UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Bulletin 849 F

LODE DEPOSITS OF EUEEKA AND VICINITY 

KANTISMA DISTRICT, ALASKA

BY 

FRANCIS G. WELLS

Investigations in Alaska Railroad belt, 1931 

(Pages 335-379)

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1933

For sale by the Superintendent of Documents, Washington, D. C. ------ Price 20 cents

CONTENTS

 Page

Foreword, by Philip S. Smith__._____._____-.___________.._._____. v

Abstract.________________________________________________________ 335

Introduction__ _________________________________________________ 336

Location and means of access.__________________________________ 336

Previous surveys.-_-__.__--_-_---_____________________________ 337

Field work and acknowledgments.______________________________ 338

Geography____._.________________________________________________ 339

Drainage. _ ___________________________________________________ 339

Relief....... ________________________________________________ 340

Climate.-____________________________________________________ 340

Vegetation.__....._..--_...-....._...___.__.._..._..__----.__ 341

Population....---__-_..-_._-_---_-_-_---_--_-_...-.._.----.__ 342

Geology --------_----..-_._-..-.--....__...-_---_-..__.__-_-_. 343

Principal features.____________________________________________ 343

Birch Creek schist__-__..__..______..-_._____-____.._-_._______. 343

Quartz-muscovite schist____-___...__.-__-_._..______-__-_ 343

Character and distribution.____________________________ 343

Structure ____________________________________________ 344

Limestone and chlorite schist.______________________________ 345

Thickness and origin______________________________________ 346

Age and correlation ______________________________________ 346

Igneous rocks0.______________________________________________ 347

Quartz porphyry._________________________________________ 347

Diabase__ ______________________________________________ 348

Quaternary deposits.__________________________________________ 349

Glaciation and glacial deposits._____-,_.--_-______-._----___ 349

Postglacial deposits______________________________________ 350

Geologic history._____________________________________________ 351

Economic geology..._._.___________-______-__.__-...._-_..____..__ 352

History of mining.____________________________________________ 352

Character of ore deposits---_----_-_____---_---_-__----_-------- 354

Structural features__-_______-_____--_______--_----_----___ 354

Mineralogy______--_---__--____----_-_--_-__---._-------- 355

Gangue minerals._______-_____---_____-___-_..__----_-_ 355

Metallic minerals.______---___--___----_---_---------- 356

Gold quartz veins._____--___----__--_--_-______----_-_ 357

Galena-sphalerite veins._______________________________ 358

Stibnite veins____________-_-___----___-_--___-__-_-_ 358

Oxidation and enrichment-_-_-_-__---___---_---_-_------__- 358

Genesis of ore____._______________-____--_____---__------_ 359

Economic factors_________-__--_____-__________-----_----__- 360

Mines and prospects______--_---_______--_---_-___--_-_-------- 360

Quigley Hill.._-._-_..----- .- .- .. -- .-. -.. 360

Red Top___--------------_------------_-------------- 361

Polly Wonder___---_-------_----------._-.----_------_ 364

Little Annie.___-_____-________________-__---__----___ 364

m
IV CONTENTS

Economic geology Continued

Mines and prospects Continued

Quigley Hill Continued Page

Gold Dollar and Golden Eagle._________________________ 366

Lucky Strike_--------_____--.___-_.__________________ 367

Galena__ ________________ _°_ ________________________ 367

Francis. ______________________________________________ 368

Silver Pick and Little Maud_-__-_-______--___________ 368

Pennsylvania and Keystone..__________________________ 370

Banjo....____________--____-__--__________ 370

Damon and Pythias and Merry Widow._________________ 371

Glacier Creek___________________________________________ 371

McGonogilL. _.-_----_-___.__--_--_______'-___-.-__-_- 372

Glen Creek__________________________________________ 372

Glen____.____________________________________________ 373

Glen Ridge No.l_--_-______--____-_____-__.__________ 373

Arkansas and Pension _________________________________ 374

Humboldt______-___-_-_--____-_________-_-_----_--.__ 374

Spruce Creek___________-___._____________________________ 374

Lena and Silver Wire._________________________________ 375

North Star___-_-_--_--_-___-_--_--___-----_-__--.._-_ 375

Eldorado Creek________-_____-__.___._..__...__.__._._._ 375

Alpha-,___________-_-_-_-_-__--_-_________._________ 375

Neversweat. ___-_-____--__---_--_-_________-_________ 376

Antimony prospects.__-____________-__-__--___-_---_______ 376

Slate Creek_______-_._________________________________ 376

Home.____________-_-______-_-__-___-_--_-_________ 377

Caribou. _ __.______________ ______________ _a_-_________ 377

Summary. ___________________________________________________ 378

Index... ._._._ -----------__----_--_-----------------------_--- 379

ILLUSTEATIONS

Page 

PLATE 28. Geologic map of Eureka and vicinity, Kantishna district. _ In pocket

29. Sketch map of lode claims in the vicinity of Friday and Eureka

Creeks ______________________--__-_.-___---___---___-- 358

30. Assay map of Red Top tunnel___------------- --------_- 358

31. Contour sketch map of Little Annie claim, showing tunnel__ 366

32. Assay map of Little Annie tunnel-_____-_---_--_------_--_ 366

FIGURE 1. Index map showing areas investigated in Alaska Railroad

belt, 1931--_---_------------------------------------- viz

45. Geologic sketch map and section of main tunnel of Red Top

claim ____________________-_-___----__--------_----__- 362
INVESTIGATIONS IN ALASKA KAILROAD BELT, 1931

FOREWORD

By PHILIP S. SMITH

To help the mining industry of Alaska and to assist in the development of the mineral resources of the Territory have been the prime 

motives of the Geological Survey's investigations in Alaska during 

the past 35 years, in which nearly one half of the Territory has been 

covered by its reconnaissance and exploratory surveys. It was 

natural, therefore, that the Alaska Railroad, when it undertook intensive consideration of the problem of rinding tonnage that would 

increase its revenues, should look to the Geological Survey to supply 

technical information as to the known mineral deposits along its 

route and to indicate what might be done to stimulate a larger 

production of minerals and induce further mining developments and 

prospecting that would utilize its service. Realization of the need for 

this information had long been felt by the officials responsible for the 

operation of the Alaska Railroad, and the need had been partly 

supplied by the Geological Survey, but funds to carry through an 

extensive inquiry of this sort had not been available until 1930, 

when a special committee of the Senate, composed of Senators Howell, 

Kendrick, and Thomas, visited Alaska, studied some of the railroad's 

problems, and successfully urged Congress to grant it $250,000 for 

investigations of this kind.

On the invitation of the Alaska Railroad the Geological Survey 

prepared various plans and estimates for the investigations that 

appeared to be most likely to contribute the desired information as to 

the mineral resources. Selection of the problems to be attacked 

proved difficult, because the choice necessarily was hedged about with 

many practical restrictions. For instance, each project recommended 

must give promise of disclosing valuable deposits a requirement 

that was impossible to satisfy fully in advance, as it involved prophecy 

as to the unknown and undeveloped resources. Then, too, it was 

desirable that the search should be directed mainly toward disclosing 

deposits which if found would attract private enterprises to undertake their development in the near future. Finally, some of the 

deposits that might be worked profitably did not appear likely to 

afford much tonnage to be hauled by the railroad. Under these
VI INVESTIGATIONS IN ALASKA EAILBOAD BELT, 1931

limitations it should be evident that the projects that could be recommended as worth undertaking with the funds available by no means 

exhausted the mineral investigations that otherwise would be well 

justified. In a large sense, all of Alaska may properly be regarded as 

indirectly contributory to the welfare of the railroad, but even in 

that part of Alaska contiguous to its tracks there are large stretches 

of country that are entirely unexplored and large areas that have had 

only the most cursory examination. Although areas of this sort 

might well repay investigation, they were excluded from the list of 

projects recommended because they were not known to contain 

mineral deposits of value, and it therefore seemed better to make the 

selection from other areas that had been proved to hold promise. 

Furthermore, several areas within the railroad zone were excluded 

because their value was believed to lie mostly in their prospective 

placers, which would not yield much outgoing tonnage; others because 

their lodes carried mainly base metals, for which development and 

the recovery of their metallic content in a readily salable condition 

were relatively expensive; and still others because their resources 

consisted mainly of granite, building stone, or some other product 

for which at present there is only a small local demand.

After careful consideration ten projects were selected, and the 

funds required for undertaking them were made available. The 

projects that were selected involved the examination of two areas 

principally valuable for their coal (Anthracite Ridge and Moose 

Creek), five areas likely to be principally valuable for gold (Fairbanks, Willow Creek, Girdwood, Moose Pass, and Valdez Creek), 

and three areas whose lodes consisted mainly of mixed sulphides (the 

Eureka area in the Kantishna district, Mount Eielson, formerly 

known as Copper Mountain, and the head of West Fork of Chulitna 

River). The general position of these different areas is indicated on 

the accompanying diagram (fig. 1). A general study of the nonmetalliferous resources of the entire region traversed by the railroad 

was included in the projects to be undertaken, but the results obtained 

were not such as to permit adequate determination of their extent at 

this time.

Examinations were made in the field in each of the selected areas, 

all the known prospects and mines being critically examined and 

sampled so far as time and other conditions permitted. The records 

thus obtained, together with all other information bearing on the 

problems, were then subjected to further study in the laboratory and 

office, in the course of which other Geological Survey specialists whose 

knowledge and experience could be of assistance were freely consulted. 

The outcome of all these lines of analysis has been the reports which 

make up this volume. Although each chapter is presented as embodying the latest and most authoritative information available regarding 

the districts and properties described up to the time field work in them
FOREWORD VII

BO Miles

FIGURE 1. Index map showing areas investigated in Alaska Railroad belt, 1931; A, Anthracite Ridge 

B, Fairbanks; C, Willow Creek; D, Mount Eielson; E, West Fork of Chulitna River; F. Eureka and 

vicinity; O, Girdwood; H, Valdez Creek; I, Moose Pass and Hope.
VIII INVESTIGATIONS IN ALASKA RAILROAD BELT, 1931

was finished, the authors make no claim that all the results they have 

presented are to be regarded as final nor as solving all the problems 

that have arisen. Actually none of the mines have been developed 

to such an extent as to furnish all of the evidence desired to solve the 

problems involved. At none of the properties is any considerable 

quantity of ore actually "blocked out" in the engineering sense of 

that term, so that instead of specific measurements as to the quantity 

and grade of ore the different camps will yield, the Survey geologists 

and engineers have necessarily had to make numerous assumptions 

and be content with estimates and generalizations as to the potential 

resources. Furthermore, the work was planned so as not to invade 

the proper field of the private mining engineer in the valuation of 

individual properties, but rather to occupy the open field of considering 

the districts as a whole.

In two of the districts, Anthracite Ridge and Moose Creek, whose 

value lay in their prospective coal resources, the examinations that 

could be made by ordinary geologic means were not adequate to arrive 

at a final judgment of the resources of the area but pointed to the 

desirability of further tests by drilling. As a consequence additional 

exploration of these districts by means of diamond drilling was 

authorized, and this work was undertaken in the season of 1932. The 

results of these tests were not available at the time the manuscripts 

of the other reports were completed, and rather than delay their 

publication until the later reports could be finished and incorporated 

in the volume these reports have been omitted here and will be 

published later elsewhere.

This is not the place to summarize the detailed findings of the 

geologists as to the merits of the different districts, as those findings 

are explained in detail and summarized in the respective chapters. 

Suffice it to say here that on the whole the principal purpose of the 

investigations was carried through satisfactorily and that while the 

studies in some of the districts indicate that they hold little promise 

of extensive mineral development in the near future, others appear to 

encourage development under existing conditions, and still others 

seem to be worth development when some of the existing factors such 

as transportation or price of base metals are improved. That conditions which are now temporarily retarding the development of some 

of the deposits will become more favorable cannot be doubted. The 

entire region is becoming more accessible each year, and as a result 

costs are being lowered and experience is being gained as to the habit 

of the various types of deposits, so that the conclusions expressed in 

this volume as to the resources of the different districts should be 

reviewed from time to time in the light of the then current conditions.
LODE DEPOSITS OF EUREKA AND VICINITY, 

KANTISHNA DISTRICT, ALASKA

By FRANCIS G. WELLS

ABSTRACT

The Kantishna mining district is about 90 miles west of McKinley Park 

"station on the Alaska Railroad. The part of the district covered by this 

report comprises an area of about 72 square miles in the form of a strip 

6 miles wide and 13 miles long.

The bedrock is mainly a metamorphic series of rocks which within the 

area has been differentiated into a quartz-muscovite schist and a calcareous 

facies that ranges from limestone to chlorite schist. A few small dikes of 

quartz porphyry and diabase intrude the schist. The general structure trends 

N. 70° E., and from an axis that extends from Eldorado Creek northeastward to 

Spruce Peak the schistosity dips to the northwest and southeast. It is along 

this axis that the heaviest mineralization has occurred.

All the veins in the area strike N. 50°-70° E., and most of them dip at 

high angles toward the southeast, though a few dip toward the northwest. 

The veins are rudely tabular, swelling and pinching along both the strike 

and dip, and range in thickness from 23 feet to a fraction of an inch. Some 

of the larger veins have been opened by drifts or other excavations along the 

strike for 500 feet, but their surface croppings have been recognized for 

even greater distances.

