Tungsten, cinnabar, manganese, molybdenum, and tin deposits of Idaho

Name: Tungsten, cinnabar, manganese, molybdenum, and tin deposits of Idaho
Author: Livingston, D. C. (Douglas Clermont)

Livingston, D. C. (Douglas Clermont)

Tungsten, cinnabar, manganese, molybdenum, and tin deposits of Idaho

Livingston, D. C. (Douglas Clermont) · 1919 · Historical

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Engineering Library Carpenter Hall

Cornell University Library TN 24.I2L78

Tungsten, cinnabar, manganese, molybdenu

3 1924 004 873 356

University Of Idaho

School Of Mines

'E3 S33,

Vol. XIV

Bulletin No. 2

Tungsten, Cinnabar, Manganese, Mol ybdenum , and Tin Deposits

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Ik

Cornell University Library

The original of this book is in the Cornell University Library.

There are no known copyright restrictions in the United States on the use of the text.

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University Of Idaho

School Of Mines

Vol. XIV Bulletin No. 2

Tungsten, Cinnabar, Manganese,

Molybdenum, and Tin Deposits

of Idaho

By D. C. LIVINGSTON

With Notes on the Antimony Deposits By Francis A. Thomson

MOSCOW, IDAHO Jan. 1919

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Chapter Iii.

Quicksilver

Quicksilver minerals 54

Production of Quicksilver 54

Fern Creek Cinnabar District 55

Black Pine, Idaho 65

Map

Idaho

Scale

Miles

Showing geogr-Apfiicai distribution of the known depos/fs of tungsten, ind Tin.

Legend-

O Tungsten.

Cinnabar.

@ Manganese.

f

Introduction And Scope Of Work

The examination of the tungsten, manganese, quicksilver, tin and antimony deposits of Idaho was undertaken in the summer of 1918.

Considerable demand had arisen for these metals due to the war and consequent lack of ships, and, in fact, in some cases there appeared to be a serious shortage threatened. It was therefore evident that an investigation of Idaho's resources of these metals was a national duty of considerable importance and the work was undertaken on this account, although other work of importance to the State had to be postponed in consequence.

A publicity campaign was started in June by sending out printed posters to all the postof fices in the State, in which the need for these metals was explained. Notices were also sent to practically all the newspapers of the State. These posters and notices requested prospectors and owners of mining properties to send in samples, that they suspected of containing any of these metals, to the School of Mines at the University of Idaho, for examination.

Arrangements were made with the local station of the U. S. Bureau of Mines at the University whereby Mr. J. H. Jonte could take charge of this work; and also analyze all samples sent in by the examining geologist. Under Mr. Jonte's direction nearly a thousand individual samples were examined and reports made to the owners and also a number of analyses were made on samples taken by the men in the field. The U. S. Geological Survey also furnished a list of owners and localities in the State where these metals were reported to occur.

Field work was started by the writer on June 11th and continued to September 14th, commencing in Boundary county and finishing in Bannock county. The quicksilver deposit near Black Pine postoffice in Cassia County was visited by Mr. E. S. Larsen, of the U. S. Geological Survey, so was not visited by the writer in order to avoid duplication of work. Professor Francis A. Thomson visited certain manganese properties in the Coeur dAlene region and also the antimony deposits near Yellowpine Basin in Valley County, for the Bureau of Mines, and his report on this district is included by permission of the Director of the Bureau.

Acknowledgements are due to the U. S. Geological Survey for information furnished and for helpful co-operation in the work. Acknowledgements are also due to Mr. C. A. Wlright, Metallurgist of the Bureau of Mines, for use of the laboratories and loan of the local station's chemist, and for kindly assistance in the office work. Professor Francis A. Thomson rendered invaluable assistance in editing this publication and in many helpful suggestions. Thanks are also due for the kind assistance and hospitality rendered by the owners of the various properties visited, whose names are tn n numerou s to mention individually. .

6 Tungsten, Cinnabar, Manganese, Molybdenum

Chapter I. Tungsten

Tungsten 1 is one of the ten heaviest metallic elements. It has an atomic weight (chemical weight of combination) of 183.4, and is exceeded in this respect by bismuth, gold, lead, mercury, osmium, platinum, thallium, thorium, and uranium only. It does not occur in nature in the metallic form as do gold, platinum, silver, copper, etc., but it has to be reduced from its ores and when thus obtained is in the form of a gray powdery or granular mass. It has high specific gravity, i. e., is very heavy, ranging from 19.3 to 21.4, or slightly heavier than gold and nearly as heavy as platinum. Its melting temperature is 5913° F., which is higher than any commercial furnace can stand and is also higher than the melting point of any other known metal. Its general appearance in the wrought or ductile form is much like that of iron or steel, but unlike those substances it does not rust or tarnish, and has been proposed as a substitute for platinum on this account, it is however, more brittle than platinum and therefore harder to manufacture into jewelry or chemical vessels.

When worked, it becomes less brittle, due to a change in structure and can then be drawn into wires less than four ten-thousandths (0.0004) of an inch in diameter, and has high tensile strength. It forms alloys with other metals such as iron, chromium, cobalt, etc.,. and in this form has its greatest commercial use.

Uses of Tungsten

Tungsten is used chiefly as an alloy with iron and carbon, in the production of the so-called "high-speed" steels. These steels contain from about 13 to 20 per cent of tungsten and usually a certain amount of chromium and due to the fact that such steels do not lose their temper at a dull-red heat as do ordinary steels, it is possible to run lathes when using tungsten-steel cutting tools, five times as fast as with ordinary steel tools.

This property of tungsten-steels has had a revolutionary effect in machine shop work, increasing the output and consequently cheapening production of all kinds of machined parts in automobiles tractors, locomotives, shells, and the like.

Tungsten is also used alloyed with steel in permanent mag-nets as it causes the magnets to retain their strength much longer than they otherwise would. Another use is in the filaments of incandescent electric lamps, in the form of very fine wire. When used in this way it is usually alloyed with the element thorium which prevents the filament from crystallizing and breaking as it otherwise tends to do. A tungsten filament lamp uses far less electricity for

1. Hess, F. h; Tungsten Minerals and Deposits: U. S. Geol. Surve-r "tii . 11-18, 1917. ' uml -' "2,

Pp

And Tin Deposits Of Idaho 7

the same amount of light than a carbon filament lamp and by the use of these lamps millions of dollars are saved annually.

Tungsten has been used to a slight extent in the manufacture of crucibles for use in vacuum furnaces. By far the larger part of all tungsten mined, however, is utilized in the manufacture of the "high speed" steels.

Tungsten Minerals

Tungsten is by no means a common element in the earth's crust, it being usually classed among the rarer metals. It occurs in nature in the following minerals :

Scheelite. CaW0 4 (CaO 19.4 W0 3 80.6 per cent.) Calcium tungstate. The color of the mineral usually varies from a brownish or yellowish white, through brownish yellow to brown. Its color is one of the most variable characteristics of the mineral, green being a color reported in some text-books. Its hardness is from 4.5 to 5, so that it can be scratched by a steel knife quite readily. Scheelite is brittle, and gives a white streak, that is, the fine powder is always white. It has a distinct cleavage in one direction and a second rather indistinct cleavage making an acute angle with the first. With salt of phosphorus it gives a blue bead in the reducing flame, and if this bead is dissolved in dilute hydrochloric acid, with the addition of a little metallic tin, it will yield a deep blue color, and if boiled for any length of time this blue color may change to amethyst or brown. It. is soluble in hydrochloric or nitric acid, leaving a yellow residue. One of the strongest characteristics in distinguishing scheelite from other light-colored minerals is its weight (this is true of all tungsten minerals), as it has a specific gravity of from 5.4 to 6.1, that is, it is more than twice as heavy as quartz and most of the other common gangue minerals.

Scheelite occurs in quartz veins, associated often with gold and with pyrite, in contact metamorphic deposits, in crystalline rocks and occasionally in placers derived from one of the above. It is typical of the deep zones of mineral deposition requiring high temperature and pressure for its formation as a primary constituent of the rock. It sometimes changes to wolframite by the replacement of the CaO by FeO and MnO, and when this takes place the wolframite usually has the crystal form of the scheelite. Occasionally scheelite is derived from wolframite by a similar but reverse process.

Wolframite. Iron manganese tungstate. 4 contains about 76.5 per cent W0 3 (tungsten trioxide).

The color is dark gray to black, with a metallic or sub-metallic luster. It often occurs in crystal form but is sometimes massive. It has a hardness of from 5 to 5.5 and a specific gravity of from 7.1 to 7.55, gives a dark brown to black streak and is slightly magnetic; is readily fusible with the blowpipe to a magnetic globule. It will

8 Tungsten, Cinnabar, Manganese, Molybdenum,

give the same solution reaction as scheelite with hydrochloric acid and tin, after fusing in a salt of phosphorus bead.

Its occurrence is similar to that of scheelite, and it is typical of the deep or high temperature zone of vein or mineral formation.

Ferberite and Hubnerite. These are less common tungsten minerals than the two preceding, and either of them grades into wolframite. Ferberite is iron tungstate, FeW0 4 , and hubnerite is manganese tungstate MnW0 4 . It s sometimes difficult to determine the dividing line between ferberite and wolframite, and the same is true for hubnerite and wolframite. They do in fact represent the extreme chemical conditions in which wolframite may occur. They differ from one another somewhat in appearance and also from wolframite. Hubnerite has a dark reddish brown color and nearly always shows good cleavage in one direction, while ferberite is more nearly black, is often crystalline, and is far more difficult to distinguish from wolframite than is hubnerite. According to Hess : hubnerite should be considered as a manganese tungstate MnW0 4 , containing not more than 20 per cent FeW0 4 , and ferberite an iron tungstate FeW0 4 containing not more than 20 per cent MnW0 4 .

Tungstite or Tungstic Ocher. A yellow powder having the chemical formula of WO g , 2H 2 0. There is no record of this mineral being mined as an ore of tungsten to any extent.

Stolzite. PbW0 4 and Cuprotungstite iCuW0 4 or (Ca. Cu) W0 4 are rare minerals, not known to occur in commercial amounts.

Consumption of Tungsten in the United States

In 1912 the total consumption of tungsten in the United States on the basis of ore containing 60 per cent W0 3 (tungstic oxide) was estimated at 3000 short tons. 2 During this same year the equivalent of 1330 tons of ore containing 60 per cent W0 3 was produced in this country, or roughly, about one-third the amount consumed. This is not necessarily accurate, however, as a large part of the consumption was from stocks previously accumulated the sources of which are not clear.

In 1915, 1534 tons was imported into the United States and 2332 tons produced, making a total consumption of 3866 tons of which nearly two-thirds was produced at home, an exactly opposite condition to that which prevailed in 1912. This increase in production was due to the rise in price consequent upon the increased demand for tungsten in the manufacture of high-speed steel for lathe work to fill munition contracts for the Allied governments in Europe

No reliable figures for production and consumption in 1916 and 1917 were available at time of going to press.

1. Hess. F. I.., Op.-Cit., p 22.

2. U. S. G-eol. Survey. Mineral Resources, 1912, pt. 1, p. 996, 1913.

And Tin Deposits Of Idaho 9

Principal Tungsten Resources in Foreign Countries

The two most important sources of the world's supply of tungsten are Burma, India, and the Shan states of Siam. In these regions, both of which are in the Malay Peninsula, wolframite is mined from placer deposits, where it occurs associated with cassiterite, the oxide of tin. These placers have been formed from the breaking down of the granite mountains, which form the backbone of the Malay Peninsula, and cover a considerable area. The wolframite occurs in lodes in these granite mountains, which have as yet been very little worked, and the tungsten resources of this region are very great. It must be remembered that tungsten produced in the United States will have to compete with tungsten produced from these cheaply worked placers with native labor, as soon as ships are more readily available, and that the price of tungsten will be largely controlled by the price of producing it in this particular region, as at the present time there is no duty on tungsten ores coming into the United States.

Other important sources of tungsten are Queensland 1 and New South Wales, Australia, where wolframite occurs in quartz veins, lodes and placers; in Portugal wolframite and scheelite are found in veins and stockworks.

In 1915 the United States was the second largest producer of tungsten, being exceeded only by the countries of the Malay Peninsula.

A notable difference between the United States and other countries is that in the former the greater part of the tungsten comes from the mineral scheelite while in the latter it comes chiefly from wolframite.

Principal Resources in the United States

Practically all the tungsten produced in the United States comes from the Rocky Mountain States. Of these California and Colorado have been the principal producers up to the present time.

Boulder County, Colorado, is probably the most important tungsten district -in the United States. 2 In 1910 the production from this district was 1221 tons of tungsten ore when the world's proi auction was about 7500 tons.

The tungsten bearing mineral in this district is ferberite the iron tungstate of the wolframite series, which occurs in a remarkably clean and well crystallized form, and is very resistant to weathering.

The district is about 25 miles northwest of Denver on a high plateau 8200 ft. above sea level. The country rock consists of granite, gneiss and schist cut by dikes of varying composition. Ferberite occurs in a series of narrow northeast-southwest veins, some of

I'. Hes 5 s,'. ir , a C n'r, P Waldem a r T., U. S. Geol. Survey Bull., 583, p. 7, 1914.

10 Tungsten, Cinnabar, Manganese, Molybdenum,

them containing gold in the form of tellurides. A good deal of the ferberite was obtained from eluvial placers as well as from the veins, and the total production of the district cannot be much less than 12,000 tons of ore containing 60 per cent of W0 3 .

California has also been a fairly large producer of tungsten ore for several years past and the indications are that it will be a still larger producer in the future, as several mills with capacities up to 300 tons per day have been installed within the last year or so.

The oldest tungsten producing district is in the country adjacent to Johannesburg and Atolia, near the Kern-San Bernardino county line, on the edge of the desert southeast of Owen's Peak near the southern end of the Sierra Nevada range.

Scheelite occurs here in gold-bearing quartz veins, 1 and also in quartz veins unaccompanied by gold. In the Stringer district, southwest of Randsburg, it occurs in narrow veins about 4 in. wide, to a depth of 400 ft. The most important deposits appear to be at the Papoose property near Atolia, and most of the production would seem to be from this mine.

One of the most interesting and valuable deposits in California is of the contact-metamorphic type and occurs in the eastern foothills of the Sierras near Bishop, in Owens Valley, Inyo County, about ISO miles north of the Atolia district. 2

This deposit was only discovered in 1913, but since that time there has been a great deal of activity in the district and several well equipped mills have been built.

The country rock is principally granite, which was forced up under a roof of steeply tilted sediments, originally composed of sandstones and limestones, but which are now highly metamorphosed, contact equivalents of these rocks. Most of these contact metamorphics have been removed by erosion, but the most deep-seated portions still remain and wherever the original rock was limestone, workable bodies of scheelite occur in a gangue of garnet, epidote and some quartz.

The ore bodies carry from 1.5 to 2.0 per cent of W0 3 and range from 20 to 60 ft. in width and from 150 to 260 ft. in length It is believed from evidence offered by erosion that these deposits' may be persistent to at least 700 ft. in depth, and when fully developed this camp will undoubtedly be a heavy producer of tungsten ore.

Similar, but if anything larger deposits of contact metamorphic scheelite have been reported by E. S. Larsen from the high Sierras of California, situated at an altitude of about 12,000 ft 3 which are now being actively exploited. This being the case,' it would

1. U. S. Geol. Survey Mineral Resources, 1906, p. 525.

2. Knopf, Adolph, U. S. Geol. Survey Bull., 640, pp. 229 and following 1917

3. Iarsen, E. S., verbal communication.

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Showing Location of

Tungsten Mine

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And Tin Deposits Of Idaho 11

appear that California should be a powerful factor in the tungsten market within the next two or three years.

Nevada is apparently developing some important deposits near Lovelocks, Humboldt County, and will probably become a much heavier producer in the next few years than in the past.

Although there will probably be a considerable demand for tungsten after the war there would seem to be a good supply in sight in the western United States and there need be no fear of shortage.

Tungsten in Idaho

(a) Boundary County.

The Tungsten Hill Mining Company, Formerly Known as the

Bull Moose Group.

This property is situated in Boundary County in Sec. 13, T. 24 N., R. 1 E., Boise Meridian, and is reached by a wagon-road from Copeland, on the Porthill branch of the Great Northern Railway, a distance of approximately 8 miles. This wagon-road is in rather poor condition at the present time, as it follows the old Forest Service trail from Copeland ranger station. The grade is fairly good over the greater part of the distance and a good road can be made at a moderate expense, entailing little change in the present location. The lower end of the road has been surveyed and was being built in the summer of 1918, as far as the Dora Mine. When this is completed an automobile can be brought to within less than 2 miles of the property, which can be reached from this point by trail. It is about 4 miles from the Dora to the Tungsten Hill by a wagon-road, which is not very good from this point. See Map No. 1 for location and accessibility of property.

The mine is well situated as regards timber, there being plenty of fir, cedar and tamarack in the immediate vicinity. Plenty of water for milling purposes can be obtained at Rock Creek, at a distance of probably less than a quarter of a mile from the mine. This camp is new, as the presence of mineral-bearing veins has only been known within the last four or five years in this immediate vicinity, although lead-silver and copper deposits have been known for some years, but these lie considerably further to the east.

Topography The mine is in a mountainous area, the elevation at the cabin of the Tungsten Hill being about 4900 ft. and the mountain rising rather steeply from this up to 5600 or 5800 ft. The country was at one time covered by the Cordilleran ice sheet, which formed morainal deposits along the foot of the mountains, and several small lakes such, for example, as Brush Lake, owe their origin to glacial activity. Rock surfaces showing glacial strias can be seen on the ridge above the mine. As a comparatively short time has

32 Tungsten, Cinnabar, Manganese, Molybdenum,

elapsed since the retreat of the ice in this region, float from veins is rather scarce, which adds to the difficulty of prospecting.

Geology

The oldest rocks in the district are metamorphosed sediments consisting of schist, slate, and quartzite and these are considerably contorted in the neighborhood of the Tungsten Hill. They are probably a part of the Belt series of pre-Cambrian sediments of Idaho, Montana and British Columbia. They have been intruded by a coarse gray granite, containing large crystals of pink feldspar (orthoclase). The granite does not outcrop on the Tungsten Hill group but occurs on the Dora property about one mile to the west. This granite is undoubtedly a part of the Idaho batholith though it contains more orthoclase than the normal type of the Clearwater Mountains but as a very similar granite has been noted on Johnson Creek in Valley County, in the center of the granite area, it may be considered a local variation of the normal batholith type.

At the Tungsten Hill, the old metamorphics have been intruded by a large dike or stock of hornblende diorite. The exact extent and boundaries of this were not located but it probably covers several square miles of an irregular area. It is probably younger than the granite but, as no contact between them was observed by the writer, this cannot be definitely stated as a fact. Such a contact must exist somewhere oh the hillside above the old workings of the Dora group. This diorite, which is made up almost entirely of green hornblende (amphibole) and plagioclase feldspar, varies considerably in texture from place to place.

