oil shale is contained in the limestone-shale series 

on and near the creek, in which the quantity of dark shale is large.

13253 23 7

INDEX.

Page.

Acknowledgments for aid______ 1, 36 

Adularia, occurrence of, in oxidized

ore__________ 28-29, 31 

occurence of, in sulphide ore_ 32, 33-34 

plates showing _ _ 28 

Adularia and quartz, pseudomorph 

of, after calcite, micrographic plate showing ._ ____ 28 

AJax prospect, description of____ 74 75 

Alpha mine, description of 48-51 

Alteration of wall rock, results of_ 35-36 

Altitude mine, development and

equipment of__ _ 69

geology of_______ _____ 69-71

location of-_________ 69

ore deposits of_______ _ 71-72

Argentite, occurrence of, in oxidized

ore_____ ____ 31 

occurrence of, in sulphide ore__ 32

Baty prospect, description of_ __ 76 

Ben Hur prospect, description of_ 74 

Big Vein prospect, description of 63 

Black Peak, plate showing _ __ 21 

Bluster mine, development and equipment of_________ 62-63 

. history of_________ 62 

location of_______-__:__ 61-62 

ore deposits of- _ 63 

plate showing___ _ 61 

Bonanza Gulch, plate showing _ 21 

Bonanza Gulch basin, head of, plate

showing____ _ 4 

Buckeye mine, description of 65 

Bullion prospect, description of 72-74

Candy prospect, description of 75

plate showing _ 61

Charleston district, geology of 79-81

location of______ _____ 78-79

metalliferous deposits in 81-83

nonmetalliferous deposits in 83

topography of 79

Claims, map of part of 36

. Climate of the Jarbidge district 5

Cold Spring mine, description of__ 66

Condition of mining in the Jarbidge

district_________ 3-5 

Copper Mountain, description of 79 

Copper Mountain district. See

Charleston district. 

Cougar Mountain prospect, description of____ 77

Page.

Crater Range, craters of______ 10-11 

description of__________ » 

plates showing _ _____ 4,10

Cross vein system, location of___ 26

Descriptions, previous, of the Jarbidge district_____ S

Bast Fork, description of_____ 12 

East vein system, features of___ 25-26 

mines and prospects on____ 69-77 

Elkoro Mines Co., acknowledgment

to _____ _ 36

First Crater, plate showing______ 4

Flaxie mine, description of____ 58-59

Future of the Jarbidge district__ 77-78

Geologic reconnaissance map and 

section of the Jarbidge 

district-_____ 4 

Geology of the Jarbidge district 12-23 

Gold, occurrence of, in oxidized ore_ 31-32 

ore of, micrographic plate

showing._______ 28

plates showing_______ 28 

Gold-silver ore, plates showing 28 

Graham mine, description of- _ 82 

Granitic rocks, nature and distribution of_________ 15-1G 

Great Basin Province, physical features of _ 6

Halloysite, occurrence of, in oxidized

ore ___________ 29, 30 

History of mining in the district 3-4

Igneous rocks, nature and distribution Of_______ 15-23

Jack Creek, description of__ __ 11

Jarbidge, mines near, plate showing

locations of 4 

plate showing-_ 4

Jarbidge Central prospect, description of __ 65

Jarbidge Mountains, geologic history

and topography of 7-11

Jarbidge Peak, plate showing 21 

mines on, plates showing 4, 21

Jarbidge River, course and tributaries of____ _ 7,11

Legitimate mine, description of 57-58

plan and section of- _ 60

plate showing 60

85
INDEX.

Page.

Jjeverrierite, description of______ 29

occurrence of, in oxidized ore_ 29, 30

location of the district_______ 1-3

Long Hike mine, development of___ 37

equipment of_____________ 38-39

geology of _______ 39 

history and production of___ 36-37 

location of- ___________ 36 

ore deposits of_________ 39-45

Mineral deposits, mode of occurrence and distribution 

of--___________ 24-25 

vein systems of___ -----__ 25-36 

Mines and prospects, descriptions

of ________ 36-77, 82-83j

Miocene (?) rocks, exposures of__ 14-15

Moore prospect, description of__ 68

Morning Star mine, description of_ 76

plate showing____ _____ 76

Xanmannite, occurrence of, in oxidized ore________ 30 

Norman mine, description of_____ 66-68 

North Mountain, plate showing__ 61 

North Star mine, analysis of ore

from___________ 28-29 

description, of___________ 45 46

0. K. mine, description of______ 46 48

Ore, oxidized, minerals of____ 26, 28-31

oxidized, prevalence of ____ 2S

sulphide, minerals of______ 32-34

Paleozoic rocks, nature and distribution of_________ 12-14 

Pavlak mine, description of 59-60 

Pick and Shovel mine, description

of_____________ 60-61 

plate showing-_ _ 61 

Placers, in the Charleston district,

origin of_ ____ 83 

in the Jarbidge district, slight

importance of _ 77 

Pliocene ( ?) rocks, exposures of 15 

Power supply, hydroelectric 3-4 

Production of the Jarbidge district-. 5 

Prunty mine, description of 82

Page.

Quartz, " fish-scale," occurrence of_ 20 

Quaternary deposits, nature of__ 15

Red Dike prospect, description of_ 

Rhyolites, old, age of_____________

old, chemical composition of_ 16,

origin and distribution of_

pinnacles and jointing in,

plate showing________

structure of_____________

Rhyolites, young, age of__________

young, composition of________

jointing and weathering in, 

plate showing________

origin and distribution of_

structure of_

Scope of the report_______________

Silver, occurrence of, in oxidized ore_ 

Silver-gold ores, plates showing__ 

Sixth Crater, plate showing_______

Snake River valley, physical features of____________

Starlight mine, development and 

equipment of________

general features of___________

history of___________________

ore deposits of- _______

Steiger, George, analyses by_____

Success mine, description of_______

7(5 

23

19-20 

16-18

20 

18-10

 >;>

20,22

28

16,

20-21

22

1

31, 32

28

10

0-7

54

51-52 

52,54 

54-57 

20,28 

63-64

Tertiary volcanic rocks, nature and

distribution of_____ 16-23 

Tertiary (?) rocks, exposures of__ 14-15 

Topographic and mine map of part 

of the Jarbidge district___________ 4

Vegetation of the district______ 5-6 

Veins, origin of_____ __ 34-35 

structure and composition of__ 26-34 

Volcanic rocks, Tertiary, nature

and distribution of 16-23

Wall rock, alteration of_ _ 35-36

West vein system, features of 25

mines and prospects on_ _ 36-68

o