The veins are of three types gold quartz veins, silver-bearing galena veins, 

and stibnite veins. The gold quartz veins consist of white quartz containing 

small amounts of arsenopyrite and pyrite with scattered nests of galena or 

sphalerite. The gold is largely associated with the sulphide minerals except 

in the oxidized parts of the vein, where it is found as free gold. The galenasphalerite veins are composed predominantly of sulphides carrying only small 

amounts of quartz and carbonate gangue. The ratio of galena to sphalerite is 

variable, and associated with these minerals are small amounts of tetrahedrite, 

stromeyerite, stephanite, and chalcopyrite, as well as pyrite and arsenopyrite. 

The stibnite veins are composed of stibnite with some quartz gangue, and 

many are massive stibnite. Enrichment appears to be almost totally lacking 

in all the veins, and they have been only superficially oxidized.

Some years ago about 1,300 tons of sulphide ore, most of which assayed 

better than $175 a ton, with the major value in silver, then worth $1 an ounce, 

was mined and shipped. The workings from which this ore was taken are now 

inaccessible. Of 104 samples taken from accessible quartz veins throughout 

the district the highest assay was 3.74 ounces of gold and 1.60 ounces of 

silver to the ton, and the average was 0.21 ounce of gold and 6.41 ounces of 

silver.

335
336 INVESTIGATIONS IN ALASKA BAILROAD BELT, 1931

The area shows excellent indications of mineralization, and it is highly 

probable that other veins not yet mined contain ore of as high grade as that 

so far discovered. The type of mineralization, the character of the ore, and 

the absence of appreciable enrichment indicate that the ore extends to considerably greater depths than those so far reached in the area by mining 

developments.

INTRODUCTION

LOCATION AND MEANS OF ACCESS

The Kantishna region x is broadly considered to be bordered on 

the south by the crest of the Alaska Range, on the north by the 

Tanana River, on the east by the Nenana River, and on the west by 

the lower Kantishna River. (See fig. 1.) This report on the lode 

deposits of Eureka and vicinity, however, treats only a small part 

of this region, an area 6 miles wide and 13 miles long, comprising 

the west end of the Kantishna Hills, between longitude 150°40' and 

151°10' W. and latitude 63°30' and 63°35' N. During summer two 

routes of travel give access to the district one from McKinley Park 

station on the Alaska Railroad by the McKinley Park road to Stony 

Creek and thence by trail to Kantishna, a distance of about 90 miles; 

the other by boat by the Kantishna and Bearpaw Rivers to Diamond, 

thence 25 miles by trail to Glacier and Kantishna. In the past the 

route by way of Diamond was most used, and practically all the 

freight has been moved over it. As the trail from Diamond to Kantishna is boggy and difficult of travel during summer the practice 

has been to bring supplies to Diamond by boat in summer and to 

haul them from Diamond to Kantishna by sled in winter. The cost 

of freighting by this route, as well as the time required to move materials over it, which is often more than a year, has been a serious 

obstacle to mining activities.

For winter travel a different route is chosen. This route leaves 

the Alaska Railroad at Kobe or Lignite, near the base of the foothills. From either of these points a trail leads westward along the 

south edge of the lowland to Knight's roadhouse, on the Toklat 

River, northwest of Mount Chitsia. Thence the Toklat River and 

its tributary Clearwater Fork are followed to Myrtle Creek. The 

trail follows Myrtle Creek up to a point near its head, crosses a low 

pass into the head of Spruce Creek, and descends that stream and 

Moose Creek to the vicinity of the mines on Moose, Eldorado, and 

Friday Creeks. The total distance along this route by sled from 

Fairbanks to Eureka Creek is about 165 miles.

The route from McKinley Park station is now being more widely 

used for travel, and with the completion of the road to Wonder Lake

1 Capps, S. R., The Kantishma region, Alaska: U.S. Geol. Survey Bull. 687, p. 7, 1919.
LODE DEPOSITS OP EUREKA AND VICINITY 337

it will be, at least during summer, the most rapid and easiest way 

for both men and materials to reach the Kantishna, In the summer 

of 1931 the road was complete to the Toklat River and was graded 

through Thorofare Pass, leaving a distance of about 20 miles to 

be both graded and graveled.

PREVIOUS SURVEYS

The first accurate survey covering part of the Kantishna region 

was made in 1902, when a United States Geological Survey party 

including A. H. Brooks, D. L. Reaburn, and L. M. Prindle left 

Cook Inlet by pack train, ascended to the head of the Skwentna 

River, and there crossed the Alaska Range into the Kuskokwim 

Basin. Proceeding northeastward they traversed the northwest slope 

of the Alaska Range to the Nenana River and followed that stream 

to its mouth. The results of this expedition form the first authentic 

information concerning the geography and geology of the Kantishna 

region and were published in a professional paper of the Geological 

Survey.2 In 1906 Prindle 3 made a hurried visit to the Kantishna 

placer district, then recently discovered, and wrote a brief account 

of its geology and gold-placer deposits. Archdeacon Hudson Stuck 4 

passed through the Kantishna district in the spring of 1913 on his 

way to and from Mount McKinley and in his account of this expedition gives some information concerning the region. Likewise 

Charles Sheldon B passed through the Kantishna district in the summer of 1906 and again in the summer of 1907 on his way to the north 

slope of the Alaska Range, and his book describing his explorations 

gives some additional geographic information.

The first survey of the area sufficiently thorough to determine the 

nature and distribution of the geologic formations as well as the 

character and extent of the economic resources was made in the summer of 1916, by S. R. Capps and C. E. Giffin, of the Geological 

Survey. Giffin prepared a topographic map of about 4,500 square 

miles on a field scale of 1 to 180,000, while Capps 6 studied the geology of the area, making a special investigation of the geologic 

conditions in the vicinity of the placer mines and examining all the 

placer mines and most of the prospects, including! placer gold 

deposits and the gold, silver, and antimony lodes.

2 Brooks, A. I-L, The Mount McKinley region, Alaska, with descriptions of the igneous 

rocks and of the Bonnifleld and Kantishna districts, by L. M. Prindle: U.S. Geol. Survey 

Prof. Paper 70, 1911.

3 Prindle, L. M., The Bonnifleld and Kantishna regions, Alaska: U.S. Geol. Survey Bull. 

314, pp. 213-221, 1907.

4 Stuck, Hudson, The ascent of Denali, Charles Scribner's Sons, 1914. 

0 Sheldon, Charles, The wilderness of Denali, pp. 3-9, 85-91, 108-112, Charles 

Scribner's Sons, 1930. 

8 Capps, S, R., The Kantishna region, Alaska: U.S. Geol. Survey Bull. 687, 1919.
338 INVESTIGATIONS IN ALASKA RAILROAD BELT, 1931

Stewart 7 visited the Kantishna region in 1920 and gave a brief 

description of the camp.

A. H. Brooks 8 and S. R. Capps,9 both of the Geological Survey, 

made brief visits to the district in 1921 and 1922, respectively.

J. A. Davis, of the Bureau of Mines, made a study of the lode deposits of the Kantishna district in the fall of 1922, and his description 

of the claims of the district was published in the annual report of the 

mine inspector to the Governor of Alaska for the year 1922.

F. H. Moffit,10 of the Geological Survey, spent 6 weeks in this 

region during the summer of 1930 for the purpose of gathering 

additional information about the mines and placers with the view of 

determining the possibilities of future production from this district.

FIELD WORK AND ACKNOWLEDGMENTS

The field work for this report was done during the summer of 

1931. The party of 5 men, consisting of the writer as geologist and 

chief, S. C. Kain, topographer, a recorder, a cook, and a packer, 

with 7 horses, left McKinley Park station June 10 and. returned 

to the station September 8, spending 77 days in actual field work 

exclusive of the time of travel to and from the railroad.

Flying levels were carried into the district from the nearest precise level bench mark, which was at McKinley Park station, by 

Mr. Kain. The primary control for the topographic map on a field 

scale of 1 to 48,000 (see pi. 28) was made according to the usual 

methods employed by the Alaskan branch of the Geological Survey, 

and the topography was mapped by the usual plane-table and 

traverse methods.

From the middle of July to the end of the field season the peaks

and ridges were frequently covered with fog, thereby greatly retarding the progress of topographic mapping, and much of the time 

it was so rainy or foggy that satisfactory work could not be done. 

Consequently the field season came to an end with the boundary of 

the map not completely filled out.

The writer takes this opportunity to thank all those whose help 

contributed to the success of the project the Alaska Railroad, 

especially Col. O. F. Ohlson; the Alaska Road Commission, especially 

Mr. C. Edmonds, whose generous assistance expedited the journey 

from McKinley Park station to the field; Messrs. Lee Swisher and

7 Stewart, B. D. (Territorial mine inspector), Annual report for 1920, pp. 12-14, 

Juneau, 1921.

8 Brooks, A. H., The Alaskan mining industry in 1921: U.S. Geol. Survey Bull. 739, 

pp. 35-37, 1923.

8 Capps, S. R., Geology and mineral resources of the region traversed by the Alaska 

Railroad : U.S. Geol. Survey Bull. 755, pp. 141-144, 1924.

10 Moffit, F. PI.. The Kantishna district, Alaska: U.S. Geol. Survey Bull. 836, pp. 

301-338, 1932.
LODE DEPOSITS OF EUREKA AND VICINITY 339

N. Anderson, of the National Park Service; Mr. and Mrs. J. B. 

Quigley, for their hospitality and assistance at all- times; Messrs. 

C. A. Trundy, 0. M. Grant, John Busia, and Charles Greiss, for 

their hospitality; and all the miners in the district, who were always 

willing to assist.

GEOGRAPHY 

DRAINAGE

The general features of the area are shown on the map (pi. 28). 

The western part of the Kantishna Hills lies within the drainage 

basin of the Bearpaw Biver, a tributary of the Kantishna Kiver. 

The drainage forms a reticulate pattern consisting of creeks flowing 

in general northeast or southwest and of others flowing northwest 

or southeast. As the area considered forms part of the headwater 

portion of the Bearpaw drainage basin, most of the streams flowing 

through the area have their source within its confines and are 

consequently short, flow in narrow valleys, and have steep gradients, 

ranging from 150 to 600 feet to the mile. The only exception, Moose 

Creek, the largest stream in the area, the floor of whose valley is. 

about a quarter of a mile wide, has an average grade of 50 feet to the 

mile. Moose Creek flows nearly westward across most of the southern part of the area, then turns and flows toward the north. Tributary to Moose Creek from the north are Spruce, Glen, Dry, and 

Rainy Creeks and tributaries too small to be named. Spruce Creek, 

about 3 miles long, flows toward the southeast with an average grade 

of 300 feet to the mile. Glen Creek is about 4 miles long and has a 

grade of 300 feet to the mile; 3 miles from its mouth it receives a 

branch from the east called East Fork, and above it the main stream 

is called West Fork. The lower part of Glen Creek, like the lower 

part of Spruce Creek, flows through a narrow canyon. Rainy 

Creek is about 3 miles long. In its upper course the creek flows 

southwestward, but about 2 miles above its mouth it turns abruptly 

and flows to the southeast. The longest tributary of Moose Creek. 

Eldorado Creek, is about 5 miles long. Entering Moose Creek from 

the southwest through a narrow steep-walled canyon about a quarter 

of a mile long, it flows in its upper course with a grade that diminishes from 150 to 50 feet to the mile through a constantly widening 

valley. Eureka Creek, which enters Moose Creek from the northeast at a point just opposite Eldorado Creek, is about 4 miles long 

and flows through a gorge in its lower course with a grade of 300 

feet to the mile. Friday Creek is small but important because of 

the fact that it has yielded considerable gold. It enters Moose 

Creek from the northeast, is 2 miles long, and has a gradient that 

averages 600 feet to the mile.
340 INVESTIGATIONS IN ALASKA BAILBOAD BELT, 1931

The second largest stream in the area is Glacier Creek, a tributary 

of the Bearpaw. Glacier Creek flows toward the northwest within 

the confines of the area, but it gradually turns and enters the Bearpaw River from the south. The valley of Glacier Creek is narrow 

and steep throughout its length and in its lower part is a canyon. 

Glacier Creek receives little drainage from the north, but tributary 

to it from the south are Twenty-two Gulch and Yellow Creek, short, 

swift streams occupying narrow, steep valleys. Caribou Creek, 

which lies just to the north of the area mapped, flows north and 

parallel to Glacier Creek on the east. It not only parallels Glacier 

Creek, but its valley is very similar. Like Glacier Creek, Caribou 

Creek receives little drainage from the north, but Crevice, Last 

Chance, and Snowshoe Creeks enter from the south. Those creeks, 

each about 3 miles long, occupy steep valleys and head against the 

ridges on the northern boundary of the area.

BELIEF

When viewed from the north the Kantishna Hills are seen to rise 

from the valley of the Kantishna River, a part of the Tanana lowlands, as a mass of large rounded hills with a relatively flat crest 

that slopes steeply toward the southwest. Although from a distance 

the region appears to be one of gentle slopes and low relief, this 

is not the case, for the hills rise from the lowland at an elevation 

of about 600 feet to 4,960 feet at the top of Kankone Peak, the 

highest point in the area. The area has been thoroughly dissected, 

and though the ridge tops are nearly flat or rounded, the valleys are 

narrow and sharply incised and have steep slopes.

What has been said for the Kantishna Hills in general is equally 

true of the specific part that is the subject of this report. The valley 

of Moose Creek ranges in elevation from 1,500 to 2,000 feet, and the 

ridge tops range from about 3,000 feet to a high point of 4,750 

feet on Spruce Peak. The ridge tops have a general slope southwestward but in detail are marked by knobs and shallow saddles. 

With the exception of Moose Creek the valleys are all narrow and 

steep, but they tend to broaden out toward their heads. The eastern 

part of the area is the most highly dissected, consequently the ridge 

tops there are narrower, and their general northeasterly trend is not 

so pronounced; toward the west, however, where the surface is less 

dissected, it shows a smoother slope toward the lowlands.