Veins

The principal vein on the Tungsten Hill is a persistent quartzfilled fissure, outcropping for about 500 ft. and showing an average width of 7 to 8 ft. where exposed by open cuts. It strikes about N. 82° E. and dips 75° to 80° to the northwest. Some wall-rock occurs in places in the quartz of the vein. The latter is crystalline in appearance, somewhat drusy in places and evidences a filled fissure with some alteration of the wall rock. The quartz contains many limonitefilled cavities and some scheelite, which occurs usually associated with the limonite. Sometimes the scheelite is in coarse crystals or masses but most of it is finely divided in the vein as can be shown either by panning or by analysis of apparently barren material. The vein where exposed lies entirely within the diorite and does not appear to extend into the metamorphics that lie to the east.

A smaller vein occurs 200 ft. to the south of the main vein and has approximately the same strike and dip. Another vein which has a north-south strike and an easterly dip occurs further up the mountain and to the northwest of the open cut on the main vein. This

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And Tin Deposits Of Idaho 13

vein should intersect the main vein several hundred feet to the south of the open cut, if it is continuous along the strike. Neither of these veins showed any scheelite, which seems to be concentrated entirely in the main vein. The vein running north and south was assayed for gold but contained none.

Workings The workings are very meager at the present time and consist of an open-cut following the main vein for a distance of 60 ft., several smaller cuts to the east of this, a 20-ft. shaft in the west end of the large open-cut and a cross-cut tunnel which has been started southwest of the large open-cut and is in about 130 ft. This tunnel should cut the vein in about another 100 ft. and will give a depth of ISO ft. below the outcrop. Most of the open cuts are badly caved, due to the heavy winter snowfall and spring frosts.

Value of the Ore

The open-cut to the east of the shaft was sampled by the standard method of cutting channels across the vein at regular distances apart, which in this case was approximately 10 ft. Owing to the fact that the footwall had caved into the cut, covering the vein with from 2 to 4 ft. of soil and country rock, it was not possible to cut a sample across the full width of the vein in every case.

The bottom of the shaft was not sampled as the timbering was so unsafe that the whole was in imminent danger of caving at the slightest jar.

The following is a list of samples taken:

Remarks

East face of cut. Vein reported 8 ft wide. 10 ft. west of No. 1 vein reported 8 ft wide, contained

some waste. 20 ft. west of No. 1 vein, over

7 ft. wide.

30 ft west of No. 1, full width

of vein.

40 ft. west of No. 1.

Total 27.5 29.97

Average S.S 1.09

No. 5 was the only one showing some visible scheelite.

The above samples show an average assay of 1.09 per cent W0 3 and an average width of S.S ft.

This sampling was checked by taking a sample of half a ton, representative of the entire dump, screening it through a quarter-inch screen and quartering down the undersize and oversize separately after measuring the two piles.

Width sample in

of ft.

%W03

Per cent x width.

S.O

0.S9

6.S

14 Tungsten, Cinnabar, Manganese, Molybdenum,

The coarse material gave 0.60 per cent WO s , the fine, through quarter-inch, gave 1.37 per cent W0 3 .

As the weight of these two samples was nearly the same, the mean of the assays 0.98 gives the approximate percentage of W0 3 in the waste dump.

As near as can be gathered from the owners, from 1000 to 1500 pounds of scheelite was shipped from the cut, which was reported to contain 68 per cent W0 3 . Taking 1200 pounds as the amount shipped this would give 816 pounds of W0 3 . About 100 tons of rock was taken from the cut and the shaft, or 8.16 pounds of W0 3 per ton or about 0.40 per cent. This added to 0.98 gives 1.38 per cent W0 3 against 1.09 per cent obtained by the other method, which is sufficiently close for ordinary purposes of valuation, and checks the samples from the cut as in only one of these could scheelite be seen.

The amount of ore available in the property is hard to estimate as there is nothing that a mining engineer would consider as ore blocked out, i. e., exposed on four, three, or even two sides. When the cross-cut tunnel is completed the downward extension of the vein can be better determined.

The present ore-shoot is in the neighborhood of 100 ft. long as a minimum and may be considerably longer than this. If only 100 ft. is allowed as its vertical extension, with the vein holding its present width of 7 ft., there would be about 6000 tons of ore available which would be worth at the present price of tungsten at least $25 per ton. This would seem to justify the erection of a small mill and the continued development of the property. It is regrettable that the mine is not being worked.

There is no reason to doubt the downward extension of the vein. It appears to be a well defined fissure-vein in diorite and not a replacement of granite by quartz as is so common in many parts of the granite area. Scheelite is a mineral formed under conditions of high temperature and pressure and it has been recognized as a contact metamorphic mineral in California, Oregon and other places. 1 Therefore, providing the vein continues downward there is no reason why the scheelite should not do the same. It will undoubtedly occur in the vein in irregular shoots or bunches, as this is its habit wherever worked, but provided development work is kept well ahead there should be no trouble on this score.

Summary

Considering the small amount of work done the showing on the property is remarkably good, and if further development is carried on intelligently, and a small well-designed mill installed, which can be added to as the necessity arises, the property should be able to produce tungsten at a profit. There is no reason why the vein should not be

1. Larsen, E. S., U. S. Geol. Survey, personal communication.

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And Tin Deposits Of Idaho 15

continuous in depth nor why other ore-shoots should not be discovered in following the strike, particularly towards the west. The property is worthy of far more attention than it has had in the past.

(&) Shoshone County. Tungsten Deposits Near Murray.

The tungsten-bearing belt of Shoshone County lies adjacent to the old gold-camp of Murray. The placer deposits of Prichard Creek, which eventually led to the discovery of the rich lead-silver mines of the Coeur d'Alene region in the early eighties, were doubtless derived from the gold-bearing quartz veins of this same belt.

The occurrence of tungsten in the form of scheelite in the Golden Chest and other veins which were mined for their gold content, has been known for many years. In the Golden Chest, masses of scheelite weighing several hundred pounds are reported to have been found. The scheelite was, however, more of a liability at that time than an asset as there was practically no market for it at any price and 'undoubtedly many tons of it were wasted.

In the spring of 1916 the price of tungsten rose to an unprecedented figure, due, undoubtedly, to heavy buying by the German government. This resulted in the re-opening of both the Golden Chest and the Golden Winnie properties and to the mining and shipping of several tons of scheelite, obtained almost entirely by hand-sorting.

This activity, however, was short lived, for when the price dropped the properties shut down, and although an attempt was made to mill the lower grade material at the Golden Chest, this apparently was not commercially feasible as the mill only ran a short while.

The area in which tungsten occurs is approximately five miles square, with Eagle or Prichard Creek in the northwest corner of the square, the southern boundary lying about half a mile south of Pony Gulch on Beaver Creek. See map No. 3. Almost the whole area is underlain bv the Prichard slate, the geology being well described by F. L. Ransome. 1 Although this area embraces the tungsten deposits known at the present time, it does not follow that no tungsten will be found outside of it.

The Golden Chest

The Golden Chest mine contains several bed or blanket quartz veins in the Prichard slate and as it has been described in detail elsewhere 2 this description will not be repeated. The mine is situated about one and one-half miles east of the town of Murray in Sec. 9, T. 49 N., R. 5 E., Boise Meridian, and is easily reached from Wallace by an excellent automobile road. The nearest railroad point at the present time is Delta on the Beaver Creek branch of the O.-W. R. &. N., about eight miles distant. Formerly the railroad, which passes

1. U. S. Geol. Survey, Prof. Paper, 62, 1908, pp. 141-149.

2. Ransome op. cit, pp. 144-146.

l& TUNGSTEN, CINNABAR, MANGANESE, MOLYBDENUM,

within a few hundred feet of the mine, along Prichard Creek was in operation, but due to the heavy floods in the winter of 1917-1918, this railroad was so badly washed out that it had not been repaired at the time the property was visited.

The mine is opened by several adit-tunnels and contains several thousand feet of workings, with many large stopes, most of which are still open and in fairly good condition.

The scheelite occurs in a very irregular manner in the largest of the blanket veins. In 1916, when the price of tungsten was much higher than it is now, the old stopes were worked for scheelite wherever they showd any indication of its presence. The search was so thorough that there is not much to be seen at the present time. A careful examination made in company with a man well acquainted with the property, showed scheelite in only two places in the old stopes, and in very small amounts.

The future of the property as a producer of tungsten is somewhat dubious as the cost of finding a new pocket of scheelite would probably exceed the amount to be obtained from mining it. The best chance of producing tungsten from this property would seem to be by the operation of small leases in those stopes which show any indication of tungsten, but as previously stated the outlook is not particularly encouraging, unless the vein carries sufficient gold to pay at least a portion of the expenses when working in ground barren of tungsten.

The Friday Group Known Formerly as The Golden Winnie.

This property is situated in Sec. 2, T. 21 N., R. 4 E., on the south side of Prichard Creek at the point where the creek bends to the northeast and at an elevation of about 2500 ft. It is between one and one-half and two miles from Murray on an excellent road. The Murray branch of the O.-W. R. & N. passes through the claims or very close to them, but this branch, as previously noted, is not operating at present so the nearest railroad point is now Delta, on Beaver Creek, about eight miles distant.

The scheelite occurs in a quartz vein, which lies between the bedding planes of the Prichard slate and which is of the same general type as the other gold-bearing quartz veins of the Murray district. The footwall is somewhat more quartzose than the hanging and may perhaps be Burke quartzite. The vein has been opened by a tunnel a few feet above the level of Prichard Creek. This tunnel follows the vein as shown on Map No. 4.

Several stopes have been started from this tunnel, both overhand and underhand, the former extend 30 to 40 ft. in height and the latter not over 12 or 15 ft. in depth. The vein has a general strike of almost due east and west, with an average dip of about 65° north. It usually consists of two quartz seams separated by about a foot of country rock, and has an average width of 3 ft.

And Tin Deposits Of Idaho 17

The vein is badly faulted in the vicinity of the creek, being heaved in every case further to the south in going west. At least five faults have been exposed in the tunnel in a distance of about 600 ft. along the strike of the vein. Apparently, there are two sets of faults; one set running northwest and the other northeast. The greatest distance the vein has been heaved is approximately 80 ft. this being the movement of the fault nearest the creek. As the tunnel advances the heave of the faults seems to decrease, the last movement near the present face, being practically nothing more than a flexure.

The quartz of the vein contains pyrite and scheelite and a small but insignificant amount of other sulphides. It also carries some gold, evidently associated with the pyrite. The scheelite seems to be fairly evenly distributed throughout the vein, and its presence in small amounts can generally be detected by panning. In places it occurs in more concentrated form in masses sufficiently large to be hand-sorted. This is true particularly in the western part of the tunnel.

Very much the same condition prevails in regard to the workings as at the Golden Chest. That is to say, all the most easily available bunches of scheelite were mined in 1916, during the high prices, and good exposures of scheelite ore are difficult to find. From 10 to 15 tons of scheelite were shipped during this time and this amount is reported by the owner, Mr. E. M. Smith, of Murray, as having been obtained from about 500 tons of ore. If the smaller figure is taken this would make the scheelite contents of the vein about 2 per cent, which is probably about right, as only the best material, where visible scheelite could be found, was mined.

Two samples were taken from the vein, both of which showed a small amount of scheelite. These could hardly be considered representative of the whole vein, but simply of those portions of the vein where scheelite could be seen. One was taken in the face of the tunnel from the hanging wall seam, which was 12 in. wide, and this gave a return of 1.06 per cent W0 3 . Another sample was taken from a stope about 150 ft. east of the present face. This sample was 2y 2 ft. wide and gave a return of 1.46 per cent WO,.

The underhand stopes in the floor were reported to contain the best ore but these could not be sampled as they were filled with water.

It is difficult to estimate either the grade of the ore or the tonnage that could be mined. There are evidently considerable portions of the vein that will run over 1 per cent of WO, and from that up to 2 and 3 per cent, or possibly better, and these undoubtedly could be mined and treated at a profit. The walls are good and very little timber is needed in the stopes.

18 Tungsten, Cinnabar, Manganese, Molybdenum,

The tunnel which follows the vein is on about as low a level as can be obtained. There is a cross-cut tunnel No. 3 (see map No. 4) which has been driven 160 ft. This will have to be advanced nearly 400 ft. further, and according to a rough survey, it is not more, than 20 ft. lower than the adit-tunnel No. 2, which follows the vein. Whether the expense of driving this tunnel to the vein is justified is questionable as the depth it gains is so insignificant. The amount of scheelite ore occuring between the present tunnel and the surface is probably not great and the future of the property depends upon the ore occurring below the present workings. This can only be developed by sinking a winze or shaft, and it would be far cheaper to straighten out the adit-tunnel and sink from there than to run the new cross-cut and then sink. A shaft would undoubtedly be wet due to the faulted condition of the ground and the vicinity of Prichard Creek, but it is the only method of developing the property below the present level. There are strong possibilities of finding more scheelite by extending the present tunnel along the vein as the face contains ore at the present time.

There is a small concentrating mill on the property equipped to handle 20 to 30 tons of ore daily, which could be put into running shape at a comparatively small expense.

Summary There is no reason, except lack of proper financing, why this property should be idle, as with proper development and milling facilities it could undoubtedly be made a steady producer of tungsten on a small scale.

Mother Lode

This property, which is owned by Mike Melly and John F. Murphy, of Murray, Idaho, is situated on the south side of Ophir Gulch about 2000 ft. from its mouth on Prichard Creek, and just below the forks of the gulch. It comprises the Mother Lode group of claims, in which are included several blanket quartz veins that outcrop on the top of the ridge west of Ophir Gulch.

These quartz veins were mined for gold several years ago and have been described by Ransome. 1

Ophir Gulch is a small ravine which debouches into Prichard Creek almost opposite the Golden Chest mine, and the quartz veins mentioned above evidently belong to the same system of mineralization as those in the Golden Chest. They may be a continuation of the same veins or beds. No tungsten was observed in the quartz veins, and so far as the writer is aware none has been reported from this property. A very good showing of scheelite ore, however, occurs about half way between the gulch and the ridge. A diabase dike which contains narrow seams of quartz and bunches of scheelite has

1. Op. cit., p. 146.

And Tin Deposits Of Idaho 19

been exposed by open cuts for a distance of nearly a hundred feet. The open-cuts have stripped the dike in a northeast and southwest direction, but its strike and dip could not be determined from the present amount of development. The surrounding country rock is Prichard slate. Scheelite occurs distributed more or less all through the dike, but appears to be concentrated in a shoot or chimney on the north end of the open-cut. A sample taken across 15 ft. of the dike gave a return of 2.84 per cent W0 3 . Many specimens on the dump show pieces of scheelite 2 or 3 in. across, but none of these were encountered in sampling.

The dike is a rather fine-grained greenish rock, consisting principally of hornblende and pyroxene and containing considerable fine pyrite and probably some pyrrhotite. This dike evidently does not extend very far to the north, as the slate outcrops on the ridge and no diabase can be seen in that direction beyond the open-cut. To the south the mountain side does not show many rock exposures and the slide-rock is fairly deep, so nothing definite can be said as to its extension in that direction. The general appearance leads to the belief, or supposition, that this exposure constitutes the apex of a rather extensive stock of this intrusive, rather than a dike. The word dike being taken to mean a more tabular form' of intrusive, or one in which length greatly exceeds the width. The quartz and scheelite are evidently replacements of the dike, derived undoubtedly from the same mineralizing solutions as deposited scheelite in the Golden Chest and Golden Winnie veins.

The small amount of development gives but little clue to the mode of occurrence and origin of the tungsten mineralization. It is highly probable that it will prove to be a contact metamorphic deposit, in which the mineralizing solutions attacked the cooling intrusive near its contact with the slate, rather than the slate itself, but this, of course, is merely a supposition. Whatever its origin the showing is remarkably good, considering the small amount of work that has been done. An open-cut driven straight into the hill from the lowest exposure of the dike would give some clue as to its extent in that direction and should also open up some good scheelite ore. A considerable amount of scheelite can be obtained by hand-sorting and the waste from the hand-sorted material would undoubtedly pay to mill. There is plenty of water in Prichard Creek less than half a mile from the outcrop and possibly enough water in Ophir Gulch to run a small mill for several months in the year.

This seems to be an exceptionally good surface showing and one that certainly should not be idle when tungsten is in demand.

Kennan Property on Pony Gulch

This property is situated on Pony Gulch, a tributary of Beaver Creek, about two miles above the mouth of the gulch. The Beaver

20 Tungsten, Cinnabar, Manganese, Molybdenum,

Creek branch of the O.-W. R. & N. railroad runs along the creek at the mouth of Pony Gulch, so the property is well situated as regards transportation. It is reached by a rather poor wagon road, but one which can be very easily repaired, and which has no bad grades. The elevation at the camp is about 2800 ft. This property, like the Mother Lode, contains blanket-veins of gold-bearing quartz, which were mined quite extensively in the early days. The country rock is Prichard slate, containing some quartzite beds.

A tungsten-bearing vein was reported to have been found in the bed of Pony Gulch many years ago. The prospector who found it, however, did nothing with it and it became covered with gravel wash and was practically forgotten. In the spring of 1918, A. B. Ward was operating the property for Chester T. Kennan of Spokane, and having heard of this deposit of tungsten, made an attempt to rediscover it by panning the gravel-wash in the creek. He discovered it without very much difficulty and uncovered the vein or lode where it crosses the creek.

The deposit, which is exposed in but one place, consists of a mineralized zone or lode in the Prichard slate with an approximate width of 60 ft. This zone follows the strike of the bedding planes of the slate which is somewhat quartzose at this point. It consists principally of seams of quartz in the shattered quartzitic slate. For i.bout 15 ft. in width this shattered zone contains scheelite. Many individual pieces of scheelite exposed in the creek bed are over 3 in. across and though on the request of the operator no sample was taken, it would be safe to say that the 15 ft. of the lode containing scheelite would assay from 3 to 5 per cent in tungsten oxide.

The strike of the lode was roughly determined at S. 40° E., and the dip is probably to the west, but this is uncertain as the length of the exposure was less than 50 ft. at the time it was visited.

From information furnished recently by Mr. Chester T. Kennan, the writer understands that the lode has been uncovered on the hillside 100 ft. to the south and that active development of the property is in progress.

This also is a remarkably good showing and one from which a considerable amount of tungsten could be mined very cheaply if the deposit holds its width and values for any distance. Interesting developments are to be expected in the next year.

Summary of the Murray Tungsten Beet

Until the last year this district had never been systematically prospected for tungsten. Of the four tungsten deposits visited the best and most important showings have only recently been discovered, and no work has been done upon them beyond removing the surface soil.

View up Patterson Creek, Lemhi County.