CLIMATE

The Kantishna district lies within the climatic province of the 

Tanana and Yukon Valleys, and in general its cl'mate is similar 

to that of the province as a whole. Owing to its position just north
LODE DEPOSITS OP EUREKA AND VICINITY 341

of the highest portion of the Alaska Range, however, its climate 

shows some marked differences. ' 

At present there is no weather station within the district, though 

one was maintained at Wonder Lake from 1925 to 1929. The records 

taken at that time may be supplemented by the records of the 

McKinley Park weather station, which has been maintained since 

December 1922 and which, being situated on the north flank of the 

Alaska Range, is in a somewhat analogous position, though 63 

miles to the east. Although the records for both stations are of 

short duration and incomplete, they serve as a basis for some general 

statements about the climate.10a

The winters are long, and the summers have moderate temperatures. Unlike the Tanana Valley proper, this area is never hot during 

summer, and no month of the year is free from frost. Snow may 

be expected any time after the first of September and rarely falls 

after the first of June, although 2 feet of snow fell on June 6, 1931. 

The rainfall is moderate, the greater part falling in the period from 

May to September. During summer the weather is squally, and 

even when the sky is not overcast showers may be expected.

VEGETATION

The Tanana lowland contains fair stands of spruce and cottonwood, especially along the courses of the larger streams and on the 

lower, well-drained slopes of the foothills, as well as some birch 

on the drier hillsides and tamarack and scrubby spruce in the 

marshes. Spruce trees furnish the only logs from which merchantable lumber is cut, and few of these exceed 24 inches in diameter 

at the base, so that they will probably furnish lumber only for 

local use. Timbered areas extend in narrow tongues from the lowland southward along the valleys of the main streams. Spruce is 

essentially limited to areas below 3,000 feet, though a few trees 

were seen as high as 3,700 feet. Even in the tracts below 3,000 feet 

in elevation there are large swampy areas in which trees are sparse 

or altogether lacking. Lumber and firewood must be hauled to 

practically all the placer claims on which mining is in progress. 

In most of the valleys, however, willow bushes large enough to 

furnish tent poles and fuel for the camper may be found at elevations several hundred feet above the upper limit of spruce, and it is 

upon such bushes that the prospector and explorer must depend.

Grass for horses can be found at almost any place where fuel 

can be had for the camp fire, and during summer it affords adequate 

forage for pack horses if they have sufficient opportunity to graze. 

The principal herbage on which the horses feed consists of redtop

10a Reed, J. C., The Mount Eielson district, Alaska: U.S. Geol. Survey Bull. 849-D, pp. 

240-243, 1933.
342 INVESTIGATIONS IN ALASKA RAILBOAD BELT, 1931

grass, bunch grass, and a vetch locally called pea vine. In autumn, 

however, early heavy frosts cause most of the grasses to lose their 

nutritive value, and horses must be fed on hay and grain if they 

are used for heavy work.

Blueberries grow profusely on the slopes above timber line and 

furnish a welcome article of food during August and September. 

A small wild cranberry is also abundant locally and is most palatable. Raspberries and currants occur within the timbered areas.

In the area here called Eureka and vicinity practically all the 

better timber has been cut. Though timber once extended up the 

valley of Moose Creek to an elevation of 2,700 feet and was fairly 

thick on the north side of the valley between Rainy and Spruce 

Creeks, this has been almost entirely removed, with the exception 

of small stands of poplar in parts of Moose Creek and a little spruce 

along the lower part of Rainy Creek, Number Four Gulch, a tributary of Glen Creek, and lower Spruce Creek.

On most of the creeks within the area success has been attained 

in the cultivation of garden vegetables, and one garden has been 

productive on the southeast side of a ridge at an elevation of 2,900 

feet. Most of the miners give their gardens but scant attention after 

they are once planted, and yet they yield fair crops. Radishes, head 

lettuce, spinach, rutabaga, cabbage, cauliflower, potatoes, rhubarb, 

strawberries, and currants have been successfully grown. Garden 

flowers, including several varieties of poppies and pansies, and many 

native wild flowers bloom in profusion. The uniform success of 

vegetable and flower gardens through many successive years gives 

assurance that miners in the region can grow many of the vegetables 

they need.

' POPULATION

The only permanent inhabitants of this region are the miners. Of 

the thousands of people who rushed into the region in the stampede 

of 1905, when placer gold was discovered, practically all left when 

it became apparent that the deposits of gold-bearing gravel were 

neither so widespread nor so rich as had been imagined. The towns 

then built, Diamond, Glacier, and Eureka, were soon practically 

deserted. A few remained to work the creeks, however, and in 1916, 

according to Capps,11 there were some 40 or 50 men in the Kantishna 

region. In 1920-21, when Mr. Aitken was working the claims of 

J. B. Quigley, the population increased slightly, but when that 

work ceased it again dwindled, until in the summer of 1931 there 

were only 19 persons in the whole region, 14 of whom were in the 

area covered by this report. Roosevelt is now deserted; only one 

trader and a trapper live at Diamond, and two or three men who

11 Capps, S. R., The Kantishna region, Alaska: U.S. Geol. Survey Bull. 687, p. 18, 1019
LODE DEPOSITS OF EUREKA AND VICINITY 343

are on the creeks during the summer spend the winter there. One 

man lives at Eureka, and two other men winter there. Most of the 

inhabitants are placer miners who work the placers in summer and 

do some trapping in winter. Two of the number, J. B. Quigley 

and C. A. Trundy, are primarily interested in lode mining.

GEOLOGY

PRINCIPAL FEATURES

The bedrock of the Eureka and vicinity area is dominantly the 

Birch Creek schist. This formation here has two distinct facies 

a quartz-muscovite schist and a calcareous schist ranging from limestone to chlorite schist. The only other rocks are the unconsolidated gravel deposits along the present streams and a few small dikes 

of igneous rocks that have intruded the schist.

BIRCH CREEK SCHIST

The Birch Creek schist, of pre-Cambrian age, as exposed in this 

area has been divided on the basis of lithologic differences recognized 

in the field into a quartz-muscovite schist and a calcareous schist. 

Though the two types show considerable variation within themselves and in places seem to be gradational one into the other, yet 

in the main they are sufficiently distinct to warrant separate mapping. 

The distribution of these two types of rock is indicated by the map 

(pi. 28) so far as information is available.

QUARTZ-MUSCOVITE SCHIST

CHARACTER AND DISTRIBUTION

Characteristically the quartz-muscovite schist where well exposed 

and free from weathering effects is a gray schistose rock composed 

predominantly of quartz and breaking in large angular blocks. On 

many of the surfaces that are at an angle to the foliation no mica 

is discernible in hand specimens, but on others it can be/ readily 

recognized. On surfaces parallel to the foliation the silvery sheen 

of muscovite is a characteristic feature. The rock usually shows 

a general color banding in tones of gray, parallel to the foliation. 

Lenses and gash veins of milky-white massive quartz entirely free 

from discoloration by the oxidation of metallic sulphides are common and parallel the foliation, but they should be distinguished 

from the mineralized quartz veins that cut the formation and are 

described elsewhere (pp. 357-358).

This rock when viewed under the microscope in thin section is 

seen to consist of a mosaic of quartz with laths of muscovite showing 

a general alinement, usually lying between the quartz grains, though 

sometimes cutting them. In some specimens there are layers of

179399 33- 2
344 INVESTIGATIONS IN ALASKA RAILROAD BELT, 1931

quartz mosaic a fraction of an inch thick relatively free from muscovite that are separated by layers of muscovite. Some sections 

show no feldspar; others show a little albite. In specimens containing albite, biotite is commonly present in small amounts. 

Another common mineral is garnet, which usually occurs in small 

crystals less than a sixteenth of an inch in diameter. Zircon crystals 

are occasionally found. On weathering the rock often becomes 

stained red or reddish brown, probably from the oxidation of the 

minute grains of pyrite scattered through the schist. Frost action 

tends to accentuate the foliation, and if muscovite is at all abundant 

the schist becomes very fissile.

Another variation of the schist is found in the canyons of Moose, 

Glacier, and Caribou Creeks. This rock is a highly micaceous 

schist, some specimens appearing to be composed of only mica and 

garnet. In such specimens the garnets are both abundant and large, 

measuring as much as three eighths of an inch in diameter. Hornblende metacrysts are found in some of the rock. In thin section 

the garnet schist shows a typical cataclastic texture and is composed 

of large grains of albite, muscovite, quartz, garnet, and clinozoisite. 

The muscovite is altered to chlorite along the cleavage lines, and 

the garnets show similar alteration along the fractures.

Scattered irregularly through the areas of outcrop of the quartzmuscovite schist and in places standing above the schist, owing to 

their greater resistance to erosion, are masses of greenstone. The 

greenstones range in color from gray with a green tinge to very 

dark green. Usually though not invariably granular in texture, they 

have the general appearance of igneous rocks, but on close inspection 

the rock is seen to be much altered and chloritized. Under the microscope such rocks are seen to contain chlorite, zoisite, quartz, albite, 

and in some specimens hornblende and calcite. The relative amounts 

of these minerals differ: some are predominantly albite and chlorite, 

others zoisite and chlorite, and still others hornblende and zoisite 

with only small amounts of the other minerals. These greenstones 

are undoubtedly derived from igneous rocks of intermediate composition. The fact that they are small in size and nowhere persist 

along the strike for more than a few hundred feet would indicate 

that they are intrusive into the original formation and are not flow 

rocks interstratified with it, and therefore they are not regarded as 

an integral part of the Birch Creek schist.

STRTTCTTTKE

In this area metamorphism has almost obliterated the original 

structure of the formation, leaving as the only survival of its former 

presence some areas of color banding. Such color banding appears 

to be in general conformable to the planes of schistosity, and from
LODE DEPOSITS OF EUREKA AND VICINITY 345

this it has been assumed that in a general way the schistosity does not

 depart widely from the original bedding planes. The schistosity 

has a prevailing strike of northeast and dips to the northwest and 

southeast, away from an axis that roughly coincides with Eldorado 

Creek, Eureka Creek, and Spruce Peak, at angles that rarely exceed 

'60°. The nature of the schistosity therefore suggests a gentle anticline. Superimposed on this structure is a slight longitudinal 

folding; the folds are about 25 feet from crest to crest and have an 

.amplitude of about 5 feet and give to some small outcrops an apparent dip that is at an angle to the dip of the major structure. 

The schist is cut by both joints and faults, which strike northwest.

The dikes and veins in the area are concentrated along this structure, and it is probable that the longitudinal fissures developed along 

the crest of the anticline during folding were an important factor 

in determining their emplacement.

The garnetiferous schist that is exposed in the canyons of 

Moose, Glacier, and Caribou Creeks is in many places highly contorted, showing drag folds, and this characteristic, combined with 

the nature of the metamorphism, suggests a zone of structural 

deformation.

LIMESTONE AND CHLORITE SCHIST

The metamorphosed calcareous sediments form a discontinuous 

band of outcrops which ranges in width from 1,000 to about 4,000 

feet. This band strikes N.75° E. Its location is shown on plate 28. 

The metamorphosed calcareous sediments in general are markedly 

different from the quartz-muscovite schists in which they occur. 

They are especially well displayed in the excellent exposures on 

lower Eldorado Creek, on the ridge south of Ruby Creek, and on 

the ridge between the head of Spruce Creek and the East Fork of

 Glen Creek. In their most distinctive form they are limestones, 

usually slate-gray in color, though they grade into black and, where 

weathered, into light gray. The rock is thinly laminated, showing 

bands ranging from less than one sixteenth of an inch to half an 

inch thick. Though banding is always visible on close examination, 

weathering brings it out very clearly, so that weathered surfaces look 

like thin-bedded granular deposits. The rock is predominantly calcite, effervescing freely in dilute hydrochloric acid, and some bands 

consist of coarsely crystalline calcite showing cleavage plainly. The 

microscope shows that the rock is completely recrystallized. Some 

specimens are practically all calcite; others have layers containing 

considerable quartz and albite and small well-formed crystals of 

zircon, and this type has more or less chlorite, which usually occurs 

as bands. The rock is highly jointed and breaks into small polygonal 

or rhombic slabs or blocks. Included in the limestone are beds of 

thinly laminated quartzite.
346 INVESTIGATIONS IN ALASKA EAILKOAD BELT, 1931

The limestone grades upward into chlorite schist, a green, thinly 

foliated rock composed almost entirely of chlorite, some of which 

shows incipient alteration to biotite and a little quartz. The chlorite 

schists in turn grade into a thinly foliated rock consisting of layers 

of quartz mosaic separated by layers composed largely of zoisite 

with some muscovite. All these variants are characterized by the 

habit of breaking into rhombic or polygonal slabs or blocks, a distinctive feature that has often caused the rock to be called a slate.

Another variant, graphite schist, should also be noted, for though 

not confined in occurrence to the limestone chlorite schist it is most 

frequently found associated with that group of rocks. No large 

outcrop of this type of schist was seen, but many fragments of schist 

rich in graphite'were found. It seems to be most abundant where 

faulting has taken place and may be a result of the metamorphism 

of the organic carbonaceous matter in the original sediment.

The structure of the limestone and chlorite schist so far as could 

be determined, is concordant with the structure of the quartzmuscovite schist.

THICKNESS AND ORIGIN

Inasmuch as neither the base nor the top of the Birch Creek schist 

is recognized within the area, its thickness could not be determined. 

To judge from the known area of outcrop the thickness of the formation must be very great, but in the absence of a detailed study of a 

complete section any figure for thickness would be only a rough 

approximation.

The preceding description of the Birch Creek schist indicates 

clearly that it was derived from sedimentary material. This material 

was dominantly a rather pure sandstone, but included in it was a 

highly calcareous facies. The formation was intruded by igneous 

rocks of intermediate or basic composition and then subjected to 

regional metamorphism. During metamorphism the character of the 

original rocks was completely changed: the sandstone became a 

quartz-muscovite schist, the limestone was recrystallized, the gradational material containing considerable quartz, calcite, and feldspar 

was turned into chlorite and zoisite schist, and the igneous material 

was altered to greenstone.

AGE AND CORRELATION

The Birch Creek schist was first described and named by Spurr,1 - 

from Birch Creek, a tributary of the Yukon River. Prindle 1S

13 Spurr, J. E., Geology of the Yukon gold district, Alaska: U.S. Geol. Survey 

Eighteenth Ann. Kept., pt. 3, pp. 140-145, 1898.

13 Prindle, L. M., Gold placers of the Fairbanks district, Alaska: U.S. Geol. Survey 

Bull. 225, p. 67, 1904 ; The gold placers of the Fortymile, Birch Creek, and Fairbanks 

regions, Alaska : U.S. Geol. Survey Bull. 251, pp. 27-29, 1905.
LODE DEPOSITS OF EUREKA AND VICINITY 347

extended the name on the basis of continuous outcrop to include the 

metamorphic rocks of the Fairbanks region, and Brooks and Prindle 14 applied the name to the metamorphic rocks in the Kantishna 

region on the basis of similar lithologic characteristics. Capps 15 

continued the usage of Brooks and Prindle, and the writer has no 

evidence that is opposed to this correlation.

Mertie 16 has definitely shown that in the east-central part of 

Alaska the Birch Creek schist is of pre-Cambrian age. In the 

Kantishna area there are no reference horizons that permit dating 

this group of rocks so definitely, but, on the other hand, there is 

no evidence which would preclude such an assignment. Therefore 

a pre-Cambrian age for these old schists in this area has been adopted.

IGNEOUS ROCKS

In addition to the greenstones already mentioned, outcrops of 

igneous rocks are limited to seven small areas, none of which exceed 

3,000 feet in largest dimensions, scattered along the central part 

of the district. Though the igneous masses were poorly exposed and 

the actual contacts with the enclosing schist were not seen, yet the 

fact that they occur as relatively long, narrow bodies was evident, 

and they are consequently considered dikes. These later igneous 

rocks have been divided into an acidic type represented by quartz 

porphyry and a basic type corresponding to diabase.

QUARTZ PORPHYRY

The quartz porphyry is best seen on Friday Creek, about half a 

mile upstream from the mouth. Here in the bottom of the creek 

it is exposed for a distance of 1,400 feet, and large boulders of it 

are found downstream from the outcrop. On exposed surfaces the 

rock is pink, but on the fresh fracture it is a light-gray rock in which 

the numerous phenocrysts of quartz and feldspar, usually about 2 

millimeters in diameter, stand out conspicuously. The groundmass 

is fine-grained. Under the microscope the phenocrysts of quartz are 

seen to be rounded and bayed by corrosion and surrounded by 

aureoles of graphically intergrown quartz and feldspar. Such aureoles also surround the phenocrysts of orthoclase, and patches of 

similar material are found in the groundmass. The groundmass 

consists of microcrystalline quartz and feldspar. The orthoclase 

phenocrysts, as well as the groundmass, are partly altered to seri14 Brooks, A. H., The Mount McKinley region, Alaska, with descriptions of the igneous 

rocks and of the Bonnifeld and Kantishna districts, by L. M. Prindle: U.S. Geol. Survey 

Prof. Paper 70, pp. 56-60, 1911.

13 Capps, S. R., The Kantishna region, Alaska : U.S. Geol. Survey Bull. 687, pp. 26-29, 

1919.

10 Mertie, J. B., Jr., Geology of the Eagle-Circle district, Alaska : U.S. Geol. Survey Bull. 

S]0. pp. 17-21, 3930.
348

cite and partly to calcite, and in the groundmass laths of muscovitehave been developed.

A somewhat larger mass of this type of rock crops out on Eldorado Creek. (See pi. 28.) Here, however, the rock is highly altered, 

the phenocrysts of quartz and feldspar as well as the groundmass 

being completely sericitized or in places changed to calcite. Scattered through the rock are many fine grains of pyrite, and many of 

the weathered specimens are stained brown by the limonite formed 

from the pyrite. Kocks of similar character are exposed on theridge lying north of the upper parts of Eureka and Yellow Creeks..

DIABASE

Dikes of basic igneous rocks are found on the ridge between Yellow 

Creek and Twenty-two Gulch and in the saddle between Iron Gulch 

and Twenty-two Gulch. At the first-named locality a dike that 

strikes N. 70° W. can be traced for a distance of 1,200 feet. It is 

probably not more than 100 feet wide. In hand specimen the rock 

is dark gray and granular; under the microscope it shows a diabasic texture formed of interlocking laths of labradorite with interstitial augite and a little quartz. The rock has suffered much alteration, the feldspar being largely changed to saussurite and then tocalcite, while the ferromagnesian mineral has altered to biotite and 

chlorite or even to calcite. From its texture and mineral composition the rock is identified as a diabase.

The dike between Iron Gulch and Twenty-two Gulch strikes 

N. 60° W., is 80 feet long and 30 feet wide, and rises as a little ridge 

above the schist. Though related to the diabase, it has a slightly 

different appearance, being black and very fine grained. Under the 

microscope the rock is seen to consist of small interlocking laths 

of labradorite, between which occurs biotite. It is identified a& 

a kersantite.

No other intrusive basic igneous rocks are found in the area,, 

but as already mentioned there are many masses of greenstones 

which have not been differentiated in mapping from the Birch 

Creek schist, although they are not considered to be part of that formation. Some of these greenstones may resemble at first sight the 

intrusive diabase, but if examined carefully they usually show the 

presence of chlorite and zoisite, and under the microscope their 

metamorphic nature can easily be detected. (See p. 344.)

No definite evidence is available as to the precise age of these 

intrusive rocks. That they are younger than the Birch Creek schist 

is evident. In the Alaska Range, 20 miles to the south, both intrusive and extrusive igneous rocks are found, but they are dissimilar in general chemical and mineral composition.
LODE DEPOSITS OP EUBEKA AND VICINITY 349

QUATERNARY DEPOSITS 

GLACIATION AND GLACIAL DEPOSITS

No glaciers are found within the Kantishna Hills, and none of 

the peaks are high enough to maintain perpetual snows. Furthermore, during the last glacial stage only the heads of Glen, Glacier, 

and Caribou Creeks were high enough to support small ice tongues, 

which never attained sufficient length to reach beyond the confines 

of their narrow valleys. Nor were the hills overridden by the large 

glaciers that descended the Alaska Kange to the south and at that 

time extended much farther to the north than at present. It is 

known, however, that at some time Muldrow Glacier, which is much 

the largest glacier on the north slope of the Alaska Range and now 

ends south of the Eureka and vicinity area, pushed northward beyond its present terminus, overflowed the divide between McKinley 

Fork and upper Moose Creek, and sent several ice lobes down Moose 

Creek as far as Friday Creek and into Stony and Boundary Creeks. 

Wonder Lake lies in the glacial basin excavated by the ice that moved 

northward into Moose Creek; the pond north of Moose Creek opposite Wonder Lake, also the small ponds north of Moose Creek between 

Rainy and Glen Creeks, as well as the peculiar courses followed by 

Spruce and Glen Creeks, testify to its presence at these places. 

Though the ancient glacier left no deposits having strongly marked 

topographic expression within the area mapped (pi. 28), evidence 

of its effect is furnished by the large boulders of coarse pink granite 

brought down from the Alaska Range, which are found on the ridge 

east of Wonder Lake, throughout the length of Eldorado Creek, and 

in the lower courses of Glen, Rainy, and Friday Creeks. Such glacial 

erratics were found in Friday and Eureka Creeks as high as the 

2,000-foot contour and in Glen Creek and Eldorado Creek up to the 

2,400-foot contour. On the ridge east of Wonder Lake and also 

along the southwest boundaries of the area large erratics occur at 

an elevation of 2,900 feet, but elsewhere in the area they are nev? er 

found above 2,400 feet. It seems probable, therefore, that the erratics found at the higher level were not deposited by the advance 

of Muldrow Glacier that pushed a lobe through Wonder Lake and 

down Moose Creek but by an earlier advance, when the glacier overrode the high land south of Moose Creek and probably banked up 

on the hills just to the north. Erosion, however, has removed all 

traces of the presence of the ice north of Moose Creek.

Little can be said as to the precise time of these two ice advances, 

and on the basis of the present evidence it is impossible to correlate 

them with the advances and retreats of the continental ice sheets 

that invaded the northern United States in Pleistocene time. The
350 INVESTIGATIONS IN ALASKA KAILEOAD BELT, 1931

earlier advance, however, which was of sufficient magnitude to ride 

over the high ridges, must have occurred during one of the Pleistocene stages of glaciation, and it is probable that the later advance 

likewise took place in the Pleistocene, though some more recent local 

climatic changes might possibly have been sufficient to cause Muldrow 

Glacier to advance to Moose Creek, only 10 to 12 miles north of its 

present terminus.

POSTGLACIAL, DEPOSITS

Bordering both banks of Moose Creek and standing at various 

levels above the flood stages of the present stream are terraced 

gravel deposits. The gravel is related to the present topography, 

having been deposited by Moose Creek when a temporarily higher 

baselevel lower in its course caused the heavily loaded stream to 

build up a deposit of gravel on its wide valley floor. As this baselevel was lowered Moose Creek began to cut away the gravel deposits, but in the process of deepening its channel it encountered 

hard-rock obstructions. Wherever this happened the checked stream 

began to meander and widen its flood plain and has left a record 

of this process in the successively lower terraces that are found along 

its course. Three well-preserved terrace levels occur along the creek, 

and in its upper course there are still others. The terraces reach 

their greatest development east of Willow Creek, where they are 

in places more than half a mile wide, and the maximum exposed 

thickness of the deposits is about 75 feet. (See pi. 28.) In material, 

degree of assortment, and structure they have all the characteristics 

of stream deposits. They show no oxidation from weathering.

The gravel deposits of the present streams are found essentially at 

the level of the streams and are subject to overflow in periods of high 

water. They consequently occur as long, narrow bands following 

the stream courses. The width of the belt of gravel along any stream 

depends on the size of the stream and the shape of its valley. Within 

the mapped area these deposits, except those in the valley of Moose 

Creek, are nowhere more than 200 feet wide and are usually not more 

than 5 feet deep, though in parts of some of the streams they reach 

a depth of 10 to 15 feet, and in a few places even greater thicknesses 

have been encountered. The material is derived from the small 

basins drained by the creeks and is in consequence poorly sorted 

gravel, coarse and subrounded. Here and there thin layers of 

" muck " are interstratified with the gravel. In these gravel deposits 

are found many of the placer gold deposits of the region, and the 

gold, like the gravel, has been derived from the bedrock that forms the 

nearby slopes, has traveled but a short distance from the veins in 

which it originated, is consequently coarse, rough, and angular, and
LODE DEPOSITS OF EUREKA A.ND VICINITY 351

frequently has some of the quartz from the vein attached to it. The 

gravel in the valley of Moose Creek is derived in large part from 

the reworked terrace gravel that occurs along the course of its 

valley as well as from material derived from the Birch Creek schist, 

much of which is brought down by its tributaries. The reworked 

terrace gravel has been shown to be partly of glaciofluvial origin; 

consequently it consists not only of the subrounded boulders derived 

from the Birch Creek schist but also of well-rounded material, the 

original source of which was the Alaska Range. This gravel is 

nowhere thick, but from the head of the rock canyon 2 miles below 

the mouth of Friday Creek to a point north of Wonder Lake it is 

reported to lie on a false bedrock of blue clay, sand, and semiconsolidated gravel. At one place a pit sunk in this underlying gravel to 

a depth of about 40 feet failed to reach true bedrock. All traces 

of this pit were obliterated when the site was visited in 1931, but 

Mr. Capps,17 who in 1917 examined the excavated material, described 

it as postglacial stream gravel.

GEOLOGIC HISTORY

The formations that crop out in the area mapped are limited to 

the Birch Creek schist, of pre-Cambrian age; recent unconsolidated 

deposits along Moose Creek; a few igneous intrusives; small exposures of Tertiary deposits just north of the area; and erratic boulders 

scattered in the creeks and along the ridges in the southern part of 

the area. Only a very fragmentary part of the history of the area 

can be deciphered within the area, and even when the evidence found 

in immediately adjacent regions is utilized, the history remains far 

from complete.

In pre-Cambrian time the Kantishna district, in common with 

much of the Tanana Valley, was a basin of deposition, receiving 

sedimentary material from a land mass, the site of which is not 

yet known. The sedimentary material was largely clastic and arenaceous and to judge from its nature was probably laid down in shallow water. The great thickness of material deposited would indicate 

that sedimentation was continued for a long period. This period was 

followed by the intrusion of igneous rocks, the folding and metamorphism of the sediments, and the elevation of the region above sea 

level.

Then followed a period of erosion which in this area may have 

continued without interruption until Tertiary time. However, the 

region to the east and west along the Alaska Range, as well as the 

Cosna-Nowitna region, which lies to the northwest, is known to have

17 Personal communication.
352 INVESTIGATIONS IN ALASKA RAILROAD BELT, 1931

been invaded by the sea many times since the pre-Cambrian,18 and it 

seems not unlikely that the Kantishna district was likewise subjected 

to some of these marine invasions, especially those of Paleozoic 

time. If such marine invasions took place, all record of them has 

been obliterated in the district under consideration.