And Tin Deposits Of Idaho 21

In both the Mother Lode and Kennan claims the tungsten occurs in separate and distinct deposits from the gold-bearing quartz veins. The tungsten-bearing lodes, however, in both cases occur within a few hundred feet of these gold quartz veins and so far as can be learned no tungsten has been found in the latter. This fact should encourage prospecting in other places in the district where the gold-bearing quartz veins occur. The tungsten-bearing lodes do not make conspicuous outcrops as do the quartz veins. One of those recently discovered occurs in a diabase dike and the other in a shattered zone of quartzitic slate, and both contain but little quartz and that only in narrow stringers. In a heavily forested and soil-covered area, such as the Coeur d' Alene, the discovery of such deposit by chance or accident is unlikely, and systematic panning of the gravel in the gulches and of the soil on the hillsides is the only sure Way of locating deposits of this kind. If such prospecting is carefully done, particularly in the neighborhood of the quartz blanket-veins it is highly probable that other deposits of tungsten will be found.

Although at present there is virtually no output of tungsten from this district, the writer firmly believes that the district has a future, that with systematic prospecting other deposits will be discovered, and that if prospecting is supplemented by intelligent development and carefully designed mills, the district should add materially to the tungsten production of the country within the next five or six years.

(c) Lemhi County. Ima Mine, Patterson Creek.

This mine is situated about a mile and a half east of Patterson, a small settlement on Patterson Creek, one of the tributaries of the Pahsimeroi River and about 60 miles from Mackay, the nearest railroad point. There are eighteen patented claims which are in Sec. 13, 14, 23, and 24, T. 14 N., R. 23 E. The elevation of Patterson Creek at the mill is about 6300 ft.

This mine was visited in 1910 by Mr. J. B. Umpleby, of the U. S. Geological Survey 1

History

The Ima mine was discovered twenty-five or thirty years ago and was worked by the Ima Mining Company, of Salt Lake, chiefly for silver, which is evidently contained in the mineral tetrahedrite. This company ceased operating about 1902 and since that time the mine has been worked in a desultory manner by leasers for tungsten, which, according to Umpleby, was first recognized here in 1903.

Five years ago the mine was leased to J. Nolan, of Salt Lake, who sold his interest to Callahan & Duffield. These men worked

U. S. Geol. Survey Bull., 528, pp. 109-112, 1910.

22 Tungsten, Cinnabar, Manganese, Molybdenum,

on the surface for tungsten, and also in a lower tunnel driven from the creek level, but did not meet with much success and they in turn sold to Jeffs and Johnson, also of Salt Lake. The latter sank a 70-ft. incline-shaft at the mouth of the lower tunnel, and are reported to have taken out eight tons of tungsten concentrate in one month during the time of high prices in 1916. The lease was again taken over by J. Nolan, in partnership with D. R. Wheelwright, of Ogden, in May, 1917. They operated from that time until January, 1918, when the mine was shut down.

There is a concentrating mill on the property equipped with crusher, rolls, jigs and five Wilfley tables. The mill is operated by water-power obtained from Patterson Creek. A gravity incline tram brings ore from the upper tunnel to the mill. The whole plant is in fairly good condition and could be put into running order without any heavy outlay. No figures on the saving effected in this mill were obtainable, but the probabilities are that the extraction was low.

Geology and Vein Formation

There are several quartz veins, some of which are of the fissure type and some of the blanket type, occurring in a gray quartzite. The quartzite beds vary from a few inches to 2 ft. thick, being almost slaty in texture in some places. They are slightly tilted, forming the limbs of a somewhat flat anticline, the axis of which appeared ro be occupied by Patterson Creek, the veins cutting across the axis. According to Umpleby the axis of the anticline is in the same direction as the strike of the veins and as he probably covered more territory than the writer his statement should be correct, but the dip of the quartzite beds along the canyon walls of Patterson Creek below the mine, leads strongly to the belief that Patterson Creek has been excavated along the axis of an anticlinal fold in a slowly rising fault-block.

That the eastern side of the Lemhi range is a slowly rising fault- Wock seems to be proved by the abrupt entrance of the creeks on to the Pahsimeroi Valley, the absence of long ridges separating the creeks and the straight, steep-sided canyon of Patterson Creek with its narrow V-shaped notch opening suddenly onto the plains, like a gash in the mountain wall.

There are no igneous rocks in the vicinity of the mine which is an exceptional condition in western mining districts.

The principal vein occurs on the Ima company's ground and consists of a quartz-filled fissure in the quartzite rock, with an average strike of about N. 40° W. and a dip of 45° to 60° S. W. The vein is traceable on the surface for over a thousand feet, up the steep mountain side which forms the canyon wall of Patterson Creek. The outcrop is covered in many places by slide rock, but wherever the vein has been exposed it shows the same general characteristics. It has

-r~

till'

And Tin Deposits Of Idaho 23

been followed underground for over 800 ft. though the longest tunnel is now caved at the entrance and inaccessible. The width of the vein varies from about a foot up to 20 ft., with an average of from 8 to 10 ft. It is badly faulted, more particularly in the vicinity of the creek, the fault movements becoming less as distance from the creek is gained. The vein-filling is a drusy white quartz with many small unfilled spaces between the quartz grains and crystals. The minerals in the quartz are hubnerite, tetrahedrite, galena, sphalerite, pyrite, molybdenite and probably others, but these are the most important. The tetrahedrite gives rise to a green copper-carbonate staining at the surface, and the molybdenite to the yellowish molybdenum oxide, molybdite, the color being also partly due to the weathering of the hubnerite.

One of the best exposures of the vein is at the mouth of a tunnel about 250 ft. above the creek level. The vein at this point ij over 15 ft. wide and shows hubnernite over a considerable portion from the hanging-wall side. The vein has been stoped below the tunnel level for about 5 or 6 ft. About 20 ft. from the tunnel mouth it has been cut off by a fault with a strike about S. 75° W. and a northwesterly dip of 40°, this fault is exposed on the surface and has thrown the vein about 100 ft. to the west on the north side of the fault. This faulting might easily give rise to the supposition that there were two veins outcropping on the mountain side instead of one, and it probably did so in the earlier days of the mine's history. Another wide exposure of the vein occurs about 800 or 900 ft. from the creek on the north side and about 400 to 500 ft. above it. Here the vein, which is chiefly quartz, is over 20 ft. wide and is well mineralized with hubnerite, some of which is in fairly coarse crystals. There are other veins besides this one but they are smaller, less persistent and show less mineralization. One of these is exposed several hundred feet to the east of the big vein and contains 3 to 4 ft. of quartz with tetrahedrite and a little hubnerite, it has a strike of N. 40° W. and a vertical dip. Another still further to the east consists of a small stringer of quartz with a north-south strike and dip of 70° E. This has been followed in a tunnel a distance of' about 40 ft. and shows a little tetrahedrite in the face.

A small bed-vein in the quartzite outcrops on the mountain side west of the main vein and about 100 ft. above the bin at the head of the incline tramway. It is about 3 ft. wide, has a strike of S. 57° W. and dips 20° N. W. It showed no mineralization as exposed in a short tunnel.

Workings

The workings, most of which have been mentioned, consist of two tunnels on the north side of Patterson Creek, one of which starts from the creek-level and the other about 250 ft. above it. Both of these follow the vein, though the lower one is now caved and in-

24 Tungsten, Cinnabar, Manganese, Molybdenum,

accessible. The upper tunnel has two entrances, due to the faulted condition of the vein mentioned above, and connects with a gravity tram to the mill. An incline-shaft starts from the mouth of the lower tunnel and is reported to follow the vein to a depth of 70 ft. ?.nd to have encountered some very good ore. At the present time this shaft is full of water and inaccessible.

There are a few short tunnels following quartz outcrops on the south side of the canyon, but these were not visited.

Tungsten Contents oe Vein

Careful samples were taken from different places in the vein in older to get a general idea of the tungsten contents. To sample the property thoroughly, would require the services of several men for a week or more and this was beyond the scope of. the work. The locations of the samples can be seen by referring to the map of the upper tunnel. See Map No. 6.

Sample No. 1 was from the face of the upper tunnel. At this point the vein is 10 ft. wide but contains 3 ft. of waste. The sample was taken from the ore only and represented 7 ft. in width. It contained silver 3.2 oz. per ton; tungsten oxide (W0 3 ) 0.78 per cent.

Sample No. 2 was taken from 6 ft. of vein on the hanging-wall side of the N. end of the underhand stope near the upper tunnel month. It contained silver 3.2 oz. per ton, W0 3 0.43 per cent.

Sample No. 3 was from the same stope 20 ft. to the south of sample No. 2, and represents 5 ft. of ore from the hanging-wall side of the vein which has a total width of 15 ft. It contained silver 3 oz. per ton, W0 3 0.6 per cent.

Sample No. 4 was taken from the floor of the big underhand stope on the north side of the fault in the upper tunnel. The sample was from 5 ft. of the hanging-wall side of the vein, which was 10 ft. wide. It contained silver 2.0 oz. per ton, W0 3 0.50 per cent.

Sample No. 5 was taken from a number of places on the tailing dump, which contains 500 to 600 tons, and may be considered a fair average of the entire dump. Its contents were : silver, 2.9 oz. per ton, W0 3 0.33 per cent.

These samples give a very fair idea of the tenor of the ore which is from about 0.5 to 1.0 per cent tungstic oxide and 3 oz. silver to the ton. There are places in the vein that will undoubtedly run much higher than this and also places that will run lower, and the writer is of the opinion that the above is a very fair average of the ore as it would be mined. This would mean a very high ration of concentration, between 75 and 100 into 1, in order to get a 50 per cent W0 3 product, with a correspondingly low percentage of recovery. The sample taken from the waste dump confirms the

And Tin Deposits Of Idaho 25

suggestion that the extraction was very low in the present mill, as in round numbers it is apparently not much more than 50 per cent.

Whether the silver, which undoubtedly occurs in the tetrahedrite, could be separated from the hubnerite is an ore-dressing problem that would have to be carefully worked out in an experimental way. This would seem to the writer to be an almost vital question, as with the low tungsten contents of the vein the difference between working at a profit or a loss would depend upon this additional $2 or $3 per ton which the silver represents at the present price.

Even with this addition it would necessitate a very carefully designed mill and an extremely cheap method of mining to pay a profit with tungsten at $20 per unit.

(d) Camas County. Tungsten on Corral Creek

Tungsten was reported, by the Director of the U. S. Geological Survey, to occur near Corral, in Camas County.

Mr. E. S. Larsen of the Survey visited this district in 1916, but as it was only a short distance from the road between Boise and Lava Creek, it was decided to spend a day in visiting the property.

The claims on which the tungsten occurs are situated on the east fork of Corral Creek, which heads on Soldier Mountain, a fairly high peak lying between the Malad River and the South Fork of the Boise River. Corral Creek flows into the Malad River, which in turn flows into WJood River through what is known as the Camas Prairie country. This prairie is a flat stretch of country with an average elevation of about 5000 ft. and it is evidently the floor of an old tertiary lake formed by the damming of the lower part of Malad River by the lava flows of the Snake River plains.

The tungsten property is 9 miles northeast of Corral, a station on the Camas Prairie branch of the Oregon Short Line and is reached from that point by a fairly good wagon road with no excessive grade, and which can be traveled by automobile all the way to the claims. The claims lie on the lower slopes of this mountain at an elevation of 6400 ft. the mountain rising nearly 3000 ft. higher. They are in Sees. 5 and 8, T. 1 N., R. 13 E., of Boise Meridian.

The property was located several years ago by W. S. Roberts, of Boise, who is still part-owner of the property. A few tons of wolframite or ferberite ore were shipped in 1916, but the property is now idle and has been for some time.

The country rock is a trachyte or syenite porphyry, somewhat light colored, with prominent white feldspar phenocrysts which are completely kaolinized in the vicinity of the mine.

Three narrow, parallel quartz veins each from z / 2 in. to 3 or 4 in. wide, and about 18 in. apart, strike N. 35° E. (magnetic) and dip

26 Tungsten, Cinnabar, Manganese, Molybdenum,

northwest 60°. These veins carry a little wolframite or ferberite in the quartz.

Outcrops are scanty as there is a heavy covering of soil where this vein occurs, and the veins are exposed on the surface in one small open-cut only.

Several hundred feet of development has been done in the form of an incline shaft 85 ft. deep, and a connecting adit-tunnel along the supposed course of the vein, with several cross-cuts and stopes and some winzes below the tunnel level. Considerable stoping was done on both sides of the shaft, from the level of the tunnel to within about 20 ft. of the surface. The extraction of the tungsten ore was very thorough and complete, as a careful search of the workings failed to discover even a specimen of wolframite, and the shoot of ore in which the shaft was sunk is evidently completely worked out.

A tunnel has been started from the creek level about 200 ft. below the collar of the incline shaft and near where the vein should be if it holds its course in that direction. The face of this tunnel was in hard unaltered trachyte or syenite porphyry showing no sign of mineralization. Unless this tunnel encounters ore, the outlook for the property is not particularly bright as the vein does not seem to extend any distance in the other direction, and the width and length of the quartz stringers precludes the probability of their having any considerable extension downwards. This conclusion is confirmed by the showing in the present workings.

(e) Idaho County. Warren District.

Tungsten occurs at Warren on a property formerly known as the Little Giant, which is now being operated by J. A. Czizek for the Unity Gold Mines.

Warren is one of the pioneer gold-camps of Central Idaho and was at one time a heavy producer of placer-gold. This camp produced vein-gold for many years, and is still doing so in a limited way. The geology and vein occurrences have been well described by Waldemar Lindgren 1 and this description will not be repeated here at any length. The camp is situated near the head of Meadow Creek at an elevation of 5800 ft. and is reached by a fairly good wagon road from McCall or Lakeport (as it is called by the railroad company), the nearest railroad point, a distance of 50 miles. This road crosses two summits, Secesh summit with an elevation of 6800 ft and Steamboat summit with about the same elevation. The snowfall is heavy, reaching a depth of over 20 ft. on parts of the road, making winter travel somewhat difficult and expensive. At the present time mail and passengers are carried by automobile stage during the summer months. A considerable part of the road be-

1. Twentieth Annual Report, U. S. Geol. Survey, part 3, pp. 246-249.

And Tin Deposits Of Idaho 2T

tween Payette Lake and Resort (Burgdorf's) is over glacial moraines with many large granite boulders, which continually keepworking to the surface, making the road extremely rough, and difficult to improve.

The Unity Gold Mines Company owns a group of claims, known as the Little Giant, Charity, etc., containing a series of parallel gold-bearing quartz veins, occuring in granite. The companyis driving a cross-cut tunnel from a point a few feet above the level of Meadow Creek to intersect these veins at depths ranging from 500 to 1000 ft. below their outcrops. This tunnel starts from the south bank of the creek immediately opposite the town of Warren.

At a distance of 1700 ft. from the portal, and 500 ft. below the surface, the tunnel had intersected a quartz vein 8 in. wide containing scheelite. This is apparently a blind vein, at least its position at the surface is not known. The vein has the same general strike as the Little Giant and Charity and evidently belongs to the same vein system. A sample taken from this vein was reported by the owners of the property to have given a return of 18 per cent W0 3 but this must have been a picked sample. No sample for assay was taken by the writer but the general appearance of the vein would indicate an average tungsten content of about 4 to 5 per cent \V0 3 across the 8 in.

No development work has been done upon this vein, aside fromits exposure by the cross-cut tunnel, and its continuity or characteristics along the strike could not be determined.

Tungsten is reported by Mr. Lindgren 1 in the Charity vein, which this same cross-cut tunnel should intersect further on, and undoubtedly other quartz veins in the district will also be found to' contain scheelite. It is difficult to give any estimate as to the future of this district as a tungsten producer for little has been done to open up the tungsten-bearing veins.

A vein 8 in. wide containing 4 to 5 per cent W0 3 would pay to mine at the present price of tungsten ($20 to $25 per unit.) and the district could no doubt produce a small amount of tungsten when some of these veins have been opened.

(/) Butte County. Lava Creek District.

The Independence group of claims belonging to S. O. Nelson of Boise, situated at the head of Lava Creek, in Sec. 13, T. 2 N., R. 23 E., Boise Meridian, contains a deposit of tungsten-bearing material.

This group is on Granite Mountain at an elevation of 8700 ft. It is reached by a trail about 6 miles long from Martin, which is on the main road between Hailey and Arco and about 20 miles from the latter, the nearest railroad point.

1. Op. cit., p. 245.

28 Tungsten, Cinnabar, Manganese, Molybdenum,

Granite Mountain is one of the highest mountains bordering the Lava plains of that part of Southern Idaho, and has a somewhat complex geological structure. Metamorphic sediments in the form of quartzites and limestones have been intruded by a variety of igneous rocks, with porphyrytic flows covering considerable areas.

A vein containing wolframite outcrops on the ridge which runs east from the highest point of the mountain and about 100 ft. below the summit, which is 8800 ft. high, according to barometric readings. This vein lies in a contact between diorite and a peculiar rock which is either a quartzite or a highly silicified trachyte, the identity of which could not be determined in a hand specimen. The strike of the vein at this point is N. 30° E., and the dip from 60° to 70° S. E. The vein has an average width of 6 ft. and is made up of a crystalline drusy quartz heavily stained with manganese. It contains considerable oxide of iron, and of manganese, with an occasional crystal of wolframite.

Several open-cuts expose the vein on the ridge from which, according to the owner's report, 20 sacks of ore containing between 30 and 40 per cent W0 3 were shipped in 1916 or 1917.

A tunnel about 60 ft. long has been driven into the mountain about 100 ft. below the ridge on the south side, but this apparently has not reached the ledge, as none of the vein material was -encountered. Further down the mountain on the strike of the vein, the igneous rocks are in contact with limestone but the exact -nature of the contact could not be determined owing to the slide-rock on the hill-side and to the fact that the only open-cut exposing it was filled with hard ice, the remains of the previous winter's snow. A small vein had apparently been exposed by this cut, -containing, among other minerals, scales of gypsum or selenite. The time spent upon the property was short, the weather conditions unpleasant and the geology so complex that definite conclusions as to the form and origin of the tungsten-bearing vein cannot be given. It would seem, however, that the vein is a mineralized fault-fissure, the wall rock of the fissure varying considerably from place to place, according to the rocks cut and displaced by the fault. The diorite on the summit of the ridge seems to have lent itself more readily to replacement by mineralizing solutions than the other rocks as the best exposure occurs at this point. More extensive prospecting along the limestone contact should be done, however, as there may be other places where wolframite occurs.

Another vein occurs on the west side of the highest point of the mountain. This vein has about the same strike and dip as the one previously described and is in a syenite or syenite porphyry, very similar in general characteristics to the unaltered rock on

1. Field classification only; may be ferberite.

And Tin Deposits Of Idaho 29'

Corral Creek at the W. O.. Roberts property. This vein shows quartz, and manganese and is about 2 ft. wide.

The property is somewhat remote and difficult of access, and these conditions combined with the elevation and exposed situation would make mining costs high. Nothing but a high-grade tungsten ore could be mined at a profit under the present conditions and there is no ore of high grade exposed at this time on the property. The showing, however, warrants more extensive prospecting than has been carried on up to date.

Tungsten Near Gibeonsviele

Some material containing manganese and giving a strong qualitative test for tungsten was sent to the University of Idaho early in the summer of 1918, by Mr. George R. Hughes of Gibbonsville.