The history during all the Mesozoic and the early part of the 

Tertiary is obscure. Probably at some time during this interval 

granite and diabase dikes were intruded. In Tertiary time the northward-flowing streams of the Alaska Kange were steepened and rejuvenated by the uplift of the mountain mass and were enabled to 

carry more and coarser material than formerly. On reaching the 

edges of the lowland to the north they deposited this gravel as a 

great alluvial sheet. As the uplift of the Alaska Range continued 

more and more of the lowlands were involved in this process of deposition, and the rivers cut their valleys more deeply into the rocks 

of the mountains.

In Pleistocene time a change of climate occurred, perhaps involving an increase in precipitation and a colder mean annual temperature. Glaciers were formed, and those on the north flank of the 

Alaska Range pushed their fronts far down the valleys and even out 

into the lowland beyond the mountains, advancing to the Kantishna 

Hills and pushing a lobe down Moose Creek. Small glaciers formed 

in the heads of the valleys of the Kantishna Hills. Later an amelioration of the climate caused the glaciers to retreat, but apparently 

glacial conditions recurred and once more caused the ice to advance 

until it reached the southern edge of the Kantishna Hills. Once 

again a period of waning of the glaciers ensued, and with their re- 

. treat stream erosion was resumed in the region. The streams began 

to deepen their valleys .until some local baselevel temporarily checked

their downcutting, causing them to broaden their valleys slightly and 

form the terraces now found along many of the major streams. With 

ihe cutting through of these temporary baselevels the streams again 

began to entrench themselves, and they have continued this process 

until the present day.

ECONOMIC GEOLOGY

HISTORY OF MINING

In 1903 Hon. George Wickersham, at that time judge of the third 

 division of Alaska, conducted an expedition from Fairbanks to the 

head of navigation on the Kantishna River and then went overland 

to Mount McKinley. While traversing the Kantishna Hills he

18 Capps, S. R., The Kantishna region, Alaska: U.S. Geol. Survey Bull. 687, pp. 29-57, 

1919 ; The Toklat-Tonzona River region, Alaska: U.S. Geol. Survey Bull. 792, pp. 87-100, 

1927. Eakin, H. M., The Cosna-Nowitna region, Alaska: U.S. Geol. Survey Bull. 667, 

pp. 23-42, 1917.
LODE DEPOSITS OP EUREKA AND VICINITY 353

found gold in the gravel of some of the stream beds, and his report of 

the occurrence of gold there induced J. B. Quigley to go into the 

region. In June 1905 Mr. Quigley and his partner, Jack Horn, 

staked claims on Glacier Creek, and in July, on going over the hills to 

Eureka Creek, they found that Joe Dalton and his partner, Stiles, 

who had come into the area from the east, knowing nothing of 

Quigley's discovery, had already staked Eureka Creek. News of 

finds of coarse gold in shallow gravel in the Kantishna started a 

stampede into the area, but as soon as it was learned that the creeks 

were short and not very rich the prospectors who had rushed in left, 

so that by the fall of 1906 there were only about 50 men remaining 

on the creeks. These men continued to work the placers, and there 

has been a steady though small production since. The total production to 1931 is estimated as approximately $500,000.

The existence of lode deposits must have been soon realized by 

the placer miners, for in some places on the creeks pebbles of galena 

and stibnite were so abundant that they caused considerable trouble 

in the sluice boxes by filling up the riffles. Likewise large boulders 

of stibnite weighing many hundreds of pounds were encountered in 

sluicing, and in some places the lodes cropped out so conspicuously 

that the prospectors could not fail to see them. Such a lode of stibnite cropped out on Last Chance Creek at its confluence with Caribou 

Creek, and the high price of antimony during the Russo-Japanese 

War induced Mr. Quigley and his partner to mine and ship some 

of this stibnite, but before the ore had reached the market the price 

of antimony fell, and the ore was abandoned. Mr. Quigley's interest 

in lode mining being aroused, he has continued to prospect ever since, 

and the development of the lodes of the Kantishna district is mostly 

a result of his efforts.

Some prospecting was done on Glacier Peak and at the forks of 

Glen Creek from 1906 to 1909 by a company formed for the purpose 

by Tom Lloyd. This same group did some work in 1912 on a deposit 

on Slate Creek. Other prospectors, including William Taylor, 

Charles McGonogill, and Charles A. Trundy, held claims in the 

district. In 1920 T. P. Aitken leased the Quigley claims, from which 

he mined and shipped about 1,200 tons of silver-lead ore. This 

stimulated prospecting, but interest soon waned when it was realized 

that the search would take a long time and cost much money and 

effort. Mr. Quigley, however, continued to prospect and in 1923 

made a further shipment of ore. Except for the prospecting of 

Messrs. Quigley and Trundy there has been no lode-mining activity 

in the Kantishna region since then, and most of the prospects other 

than the patented claims have lapsed.
354 INVESTIGATIONS IN ALASKA RAILROAD BELT, 1931

The total shipment of ore from the lodes of the Eureka and vicinity area has been slightly in excess of 1,300 tons of lead-silver ore,, 

practically all of which came from the claims of J. B. Quigley. The 

ore that has been shipped from the Quigley property ranged in 

value from $128 to $400 a ton (silver at $1 an ounce), and three 

quarters of it exceeded $179 a ton. About 10 tons of lead-silver ore 

is reported to have been shipped in 1921 from the Alpha claim, now 

owned by Lawrence Ferrar. This ore is said to have assayed more 

than $200 a ton (silver at $1 an ounce). The major part of the 

value was in silver, although some of the ore contained as much as 

2.5 ounces of gold to the ton. No ore has been mined in the area 

for its gold content alone, however. A few tons of antimony ore 

was mined in 1905 and again during the World War, but none of the 

ore ever reached outside markets, though some of it was freighted to 

Koosevelt.

CHARACTER OF ORE DEPOSITS

The study of the veins of the area was hampered by the meagerness of accessible underground workings and the mantle of soiL 

Though many of the veins had formerly been exposed by both underground workings and a large number of open cuts, most of the openings are now caved and the open cuts are so filled in that the only 

existing evidence of the former presence of many of them is small 

depressions in the soil. Soil creep and sliding are so prevalent that 

even such depressions cannot be assumed to be in place, nor is it safe 

to depend solely on the distribution of material lying on the surface. 

Parts of eight tunnels with an aggregate length of 1,800 feet were 

accessible in the summer of 1931. The longest drift along a vein was 

about 500 feet, and the greatest depth attained below the surface was 

about 90 feet. It was practicable to clean out a few of the old open 

cuts, but the work necessary to open up caved workings was too great 

to be undertaken for the purposes of the present investigation. The 

statements that follow, therefore, are based in large part on information obtained by earlier workers in the region, especially from reports 

by Capps,10 who visited.the area in the summer of 1915, by Davis,2a 

who visited the area in the fall of 1922, and by Moffit,21 who visited 

the area in 1930, supplemented by observations made by the writer 

in 1931.

STRUCTURAL FEATURES

The strikes of all the veins in the district range from N. 30° E. 

to due east, but most of the veins strike N. 50°-70° E. As a rule

"Capps, S. K., op. cit. (Bull. 687), pp. 95-109, 1919.

20 Davis, J. A., in Annual report of mine inspector to the Governor of Alaska for 1922, 

pp. 113-134.

21 Moffit, F. H., The Kantishna district, Alaska : U.S. Geol. Survey Bull. 836, pp. 301- 

338, 1932.
LODE DEPOSITS OF EUREKA AND VICINITY 355

the veins dip at angles from 60° to nearly vertical toward the southeast, but a few veins dip at steep angles to the northwest. Each of 

the north westward-dipping veins, however, intersects a southeastward-dipping vein. The strike of the veins in general is the same as 

that of the foliation of the country rock, but owing to differences 

in the dip of the veins and the dip of the foliation the veins cut 

the schist. This serves in a measure to distinguish the veins from the 

lenses of milky-white massive quartz, entirely free from discoloration caused by the oxidation of metallic oxides, that form part of 

the schist and that are parallel to its structure. The' concentration 

of the veins along the anticline in the Birch Creek schist (p. 345) 

and their strike parallel to the axis of the fold strongly suggest that 

the veins were formed in longitudinal fractures developed in the 

schist by the folding.

The veins show considerable variation in width, from a maximum 

of 23 feet to a few inches. In general they are rudely tabular, 

swelling and pinching along both the strike and dip, or they are 

lenticular, pinching out at the ends but being succeeded along the 

strike by other lenses. In some places two or more parallel veins are 

separated by narrow layers of schist, and many of the veins include 

horses of schist. The contact of the vein and the hanging wall is 

usually sharp, in places being marked by a selvage of clay gouge 

a fraction of an inch thick, and the ore may show slickensiding. 

The footwall, on the contrary, is commonly cut by veinlets and 

stringers of mineral, and the contact is usually indefinite. Several of 

the veins are displaced by northwestward-striking normal faults, but 

the movement was not great, and the displacement is nowhere large. 

It is probable that the veins are fairly persistent along the strike. 

The vein on the Little Annie claim has been followed for 500 feet 

along the strike. The vein is strong in both ends of the drift and 

gives evidence of continuing both to the east and west. Little evidence is available on which to base a judgment as to the continuation 

of the veins in depth. To date the maximum vertical distance below 

the surface to which any vein has been opened up is 90 feet. From 

the nature of the mineralization, however, it seems reasonable to 

assume that the veins extend down the dip. for several hundred feet.

MINERALOGY

GANGTTE MINERALS

Quartz, calcite, siderite, epidote, scheelite, and rhodonite are the 

gangue minerals reported from the district. Of these the writer 

has seen quartz, calcite, siderite, and epidote in place. Scheelite 

is reported from the Red Top vein by Paul Hopkins, and other 

occurrences have been reported. Rhodonite, however, though com-
356 INVESTIGATIONS IN ALASKA RAILEOAD BELT, 1931

mon as large boulders in Glen Creek, has never been found in place. 

Quartz is the dominant gangue mineral. The carbonates are later 

than quartz and in places occur without accompanying metallic 

minerals. Epidote occurs as a small well-crystallized accessory 

mineral in the quartz, and the skarnlike rock that makes up part of 

Iron Hill and that contains arsenopyrite scattered through it has 

a high epidote content.

METALLIC MINERALS

Gold, arsenopyrite, pyrite, sphalerite, chalcopyrite, galena, tetrahedrite, freibergite silver-bearing tetrahedrite, stromeyerite (a 

sulphide of copper and silver), bournonite (a sulphide of lead, copper, and antimony), stephanite (a sulphide of silver and antimony), 

stibnite, pyrargyrite (ruby silver), and oxidized products of these, 

scorodite (a hydrous ferric arsenate), azurite, cerusite, melanterite, 

and stibiconite and kermesite (antimony ochers) are the metallic 

minerals reported to have been found in the district. Of these 

minerals the writer has seen all but stromeyerite, bournonite, 

stephanite, pyrargyrite, and scorodite, and Paul Hopkins, who reported the presence of stephanite, stromeyerite, and bournonite,. 

said that these minerals were not found in sufficiently large crystals 

for identification, so possibly mixtures of the simple sulphides were 

taken for these complex minerals. The relative abundance of these 

minerals is very different in different veins, but pyrite, arsenopyrite,. 

sphalerite, galena, and stibnite are the most common.

The vein deposits in the district can be divided into three types 

on the basis of the predominant mineral present (1) quartz-arsenopyrite-pyrite gold veins which contain scattered small bunches of 

galena and sphalerite; (2) galena-sphalerite-tetrahedrite-pyritechalcopyrite veins with but little gangue, which usually is carbonate, 

though some quartz is always present; and (3) stibnite-quartz veins, 

as a rule practically free from other minerals. The nests of galena 

and sphalerite found in the Little Annie quartz vein show under the 

microscope not only the arsenopyrite and pyrite typical of the quartz; 

veins but also the complete mineralogy of the galena-sphalerite veins, 

thus clearly indicating the relationship between these two. With the 

specimens available no relationship can be shown between the stibnite veins and the others, though the presence of antimony in such 

minerals as tetrahedrite and jamesonite would indicate that the stibnite belongs to this stage. Furthermore, in the Fairbanks district,22 

where similar veins occur, this relationship has been definitely 

established.

30 Hill, J. M., The lode deposits of the Fairbanks district, Alaska: U.S. Geol. SurveyBull. 849-B, 1933.
LODE DEPOSITS OF EUEEKA AND VICINITY 357

The minerals in order of their deposition from oldest to youngest 

are arsenopyrite, pyrite, sphalerite, galena, chalcppyrite (overlap), 

tetrahedrite, jamesonite, and marcasite. Quartz came prior to the 

sulphide minerals, but calcite did not come until after arsenopyrite 

and pyrite.

GOLD QUARTZ VEINS

Several veins composed predominantly of quartz with gold as the 

valuable metallic constituent are found in the area. Of these, the 

Little Annie vein has been most extensively opened up by both 

trenching and tunneling and therefore offers the best opportunity 

for study, and the statements that follow are based largely on observations made at this vein, though applicable to the others.

The vein is composed of white quartz stained brown by iron oxides. 

Much of the quartz is shattered and breaks readily into small angular pieces, but even if it does not break readily the lines of fracture 

can be seen traversing the mass in all directions. In places the vein 

shows brecciation, angular pieces of white quartz cemented by other 

quartz and occasionally small patches of partly silicified schist being 

found. Rarely the quartz shows good crystal outlines. The metallic 

minerals arsenopyrite and pyrite occur as small well-formed grains 

which are seen only when the rock is examined closely. Bunches of 

galena and sphalerite from a fraction of an inch to an inch or more 

in diameter are found at places in the veins. With the help of the 

hand lens free gold can be seen in some of the quartz. The gold 

usually occurs either with or near the sulphides, much of it in ironstained cavities. In the Pennsylvania lode crystallized gold was 

found, and some of the largest dendritic pieces pounded out of the 

quartz by Mr. Quigley weighed as much as a tenth of an ounce each.