The Gibbonsville district was visited on August 28th, 1918,. one day being spent in examination of the property reported to contain tungsten. The property, known as the Roland and Taylor Group, is owned by Mr. George R. Hughes and is situated on Anderson Creek, about a mile north of Gibbonsville. This group of claims, together with the topography and general geology of the district, has been described by Jos. B. Umpleby. 1 The district isreached from Salmon, a distance of 35 miles over an excellent road, the cost of freight from Salmon by trucks being between $5 and $10 per ton.

A mineralized zone or lode about 100 ft. wide with a strike of N. 20° E. and a clip of 70° to the S. E., lies between a diorite hanging-wall and a talcose-schist or slate foot-wall. This lode is reported to outcrop for about 2 miles and shows considerable ironstaining on the surface, forming a prominent geological feature.

The lode consists chiefly of creamy white quartz, rather rotten and crumbling with bands of dark manganese-stained material running through it. The first 60 ft. from the footwall shows seams of iron-stained quartz, interbanded with schist. The remaining 40 ft. shows a granular, sugary quartz stained with bands of manganese. As mentioned by Umpleby 2 occasional pieces of unoxidized copper .ore are found in this lode; the writer identified tetrahedrite in addition to chalcopyrite and pyrite as described by Mr. Umpleby.

Mr. Hughes reports this lode to average about $3.50 to the ton in gold. The workings consist of two cross-cut tunnels driven in from Anderson Creek to intercept the lode and situated about 500 ft. apart. The most southerly of these is caved near the mouth but shows a considerable amount of copper on the dump in the form of carbonate and a little tetrahedrite. The other tunnel about 400 ft. long has completely cross-cut the lode, and has also followed it for

1. Geology and Ore Deposits of Lemhi County, Idaho, U. S. Geol. Survey, Bull. 528, pp. 127-132, 1913.

2. Op. cit., p. 134.

Jo Tungsten, Cinnabar, Manganese, Molybdenum,

some distance. An 80 ft. vertical shaft has been sunk close to the creek on the west side and has partly cut the lode on the dip, Taut this is now filled with water and inaccessible.

A sample of the manganese stained material sent to the University by Mr. Hughes gave a strong qualitative test for tungsten. Two samples taken by the writer in the cross-cut, which aggregated 92 ft. of vein material gave only a trace of tungsten. The probabilities are that careful sampling and panning of the different manganese seams might discover the one that carries tungsten.

Chapter Ii.

Manganese

Manganese is a whitish metal very like cast-iron in appearance but with a peculiar reddish luster, an atomic weight of 54.9 and a -specific gravity of 7.1 to 8. 1

It oxidizes very readily in the air and is never found in the free, metallic state in nature. It can be prepared from its ores by several chemical processes and by electrolysis, but a discussion of these is beyond the scope of this publication.

The following are the more important manganese minerals:

Psilomelane (Mno 2 2 0. A complex oxide of manganese, potassium and barium with considerable water. The manganese content varies between 45 and 60 per cent. It is a grayish black mineral usually occurring in massive or amorphous form with a sub-metallic luster, a hardness of 5 to 6, and a specific gravity of 3.7 to 4.7.

Pyrolusite (Mn0 2 ) manganese oxide often containing a little water. When pure it contains 63.2 per cent manganese. It is a grayish black to black mineral with crystalline or granular structure, and has a hardness of 2 to 2.5 and a specific gravity of 4.8. It usually occurs associated with psilomelane.

Braunite (3Mn 2 0, MnSi0 3 ). A combination of manganese oxide and manganese silicate. When pure, it contains 69 per cent of manganese. It usually occurs in fine crystalline form and is brown or black in color. It has a hardness of 6 to 6.5 and a specific gravity of 4.8.

Manganite (Mn 2 3 H 2 0). A black mineral, containing 62.4 per cent manganese when pure, with a hardness of 4 and a specific gravity of 4.3.

Wad is a soft impure mixture of manganese oxides usually earthy in texture. It often occurs in the cracks and joints of veins and the adjoining rock, in the form of dark branching fern-like growths known as dendrite.

1. Harder, E. S., U. S. Geol. Survey Bull. 427, p. 224, 1910.

And Tin Deposits Of Idaho 31

The most important carbonate is Rhodochrosite (MnC0 3 ), a pink mineral which effervesces in warm hydrochloric acid and contains, when pure, 47.6 per cent manganese. It has a hardness of from 3.5 to 4.5 and a specific gravity of 3.5. It often occurs in association with ores of silver, lead, copper and zinc.

Rhodonite (MnSi0 3 ) Manganese Silicate. A pink mineral often occurring in ores or pegmatite veins. When pure it contains 41.9 per cent manganese. It has a hardness of 5.5 to 6.5 and a specific gravity of 3.4 to 3.7.

There are other and rarer manganese minerals but these are the only ones of any economic importance.

Uses of Manganese

Manganese is used chiefly as an alloy with iron. It is always found in iron and steel to some extent but it was not until about 30 years ago that R. A. Hadfield, an English metallurgist, discovered its true effects and properties.

When more than 2 per cent and less than 6 per cent of manganese is added to steel it makes it very brittle, so that it can be powdered under a hammer. When over 6 per cent is added this brittleness gradually decreases until when 12 per cent is reached the former strength returns and reaches its maximum at about 14 per cent. By adding from 10 to 15 per cent of manganese a steel is formed so hard that it cannot be machined or drilled in the ordinary way, and so tough that it can be bent and twisted into peculiar shapes without breaking. It has to be cast in practically the form or shape in which it is to be used.

It is used wherever extreme hardness is required, 2 in cases where there is heavy wear and tear as in dredging machinery ; dipper-teeth of steam shovels ; for crushing and grinding machinery ; for agricultural implements ; for wheels, tires and axles on railway cars, etc. ; for railroad rails at curves, for burglar-proof safes and many other purposes.

Consumption and Production of Manganese in the United States

The Geological Survey classifies manganese ores into four main divisions, (a) Manganese ores; (b) Manganiferous iron ores; (c) Manganiferous silver ores, and (d) Manganiferous zinc residuum. Materials containing more than 40 per cent of manganese are grouped as manganese ores with the exception of ores carrying more than 20 per cent of silica, 3 when they are rarely accepted for any purpose. Material containing from 15 to 40 per cent manganese, in

1. Lake, M. F., Composition and Heat Treatment of Steel, p. 71, 1910.

2. Harder, E. C, U. S. Geol. Survey Bull. 427, p. 255, 1910.

3. Hewitt, D. F., Manganese and Manganiferous Ores in 1916. Mineral Resources of (he U. S. Geo!. Survey, p. 733, 1918.

32 Tungsten, Cinnabar, Manganese, Molybdenum,

which practically all the remaining material is iron oxide, is classed as ferruginous manganese ore.

In 1916, 576,321 tons of manganese ore were shipped into the United States and only 26,997 tons were produced, or in other words only 4.7 per cent of the manganese ore, containing 40 per cent of manganese or better, used in the United States in 1916 was produced here. Of the total amount imported 471,837 tons or nearly 82 per cent came from Brazil, which was 95 per cent of the total production of that country.

There was a marked increase in 1916 in the amount of manganese iron ores produced in this country. In 1910, 61,101 tons were produced, most of which was used as flux in lead smelting, while in 1916, 176,130 tons were produced, nearly all of which was used in the iron industry. A very large percentage of this increase came from the western states.

Production in Foreign Countries Previous to the war Russia was the largest producer of manganese ores, being credited with 1,289,370 tons in 1913. Next came India with a production of 815,047 tons in 1913 and then Brazil with 120,368. In 1915 figures regarding Russia's production were hard to obtain, India had dropped to 450,436 tons and Brazil had risen to 284,111 tons. Prior to the war the United States was almost entirely dependent upon other countries for her manganese supplies, and is so yet to a very large extent.

The position of the United States in regard to manganese is somewhat peculiar; it is at present the greatest iron and steel producer in the world and consequently needs a large supply of manganese, nearly all of which has to be imported from foreign countries. The advantages that would accrue to the country in the discovery of large bodies of manganese ore does not, therefore, need to be enlarged upon.

Production in the United States Most of the manganese ore produced in 1915 came from Nevada and Colorado. This should be classed as manganiferous iron ore and was smelted at Pueblo, Colorado, and comprised nearly 90 per cent of the total production of the country. Other states producing manganese ores are Montana,, Arkansas, California, New Mexico, Utah, Virginia and Washington.

Manganese Deposits oe Idaho Snake River Manganese ores were reported to occur on the Snake River near Sturgill Creek about 20 miles below Huntington, both by the U. S. Geological Survey and by local people. The district was visited in the middle of July, four days being spent in the examination of the different properties.

And Tin Deposits Of Idaho 33

.The particular belt in which these deposits occur lies along the Snake River between Huntington and Homestead on the Homestead branch of the Oregon Short Line and about three or four miles above Robinette, a small town near the mouth of the Powder River, Oiegon. The district is easily accessible as none of the properties are more than three miles from the railroad, although on the opposite side of the river.

The country is arid with little rainfall in the summer and very little snow in the winter and is utilized chiefly for cattle and sheep grazing. There is no timber along the river, but plenty is available further back in the mountains as soon as an elevation of about 5000 ft. is reached. There are several hay ranches along the river, on the bars or benches wherever water is available for irrigation.

Topography. The country has been deeply eroded by the Snake River and its tributaries. The latter flow from the Hitt Mountains, which may be considered a southern extension of the Seven Devils range. This range of mountains lies between the valley of the Weiser, which is a structural valley, and the valley of the Snake, which is an erosional valley of comparatively recent date. Weiser River on the east side of the Hitt Mountains, flows almost due south and Snake River on the west side flows almost due north.

Snake River at this point flows in a deep canyon, the elevation at the mouth of Sturgill creek being about 1900 ft., while the elevation on the summit of the Hitt Mountains is about 7500 ft., giving a relief of 5400 ft. This is not quite so deep or rugged a canyon as that lower down the river opposite the Seven Devils. At that point the depth of the canyon is nearer 7000 ft. than 5000 ft. and is infinitely more rugged.

The canyon now occupied by the Snake River has been cut since the Miocene lava flows of the Columbia basin were outpoured, prior to which event it undoubtedly occupied an entirely different channel.

All the tributary streams flow in deep canyons but have in places a small strip of bottom land along the creek which is utilized in many instances by ranchers for hay growing.

Geology. The rocks of the district consist chiefly of quartzite, schist and slate, with occasional small areas of crystalline limestone. One of these limestone areas is on Sheep creek, where it shows as a gray crystalline rock containing many seams of calcite, and evidently very highly metamorphosed. The general strike of the schists and quartzites is N. 75° E., but the dip is very variable. They are usually very steeply tilted and have evidently been subjected to profound movement. Dark basic dikes, that might be classified as diabase, in the field, intrude these metamorphosed sediments. These dikes are similar in characteristics wherever they were noted by the writer, and consist of a heavily-jointed, dark-gray rock of fine crystalline texture, weathering to a dark reddish brown. They are some-

34 Tungsten, Cinnabar, Manganese, Molybdenum,

what harder than the surrounding country rock and usually form prominent outcrops. A good exposure of one of these dikes can be seen on Reservoir gulch about a quarter of a mile above its junction with Sturgill Creek.

The manganese occurs in veins which are interbedded with slate, although there are a few fissure veins containing manganese but these are not so large or continuous as the former type of deposit.

Placer gold is being mined by hydraulicing from a high bar below the mouth of Sturgill creek. This high bar evidently represents the bed of the river which was wide enough at that time to be considered as a lake at this particular point. This lake was formed either by a landslide or a lava flow further down the river, and after the obstruction had been cut through by the river, these river or lake deposits were left nearly 200 ft. above the present water level. The gold occurs in a bed of gravel, made up entirely of fragments of mica schist which lie upon a bed rock of hard clay containing many large boulders which have rolled in from the mountain side. This bed of schist does not usually exceed 3 or 4 ft. in thickness and is very irregular and patchy in its occurrence. This deposit was visited late one evening and only a short time was spent on the ground so no theory can be advanced for the occurrence of the gold in this particular bed of schist gravel. These old river or lake beds offer an interesting study and afford considerable evidence as to the history of the Snake River and the various changes through which it has passed.

T. F Adams' Sturgill Creek Property. This property is situated on the north side of Sturgill creek about 2 miles above its mouth and about 800 ft. higher than the creek, at an elevation of 3500 ft., in Sec. 34, T. 16 N., R. 6 W., Boise Meridian. There is a good wagon road up the creek which is passable for automobiles to within less than half a mile of the outcrop. From there it is a steep climb with no trail. A vein containing black manganese oxide outcrops along the mountain side for a distance of 400 or 500 ft. This vein follows the lamination planes in quartzite schist and like most veins of this kind is more or less lenticular in character. The strike of the vein is N. 75° E., with a dip of 60° to the southeast and a width varying between 4 and 15 ft. It has been exposed by several open-cuts, one over 40 ft. long following the strike, and a small tunnel about 15 ft. in length. The vein filling consists chiefly of oxides of iron and manganese in a gangue of quartz and jasper. In some places the jasper and quartz predominate in the vein, in others the black oxides. About 2000 ft. to the southwest of these exposures and about 200 ft. vertically above Sturgill creek is another opencut exposing a similar type of mineralization. The vein here is only 2 ft. wide, however, and though it has the same strike as the one

And Tin Deposits Of Idaho 35

higher up the mountain it dips in the opposite direction. It may be a continuation of the same vein, but this is not definitely clear.

About 200 tons of material have been extracted from the large open-cut and are piled up in the cut. A sample was taken across 6]/ 2 ft., in the northeastern face of the large open-cut, and included only that portion of the vein containing the black oxides. It was fairly representative of the material in the pile and gave the following analysis :

Mn Ft S SiO, P

18.57% 1.50% 0.025% 55.23% 0.045%

Another sample taken across A l / 2 ft. in the face of the small tunnel gave the following analysis : Mn Fe S Si0 2 P

15.30% 2.00% 0.022% 45.28% 0.10%

An open-cut below the tunnel showed mostly jasper rock with very little manganese and was not sampled.

An attempt was made on a small scale at the University to see if this material could be concentrated into a richer product, that could be shipped, but the results obtained were discouraging as the richest looking pieces that could be picked out only contained 16 per cent of manganese.

The amount of work done upon the property is insufficient to definitely prove it one way or another, but the indications are that this deposit is not of sufficiently high grade to be classed as manganese ore. If near to an iron blast-furnace it might be possible to utilize it but even that is doubtful on account of its high silica contents. Higher grade bodies of manganese might be found along the strike of this vein and this would seem to offer the best chance as there is not very much probability of enrichment of this particular shoot with depth. The manganese oxides have apparently been derived from rhodonite or rhodochrosite, or both.

T. F. Adams' Sheep Creek Property. This property consists of two claims in Sec. 8, T. 15 N., R. 6 W., Boise Meridian. These claims are located about two miles above the mouth of Sturgill creek and extend from the water's edge at the Snake River over to Sheep creek.

The country rock is schist and the vein which is from 7 to 15 ft. wide lies in between the planes of schistosity. The vein is chiefly quartz stained black by oxides of manganese. The general strike is N. 75° E. with a dip to the northwest of from 60° to 70°. A sample taken across iy 2 ft., from the vein exposed on a bluff about 150 ft. above the river, gave the following results: Manganese, 2.4 per cent; iron, 8.7 per cent.

The vein can be followed up the mountain from the river for several hundred ft. and evidently extends to the top of the ridge be-

36 Tungsten, Cinnabar, Manganese, Molybdenum,

tween the Snake river and Sheep creek. What is apparently the same vein occurs on the north side of Sheep creek about 1500 to 2000 ft. above its mouth. A small open-cut on this vein is 18 in. wide, and a sample taken across this width gave the following- returns : Manganese, 5.1 per cent; iron, 15.5 per cent; silica, not determined.

The vein was not fully exposed by this open-cut and is probably wider than the exposure in the cut. The only workings on the property are the open-cut just mentioned and another small cut on the bluff above the Snake River.

There may be places on this vein where a better grade of manganese ore occurs, otherwise the vein is altogther too low grade to be of any value as a source of this element.

The J. T. Reilly Property consists of several claims situated near the head of Reservoir gulch, the first large gulch that comes into Sturgill creek from the north. The claims lie on the ridge between Reservoir gulch and Lone Pine gulch, which empties into Snake River, and are in Sec. 29, T. 16 N., R. 6 W., Boise Meridian, at an elevation of about 3500 ft.

A somewhat dim cattle trail follows Reservoir gulch from Sturgill creek to the claims. Two veins have been exposed ; one a fissure vein in slate containing a little manganese and about 2 ft. wide, has a strike of N. 30° W. and the other a bed or blanket vein in slate with a strike of N. 75° E. and a dip of about 40° to the northwest. This vein is about 8 ft. wide, is heavily iron stained and contains a little manganese oxide in a quartz and jasper gangue. A sample taken across 6 ft. of this vein gave the following results : Manganese, 11.2 per cent; iron, 3.2 per cent.

/. G. Hill's Property is situated about three-quarters of a mile from the Snake River on a ridge north of Wayle creek, close to the line between Sees. 18, and 30, T. 15 N., R. 6 W., at an elevation of 3000 ft., or approximately 1000 ft. above the river. The workings consist of a small open-cut which has exposed a fissure vein about 2 ft. wide in slate, with a strike of N. 60° W.and a clip to the north east of 60°. The length of outcrop is not known as the vein was exposed in this one place only. The gangue is quartz containing a considerable amount of black manganese oxides. Some very good looking ore has been piled up on the dump.

A sample taken from this cut with a width of 2 ft. gave the following returns: Manganese, 20.6; iron, 5.2; silica, 46.6; sulphur, 0.04; phosphorus, 0.04 per cent, respectively.

This is the best grade of manganese ore seen in the district, and the vein should be worth prospecting along the strike to see if any wider places containing ore could not be found.

And Tin Deposits Of Idaho 37

Summary and Conclusion

The district was somewhat disappointing as a possible source of manganese. Several good sized veins exist but most of them are too low grade and too silicious to be considered as available resources of manganese ore. The highest grade ore in the district comes from quite a small vein.

It may be that more extensive and careful prospecting might uncover other veins, or that richer places might be found in prospecting the present discoveries along their strike. The fact that the country is free of timber and underbrush makes prospecting easier than in many places in Idaho and the likelihood of any new discoveries being made is consequently greatly lessened.

Manganese in Shoshone County

Cumming's Property. A deposit containing manganese occurs about one mile east of Prichard, which is at present the terminus of the Murray branch of the Oregon Short Line.

The property is owned by Mrs. E. V. Cummings of Wallace, Idaho, and was operated at one time by Mr. L. J. Tefft, of Wallace. The outcrop is about 1500 ft. northeast of the wagon-road between Murray and Prichard and about 850 ft. higher than Prichard creek. It is in Sec. 21, T. 22 N., R. 4 E., Boise Meridian.

The country rock is Revert quartzite, in which a crushed and brecciated zone over 50 ft. wide has been cemented, by manganesebearing material consisting partly of psilomelane. This zone has a strike of S. 80° E. and is reported to have one well-defined wall, but this was not seen by the writer and its dip is not known. It is reported to outcrop for a distance of over 4000 ft. Some of the quartzite beds have been more replaced and mineralized with manganese than others. There has been considerable movement along this zone . and it is probable that the zone itself is a fault. This zone has been exposed in one place by a short and branching cross-cut tunnel containing 70 or 80 ft. of workings in all.

This tunnel shows about 50 ft. of this black oxide material in the quartzite. Some of it is soft and rotten but most of it is badly mixed with quartzite.

Two samples were taken; one from the best looking material in the cross-cut, represented a width of 20 ft. This sample contained: Manganese, 11.02; iron, 1.8; silica, 74.6; sulphur, 0.016. and phosphorous 0.08 per cent, respectively. The other was a sample of the highest grade material that could be obtained by hand sorting the rock from the vein, and contained: Manganese, 19.5; iron, 3.7; silica, 55.1; sulphur, 0.045, and phosphorous 0.08 per cent, respectively.

Experiments made in the metallurgical laboratory at the University of Idaho showed that it was not possible to concentrate this

38 Tungsten, Cinnabar, Manganese, Molybdenum,

material to a shipping grade of manganese ore. Evidently the high silica content of this material precludes it as a possible source of manganese, unless some method could be devised for raising the manganese content and at the same time reducing the silica below 20 per cent. There is evidently a large tonnage of this kind of material available on the property that could be mined and handled very cheaply if such a method of treatment could be worked out.

As the tunnel cut the deposit only a few feet below the surface the workings are entirely in the oxidized zone, and hence it was not possible to arrive at any definite conclusion in regard to the origin of the manganese, but the probabilities are that it was derived by means of surface waters from manganiferous siderite in the surrounding rocks.

The Butte-Detroit Property owned by Charles T. Anderson is situated about two miles below Delta and about 200 or 300 yards to the east of Beaver creek, in approximately Sec. 4, T. 21 N., R. 4 E., Boise Meridian.

The outcrop was not visited but samples seen in Mr. Anderson's cabin showed a very similar type of manganese occurrence to that which occurs on the property just described, and which is between two and three miles to the north.

The country rock is also Revett quartzite and the manganese mineralization is practically identical. The outcrop was reported by Mr. Anderson to be a crushed zone over 65 ft. in width with an east-west strike. The manganese bearing material is a recent discovery and there has been very little work done upon the property.

The lone Group is owned by Mr. Dan Sieger of Murray and is situated near the top of the ridge between Bear Gulch and Paragon Gulch and about a quarter of a mile east of the Bear Top mine. It is eight miles from Murray, by wagon-road as far as the Bear Top buildings on Bear Gulch, and then by trail. The outcrop is at an elevation oi 4700 ft. and 1500 ft. above Bear Gulch.

A fissure vein in Prichard slate with an east-west strike and a dip of 60° to the south outcrops for 600 or 700 ft. along the side of the ridge. Mr. Sieger has shipped about a carload of lead ore from an open cut on this vein. An adit tunnel follows the vein for 300 or 400 ft.

About 40 ft. vertically above the mouth of this tunnel the outcrop of the vein is heavily stained with manganese and has been opened up by a tunnel about 10 ft. long. A sample 5 ft. wide from the vein in this tunnel contained 4.54 per cent of manganese and 11.6 per cent of iron. This is entirely too low grade to" be considered as manganese ore.

Waring's Property. A mining claim owned by D. E Waring of Wallace, was reported to contain manganese ore. This property,

And Tin Deposits Of Idaho 39

which is situated about three miles from Wallace on Ninemile Creek, and a quarter of a mile down the creek from the Black Cloud mill, is developed by a cross-cut adit-tunnel driven in the west side of the gulch above the main road, the tunnel having been run with the object of intersecting a deposit showing an iron-capping on the hill above. About 380 ft. from its portal, this tunnel intersects a fissure or water-course from 6 to 12 in. wide with a strike of S. 45° W., and a dip of 45° N. E., containing considerable black manganesebearing mineral, forming a sort of breccia of country rock (Revett quartzite) held together with a manganiferous cement. The deposit is similar in many respects to the limonite (hydrous iron oxide) filling characteristic of the more or less open fissures common in nearly all metal mines close to the surface. Such limonite deposits are universally recognized as the result of the oxidation and leaching of surrounding iron-bearing rocks by descending surface-waters. The metamorphic rocks of the Coeur d'Alene region contain much siderite, most of which is slightly manganiferous. It seems logical, therefore, to conclude that manganese deposits of the kind just described are entirely secondary in character and not likely to be extensive.

A further difficulty in the way of utilization of such material, even should the deposits prove to be more extensive than is here suggested, lies in the extremely low tenor of the black mineral, clean segregated specimens of which show only 16 per cent manganese. Concentration of such material up to marketable grade is obviously impossible.

A deposit, similar in all respects to the foregoing was examined in the Vienna-International Mine, which is situated on Placer Creek about seven miles by wagon-road from Wallace. What has been said concerning the Waring property applies equally to the manganese vein inspected in the Vienna-International.

Molybdenum

In addition to tungsten, quicksilver and manganese deposits, molybdenum and tin were included in the list of minerals necessary for carrying on the war, and wherever these minerals had been reported that district was visited.

Molybdenum is used as an alloy of iron and carbon in the manufacture of certain high-speed steels, in much the same way as tungsten, though not so extensively.

Its principal economic mineral is molybdenite the sulphide of molybdenum though it is extracted also from wulfenite the molybdate of lead. Molybdenite occurs rather commonly in many quartz veins, in association with other sulphides but rarely in workable amounts. It is a soft, black, mineral with a highly metallic luster, usually in flaky scales and easily scratched with the finger nail. It

40 Tungsten, Cinnabar, Manganese, Molybdenum,

may be mistaken for graphite, but can be distinguished from it by the streak that it gives when scratched upon a smooth porcelain plate, molybdenum giving a greenish streak while the streak of graphite is black.

Molybdenum may be recognized by heating a small piece of the mineral, supposed to contain it, in a porcelain crucible with a few drops of sulphuric acid. After the fumes have ceased and the crucible is cool, a deep blue color will form if molybdenum be present. The mineral molybdenite must be first oxidized by heating with nitric acid or by roasting in the air before adding sulphuric acid, but with other molybdenum minerals this is not necessary.

Like the other so-called war minerals the production and consumption of molybdenum in the United States for the last two or three years is not available.

Previous to 1914 the price was from 20 to 40 cents per pound for nearly pure molybdenite, but in that year the demand for this metal in the steel industry caused it to advance to about $2 per pound. Practically no molybdenum was mined in this country prior to 1914, the small amount used for chemicals, coloring matter, etc., being imported.

Boundary County

A. J. Kent of Bonner's Ferry owns a property situated in Sec. 9, T. 64 N., R. 1. E., Boise Meridian, which contains molybdenum.

It is close to the road that runs to the Dora and Tungsten Hill mines described in (Chapter 1 and about one and a half miles from the Copeland Ranger Station, on the bench near the top of the first grade on the wagon road. (See Map. No. 1.)

The country rock is granite, and molybdenite occurs in a pegmatite phase of the granite which consists chiefly of irregular bunches of quartz and light colored mica (muscovite). The molybdenite crystals are in some cases over an inch across and have a radiating structure as have also the mica crystals with which it occurs. I

The deposit, which is very irregular and bunchy, has been opened up by a few shallow open-cuts only and the development is not sufficient to allow any intelligent estimate of the amount of molybdenite available.

Lemhi County

A similar type of molybdenite deposit occurs in Lemhi County on west Eightmile Creek in the Lemhi range, 12 miles west of Leadore on the Gilmore & Pittsburg Railway. It is owned by A. R. Mulkey, of Leadore. The property is on the east side of the Lemhi range at an elevation of 8500 ft. It is about three miles from the Bohannon ranch and a mile from West Eightmile creek on the south side of the creek. There is a wagon-road to within about a mile of

And Tin Deposits Of Idaho 41

the property, which passes up the creek 1000 ft. below the outcrop. This wagon-road crosses the divide between West Eightmile creek and Patterson creek, where the Ima mine is situated, but is washed out and in bad repair at the present time.

The country rock is granite or monzonite and the molybdenite occurs in a very irregular and bunchy pegmatite vein. The workings consist of a short tunnel and a winze about 20 ft. deep, which followed down a narrow chimney of molybdenite ore from which several hundred pounds were shipped.

The shoot of ore that outcropped on the surface and which was followed down in the winze mentioned has been mined out, and there was little to be seen at the time of writing. A little scheelite occurs associated with the molybdenite.

Adjoining this property is a deposit of oxidized copper ore containing chrysocolla and azurite. This has been exposed by several shallow tunnels and open-cuts and by a shaft about 60 ft. deep. These openings, which are several hundred feet apart, along the strike of the deposit, show a crushed and brecciated zone of granite, the exact width of which has not been clearly demonstrated in the workings, but which is evidently in excess of 50 ft. Chrysocolla and azurite occur all through this crushed zone in sufficient amounts to made the whole width carry probably over 2 per cent of copper in places. Some very beautiful specimens of chrysocolla can be seen on the dump at the lowest of the tunnels.

The horizontal extent of this deposit is not definitely known but from observations made during a hasty examination and reports from local people it would appear to outcrop for at least a half a mile. Copper ore is also reported to occur near the head of Patterson creek and this district would seem to be more valuable for copper than for molybdenum, and is worthy of more attention than is being given to it at the present time.

Idaho County

Molybdenum occurs on a group of claims owned by W. G. Cadby of Warren, situated about half a mile west of the South Fork of Salmon River and about four miles north of the wagon-road between Warren and Dustin's ranch on the South Pork. The workings are almost opposite the mouth of Grouse creek on the east side of the river and about 1000 ft. above it, at an elevation of 3900 ft. The property may be reached from Warren, which is about 12 miles from the claims. There is a fairly good wagon-road from Warren to the Hayes Ranger Station and from this place to the property the distance is only about two miles by trail. The distances and elevations are about as follows : Warren, 5900 ft. ; Warren to Warren Summit, 4 miles, elevation at summit, 6800 ft. ; Summit to Hayes Ranger Station, 6 miles, elevation at Ranger Station, 4200

42 Tungsten, Cinnabar, Manganese, Molybdenum,

ft.; Hayes Ranger Station to Cadby's cabin, 2 miles, elevation at Cadby's cabin on Big Flat creek, 3900 ft.

Topography. The topography is the steeply eroded mountain type of Central Idaho, the South Fork of the Salmon River having cut a canyon to a depth of from 3000 to 6000 ft. The slopes of he canyon-side vary from almost perpendicular bluffs to about 25°. There are benches or flats at different levels which evidently show stages in the erosion when the stream was comparatively inactive, due to a cessation in the elevation of the country, and which resulted in lateral cutting of the river in place of vertical cutting. One of these benches is about 1000 ft. above the river and is well exemplified on Big Flat creek, where Mr. Cadby's cabin is located.

Geology. The oldest rocks are schist or gneiss containing considerable amounts of garnet and mica. Beds or sills containing dark green hornblende occur in the schist. Whether these are intrusive into the schist Or whether they represent portions of the schist that have been entirely recrystallized due to contact metamorphism is not entirely clear, but the former supposition appears the most likely. Granite underlies these old metamorphics and has been intruded into them in an extremely irregular manner. This is the normal light colored biotite granite or monzonite of Central Idaho. The schist and hornblende sills have a general strike of N. 75° E., and are very variable in dip. They evidently represent an uneroded remnant of these rocks the greater part of which have been removed by erosion, exposing the underlying granite batholith. They are strikingly similar in appearance to a series of rocks that occur in the northern part of Latah County. In some places these rocks in Latah County contain very similar hornblende sills and where they contain these sills they are usually mineralized with pyrrhotite and chalcopyrite. In Mr. Cadby's property the hornblende sills and adjacent parts of the schist are mineralized with pyrrhotite and molybdenite. The schist of Latah County is a part of the Belt series of pre-Cambrian or Algonkian sediments and for lack of better evidence the schist at Mr. Cadby's property may be considered as belonging to the same age and series.

As previously stated molybdenite occurs with pyrrhotite in the garnetized schist and hornblende sills. It is usually in very fine grains although crystals over a quarter inch across occur locally. The zone in which the molybdenite occurs is about 150 ft. wide and is reported by Mr. Cadby to be traceable on the surface for over 2300 ft., showing molybdenite all the way. It is locally intruded by the granite with irregular tongues of granite running through it in all directions.

As the workings consist of but one short tunnel, not over 30 ft. long, and a few open cuts it was impossible to form any estimate of the amount of molybdenum available or to obtain any representative

And Tin Deposits Of Idaho 43

samples. There is undoubtedly a large tonnage of material that can be easily mined, which will average about 1 per cent of molybdenite, and there are certain to be places of local enrichment where the percentage of molybdenite will exceed this figure many times.

If development progresses to a point where concentrates are being produced it would be possible to ship these to Lewiston by scow down the Salmon River, although the risk of loss by capsizing would be very great.

Tin

The principal mineral of tin is cassiterite, the natural oxide of the metal.

This is a brown to black mineral with an adamantine, or semimetallic luster, a hardness of 6 to 7 and a specific gravity of from 6.8 to 7.1, which places it among the heaviest minerals.

It occurs in veins and stockworks, in granite, gneiss and schist often associated with wolframite and scheelite. It is but little affected by the atmosphere and occurs in placer deposits, derived from the veins or lodes, one of the most celebrated of these being the placers of the Shan States and Burmah, in the Malay Peninsula, which have been previously mentioned as producers of tungsten.

The easiest test for tin is to boil the mineral in dilute hydrochloric or sulphuric acid with metallic zinc, when a metallic coatingwill be formed on the mineral, which can be polished bright with the hand and will yield the peculiar and characteristic odor of tin.

The Malay Peninsula is the most important producer of cassiterite in the world, the production of the United States being insignificant in comparison.

In normal times the United States uses between 50,000 and 60,- 000 tons of tin a year and its production of cassiterite does nor usually exceed 200 to 300 tons.

Tin in Idaho

Tin was reported to occur in Lemhi County by Jos. B. Umpleby of the U. S. Geological Survey and the occurrence is described 1 by him.

The district in which the cassiterite was reported to occur was visited by the writer on Aug. 26th, 1918, a day being spent on the ground.

Unfortunately the property was not operating at the time of the visit and had the appearance of having been idle for some time, as the workings were badly caved and washed down, which made proper sampling almost impossible.

Location. The deposit is situated at the junction of Panther Creek, Musgrove Creek and Moyer Creek, which unite to form the

1. U. S. Geol. Survey Bull., 528, p. 74, 1913.

44 Tungsten, Cinnabar, Manganese, Molybdenum,

upper part of Big Creek, an important tributary of the Salmon River. The distance from Salmon, the nearest railroad point, is 35 miles over a very mountainous and rough road. The following tabulation of distances and elevations will give some idea of the grades.

Reading

Barometer

Place Distance Feet

Salmon 4000

Leesburg Summit 9 8400

Leesburg 14 6300

Leacock's 23 5200

Musgrove Creek 35 5700

Topography. The property is situated at a point where there is a decided change in the topographic features of the country- Above the junction of the three creeks previously named, Panther Creek, which occupies the main valley, flows in a broad, flat, wash-filled depression very similar to the valleys of Lemhi Creek and the Pahsimeroi River, which lie on the south side of the Salmon River. Umpleby 1 explains this topography as being due to glacial wash from the mountains having filled the valley, and this is no doubt an important factor. The striking similarity between this valley and the broad washed filled valleys south of the Salmon River lead to the supposition that this may possibly be an elevated portion of a northward continuation of the Pahsimeroi valley, with the Salmon River occupying the fault that caused the separation, and that the effect of glaciation in the structure of the valley of Panther Creek is entirely secondary. Below the junction of Panther Creek with Musgrove Creek the valley is of the typical narrow erosion type of Central Idaho.

Napias Creek also shows a sudden change in slope due to elevation of the country and rejuvenation of the stream, the upper part shows rounded and mature topography with the stream occupying a comparatively broad depression filled with gravel, most of which has been placer mined for gold. A mile or two below Leesburg, Napias creek plunges into a steep walled canyon and has a fall of between 200 and 300 ft. to the mile, forming a succession of falls and rapids to its junction with Big Creek.

Tin Deposits. The gravel deposit in which tin was reported to occur occupies a flat of about 20 acres, at the junction of the th;ee creeks just mentioned. This flat extends up Musgrove creek a short distance and there are undoubtedly many similar gravel bars on Panther Creek above, this point.

About 3 to 6 ft. of gravel containing medium sized boulders lies on top of a slate bed-rock which is very similar in appearance to the Prichard slate of the Coeur d'Alene region.

1. Op. Cit., p. 40.

And Tin Deposits Of Idaho 45

Considerable work was done several years ago, consisting of a bed-rock flume or drain built from the junction of Meyer Creek with a length of about 200 yards, a ditch from Panther Creek giving a head of about 50 ft. and a flood-gate on Musgrove Creek. Several hundred cubic yards of gravel were washed.

A considerable amount of gravel was panned by the writer but did not show the presence of cassiterite and only a small amount of gold. As tin has been reported both by Mr. Umpleby 1 and Mr. R. N. Bell, State Mine Inspector, to occur here, the writer evidently failed to locate the channel containing it due to lack of a guide familiar with the property. To prospect the ground properly would necessitate either the digging of pits in a systematic manner across the gravel bar or the employment of churn drills in a similar way.

Antimony

By Francis A. Thomson.

Antimony is a silver-white, shining, brittle metal. It has a specific gravity of 6.8 and its atomic weight is 120. Its most notable characteristics are its fusibility, (melting point 630° C.) and the volatility of its oxide and sulphide.

Antimony is occasionally found native. Various oxides and oxysulphides of yellow to reddish color are frequently found in the outcrops of antimony deposits.

Stibnite, the sulphide (Antimony 71 per cent, Sulphur, 29 per cent) is practically the only mineral which is mined for its antimony. It is a soft, brittle, shining, lead-gray mineral which readily tarnishes to a bluish-black. It occurs frequently in long-bladed crystals or aggregates which are usually deeply grooved or striated lengthwise. Stibnite is easily fusible, thin splinters melting in an ordinary candle flame. Heated on charcoal with the blowpipe, stibnite gives a dense white coating on the coal and yields fumes of sulphur dioxide.

There are many ores, particularly those of copper, lead and silver, which carry appreciable amounts of antimony, but none of them -are regarded as antimony ores, although small quantities of antimony are recovered from them as a by-product of lead and copper smelting.

Antimonides or sulph-antimonides of nearly all the metals occur in nature, none except those of copper, lead and silver are of any economic significance.