Under the microscope the quartz is seen to be a breccia composed 

of angular fragments of clear quartz surrounded by a fine-grained 

dirty quartz mosaic. Though all the quartz in any one fragment has 

the same crystal orientation, it has very irregular extinction, owing 

to crushing. Some veinlets of quartz cut these fragments. The 

space between the fragments of shattered quartz is filled with finegrained dirty quartz mosaic in which there are a few small crystals 

of clinozoisite. The crystals of arsenopyrite and pyrite usually 

occur in this interstitial mosaic, though here and there they lie in 

the large fragments along fracture lines. It is evident that after 

the deposition of some of the quartz movement took place along the 

vein whereby the quartz was fractured, some of it being finely comminuted, and then sulphides and additional quartz were introduced. 

A study of the distribution of sulphides in polished sections shows 

that movement continued in the vein until the end of sulphide
358 INVESTIGATIONS IN ALASKA EAILEOAD BELT, 1931

mineralization. This fracturing followed the deposition of arsenopyrite; then pyrite, sphalerite, galena, and chalcopyrite were formed; 

further fracturing was followed by the deposition of jamesonite, 

which in turn was fractured; and the period of mineralization ended 

with the introduction of quartz and carbonates.

GALENA-SPHALERITE VEINS

With the exception of the Red Top vein and a few feet of the 

Alpha vein none of the galena-sphalerite veins were accessible when 

the writer visited the region, so the description of their larger features is derived mainly from previous reports, and most of the specimens studied in polished section were collected from the dumps. 

The veins consist predominantly of sulphides, and many a whole 

vein is a solid mass of sulphides. The most abundant of these are 

galena, sphalerite, and pyrite. Some of the veins are almost solid 

galena, part of which is very finely crystalline and part coarsely 

crystalline. If the vein matter is composed largely of sphalerite, 

pyrite and galena are present in noticeable amounts. Though chalcopyrite occurs as a conspicuous mineral at the Neversweat prospect, 

on Eldorado Greek, it usually occurs only in small amounts, and 

in many places its presence can be detected only by means of a lens. 

The same is true of the occurrences of tetrahedrite and the other 

silver-rich minerals jamesonite and pyrargyrite, which are rarely 

visible in hand specimens. The usual gangue minerals are calcite 

and siderite, though quartz is everywhere present and may 

predominate.

STIBNITE VEINS

The stibnite veins consist of quartz and stibnite, and no other minerals except the oxidation products stibiconite and kermesite have 

been found associated with them. Many of the veins consist of solid 

stibnite containing no gangue mineral. The stibnite in places is 

coarsely crystalline, showing its characteristic prismatic development, but more commonly it is fine-grained and may closely resemble 

galena. When examined in polished section the fine-grained variety 

is seen to be a mosaic of stibnite. Some large angular fragments of 

stibnite are surrounded by a fine-grained mosaic of the same mineral, 

strongly suggesting that after the formation of the large crystals 

movement took place, breaking the crystals; and then later this 

breccia was cemented with later stibnite.

The upper portions of all the veins show some evidence of oxidation, iron staining is prevalent, cavities have been formed by the 

removal of metallic minerals, and oxidation minerals such as scor-
OH rt> o 0?.o-° 

O o D-° 

0) 3 n>qo> S»£-3c' ~n CD cr ^- 

D o)-o J O. en o ^ 

_ 

m <" rr 

g10-^^§§C, £0-0, 

O

;; (" T TT ° r+ ^ ? 

0) D- 01
D.S. GEOLOGICAL SURVEY BULLETIN 849 PLATE 29

EXPLANATION

1,000 3,000 Feet

U.S.L.M.

360

Tunnels and workings

SKETCH MAP OF LODE CLAIMS IN THE VICINITY OF FRIDAY AND EUREKA CREEKS.
U.S. GEOLOGICAL SUEVEY BULLETIN 849 PLATE 30

Samp/eD 

Width 3ft 

Gojd $26.46 

Silver 661.20

Sample C 

Width M 3ft 

Gold #35.55 

Silver 632.30

Samp/e25 

Width 0.7ft 

Gold $0.83 

Silver 0.10

Width 3.3ft. Width 4ft

Gold #0.83 Silver $O.IO

Samp/e 24 

Width 2 ft 

Gold $ 1.65 

Silver 1.20

Width . 5ft Width 4ft

Gold $0.83 Gold $0.83

Silver 0.20

Samp/e 23 

Width^ 2.5ft 

Gold $35.97 

Silver 6.40

Gold #1.24

Silver 0.20

WIN2E 

/ /2'/£>EEP

Sam pie 28 

Width' 3 ft 

Gold $2.89 

Silver 2.40

Sam pie I 

Width 2 ft 

Gold $1.24 

Silver 0.20

Sam pie 2 

Width 2 ft 

Gold M trace 

Silver $0.60

Sample 3 

Width M 0.7ft 

Gold $4.13 

Silver 60.60

Samp/e 4 

Width M 1.8ft 

Gold $1.65 

Silver /.20

Samp/e 5 

Width 2.5ft 

Gojd $1.24 

Silver 0.40

Samp/e 6 

Width M 1.7ft 

Gold $ 2.07 

Silver 0.20

Samp/e 7 

Width 0.8 ft 

Gold $ 0.83 

Silver 0.20

Samples 

Width' 1.5ft 

Gq/d $ 4.96 

Si/ver 0.80

Sam pie 9 

Width /.8ft. 

Gold .trace 

Silver $0.10

SamplelO 

Width' 2ft 

Gold $/.6S 

Silver 0.40

Sample/I 

Width M 2ft 

Gold $ 3./0 

Si/ver 0.60

Sample/2 

Width M /ft 

Gold $/.86 

Si/ver 0.60

Samp/e /4 

Width 4ft 

Gold ;trace 

Silver® 0.20

Samp/e 20 

Width ' 3 ft 

Gold $7.44 

Si/ver /.20

Samp/e 21 

Width. 3.7ft 

Gold $5.79 

Silver //.30

Samp/e22 

Width / ft 

Gold $2.89 

Si/ver 6.20

Samp/e 27 

Width ^3.7ft 

Gold $1.24 

Silver 1.60

Samp/e26 

Width M 3 ft 

Gold $ 2.46 

Si/ver J0.50

Samp/e 29 

Width 3.3ft. 

Go/cf $3.3t 

Silver (3.50

Samp/e30 

Width 2.9ft. 

Gold $9.10 

Silver 6.00

Sam/e 37 

5ft 

Gold ti/0.75 

Silver 1.60

Samp/e 36 

Width 3 ft. 

Gold $9.10 

Silver 1.80

Samp/e33 

Width ^4 ft 

Gojd $ 2.07 

Silver 0.20

Samp/e32 

Width^ 2.5ft 

Go./d $ 4.96 

Si/ver 3.SO

Samp/e 3I 

Width ^ 2.8ft 

Gq/d $ 2.69 

Si/ver /.40

ASSAY MAP OF RED TOP TUNNEL.
LODE DEPOSITS OF EUREKA AND VICINITY 359

odite, cerusite, malachite, stibiconite, and kermesite have been 

formed. The process has not been active, however, as most of the 

original readily oxidizable sulphide minerals still remain. Furthermore, the frozen condition of the ground does not allow free circulation of downward-moving oxygenated water. The presence of 

melanterite, a highly soluble and readily oxidized mineral, in the 

veins near the surface is excellent proof of this. Hence, though 

some oxidation has taken place in the upper few feet of the veinsr 

it appears to have been neither extensive nor deep in this district. 

As gold is practically insoluble and silver relatively so, these metals 

are left behind or migrate only a short distance in the process of 

oxidation, so the removal of other material from the vein near the 

surface leaves a product relatively richer in gold and silver. Such 

negative enrichment has probably taken place in the upper few feefc 

of the veins in the Kantlshna district.

No silver-bearing minerals that are formed only under surface 

conditions have been found in the veins of the district. The absence 

of extensive downward movement of ground water makes it seem 

unlikely that surface enrichment of the veins has taken place, either, 

during the present geologic epoch or in the Pleistocene, when glaciation prevailed. The absence of mineralogic and textural evidence 

of enrichment makes it seem improbable that any significant enrichment has taken place. There is no reason, therefore, to expect that 

the gold and silver content of the veins should diminish rapidly 

in depth.

GENESIS OF ORE

The distribution of the veins in close proximity to igneous intrusives indicates that the veins were formed by solutions given off by 

the magma that furnished the dikes. The solutions filled openings 

in the schist produced by faulting, and movement continued throughout the period of mineralization.

The mineral association, as well as the structure and texture of 

the veins, clearly places the deposits in the mesothermal or intermediate-temperature group of Lindgren.23 The clinozoisite, scheelite, and cassiterite if the cassiterite found in the placers is derived 

from these veins indicate an affiliation with the high-temperature 

deposits, whereas the stibnite veins show lower-temperature relations. 

It would seem, therefore, that although the major mineralization 

took place at intermediate temperatures, the initial temperatures 

were somewhat higher and the end temperature slightly lower than 

those characteristic of mesothermal conditions. The quartz veins of 

the Eureka and vicinity area are related in type to the gold quartz

28 Lindgren, Waldemar, Mineral deposits, 3d ed., pp. 598-717, 1928. 

179399 33 3
360 INVESTIGATIONS IN ALASKA KAILROAD BELT, 1931

a

veins of the Sierra Nevada,24 and the galena-tetrahedrite-carbonate 

veins of the Kantishna district are similar to the Wood River type 

of silver-lead veins.25 Unlike mesothennal deposits, which usually 

occur in or near intrusive bodies such as stocks or batholiths, the 

veins are found near dikes which are neither very wide nor very 

long (p. 348). This anomalous fact might be explained if the dikes 

are apophyses occurring along the flank of a large batholith. No 

direct evidence, however, has been observed either for or against 

this interpretation.

ECONOMIC FACTORS

Most of the economic factors related to the development of mines 

in the Kantishna district are largely dependent on transportation. 

As the completion of the McKinley Park road (p. 336) will basically 

change the facility and cost of transportation into the Kantishna 

within a few years, existing conditions are of only current significance, and therefore these factors will be discussed here only briefly. 

Formerly shipments of ore were hauled on wagons to Roosevelt and 

taken by boat from Roosevelt to Nenana. The cost of hauling ore 

from Friday Creek to Roosevelt was $32 a ton, and the charge from 

Roosevelt to Nenana was $25 a ton. If there were any considerable 

tonnage the cost from Roosevelt to Nenana could be somewhat 

lessened. Labor is very scarce, and the customary wage is $7 a day 

if board and lodging are furnished or $8 a day if the man provides 

his own subsistence. Except for the few cabins owned and occupied 

by the placer miners there are practically no buildings in the area. 

The nearest source of timber is on Bear Creek, a distance of 10 to 15 

miles over ground that is practically impassable during summer. 

Here an abundant supply of spruce suitable for mining purposes 

is available. On upper Moose Creek lignite beds of a fair grade as

much as 10 feet thick are exposed, and a considerable tonnage of 

lignite suitable for local fuel could be mined without much difficulty. 

Good water is abundant. Moose Creek could furnish water sufficient 

for any ordinary operations likely to take place. The canyon of 

McKinley Fork, about 10 miles to the west, is open the year round 

and might offer water-power possibilities.

MINES AND PROSPECTS 

QUIGLEY HILL

Quigley Hill is the ridge lying between Friday and Eureka 

Creeks and bounded on the west by Moose Creek. At its east end 

it attains a maximum elevation of 3,1QO feet, but its general elevation is 2,900 feet, or about 1,300 feet above Moose Creek. The

24 Lindgren, Waldemar, op. cit., pp. 616-629.

25 Idem, pp. 642-645.
LODE DEPOSITS OF EUEEKA AND VICINITY 361

location and general form of the hill are clearly shown on the topographic map (pi. 28). The systematic prospecting of J. B. Quigley, 

after whom the hill was named, has uncovered both quartz and 

galena lodes from which over 1,000 tons of ore has already been 

mined and shipped. Most of the proved mineral ground on this 

hill has been patented, some 25 patents having been issued, most of 

which are owned by Mr. Quigley. (See pi. 29.) In general, the 

hill is smooth and is covered with soil and rock debris; but its south 

slope is largely covered by alder bushes. Outcrops are mostly confined to a few ledges along the creeks and to the knobs on the ridge 

tops. The bedrock of the north slope of the hill has been mapped 

as dominantly limestone and chlorite schist. (See pi. 28.)

BED TOP

The Red Top claim (J. B. Quigley, owner) is regarded as one of 

the most promising claims in the district. It lies near the west end 

of Quigley Hill just south of Friday Creek. (See pi. 29.) The long 

dimension of the claim trends N. 67° E., roughly parallel to the 

trend of the ridge. Open cuts, shafts, tunnels, and winzes have exposed the Red Top vein for a total distance along the strike of 300 

feet and for a vertical distance down the dip of 150 feet.

The portal of the main tunnel, -the principal as well as the most 

westerly opening, is 100 feet east of the western boundary of the 

claim. The tunnel extends for 300 feet in a winding course along 

a shear zone. Short crosscuts were driven from it, and two winzes 

connect the tunnel to two stopes, a lower stope whose floor is 32 

feet below the tunnel level and an upper stope where the floor is 

12 feet below the tunnel level. The upper stope was mined to the 

surface, and both stopes were connected with the surface by a shaft. 