The following statement of uses and production of antimony is taken from "Antimony in 1916" by Edson S. Baston. 2

Uses op Antimony Metallic antimony unalloyed has few industrial uses. In the form of fine powder, known as "iron black," it is used for produc-

1. Op. Cit., p. 74. 2. U. S. Geol. Survey, Mineral Resources 1917, part 1, pp. 725-729, 1918.

46 Tungsten, Cinnabar, Manganese, Molybdenum,

ing the appearance of polished steel on articles made of papiermache or pottery. For these purposes it is precipitated by the action of metallic zinc on an acid solution of antimony salts. Antimony alloys readily with most heavy metals, the alloy being- harder than the two pure metals and also in most cases, possessing the property of slight expansion on solidifying. Type metal is an alloy of antimony, lead, and tin; babbitt, antifriction, or bearing metal is usually an alloy of antimony, tin and copper. Britannia metal, also known as "white metal," is an alloy of antimony, tin and copper, with some zinc and, rarely, small quantities of other metals. It is used in making cheap domestic tableware, teapots, spoons, etc. Antimony alloys find minor utilization in battery plates, toys, cable coverings, etc. Leadantimony alloy or hard lead is used in making "acid resisting valves. .

White antimony oxide, mainly the tetraoxide (Sb 2 4 ) is used for making opaque white enamel and other sanitary ware. In this use antimony oxides compete with tin oxide. Antimony oxi: 1 :, mainly trioxide, is used as a coloring agent in manufacture of glass, as it is more readily fusible than tetraoxide and does not impart opacity to the glass. Antimony oxides are further used as paint pigments.

The red sulphides of antimony are used in vulcanizing and coloring red rubber, and also as paint pigments. The natural antimony trisulphide, stibnite, enters into the composition of safety matches or the compound is put on the match box.

Antimonate of lead containing an excess of lead oxide, known as "Naples yellow," is used in oil paints and in the glass and ceramic industries. The antimony salt, tartar emetic (double tartrate of antimony and potassium) and antimony fluoride are employed as mordants in dyeing. Tartar emetic and antimony trioxide are employed medicinally.

Antimonial lead carrying 12 to 13 per cent of antimony is employed in the manufacture of shrapnel bullets. Smaller quantities of liquated antimony sulphide are used in the primers of shells. For this last purpose it is claimed the material must carry less than 2 per cent of impurities insoluble in hydrochloric acid. Antimony sulphide as a powder is used in the charge of some shells to produce on explosion a dense white smoke which is of service in range finding.

U. S. Production

The production of antimony ores in the United States in 1916 according to the best information available, was about 4500 short tons, valued at $40,580. The metallic antimony content of this material was about 1770 short tons'. The average tenor of the ore in metallic antimony was therefore about 40 per cent.

The principal producing states in order of importance were Nevada, California, Alaska, Washington, Oregon, Idaho and Arkansas. Utah and Arizona produced insigficant amounts.

And Tin Deposits Of Idaho 47

In Nevada the principal producing districts were in Humboldt, Lander, and Elko counties, although minor amounts were produced in Churchill and Nye counties. The Sutherland mine, near Lovelock, Humboldt County, was the principal producer. Development work was in progress at the Star Antimony mine, operated by J. M. Pine, near Battle Mountain, Lander County. Development work was in progress also at the Antimony King mine, near Austin, Lander County, operated by the Nichols-Layng Chemical Co., of San Francisco.

In California the production came mainly from Kern and Inyo counties, minor amounts being produced in San Bernardino and San Benito counties. The greater part of the output was from two mines in Inyo and Kern counties, operated by the Western Metals Co., of Los Angeles, the ore being shipped to San Pedro, near Los Angeles, for smelting.

In Washington the antimony was produced at the property of the Gold Creek Antimony Mining & Smelting Co., near Methow, in Okanogan County. This property was until recently involved in litigation, and the production in 1916 was made by the unsuccessful claimants. A small production was also reported from the Wienatchee district, Chelan County.

In Oregon the production came largely from Baker County, the Jim Dandy mine, near Baker City, being the principal producer. The product from this mine is understood to be mainly oxide ore. A small production of mixed stibnite and oxide ore was reported from the Palmer Creek district in Jackson County.

In Idaho the production was all from Shoshone County, although prospects are known in Blaine, Custer and Idaho counties. The production in Shoshone County was mainly from Pine Creek, in the Yreka district.

In Arkansas one property at Gillham, Sevier County, produced a noteworthy output of ore in 1916 and also produced a small quantity of metallic antimony at a local reduction plant.

In Utah the antimony ore mined came from Box Elder County.

In Alaska the production was mainly from the Fairbanks district, with small quantities from the Nome district, the ore being shipped to Los Angeles and Seattle for smelting.

In contrast to the small domestic production of antimony ore — about 4500 short tons — the total imports in 1916 amounted to 7764 short tons of antimony ore and 9876 short tons of metallic antimony.

Foreign Production

Bolivia.— Antimony mining in Bolivia has undergone rapid expansion since the beginning of the war. Prior to 1915 production appears not to have exceeded about 300 tons in any one year; in 1915 it rose to 17,923 tons, and in 1916. according to the American

48 Tungsten, Cinnabar, Manganese, Molybdenum,

legation at La Paz, it reached 27,414 tons. Great Britain is known to have purchased large quantities of Bolivian ore, and only a small percentage of the production has come to the United States. According to the Western Metals Co., of Los Angeles, an analysis of high-grade ore from one of the principal Bolivia producers showed antimony (Sb) 66 per cent; silica (Si0 2 ) 7.25 per cent; iron oxi ie (FeO) 1.32 per cent; lime (CaO), 2.6 per cent, and sulphur (S), 14.04 per cent.

China. Southern China has long been the principal producing district in the world for antimony ores, and at present is the main source of supply for this country. The most important deposits are in the Province of Hunan, where the largest smelting center is Changsha.

According to the United States consul general at Shanghai, the exports of antimony ore from China in 1916 were 81,964 tons, as against 1,843 tons in 1915, and of liquated antimony sulphide and metallic antimony (crude and regulus) 24,740 tons, as against 23,931 tons in 1915. Of the exports lumped in one classification as crude and regulus the larger part was probably crude. In 1915, for example, the exports were 10,664 short tons of crude and 2,115 short tons of regulus. The crude or liquated sulphide carries from 68 to as high as 76 per cent antimony.

Portugal. Imports credited to Portugal in 1916 probably came from the Oporto and Braganza districts, where are located the principal antimony deposits of that country. The total exports of antimony ore from Portugal in 1916 were 4,330 tons.

In 1914 normal prices were maintained until the outbreak of the war, when the price rose from an average of 7.2 cents in July to 17.2 in August.

The price at the beginning of 1916 was about 42 cents a pound, from which it rose to 46 cents in March and then declined steadily to about 1 1 cents early in October. Later there was a slight recovery to about 15 cents at the close of the year. The decline was the result of overproduction in China, which flooded the American market with the Chinese products. With these the American antimony miners soon found themselves unable to compete, and the latter part of the year witnessed a great decline in antimony mining in this country.

Metallurgy

Owing to the extreme fusibility of stibnite the metallurgy of antimony is in most respects decidedly simple. Antimony matte or liquated antimony is produced by the simple process of subjecting the ore to a dull-red heat in a reducing atmosphere, when the antimony sulphide is melted or "liquated" away from the gangue. This "crude" or "needle antimony" is run into molds, cooled and shipped to the refinery.

And Tin Deposits Of Idaho 49

To produce antimony metal, or "regulus" direct from the ore it must first be roasted under conditions of careful temperature regulation for the production of antimony oxide, and the roasted product is then smelted in a reducing atmosphere to slag and metal. Antimony matte is sometimes refined by wet processes, also by resmelting in crucibles with metallic iron resulting in the production of metallic antimony and iron matte.

Antimony in Idaho (1) Valley County. Deposits of antimony have been known for several years on the southern rim of Yellowpine Basin near the center of Valley County.

The basin itself is formed by the confluence of Profile Creek flowing in from the north, the East Fork of the South Fork of Salmon River flowing from the eastward, and Johnson Creek flowing in from the south. The antimony ore is found about four miles from the mouth of the last named stream and the same distance south of Yellowpine postoffice.

The district lies about 15 miles west of Cinnabar (see p. 55), and the antimony and mercury ores are probably related genetically.

The properties are reached by wagon-road, some 60 miles in length from Cascade, a station on the Long Valley branch of the Oregon Short Line. This road leaves the road to Cinnabar camp at the crossing of Johnson Creek. For about half the distance the road is fair and for the other half decidedly bad, furthermore, several summits are crossed which are deeply covered with snow six months in the year. At the present time the district has neither telephone, telegraph nor mail service; there is a weekly stage and the stage driver carries mail if so disposed.

Freighting costs 3c per pound from the nearest railroad point, and winter transportation is precarious and subject to much interruption. A more feasible road-route could doubtless be found if road construction were justified.

Geology. The general geology is simple, the country rock being the biotite granite characteristic of the Central Idaho region. Dikes of pegmatite, aplite and complimentary basic dykes are in evidence, and there are the usual magmatic quartz veins usually goldbearing, in connection with which and with the pegmatite the antimony ore occurs, the whole occurrence being entirely regular and normal. There are places, however, in which the stibnite appears as patches or islands in the granite in a manner which suggests a direct replacement, such an occurrence is unique as far as the writer is aware and deserves further study as a problem in ore-genesis.

The antimony mineral is of course stibnite as has been stated, it is very clean and free from admixture of other sulphides. The sul-

50 Tungsten, Cinnabar, Manganese, Molybdenum,

phide ore reaches practically to the surface, there being- nothing more than a mere skin of the oxides of antimony.

The Ore Deposits. It is convenient for purposes of discussion to divide the district into the east side and the west side respectively of Johnson Creek.

The east side deposits on which development work has been done, appear to consist essentially of two or perhaps three distinct quartz-stibnite veins. One of these striking north, is traceable for 4000 ft. in the course of which, as exposed in frequent cross-trenches, it shows from 6 to 18 in. of clean stibnite. The lowest exposure on this vein is 1700 ft. above Johnson Creek. Just beyond the point where this vein should cross over the ridge parallel to Johnson Creek and 2300 ft. above it, and on the eastern slope of the ridge is the most important exposure on the east side. Here, due possibly to the intersection of a system of linkage veins are several lenses of practically clean stibnite, the largest one of which has a maximum width of 5 ft., a length of 30 to 40 ft., and an undetermined depth, possibly 15 or 20 ft. The ore here shows both the quartz-stibnite vein type of deposition and an irregular replacement or segregation occurrence in the surrounding pegmatite-granite formation. This rather remarkable ore-shoot or concentration has been poorly developed and badly gutted by underhand stoping from a grass-root tunnel by previous operators, who are said to have shipped several cars of ore to Chicago from this point. The logical method of development here would be by an adit-tunnel further down the eastern slope.

As to the croppings of the continuous exposure on the western slope these can bo tapped by an adit-tunnei on the vein and fair depth will be gained. A short adit which, however, missed the vein at the portal and diverged from it as it progressed, has been started, but common sense development here would give valuable information and a depth of perhaps 20 to 25 ft. per 100 ft. driven would be gained.

Altogether the showing on this side of the creek is favorable and abundantly justifies vigorous development.

While on the east side the valley is quite flat and then rises by gentle slopes to the summit, on the west side the cliffs rise abruptly from a steep talus slope which reaches practically into the creek bed. Whether this cliff represents a faultscarp or merely defines a zone or rib of weather-resistant material, I am unable to say. The material composing this cliff has been designated quartzite, pending the examination of a thin section, the writer is inclined to classify it as aplite or alaskite, or possibly a silicified phase of the granite formation. In any event, the significant thing is, that distributed apparently sporadically both vertically and horizontally over the face of this cliff which is a mile long and 500 ft, high, there are patches and bunches of stibnite, and in the

And Tin Deposits Of Idaho 51

talus slope at the foot are great boulders of three or four tons, some of which contain at least 25 per cent of the same mineral.

No work has been done, and one of three explanations is possible, (a) that the face of the cliff represents one wall of a vein or dike in which the stibnite occurs in small, irregular shoots; (b) that there is a series of veins or dikes intersecting the face of the cliff and that the stibnite lies in these, and (c) that the stibnite lies in segregated bunches throughout the general rock-mass of the cliff. Subject, of course, to further data to be furnished by development, I am inclined to the last hypothesis, some confirmation of which is furnished by the fact that country-rock samples on the east side show over one-half per cent antimony due to small specks of stibnite visible under the microscope. It is conceivable that the entire mass of this great cliff may prove to be of sufficient grade to justify large scale mining followed by water concentration for which all natural facilities are at hand.

Sampling Results. The following assays and analyses on samples taken, are included rather as qualitative than as quantitative data. Some rather extravagant claims were made as to gold values in the stibnite; these are not substantiated by the results obtained. 1 Sample No. Description Gold Silver Antimony

1 Average across 1 ft. in tunnelstope on Idaho claim (Nowak

property.) None 0.1 oz. 40.4%

2 Average across 2 ft. in best lens

in same working Trace 4.7 oz. 43.5%

3 Granite country rock between

quartz veins in above workings None None oz. 0.54%

4 . Representative samples of bluff

deposit taken by chipping typical exposures None Trace oz. 4.20%

Selected particles of high-grade were segregated from No. 1 to give an indication of what might be expected by concentration or segregation.

Results were as follows :

Antimony, 63.10 per cent; Arsenic, none; Lead, none; Sulphur, 25.50 per cent; Iron, 0.56 per cent; Insoluble, 2.7 per cent.

(Doubtless the balance of the sample consists mainly of the more soluble felspathic portion of the gangue.)

Present Operations. The east side deposits are held under lease from the Idaho Antimony Mining Co., by Frank Nowak, Inc., a concern which it is understood is controlled in Chicago. The present operators, for whom Mr. Frank Nowak is in charge on the

1. Analyses made by the Seattle Station of the U. S. Bureau of Mines.

52 Tungsten, Cinnabar, Manganese, Molybdenum,

ground have done a small amount of development work and have completed a "go-devil" road some three miles long to their oretreatment plant. This plant is situated near the river and in an airline perhaps a mile from the east side workings. It consists of a Stroud disintegrator for crushing the ore, a small mechanicallyrabbled flat-hearth dryer operated by a one horse-power engine, and a small liquation furnace. In addition the plant is equipped with a standard Wilfley table, the place of which in the flow-sheet was not clear to the writer. The plant is expected to have a capacity of one ton per day.

The west side deposits are owned by Mr. Albert Hennessy of Yellowpine, who is holding them in the hope of their being developed by outside parties.

In conclusion, it is evident from the foregoing that the Yellowpine antimony deposits are of exceptional purity and offer considerable promise if ever transportation becomes available. To market a metal worth only 5 to 10 cents a pound, however, under present conditions appears to the writer practically out of the question.

There is some disposition locally to regard the antimony deposits as necessarily superficial in nature and unlikely to extend more than a few hundred feet in depth. There seems no justification from any point of view for such a conclusion.

It is easily conceivable that the west side deposits may prove in time to be the more important, meanwhile the east side offers the greater promise to small operators, but of course far more development even on these is necessary, before definite conclusions as to the extent of these deposits can be drawn. Such development is in the writer's opinion abundantly justified provided the product could be profitably marketed.

Antimony ore of similar character to the foregoing is reported at Cinnabar, also near Edwardsburg in the same county.

(2) Shoshone County. The occurrence of antimony ore on Pine Creek, a tributary of the South Fork of Coeur d'Alene River, has been known for many years.

The Coeur d'Alene Antimony Co. is operating a property which has been worked intermittently for 20 years and in that time has produced approximately 2000 tons of ore containing 500,000 pounds of antimony metal.

The property is at present being operated by a company of which Mr. M. E. Jolly, of Davenport, Wash., is president and manager. For convenience of access, no mine could be better situated, as it lies on the western edge of the wide valley at the mouth of Pine Creek and within a few hundred yards of the main line of the O.-W. R. & N. Railway, between Harrison and Wallace, and about a quarter

And Tin Deposits Of Idaho 53

of a mile from Kingston Station on this line, Kingston being about five miles west of Wardner-Kellogg.

The vein is apparently a fissure striking N. 45° W, and dipping 45° to the southeast. The country rock is Prichard slate. Adequate inspection of the property was rendered almost impossible by the condition of the underground workings, the mine having been largely in the hand of leasers with the inevitable result that timbering was neglected and practically all the workings were caved. Enough was seen, however, to show that south of the incline shaft, on the 75 and 150-ft. levels, a shoot of stibnite ore from 6 in. to 2 ft. in width had been developed for a length of perhaps 100 ft. It was also stated that 200 or 300 ft. north of the shaft an ore-shoot had been found near the surface which had not been developed below.

At the time the property was visited a drift to the south on the vein at the 250 ft. level was being run to tap the south ore-shoot, but at last accounts the ore had not been reached. While the vein on this property is not large and the ore-shoot is decidedly "lens" and likely to be somewhat erratic in its variations, due largely to the formation in which it occurs, there seems no reason why a vigorous policy of development should not result in opening up a good tonnage of medium-grade ore. The property is so favorably located that transportation and mining costs should be a minimum and if a reasonable price for the product could be assured it should be possible to operate at a profit.

Of course, in common with other American properties, it may be impossible without a protective tariff to compete with Bolivian :and Chinese antimony when shipping becomes available.

The property is equipped with a concentrating plant, consisting largely of jigs, with one Wilfley table and two K. & K. flotation machines. From the 500-ton pile of ore outside the mill, coarse concentration would hardly seem to be indicated as the proper treatment.

The Star Antimony Property is situated on the ridge above Masonia some five miles up Pine Creek. This property was not visited but from descriptions received it would appear to be similar to the one just described, except that it lacks the favorable situation.

In Idaho County, just off the wagon road between Orogrande and Elk City a property in Deadwood Gulch was visited. From a hasty inspection in a 10 ft. prospect hole it appeared to be quite similar to some of the Yellowpine deposits, being a replacement of the granite adjacent to a quartz vein. The remoteness of the deposit from transportation excludes it from consideration at present.

Stibnite is reported in considerable quantities in Blaine County in the Sawtooth Range, also in Custer County.

54 Tungsten, Cinnabar, Manganese, Molybdenum,

Chapter Iii Qucksilver

Quicksilver or mercury, the physical properties of which are toowell known to need description here, is used chiefly in the manufacture of fulminate for explosive caps or detonators used in blasting,, shells, etc. Consequently the war has caused a heavy demand for this metal. It is also used for making vermilion paints, in drugs, for electric lighting apparatus, scientific apparatus and in the beneficiation of gold and silver ores. 1

There are a number of minerals which contain mercury, most of them rare, and of little economic importance. The most important economical mineral of quicksilver is cinnabar (HgS) mercuric sulphide. It is a brilliant cochineal-red mineral with a scarlet streak,, a hardness of 2 to 2.5 and a specific gravity of 8.0 to 8.2 and contains when pure 86.2 per cent of mercury. It occurs associated most commonly, in veins or replacements, with pyrite and marcasite and the sulphides of antimony and arsenic. When quicksilver occurs in the form of cinnabar it is probably the easiest of all sulphides to reduce to the metallic condition. All that is required is heat produced by some reducing agent as charcoal or coke and the mercury can thus be distilled off in retorts. Quicksilver furnaces, therefore, -ire cheaply erected, being usually in small units of simple construction. As it becomes necessary to work lower and lower grade oresthere will undoubtedly be a change in the present metallurgical practice which has advanced but little, compared with the metallurgy of lead and copper for example.

Quicksilver is like gold and silver in the fact that the finished product is highly valuable per unit of weight and can accordingly be worked in remote regions where less valuable metals, such as lead and copper, could not be profitably extracted.

Production of Quicksilver

Spain, with an annual production of over 40,000 flasks of 75- lbs., is the greatest producer of quicksilver. The last year in which complete statistics are available is 19 13 2 and this year shows a total' world production of 124,654 flasks, Spain producing 43,799; Italy, 29,513; Austria-Hungary, 26,720; United States, 20,213, and Mexico and other countries, 4,140. Of the 20,213 flasks produced in the United States in 1913, California produced 15,591, or over 77 per cent; Arizona, Oregon and Texas, 2,977, and Nevada, 1,645. In 1915 California produced a little less and the others somewhat more than in 1913, giving California 68 per cent of the country's production.

U. S. Geol Survey Mineral Resources of the United States, part 1, p. 889, 1911. 2. U. S. Geol. Survey Mineral Resources of the United States, p. 274, 1915.

And Tin Deposits Of Idaho 55

Summing up the quicksilver situation; the United States is an important world producer of this metal and in the United States, California produces about 70 per cent of the total output.

New discoveries of quicksilver are rare, and the demand for it, even after the war, is not likely to fall off to any great extent, and it would seem unlikely that the price will drop below $100 per flask for some time to come.

Tenor of Quicksilver Ores In 1915 there were treated in California 129,521 tons of ore from which 14,283 flasks of quicksilver were obtained. This gives an ore content of 0.4 per cent or 8 lbs, of quicksilver per ton, extracted. No figures are available as to the percentage of quicksilver extracted from the ore, in other words, of the saving effected. The value of the ore mined and treated in California during 1915 was $1,174,881.00, almost exactly $9.00 per ton, with the average price about $80.00 per flask. The yield per ton of the ore mined in Nevada during the same year was also 0.4 per cent of quicksilver.

Fern Creek Cinnabar District Field Work and Acknowledgments, Etc. The Fern Creek district was visited by the writer early in August, 1918. It was understood in the spring that Mr. F. L. Ransome, of the U. S. Geological Survey, would visit this district and it was the intention to endeavor to make the examination jointly with him if this could be arranged. Mr. Ransome did not come west and the director of the Survey was unable to give any definite information as to when a representative would visit the district, so the writer decided that as the district ought to be examined and reported upon, the trip was made independently of the Geological Survey. Mr. E. S. Larsen, of the Survey, visited the district several weeks after the writer which unfortunately caused duplication that might have been avoided.

Ten days were spent altogether on the trip after leaving Cascade, five of which were spent in traveling and five in the district. Of these five days, two were spent in examining the different prospects and workings and the other three in the construction of a geological map in the vicinity of the Fern mine.

Acknowledgments are due to Mr. Walter Hovey Hill for the claim map of the district and also for the excellent detailed map of the workings and geology of the Fern mine. Acknowledgments are also due to the various operators of the district for their assistance, and particularly to Mr. E. H. VanMeter for personal courtesies and invaluable assistance to the writer during his stay in the

Location and Roads. This district is situated in Valley County in unsurveyed territory in what is almost the geographical center of Idaho It is in the Yellowpine mining district and about seven miles

56 Tungsten, Cinnabar, Manganese, Molybdenum,

from the once prosperous but now water-covered town of Roosevelt, the former metropolis of the once celebrated Thunder Mountain gold camp.

It is reached from Cascade, the county seat of Valley County, which is on the Long Valley branch of the Oregon Short Line. A wagon-road extends from Cascade to the district, a distance of about 70 miles. This road was built during the Thunder Mountain boom, some 15 or 16 years ago, and since that time has had little work done on it, so on the whole it is in a bad condition. An automobile in good running order can go as far as Knox, which is about 26 miles, but beyond that point it is not practicable for cars on account of high centers, sharp rocks and excessive grades. Between the railroad and the mines in the Cinnabar district four summits have to be crossed; the following figures give the elevations along the road at different places, taken with a barometer going in and checked coming out. The distances are only approximate.

Place Distance Barometer

in mi. ; approximate. readings.

In Out Av'ge.

Cascade 4750 4800 4775

Summit b'tw'n Knox and Cascade 18 6500 6400 6450

Knox, near S. Fork of Salmon R. 26 5100 5200 5150

Cabin Creek Summit 31 6800 6900 6850

Half-way House 38 5800 5700 5750

Johnson Creek Bridge 42 5100 5300 5200

Trapper Creek Summit 54 7650 7850 7750

Reardon Creek Crossing 56 6750 6850 6800

Reardon Creek Summit 60 8100 8300 8200

Fern Creek Camp 70 7900 8100 8000

J. P. Smith's Cabin on Cinnabar

Creek 72 7200 7200

After Reardon Creek summit is reached the road follows the high ridge forming the divide between the South Fork and Middle Fork of the Salmon River, which is evidently a remnant of the original plateau from which, according to Umpleby 1 the central mountain region of Idaho was carved.

The road is rough but interesting, both from a scenic and geological point of view. Soon after leaving Cascade glacial morainal deposits are encountered containing many large granite boulders. The country lying between the North Fork of the Payette River and Johnson Creek was evidently ice-covered in the glacial period, with ice tongues extending well down into the valleys, and is part of a region which was evidently covered by a local glacier of considerable area. The center of this glacier appears to have been somewhere in

1. U. S. Geol. Survey Bull. 528, pp. 23-30, 1913.

Hl

pp

1m

Hanging Valley, on Johnson Creek.

Buildings at Fern Aiine, Valley County.

And Tin Deposits Of Idaho 57

the rugged granite mountains that form the divide between the North Fork of the Payette River and the South Fork of Salmon River. Morainal deposits extend down to Long Valley from this glacier, as well defined drumlins (gravel ridges deposited by glaciers) extend some distance into the east side of the valley a few miles south of Payette Lake, and this lake itself has been formed by the blocking of the valley with morainal material. Upper Payette Lake has also been formed by the damming of the North Fork of the Payette River by a moraine from the mountains to the east. This glacier evidently also covered the rugged mountain area lying between Payette Lake and the Little Salmon. It did not extend as far north as the Salmon River as there is no evidence of glaciation in the Warren district. Small local glaciers of the alpine type existed in all the higher mountains of Central Idaho, the Fern Creek camp itself being located in an old glacial cirque, but this particular area seems to have been covered by ice of considerable extent and thickness. It is interesting to note that this is a region of heavy snowfall at the present time, which might be a possible clue to the glacial conditions in the past. This region offers an interesting field for study in local glaciation and it is hoped that at some future time it may be more thoroughly investigated.

It is difficult to see how the grades on the present road could be much improved without spending nearly as much money as a new road would cost. The grade over Cabin Creek summit could be lessened by some more switch-backs on the Cabin Creek side, thereby lengthening the distance to the summit, and the same is true on the other side though the grade here is not excessive. The grade from Johnson Creek to Trapper Flats could have been lessened by striking Trapper Creek lower down, as considerable grade is lost by rising too high and then coming down hill to the crossing of Trapper Creek. This would be very expensive and would entail rebuilding several miles of road. The worst grade on the road is from Trapper Creek summit down to the crossing of Reardon Creek and except for the avoidance of rock-work seems to be entirely unnecessary. Parts of this grade are in excess of 20 per cent, and it is a physical impossibility for a team to haul much more than an empty wagon up this hill. The grade from Reardon Creek to the Reardon Creek summit is bad but not so steep as on the other side of Reardon Creek and as mentioned above, both these could have been practically eliminated by crossing Reardon Creek a mile or so further up.

It is unfortunate that this new cinnabar camp is handicapped with such a road, for though the country is mountainous and rugged, it would have cost but little more in the first place to have built a road with no grade exceeding 10 to 12 per cent if it had been put in the right place to begin with, whereas now, there, are many

58 Tungsten, Cinnabar, Manganese, Molybdenum

places on the road where the grade exceeds 20 per cent and some probably as high as 25 per cent.

Most of the freighting is done by the day and there were no teams hauling by contract, but the cost of freight to the camps, figured from the time necessary to make a round trip, is in the neighborhood of $100 per ton, or 5 cents per pound.

History. Cinnabar float was discovered in Cinnabar Creek, a tributary of the East Fork of the South Fork of Salmon River, during the Thunder Mountain boom in 1902 by Pringle Smith.

Mr. Smith discovered the vein from which this float came and located three claims known as the Hermes group, upon which he has faithfully performed his annual assessment work ever since. After the Thunder Mountain excitement died down the district was deserted and until 1917 Mr. Smith was for. many years the only prospector or resident in this inaccessible and lonely region, except for an occasional sheep-herder.

In 1917 Mr. E. H. Van Meter, a well-known mining man of Central Idaho, and a former partner of Mr. Smith, located the Fern group of claims on the other side of the ridge from the Hermes group and adjoining these claims. He erected a small retorting furnace and began extracting quicksilver. His success resulted in a number of men coming into the district and locating ground, particularly in the spring of 1918. Although there are many legitimate locations among the more recently staked claims, the majority are entirely worthless- and were staked with the sole intention of holding ground which somebody else's work might make valuable, a mineral discovery being entirely a secondary matter. The result has been detrimental to the district, as several experience prospectors who came in during the summer of 1918 turned back in disgust when they found the whole country covered with locations, many of which were made in the snow.

In the summer of 1918 the following claims were being operated: The Fern group, by Mr. Van Meter; The Hermes group, bonded from Mr. Pringle Smith, was being worked by Mr. Oberbillig, of Boise; The Buckbed group, owned by the Marks Bros, and associates of Boise, was being worked by Mr. Ray Call, and the White Metal group adjoining the Buckbed, was being worked by Mr. George C. Brewer.

With the exception of the Hermes group all of these properties are located on the east side of a high ridge separating the heads of Fern and Cinnabar Creeks, both of which are tributaries of the East Fork of South Fork of Salmon River. The buildings of the Fern property occupy a glacial cirque, or basin, at the head of Fern Creek.

Topography. The Fern Creek camp is situated close to the divide between the South Fork and the Middle Fork of the Salmon

And Tin Deposits Of Idaho 59

River. This divide has an average elevation of between 8000 and 8500 ft. with occasional points or mountains upon it with elevations up to 9000 ft. or more. Nearly all the claims in the district lie upon the South Fork side of the divide. The topography is very similar to that which prevails all over Central Idaho and consists of steep sided canyons separated by high ridges, some of which are flat topped, showing the present shape of the country to have been derived from the elevation and subsequent erosion of a rolling plateau.

This high region was occupied by local glaciers during the Pleistocene or Glacial period. These glaciers did not apparently cover the whole of the region, as they must have done further to the west, but consisted of small disconnected alpine glaciers along the high ridges. These glaciers have formed many cirques or circular amphitheater-like depressions at the heads of the creeks.

The creek valleys below these cirques are U-shaped and the floors of the valleys are covered with glacial wash.

Geology. Rocks of the District. The district is underlain by a series of steeply tilted and highly metamorphosed sediments consisting of quartzites, limestones and schists, intruded locally by quartz porphyry dikes and also by outliers of the great granite batholith of Central Idaho.

The age of these metamorphics is uncertain as no definite fossils were noted. Certain crushed and deformed white objects in the crystalline limestone may possibly be crinoid stems, but this isextremely doubtful. The metamorphics are older than the Cretaceous period, as they are intruded by granite of that age, and are probably of the same age i. e. (Lower Paleozoic) as the sediments at Gilmore and other parts of Lemhi and Custer counties, but this is merely a supposition.

The outcrops are best seen on the ridges along the heads of the old glacial cirques. The depressions occupied by the streams are filled in many cases with glacial debris and the outcrops are somewhat meager. Map No. 5 gives, in a general way, the topography and geology covering about four square miles and shows the main geologic relations. It makes no pretense of extreme accuracy, as it was made in less than three days by means of a pacing and compass survey with a traverse board, using a barometric base for the elevations.

The claim maps and map of the Fern Creek workings were made by Mr. Walter Hovey Hill, of Boise, a Mineral Surveyor and mining engineer, who spent several weeks in the district surveying claims for patent, and are consequently accurate maps.

In mapping the geology the ridge between Sugar Creek and Fern Creek was followed and also the ridge between Sugar Creek and the East Fork of the South Fork of Salmon River. On both these ridges the same sequence of formations was found, and the

60 Tungsten, Cinnabar, Manganese, Molybdenum,

same sequence has been mapped as occurring in the intervening- lower ground, though this is largely covered with morainal material.

Taking these formations in order from the north to south, they consist first of a purplish to gray shaly limestone, which outcrops on the ridge northwest of the Hermes group and is also found in the workings of those claims. It occurs in narrow bands or beds with well marked bedding-planes and its .thickness is not known.

Next to this is a massive crystalline quartzite, sugary in appearance and varying in color from white to almost black in places. It is heavily iron stained and being very hard and less easily weathered than the other rocks of the district, has remained in the form of steep bluffs along the cirque walls. It contains small gash veins of quartz in places, many of which were staked in the Thunder Mountain boom. It has a thickness of about 2000 ft.

South of this is a micaceous schist containing bands of green hornblende, which gradually grades, in going south, into a limey slate of purplish color with hard cherty bands. This slate is considerably contorted, the bands being crumpled into a complexity of folds. Its thickness is from 700 to 800 ft.

Next to this comes a yellowish and highly crystalline soft limestone, which weathers and disintegrates into a yellowish sandy soil, giving more easy slopes to the mountain side. This contains in places some crushed and flattened white objects that may be crinoid stems. The cinnabar ore of the Fern and adjacent properties occurs in this limestone. Between this and the slates lies a bed or sill of almost pure tremolite, or white fibrous hornblende, with an average width of 10 ft., and apparently very persistent, as it outcrops on both ridges and also between the ridges at the head of Cinnabar Creek. The thickness of the yellow limestone is about 500 ft.

South of the limestone is a massive quartzite conglomerate with quartz pebbles up to 2 or 3 in. long. This grades into a massive gray crystalline quartzite and further to the south the conglomerate again shows with a total thickness or outcrop width of from 2500 to 3000 ft.

South of this the same soft yellowish limestone as appears at the Fern property comes to the surface. It is somewhat shaley in places, but is undoubtedly the same rock. Time did not permit further exploration to the south to see if any of the other formations were repeated, but the indications point to an eroded fold with the quartzite and conglomerate probably the lowest members of the series.

The igneous rocks in the area embraced by the map are not quantitatively important and occur in only a few places. Further to the east the country rock is made up largely of certain effusives of different kinds, many of them in layers, or flows, one of the best examples of which is Rainbow Peak, which derives its name from

Map 3

Cinnabar

Yellow Pine Mining Dist.

Valley County

Idaho

And Tin Deposits Of Idaho 6L

the red and yellowish bands of igneous rock of which the mountain is made up. To the west the big granite batholith comes to the surface, and the particular area in which the cinnabar occurs lies between these two, and is either an uneroded remnant of metamorphosed sediments or else a part of the sediments that escaped the lava flows of the Tertiary period. It is undoubtedly underlain by the granite at no very great depth. In the southwestern part of the area a tongue of granite intrudes the yellow limestone. It is identical with the granite found elsewhere in Idaho and described in other publications and is a high point or outlier of the big mass of this rock to the west.

In the neighborhood of the Fern mine several dikes of quartz porphyry occur. A similar rock is seen in the Hermes group to the north, one of these dikes being cut by the middle tunnel on this property. This tunnel passes through 16 ft. of porphyry which is very much decomposed and appears to be in the form of a sill with blue lime on the footwall and yellow crystalline lime on the hangingwall side.

A dark, fine-grained basic dike rock is seen on the trail between the Hermes group and the Fern mine. This same rock can also be seen on the ridge west of this trail and is probably continuous for some distance below the morainal material piled up at the mouths of the cirques.

The most important of these igneous rocks would seem to be the quartz porphyry, as it is an accompaniment, wherever it occurs, of the cinnabar mineralization. This, of course, may be merely a coincidence, but it is difficult to recognize it as such, and indications point to the suggestion that the solution that brought in the cinnabar had their origin in the same volcanic source as that which formed these dikes.

Ore Deposits

Fern Mine. This is situated at the head of Fern Creek in a glacial amphitheater. Cinnabar occurs in chalcedonic quartz seams in the soft, yellowish limestone already described. These seams vary in width from a few inches up to 3 or 4 ft. Several of these seams outcrop over a width of about 50 ft., most of them containing cinnabar ore of good grade. These cinnabar seams or veins are irregular in their occurrence and are evidently replacements of the limestone by mineral-bearing solutions. Although irregular in size, they seem to be fairly persistent where followed along their strike, as one of them has been followed for a distance of about 80 ft. by a tunnel and showed 2 ft. of ore in the face that contained 3.8 per cent of mercury.

The general strike of these seams on the Fern property is about N. 35° E. with a dip to the northwest. This strike is almost at right angles to the general strike of the metamorphic beds. The mineral-

62 Tungsten, Cinnabar, Manganese, Molybdenum,

ization of these deposits is very simple as cinnabar is the only sulphide mineral present and the gangue is a chalcedonic quartz full of vugholes and containing in some cases a reddish chert or jasper. "The limestone in the neighborhood of the cinnabar veins is full of solution cavities and these deposits probably occupy what were formerly solution cavities in this easily replaceable rock.

At the present time there is no great quantity of cinnabar ore in sight as the workings consist only of two tunnels about 80 ft. apart .and not over 100 ft. long and some open cuts and quarry holes that follow the cinnabar bearing seams into the hillside.

Considering the small amount of work that has been done the showing is good, as there are at least five of these irregular seams occurring over a width of 50 ft. and most of these show ore running from 3 to 8 per cent in mercury.

About five tons of ore that would average 5 to 6 per cent of mercury, was being extracted daily to supply the small retorting furnace. This ore was being obtained from development work and not from stoping.

These deposits occur only a short distance (not more than .200 ft.) from the contact with the quartzite conglomerate and it is possible that underground exploration towards this contact might discover other replacement-seams as the impervious nature of the quartzite would undoubtedly cause a damming back of solutions thus making a likely place to find ore.

Hermes Group. This group is situated about a mile north of the Fern mine and has several hundred feet of workings in the form of tunnels on the property.

A heavily iron-stained zone outcrops on the hill north of Cinnabar Creek, in the bluish lime previously mentioned. This iron-stained outcrop consists of shattered lime and some bluish quartz and contains disseminated cinnabar all through it. It is 50 to 60 ft. wide and in one place is harder than the surrounding country rock and makes a bold and prominent exposure. Some large boulders of float have rolled down the mountain from this outcrop. One of them larger than a railroad box car contains a considerable amount of finely disseminated cinnabar. This mineralized zone occurs in the lime a short distance from the dense, iron-stained quartzite previously mentioned.