(See fig. 45.) Ore amounting to 102 tons was mined from these 

stopes in 1923, 80 percent of which ran equal to or better than 0.90 

ounce of gold and 214.4 ounces of silver to the ton.

About 170 feet east of the portal along the strike of the vein and 

86 feet higher up the hill is a 50-foot shaft from which drifts have 

been driven at the 25-foot level and the 50-foot level, crosscutting 

the vein. About 70 feet farther east and 24 feet up the hill is an 

open cut exposing the vein, which there has a width of 22 feet. 

Ore amounting to 28 tons was taken from the shaft and open cut. 

Though other work has been done on the claim, it had caved and 

was inaccessible in the summer of 1931.

Limestone crops out on the Red Top claim, and the limestone 

chlorite schist is found, throughout the claim. The vein, which 

strikes N. 60° E. and dips at a steep angle to .the southeast, is of 

the fissure-vein type, thinning and thickening considerably along
Quartz with some sulphide 

and included patches of schis

Quartz sulphide 

and melanterite

DETAIL OF P

I foot Of gOU£

melanterite along contact

 Geologic sketch map and section of main 
LODE DEPOSITS OF EUEEKA AND VICINITY 363

content and the gold and silver, the highest precious-metal content always occurring where the arsenic is highest. Furthermore, 

the lowest precious-metal content is associated with the largest lead 

content and the lowest arsenic content. This shows conclusively that 

the precious metals are closely associated with arsenopyrite, tetrahedrite, and jamesonite and that these minerals are not generally abundantly associated with the galena. Some of the sulphide masses 

are fairly large; the one mined, although according to Mr. Quigley 

the boundaries of the sulphides were not reached, was 27 feet along 

the strike, 4 feet thick, and 68 feet wide down the dip. Much 

melanterite occurs in the upper shaft, and Davis 26 reports sulphur 

in one of the trenches. Though these are oxidation minerals, -there 

seems to be little evidence of enrichment. The vein has been cut off 

at the east by a fault that cstrikes N, 87° W. and dips 70° S. The 

vein has not been found beyond the fault, but by drifting along 

the footwall side of the fault to the west the continuation of the 

vein should be picked up.

In the trench the vein is 22 feet wide and consists of quartz carrying galena. Assays of 5-foot samples starting at the footwall and 

crossing the vein are given below:

Sample no.

85.......... ....

86..................

Distance

from 

footwall

(feet)

0-5

5-10

Gold

(ounce 

to the

ton)

0.02

.26

Silver

(ounces 

to the

ton)

1.30

40 dC\

Sample no.

93......... .........

<u

Distance

from 

footwall

(feet)

10-15

15-22

Gold

(ounce 

to the

ton)

0.04

.10

Silver

(ounces 

to the

ton)

2.60

2.40

On the lower level of the shaft workings the following assays 

were obtained:

Sample no.

East crosscut: 

100.................................

101.................................

West crosscut: 

102.................................

103.................................

Distance 

from 

hanging 

wall (feet)

0-5

5-10.5

0-15

15-21

Material

Gold 

(ounce to 

the ton)

0.04

.03

.20

.05

Silver 

(ounces 

to the ton)

1.90

.80

15.00

1.50

The assays obtained by J. A. Davis from the main level are 

shown in plate 30. Samples A to H were taken by the owner. The 

silver was calculated as worth $1 an ounce.

The smelter returns for all the ore shipped from the stoped part 

of the Red Top vein show that 80 percent of the ore ran equal to

20 Davis, J. A., Annual report of the mine inspector to the Governor of Alaska for 1922, 

p. 12.
364 INVESTIGATIONS IN ALASKA KAILEOAD BELT, 1931

or better than 0.90 ounce of gold and 214.40 ounces of silver to 

the ton. The richest ore and poorest ore yielded the following 

assays:

Gold ..ounces to the ton _

Insoluble _______ do __

Richest

2.53 

325. 15

2

1.6

41.0

Poorest

0.22 

128.00

50.6

.6

6.8

Iron _______ percent..

Richest

11.9 

0

10.8

4.6

Poorest

6.3 

9.5

19.1

2.5

It is clear from the assays of the samples from the tunnels and 

open cut that throughout much of the vein at those places the ore 

carries less than $5 in gold and 1 or 2 ounces in silver to the ton 

but that in places there are shoots of high-grade ore.

0

POLLY WONDEB

The Polly "Wonder lies to the east and along the general trend of 

the Red Top vein, on the north slope of Quigley Hill. (See pi. 29.) 

On this property an open cut exposed a mineralized quartz vein 7 

feet wide. A sample taken across the vein assayed 0.12 ounce in 

gold and 2.20 ounces in silver to the ton. Joseph Dalton owns a 

third interest in the claim, and the remainder belongs to J. B. 

Quigley.

LITTLE ANNIE

The Little Annie claim, one of the three claims in the district from 

which ore has been shipped, is situated on the north slope of Quigley 

Hill. (See pi. 29.) Two veins have been found on the claim the 

principal vein, on which most of "the work has been done, and a small 

secondary vein from which some ore has been mined and shipped.

The smaller vein, which lies to the south of the main vein, was 

opened by a tunnel about 170 feet long and by a shaft and stope. 

At the time the writer visited the property in 1931 these workings 

were filled with solid ice, and as no maps had been made of them 

little specific information could be obtained. Davis 27 states that the 

strike of the vein is N. 20° E. and its dip 65°-70° SE. The small 

vein trends toward the main vein, though their dips are parallel. 

The ore is reported to have been almost solid galena with some 

sphalerite and a little tetrahedrite. The gangue where present was 

either siderite or calcite. It is further stated that rich ore rarely 

continued to a depth of more than 60 feet from the surface.

About 700 tons of lead-silver ore was shipped from the south vein 

in 1920. The ore averaged approximately 25 percent of lead and 

0.16 ounce of gold and 130 and 150 ounces of silver to the ton. Paul

27 Davis, J. A., op. cit., p. 128.
LODE DEPOSITS OP EUREKA AND VICINITY 365

Hopkins states that the gross return on 438.6 tons of the ore was 

$78,546.93, or an average of $179.08 a ton. At that time silver sold 

for $1 an ounce.

Five trenches roughly 50 feet apart have uncovered the main 

vein at the surface for a length of 210 feet. In this distance the vein 

ranged from a maximum width of 32 feet to a minimum of 15 feet. 

The same vein, cut in depth by an adit 85 feet long trending S. 40° 

W., has been opened by a drift 510 feet long and 11 crosscuts spaced 

at intervals of about 40 feet. (See pi. 31.) This level is 90 feet 

below the highest point of the vein as shown in the trenches at the 

surface. The vein strikes N. 59° E., dips 58°-74° S., and seems to 

be lenticular in outline, ranging in width from 3.5 feet at the east 

end to 23 feet at a point 160 feet to the west and then pinching to 

a width of 9 feet. The vein, which occurs in the schist, is of the 

fissure type and has a smooth hanging wall; the footwall is less 

definite, containing in places numerous small stringers of quartz. 

Furthermore, patches and horses of schist occur within the vein, 

and these are in places so cut by small quartz veinlets as to be largely 

composed of quartz. Movements along transverse faults that have 

a northwesterly strike have offset the vein a few feet, and movements 

along planes parallel to the vein have fractured, grooved, and slickensided the quartz.

The vein material is principally shattered quartz, usually ironstained but where unweathered consisting of broken white quartz 

with small cavities of limonite. In some places two generations of 

quartz are evident, the first consisting of angular fragments of 

quartz cemented by later quartz. As a rule sulphides are sparingly 

present, only small crystals of pyrite and arsenopyrite being seen 

scattered through the quartz. In some places, however, patches of 

galena and sphalerite from a fraction of an inch to about an inch 

in diameter are found in the quartz, and a few veinlets of quartz 

and galena occur within the main quartz vein. When such patches 

of galena or sphalerite are examined in polished sections they are 

found to contain sphalerite, galena, pyrite, arsenopyrite, chalcopyrite, and tetrahedrite. Gold occurs free in small specks.

The vein shows no true gossan, for though it is iron-stained and 

much of the arsenopyrite is completely oxidized to limonite the 

galena is fresh and unoxidized. Galena is notably resistant to 

weathering, but if the vein had been subjected to weathering for a 

prolonged period and the products were not removed by erosion it 

should be at least partly oxidized. The absence of oxidation of the 

galena therefore seems to preclude the probability of enrichment 

below, and this leads to the conclusion that the vein has not been 

materially enriched either above the water table by the removal of
INVESTIGATIONS IN ALASKA RAILROAD BELT, 1931

material or below the water table by addition of material of supergene origin. Stated otherwise, as rich ore should be found in depth 

as has already been opened up.

The west end of the main drift is still in the vein, but if the vein 

maintains its present strike it will come through to the surface in 

100 feet. Surface trenching along the eastward projection of the 

vein has failed to uncover it, but though possibly it may have been 

somewhat offset by faulting, its continuation will probably be found 

in the vicinity.

The vein as exposed in the tunnel and trenches was sampled. 

Channel samples were taken across the vein at 10-foot intervals, 

and 5-foot samples were taken along the walls of the crosscuts. 

Plate 32 is an assay map of the tunnel. With the exception of 

sample 33, which gave an unusually high assay, the average of 

all the samples taken was 0.10 ounce in gold and 2.10 ounces in 

silver to the ton for a length of 468 feet along the strike and an 

average width of 17 feet. The trench samples are listed below. 

It is possible that the vein has been slightly enriched at the surface 

by weathering.

Assays of trench samples from Little Annie claim

Sample no.

Trench 1: 

58.... .... ........ ....

59.. ..1...........................

60...-.. ............................

61... ....... ...... ........... ........

62.......... ....... ...... . .........

63... ..... .............. ................

Trench 2: 

55....... ..................... ..........

56 ....... ......... ................

57.................... ..................

54...... ................................

Trench 3: 

50... . ..- . - --

51.... ..............................

52...... .... ............................

53.. . 

Trench 4: 

U... ............................... ....

K. ............................. ........

26 

27...... ...................... ...... ....

28 

Width (feet)

5 to 10............ ....... ...... ...... ......

10 to 15.. . . . _

15 to 20............ ........... ...... .......

20 to 24..... ....... ............. ..-. ..

28 to 32...... ..............................

5 to 10 ....... ........ ... ....... ... ...

10 to 15 ....... ............ ............

15 to 20 .................. .... ... 

5 to 10. ...... ........ ... . -

10 to 15............. ............... ........

15 to 22........ ............................

10 to 20.............. __ ..................

20 to 23.. .......... ......... . . ..

Footwall to 10.. - .. 

10 to 16...... ....... ....... ....... ......

Gold 

(ounces 

to the 

ton)

3.48

.22

.30

.08

.30

2.60

.08

.06

.09

.09

.06

.09

.56

.42

.64

.24

.08

,04

.18

Silver 

(ounces 

to the 

ton)

30.20

35.00

.40

6.20

12.60

17.90

34.80

32.30

13.00

3.60

4.80

11.60

3.00

4.00

4 

1.60

.20

2.60

.10

1.40

GOLD DOLLAR AND GOLDEN EAGLE

The adjoining Gold Dollar and Golden Eagle claims lie at the head 

of Friday Creek and are contiguous to the Little Annie and Little 

Annie No. 2 claims. About 500 tons of high-grade silver-lead ore 

was mined from the Gold Dollar in 1921. The smelter returns show 

that the ore averaged more than $70 to the ton, the silver running as
TJ.S. GEOLOGICAL SURVEY BULLETIN 849 PLATE 31

Surface topography and 

mine workings surveyed 

byS.C.Kain,D.S.G.S,l93l

200 Feet

Contour interval 10 feet 

Datum is assumed sea level

CONTOUR SKETCH MAP OF LITTLE ANNIE CLAIM, SHOWING TUNNEL.
U.S. GEOLOGICAL SURVEY BULLETIN 849 PLATE 32

ASSAY MAP OF LITTLE ANNIE TUNNEL.
LODE DEPOSITS OF EUREKA AND VICINITY 367

high as 152 ounces and the gold as high as 0.18 ounce to the ton. The 

workings are now completely caved and inaccessible. According to 

Davis 28 the vein on the Gold Dollar averaged 3 to 4 feet in width 

and contained galena, sphalerite, tetrahedrite, and stromeyerite. The 

vein, which strikes N. 65° E. and dips 75° S., was developed by a

 shaft 38 feet deep and a tunnel 250 feet in length. Mr. Davis

 described the workings on the Golden Eagle as follows:

At discovery cut, near the west end line of the Gold Eagle claim, a vein

 approximately 3 feet wide was disclosed containing galena, pyrite, sphalerite, 

and the oxidation products of these minerals. The sulphides carry high values 

in silver. A tunnel was started on the east side of the small draw to intersect 

this vein and follows a crushed and slickensided zone for 60 feet along a course 

N. 70° E. It then swings to the north for an additional 60 feet, where it 

intersects the vein and follows it for 30 to 40 feet along a course N. 65° E. 

The vein dips 75° SE. The vein in the tunnel, which is chiefly quartz, does not

 contain as many sulphides as are found in the surface cut. In the tunnel these 

are confined to a band 8 or 10 inches wide near the footwall. Three or four 

tons of high-grade ore, valued at $170 per ton, were mined from the surface cut 

by the lessee in 1920.