This hard mineralized zone does not seem to extend far down the mountain, but the cinnabar mineralization is found almost as far down as Cinnabar Creek, and has been opened up by three tunnels.

The lowest of the tunnels follows a shattered mineralized zone, which appears to be along a contact between the quartzite and the lime. At the mouth of this tunnel there is exposed in an open-cut about four feet of cinnabar ore which gave an assay of 3.22 per cent of mercury. The tunnel is about 135 ft. long and runs N. 35° W.

And Tin Deposits Of Idaho 63

(magnetic) which is the general direction or strike of the metamorphosed sediments. The shattered limestone in this tunnel shows a little cinnabar, a sample giving a return of 0.20 per cent of mercury. The middle tunnel is 80 ft. long and has a course of N. 10° E., so it partly crosses the mineral formation. The first 50 ft. is in blue lime carrying a little cinnabar. It then passes through a rotten porphyry dike or sill 16 ft. wide and the face is in hard, yellow crystalline limestone with a strike of N. 60° W. and a southwest dip of 80°.

The upper tunnel is mostly in unmineralized limestone, it appears to have reached the mineralized zone in the face, but no verydefinite information can be obtained from this tunnel.

A somewhat hasty examination of the property seems to establish the occurrence of a wide belt of shattered mineralized limestone, somewhat hardened by silicification in places and also heavily ironstained, running in a northwest direction close to a contact with a hard, dense iron-stained quartzite. Cinnabar occurs all along and through this zone for a distance of at least 600 ft., and possibly further.

Most of the cinnabar is too finely disseminated to be classed as ore, but there are local concentrations of higher grade material which can undoubtedly be worked at a profit, and there seems no reason why development along this zone should not open up considerable cinnabar ore of workable grade.

The deposits of the Fern and Hermes groups are similar in the fact that both occur in limestone close to a contact with a more impervious rock which is quartzite, and are both associated with the same kind of porphyry dikes.

Their origin is undoubtedly similar and is probably to be explained by heated waters, similar to certain kinds of hot springs now in existence, which deposited the mercury minerals and cherty quartz either by replacement of the limestone or by filling of solution cavities along fracture planes.

The porphyry dikes are probably connected with a deeper seated mass which supplied the heat to the waters forming the veins and possibly furnished the minerals. The explanation for the cinnabar mineralization close to the quartzite contact is possibly that this rock being more impervious to water than the adjoining limestones would interfere with the underground flow of water in the latter, damming back the solutions and thereby giving more chance for chemical interaction and precipitation. It is a well known fact that ore shoots or bonanzas in gold and other mineral veins often occur near faults and this is explained by the gouge of the fault plane acting as a barrier to the water in the manner just described, and thereby causing enrichment of the vein at that point. Cinnabar is widely distributed

64 Tungsten, Cinnabar, Manganese, Molybdenum,

in this district, but other workable deposits of it will most likely be found in the limestone near some such impervious barrier as a contact, a dike or a fault.

The Buckbed Property is situated about 1000 ft. to the east of the Fern mine and in the same belt of lime.

There are several open cuts which show the same character of chalcedonic quartz replacements in the lime as at the Fern, running about north and south. One of these shows some fairly good cinnabar ore, but not enough work has been done upon it to prove the value of the property, though its general appearance is encouraging. A good camp has been built with substantial houses designed to withstand the deep snows of this region in winter time. A tunnel has been started near the lowest end of the claim and within a short distance of the camp. This tunnel will tap the cinnabar bearing vein about 150 ft. below the surface and should show some interesting developments. The camp has been built close enough to the mouth of this tunnel so that the latter can be reached by a covered path from the cabin.

The White Metal Group is owned by the Idaho Quicksilver Mines Co., of Boise, Idaho, and operated by George C. Brewer.

They join the Buckbed claims and the same geological conditions prevail as on that property. A gray chalcedonic quartz replacement-vein 4 or 5 ft. wide containing jasper and cinnabar and with a strike of N. 30° W. has been traced for several hundred feet and exposed by open cuts. The lowest of these open cuts show a little copper carbonate as well as a little cinnabar, and some cinnabar is also to be seen in the open cuts higher up the mountain.

The same company owns a claim about half a mile further down Fern Creek, where some ore containing galena, stained with copper carbonate and containing a little cinnabar, has been exposed by a small open cut in limestone, on the west bank of Fern Creek. The extent of this exposure is not known as the open cut was partly caved, but the prospect would seem to be worthy of further development.

H. T. Abstein' s Property lies to the east of the White Metal group and not far from the divide between Fern Creek and Monumental Creek. The country rock is the same yellowish lime and exposed a similar type of deposit to those which occur on the properties just described. Some excellent cinnabar float has been found by Mr. Abstein on this ground, though the vein from which it came had not been uncovered at the time of the writer's visit to the property, though Mr. Abstein reported later that he had found this vein and that it contained good ore.

The Hennessy Property is situated in one of the cirque walls at the head of Cinnabar Creek and about half a mile south of the

Missing Page

East Fork of South Fork of Salmon River. Trail to Yellowpine.

Canyon of South Fork of Salmon River.

And Tin Deposits Of Idaho 65

Hermes group. The country rock is the yellowish limestone, of the same belt as that in which the Fern and other properties occur, but further to the northwest. A vein occurs in the lime with a strike of N. 45 to 50° W. and a dip of 50° to the northeast. This vein consists of a shattered quartz and lime gangue and contains a little cinnabar. It is probably a bed or blanket vein as it had the same general course as the stratified rocks of the district. A small quartz vein from 1 to 6 in. wide and running due north and south (magnetic) intersects the larger vein and an incline shaft has been sunk at the junction of these two veins. The dump shows considerable stibnite with small specks of cinnabar. This stibnite streak must have come from the small vein and does not appear to be more than 3 or 4 in. wide at the most.

Summary and Conclusion

No very definite statement as to the probable future of the camp can be made in the present state of its development. The total amount of development work at the time of writing does not aggregate much over 1000 ft. The general indications from the work that has been done, however, are very encouraging and there seems no reason why this district should not be a producer of quicksilver to no small amount when more fully developed. The nature of the ore occurrences at the Fern and adjoining properties i. e. replacement veins in limestone, is such that the continuity of any one of these for any distance is extremely doubtful, but providing there are enough of them, as there seem to be, this fact should be no great detriment.

At the Hermes group, on the other hand, there seems to be a larger and more continuous body of disseminated cinnabar which requires considerable development to properly exploit, but this may prove of greater value than the richer but more uncertain deposits on the other side of the ridge. The remoteness of the region and its high altitude are its greatest drawbacks, and gold, silver and mercury are about the only metals that could possibly be mined at a profit under such adverse conditions. The greatest need at this time is a better road as the present one is a disgrace and only fit to drive sheep over, and if the transportation was improved there is little doubt that the district would go ahead and prove a valuable asset to the mining resources of the state.

The Occurrence oE Cinnabar Near Beack Pine, Idaho Esper S. Larsen. 1 U. S. Geological Survey.

Introduction. — This report is based on a three-day trip to the Black Pine district, most of the time being spent on the journey to and from the deposit. The work was done for the United States

66 Tungsten, Cinnabar, Manganese, Molybdenum,

Geological Survey as a part of its investigation of the quicksilver deposits of the United States.

Location and Topography. The claims of the Valentine Cinnabar Mining Company, which are the only known quicksilver prospects in the Black Pine district, are located in the extreme eastern part of Cassia County about 4j4 miles west of Black Pine postof fice, Idaho, on the eastern slope of the Black Pine Mountains. Black Pine is connected with Malad City and Tremont, Idaho, both on the Malad Valley railroad, and respectively 55 to 60 miles distant to the east, by fair auto roads, although two considerable mountain ranges intervene; it is only 30 miles from Kelton, Utah, with a gentle and uniform grade up the valley but the railroad service to Kelton is only weekly. The cinnabar prospect is reached by a fair wagon road — nearly impassable for an automobile — from Black Pine.

The Black Pine Mountains are a high range rising to an elevation of several thousand feet above the valley, while the broad, nearly flat valley to the east is several miles across and gives place on the flanks of the mountains to a succession of terraces and to steeper slopes. The cinnabar prospect is below the steeper -mountain slopes and near the prospect the gulches are not deeply incised so that the relief is not great. The elevation at Black Pine is about 4700 ft. and at the mine about 6000 ft.

The climate of this region is arid and the gulches near the cinnabar prospects are dry during most of the year, but springs are common around the border of the valley at about the elevation of Black Pine postof fice, and numerous .wells, have been put down in the valley. All water used at the prospects must be hauled from the valley, about four miles away. On the slopes about the prospect is a scattered growth of juniper and mountain mahogany timber, suitable for firewood and some types of mine timber. In the valley beans, grain and corn are raised by dry farming, but the aridity of the. climate and the abundance of rabbits make the crops uncertain.

Geology. The Black Pine Mountains are elongated in a general north-south direction and are made up of a great thickness of . sedimentary rocks, mostly limestones and no doubt of Paleozoic age, that strike with the range and dip at moderate angles to the west.. No igneous rocks are known nearer than the basaltic lavas that make up the range to the east, across Black Pine Valley. The Black Pine Valley is an arm of old Lake Bonneville and a succession of gravel terraces extend to a considerable elevation above the valley on the flanks of the mountains.

Mineralization. The cinnabar deposit is at the top of a limestone bed beneath a shale horizon and has been formed through a replacement of the limestone. It has the form of a chimney and dips with the bedding of the sediments at about 30° to the west.

And Tin Deposits Of Idaho 67

In horizontal section it is elliptical or lenslike, and about 10 ft. long by 5 ft. wide with some stringers of mineralization extending along the bedding for 10 ft. or more in both directions beyond the main chimney ; it has been opened up for a depth, measured alone: the din of about 40 ft.

The material of the mineralized chimney is porous and friable, breaking up into a coarse sand, and is made up in large part of barite and quartz; tabular crystals of barite commonly project into the cavities, which are of small size. The cinnabar is unevenly distributed and forms a very thin, sooty or dust-like coating on the quartz and barite crystals of the cavities ; in places it is abundant enough to impart a decided red color to the rock, but was nowhere seen to form more than a very small part of the material. This red coating carries a little arsenic as well as mercury and is probably a mixture of cinnabar and realgar. Near the surface there is much scorodite (a hydrous arsenate of ferric iron) in leek-green, botryoidal, fibrous crusts coating the quartz and barite crystals.

Some gold is reported to be present in the deposit, notably in some of the narrow seams that extend along the bedding, from the main chimney. A prospect hole about 50 ft. to the east of the chimney has been sunk about 12 ft. and exposes some crushed, ironstained material that is said to carry gold with some silver and lead.

No sulphides other than cinnabar were recognized in the cinnabar ore, but a little antimony is reported to occur about a mile to the west and prospects within a mile or so to the north are reported to carry zinc, silver, and copper, or silver, lead and zinc.

Conclusion. Clearly the mineralization is a replacement of the limestone; the barite and quartz were deposited first, the cinnabar later, and the scorodite was probably last. The character of the mineralization — abundant barite, considerable porosity, and the sooty character of the cinnabar — indicate a mineralization at no great depth, and it seems probable that the deposit is the result of hot spring action of comparatively recent geologic age — probably since the development of the main features of the present topography.

Index To Illustrations.

Map of Idaho

Hanging Valley on Johnson Creek ™ A

Buildings at Fern Mine, Valley County ...ZZZ 57

View up Patterson Creek, Lemhi County ZZ. 21

East Fork of South Fork of Salmon River .' 6 r

Canyon of South Fork of Salmon River "" Z-

Map showing Tungsten Properties near Murray, Idaho ZZ. IS

Tungsten Hill Mine, showing Claim Lines, Veins, etc "'. 11

Map showing Workings of "Friday" Group of Claims ZZZZ 17

Map of Ima Mine, Lemhi County ,3

Map of Cinnabar District, Valley County eg

Claim Map of Cinnabar Camp fi ,

Plat of Part of Cinnabar " ,.

Map showing Location of Tungsten Hill Mine 11

Index To Contents.

Abstein, H. T, property in Fern Creek District 54

Acknowledgments c -c

Adams, T. F., property on Sturgill Creek ' 34

Adams, T. F, Sheep Creek property 35

Analyses, manganese near Sturgill Creek 35

Anderson, Chas. T 3g

Antimony 67

Antimony, minerals of 45

Antimony, uses of 45

Antimony, production in U. S 46

Antimony, foreign production 47

Antimony, metallurgy 48

Barite 67

Bell, R. N """ 45

Black Pine, cinnabar near 65

Black Pine, geology 66

Black Pine, mineralization 66

Boundary County, tungsten in 11

Boundary County, molybdenum in 40

Braunite 30

Buckbed group, Fern Creek District 58, 64

Butte County, tungsten in 27

Butte-Detroit manganese property 38

Cadby, W. G., molybdenum property 41

California, tungsten in 9, 10

Camas County, tungsten in 25

Charity vein Warren's 27

Cinnabar - 54, 65

Coeur d'Alene Antimony Co 52

Colorado Antimony 9

Copper in Lemhi County 41

70 Index.

Copeland, Boundary Co 11

Corral Creek, Camas County 25, 29

Cummins, Mrs. E. V., manganese property of 37

Czizek, J. A. 26

Diabase 18

Dora Mine, Boundary County 11

Elevations on road to Fern Creek Cinnabar District 56

Ferberite 8, 26, 28

Fern Creek Cinnabar District 55

Fern Creek Cinnabar District, History of 58

Fern Creek Cinnabar District, Geology of 59

Fern Creek Cinnabar District, Topography of 58

Fern Creek Cinnabar District, Ore deposits 61

Friday Group, near Murray 16

Gibbonsville, tungsten near 29

Glaciation 11, 56, 59

Golden Chest Mine 15

Golden Winnie Mine 15, 17

Granite :. 12, 61

Hennessy, Frank, antimony property of 52, 64

Hermes Group, Fern Creek District 58, 62

Hill, J. C, Manganese property on Snake River 36

Hill, Walter Hovey 55, 59

Hubnerite 8, 23

Hughes, Geo. R 29

Idaho County, tungsten in 26

Idaho County, molybdenum in 41

Idaho Antimony Mining Co 51

Idaho County, Antimony in 53

Ima Mine, history of 21

Ima Mine, geology and vein formation at 22, 23

Ima Mine, workings 23

Ima Mine, tungsten contents, samples from 24

Independence group of claims, Butte Co 27

lone, group near Murray 38

Kennan property on Pony Gulch 19

Kennan, Chester T 20

Kent, A. J., molybdenum property of 40

Larsen, E. S 5, 10, 25, 55, 65

Lava Creek, Butte Co - 27

Lemhi County, tungsten in 21, 29

Lemhi range 22

Lemhi County, molybdenum in 40

Lemhi County, tin deposits in 43

Lindgren, Waldemar 26

Little Giant Mine, Warren's 26, 27

Index. 71

Manganite

Manganese, properties and minerals of 3q o.

Manganese, uses of '

Manganese, consumption and production of in U. S 31

Manganese, Snake River „

Manganese, deposits in Idaho """" 32

Manganese, production in foreign countries 32

Martin, P. O "" 2 i

Mercury, see quicksilver

Melly, Mike ,g

Molybdenite 3 9, 40, 41, 42

Molybdenum, uses of, tests for, etc ' 39

Mother Lode io

Mulkey, A. R., Molybdenum property of 40

Murray, tungsten deposits near 15

Murray tungsten belt, summary of 20

Murphy, John F lg

Nelson, S. O 27

Nevada, tungsten in 1

Nowak, Frank 51

Pahsimeroi valley 22

Panther Creek, Lemhi County 44

Patterson Creek, Lemhi Co 21

Placer gold on Snake River 34

Prichard Slate „ IS, 16

Psilomelane 30

Pyrolusite 30

Pyrrhotite 42

Quicksilver, production of 54

Quicksilver, properties of, uses of, minerals of 54

Quicksilver, value of ores of 55

Ransome, F. L 15

Realgar 67

Reilly, J. T., Manganese property on Sturgill Creek 36

Rhodonite 31

Rhodochrosite 31

Roads, condition of road to Fern Creek 57

Roberts, W. S - 25

Scheelite - 7, 9, 10, 17, 18, 27

Scorodite 67

Shoshone County, tungsten in 15

Shoshone County, antimony in 52

Sieger, Dan, manganese near Murray 38

Smith, E. M 1 7

Smith, J. P 58

Star Antimony, property S3

Stibnite 45, 50, 51

Stolzite 8

72 Index.

Sturgill Creek, manganese on 32

Sturgill Creek, topography, geology, etc 33

Thomson, Francis A 45

Thunder Mountain 58

Tin, in Idaho 43

Tin, minerals of, tests for, etc 43

Tungsten, consumption of in U. S 8

Tungsten, Uses and properties of 6

Tungsten Minerals 7, 8

Tungsten, foreign countries 9

Tungsten, contact-mctamorphic 10

Tungsten Hill Mine, topography, geology, veins 11, 12

Tungsten Hill Mine, value of ore of 13, 14

Tungstite 8

Tungstic Ocher 8

Umpleby, J. B '. 21, 29, 43, 45

Unity Gold Mines Co 27

Valley County, Antimony in 49

Valley County, quicksilver in 55

Van Meter, E. H - 55

Vienna, International Mine, manganese in 39

Wad - 30

Ward, A. B 20

Waring, D. E., manganese near Wallace 39

Warren district, Idaho County 26

White Metal Group 58, 64

Wolframite 7, 26, 28

Yellowpine Basin, Antimony deposits of 49

Yellowpine Basin, sampling results of antimony 51

Yellowpine Basin, Geology and ore deposits of 49, SO

Yellowpine mining district, quicksilver in 55

Tungsten, cinnabar, manganese, molybdenum, and tin deposits of Idaho

J

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School Of Mines

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Table Of Contents

Chapter Iii.

Map

Idaho

Legend-

Introduction And Scope Of Work

6 Tungsten, Cinnabar, Manganese, Molybdenum

Chapter I. Tungsten

Pp

And Tin Deposits Of Idaho 7

8 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 9

10 Tungsten, Cinnabar, Manganese, Molybdenum,

T.64 N,

M/A P

And Tin Deposits Of Idaho 11

32 Tungsten, Cinnabar, Manganese, Molybdenum,

Tl//V6St£N H / Ll M/Me

And Tin Deposits Of Idaho 13

Remarks

%W03

S.O

0.S9

6.S

14 Tungsten, Cinnabar, Manganese, Molybdenum,

J

Map N?3

And Tin Deposits Of Idaho 15

And Tin Deposits Of Idaho 17

18 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 19

20 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 21

22 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 23

24 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 25

26 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 2T

28 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 29'

Jo Tungsten, Cinnabar, Manganese, Molybdenum,

Chapter Ii.

Manganese

And Tin Deposits Of Idaho 31

32 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 33

34 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 35

36 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 37

38 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 39

Molybdenum

40 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 41

42 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 43

Tin

44 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 45

Antimony

46 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 47

48 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 49

50 Tungsten, Cinnabar, Manganese, Molybdenum,

And Tin Deposits Of Idaho 51