LUCKY STRIKE

The tunnel and open cuts on the Lucky Strike claim were caved 

and completely inaccessible in 1931. Davis 28 gives the following 

description:

Two veins have been discovered on the Lucky Strike claim in the bluff overlooking M<»ose Creek. A tunnel has been driven along the strike of one of these 

veins, which is N. 59° E. The vein, which dips 84° S., is exposed for 20 feet 

above the tunnel and shows at least 6 feet of quartz between schist walls. The 

hanging wall is highly silicifled. A sample of this vein next the footwall,

 consisting of highly mineralized quartz and thought to be the richest portion, 

shows 0.04 ounce'of gold and 6.40 ounces of silver per ton. A sample of the 

next 3 feet of the vein shows 0.05 ounces of gold and 10 ounces of silver per ton. 

The vein is reported to carry valuable minerals beyond this width, but a sample

 could not be obtained.

The second vein has been exposed in two open cuts about 40 feet apart and 

lying 125 feet north of the tunnel just mentioned. They show a strong quartz 

vein, well mineralized, and probably about 8 feet wide, although the cuts were 

so badly caved that the width could not be accurately determined, nor could 

a representative sample be secured. A number of pieces of vein matter that 

were broken off at random assayed 0.04 ounce of gold and 1.40 ounces per 

ton in silver. The samples were taken by Mr. John Gross, metallurgist of the 

Bureau of Mines.

GALENA

The Galena claim lies near the west end of Quigley Hill about 

2,000 feet south of the Red Top, and is adjoined by the Francis claim 

on the east. The principal developments on this claim are a tunnel 

near the discovery stake and an open cut about 300 feet to the northeast. At the time of visit the tunnel and the open cut were partly

58 Davis, J. A., op. cit., p. 124.
368 INVESTIGATIONS IN ALASKA RAILROAD BELT, 1931

caved, so that much of the information given is derived from the report of Davis.30

The tunnel was driven through schist country rock for a distance 

of 30 feet, to a vein that strikes N. 45° E. and dips 58° SE. The vein 

was followed for 30 feet, and a winze was sunk to a depth of 20 feet. 

The vein, where now accessible, is about 2 feet wide but is reported to 

have attained in places a width of 8 or 9 feet and to have consisted of 

broken quartz containing galena, arsenopyrite, zinc blende, and tetrahedrite. On the hanging wall the vein has a sharp contact, being 

separated from the schist by about 1 foot of gouge, but on the footwall its contact is gradational, the schist being replaced by quartz, 

containing some sulphides.

The open cut northeast of the tunnel shows a quartz vein about 

a foot in width containing tetrahedrite and chalcopyrite. The strike 

of this vein is N. 45° E. and the dip nearly vertical. Between 50 

and 100 tons of ore derived partly from the tunnel and partly from 

the open cut has been mined and shipped to a smelter in California.

FRANCIS

Developments on the Francis claim consist of a tunnel along the 

strike of the vein TO feet in length, the first 40 feet of which is 

timbered, and a series of open cuts on the surface extending along 

the strike of the vein, which is N. 55° E. The vein matter in the 

tunnel is chiefly white quartz carrying a few scattered crystals of 

pyrite and some °gold. The vein changes from a nearly solid body 

of quartz 1 foot wide at the end of the timber to a network of 

quartz stringers cutting the schist at the breast. A series of samples 

gave the following assays:

Distance 

from 

portal 

(feet)

50

60

70

Width 

(inches)

12

8

12

Gold 

(ounce to 

the ton)

0.02

.04

.02

Silver 

(ounce to 

the ton)

0.80

.70

.60

As the open cuts were filled with material that had caved from the 

sides, nothing regarding the character of mineralization in them 

could be determined.

SILVER PICK AND LITTLE MAUD

The Silver Pick claim parallels the Little Maud and Little Annie 

claims and is contiguous to them on the south. (See pi. 29.) These

80 Davis, J. A., op. cit., p. 123.
LODE DEPOSITS OF EUREKA AND VICINITY 369

claims are situated on the top of Quigley Hill near its west end. 

About 200 feet east of the western boundary of the claims two veins 

that strike N« 35° E. have been uncovered at the surface by open 

cuts. The larger vein is in a shear zone about 10 feet wide made up 

of crushed iron-stained quartz with some scattered bunches of 

galena. The second vein, exposed in an open cut about 175 feet to 

the southwest, is 8 feet wide and assayed 0.04 ounce of gold and 

17.60 ounces of silver to the ton. A straight adit 150 feet long 

trending S. 34° E. was driven to cut the veins. At 50 feet from 

the portal it encountered a crushed quartz zone 5 feet wide, containing numerous bunches of galena and some pyrite and dipping 

about 65° NW. The remainder of the tunnel is in schist cut by 

numerous stringers of quartz an inch or two thick.

When Capps 31 visited the district in 1916, the tunnel was 188 

feet long, and a second vein was exposed in the face of the tunnel. 

Capps describes this vein as follows:

Near the breast of the tunnel the main vein consists of a 13-foot zone 

striking N. 35° E. and dipping 67° SE. and is therefore approximately parallel 

in strike with the vein already described but lies 130 feet northeast of it. 

This zone consists of 1 foot of calcite on the footwall and 12 feet of quartz 

and schist, more or less sheeted, the quartz predominating in bulk over the 

country rock. Little galena is seen in the tunnel, but it is abundant along 

the surface crop of the vein. The whole zone is brecciated and leached, and 

large open cracks extend from the tunnel to the surface. Pyrite, arsenopyrite, 

and small amounts of galena and sphalerite were observed, and along some 

of the cracks deposits of a soluble salt, which on analysis proved to be 

the iron sulphate melanterite, were found.

Just north of the boundary of the Silver Pick claim on the Little 

Maud claim a vein striking roughly N. 55° E. has been crosscut by 

two trenches. The vein is 13 feet wide, consists predominantly of 

quartz with some large areas of fine-grained galena in which are 

threads of chalcopyrite. Samples across the vein gave the following 

returns:

Sample no.

East trench:

88....................................................................

89---. .. .. . ........ ...........................

90. .- - - .... .....- ...................

West trench:

96.. ......................- ... ..... .........

97.. .....-.-.......... ......... . . .. .. 

98--.......... ............ ................... ... ...................

Distance

from 

north 

edge of 

vein

(feet)

0- 5

5-10

10-13

0- 5

5-10

10-13

Gold 

(ounce to 

the ton)

0.12

.10

.10

.03

.22

.08

Silver 

(ounces to 

the ton)

18.00

75.40

75.40

33.60

22.50

.80

81 Capps, S. R., The Kantishna region, Alaska: U.S. Geol. Survey Bull. 687, p. 105, 1919.
370 INVESTIGATIONS IN ALASKA BAILROAD BELT, 1931 

PENNSYLVANIA AND KEYSTONE

The workings on the Pennsylvania and Keystone claims were so 

badly caved and filled that they were inaccessible in 1931. Davis 32 

gives the following description of the veins on these claims:

There are.two principal veins on the Pennsylvania claim, which have been 

named Pennsylvania and Keystone by the owner.

The Pennsylvania vein crosses the west end line of the claim (which lies at 

the bottom of Iron Gulch) about 100 feet north of the center and extends 

up the east slope toward the Pittsburgh claims. The strike of the vein is 

N. 65° E. with a dip of 85° S., and it has been traced for over 500 feet by a 

series of open cuts spaced at approximately 100 feet intervals. Although there 

is a gap of about 1,000 feet which has not been prospected yet, hence the 

continuity is not absolutely established, it is quite likely that this vein is 

the same one that is exposed in the discovery cut on the Pittsburgh claim. 

The vein matter is quartz containing some pyrite and calcite, and free gold 

can be panned from samples taken along the outcrop.

The Keystone vein crosses the west end line of the claim at a point 100 

feet south of the Pennsylvania vein. It has a strike of N. 50° B. with a dip 

of 60° S. and extends up the hill toward the northeast corner of claim, intersecting the Pennsylvania vein about 400 feet from the west end line. It 

has been traced along the surface for more than 1,200 feet by 20 open cuts 

on the outcrop. The vein matter is chiefly quartz containing a considerable 

quantity of pyrite and arsenopyrite and some sphalerite and galena. It varies 

from 4 to 6 feet in width. A tunnel starting near the western end line of the 

claim has been driven for 50 feet along the hanging wall of the vein, and a 

shaft was sunk to a depth of 30 feet at a point near the intersection with the 

Pennsylvania vein. A sample taken by Mr. Gross across 14 inches of vein 

matter in the face of the tunnel assayed 1.6 ounces of gold and 1.60 ounces of 

silver per ton. Several ounces of finely crystallized gold were obtained by 

panning in a small open cut 60 feet east of the portal of the tunnel. A sample 

taken in the shaft by the writer gives the following assay: Gold, 0.96 ounce 

per ton, and silver, 0.20 ounce per ton.

Both the Keystone and Pennsylvania veins have been traced by open cuts

for 300 or 400 feet on this claim. There is a third vein which outcrops near 

the east end line of the claim between the other two veins and intersects both 

of them. The strike of this vein is N. 30° E., and it has a steep dip. It is 

developed by a tunnel which is 50 feet long and by several open cuts on the 

surface. The vein matter is quartz carrying galena and some pyrite. The 

vein is 3 feet wide at the portal of the tunnel but narrows to 12 inches at the 

face. Some of the assays of weathered quartz taken from the surface cuts 

show high values in gold, while others show but a trace, indicating that the 

 deposit is extremely " spotty."

BANJO

The Banjo claim is located on Lucky Gulch, a small southwardflowing tributary of Eureka Creek. (See pi. 28.) The surface is 

strewn with quartz carrying free gold. J. B. Quigley, the owner, 

has dug a series of open cuts to locate the vein in place, but in all of 

them the vein uncovered was in a block that does not appear to be

82 Davis, J. A., op. cit., pp. 129-130.
. LODE DEPOSITS OF EUEEKA AND VICINITY 371

in place. A tunnel driven 60 feet into the hill at an elevation of 

3,100 feet traversed only black graphitic schist.

DAMON AND PYTHIAS AND MEREY WIDOW

Southeast of the Banjo claim and at about the same elevation are 

the Damon and Pythias and Merry Widow claims of William 

Taylor. The only accessible working, a tunnel, follows a quartz 

vein for 90 feet to a point where the vein is cut off by a fault 

that strikes N. 52° W. and dips 30° SW. The tunnel was continued 

through the fault and 30 feet southeastward but failed to disclose 

the continuation of the vein. The vein is composed of fractured 

quartz sparsely flecked with sulphide. The vein strikes N. 84° E. 

and is about 7 feet wide.

GLACIER CEEEK

Glacier Creek and its tributaries, Yellow Creek and Twenty-two 

Gulch, have yielded considerable placer gold, and, as on the other 

auriferous creeks, considerable galena is found in the concentrates. 

Most of the prospecting for lodes has been done by surface trenching, but these trenches are now so completely caved that they show 

almost nothing as to the geology of the neighborhood. Iron-stained 

quartz, with numerous cavities, occurs both as float and croppings 

at intervals along the divide between the Glacier Creek Basin and 

those of Eureka and Dry Creeks. The float occurs in a band that 

strikes a few degrees north of east and conforms to the general trend 

of the schistosity. A series of open cuts across the quartz croppings 

was dug some time ago by William Taylor, but as far as could be 

ascertained from the surface dumps the material was predominantly 

quartz with a little sulphide.

Several prospect pits were sunk on Wickersham Dome and on 

the ridge west of the west fork of Twenty-two Gulch. A claim 

named the Florence Lode was prospected by a trench and shaft, both 

now caved. At this property was a small pile of ore consisting of 

pieces of galena showing many cavities coated with malachite. The 

galena is fine-grained and contains considerable tetrahedrite. The 

prospect is situated at an elevation of 3,500 feet. Its location is 

shown by the appropriate symbol on plate 28.

On a spur just west of the fork of Twenty-two Gulch at an elevation of about 2,700 feet is a prospect said to be owned by Otto 

Bosart. This property has been developed by two trenches and a 

shaft, 25 feet apart, along a line that strikes N. 40° E. When 

visited the trenches were caved and the shaft was full of water, 

but a small pile of sorted ore showed that the principal mineral was 

galena, some of which was coarsely crystalline but most of which was
372 INVESTIGATIONS IN ALASKA KAILEOAD BELT, 1931

finely crystalline. Associated with the galena were sphalerite and 

considerable tetrahedrite.

MCGONOGILL

The McGonogill claims are located on McGonogill Gulch, a 

small tributary of Glacier Creek near its source.

The upper claim lies at an elevation of about 3,400 feet. The 

vein, which is exposed at the surface and developed by a tunnel 

40 feet long, strikes N. 58° E., dips 34° NW., and cuts graphitic 

schist. In the face of the drift 8 feet of mineralized quartz was 

exposed. The quartz is divided into bands about a foot thick 

which are separated by seams of altered schist 1 to 5 inches thick. 

The quartz contains veinlets and scattered crystals of pyrite and 

arsenopyrite. Galena and stibnite are said to occur in the quartz, 

but neither was seen by the writer.

Part of the tunnel on the lower vein was caved at the time of visit.

The following description is taken from the report by Davis.83

«

The lower claim is also situated on the right limit of the [gulch] but approximately one-quarter of a mile toward the west and about 250 feet lower in 

elevation. The vein is exposed at the surface and consists of 18 inches of 

quartz which is free milling. One ton of ore from this outcrop was sent to 

a testing plant in Seattle and milled, yielding $80 in gold. A crosscut tunnel 

was started from the bank of the [gulch] and driven to intersect this vein. 

At a distance of 30 feet from the portal it encountered a 3-foot shear zone 

impregnated with gray copper, stibnite, and chalcopyrite, from which assays 

containing as high as 52 ounces of silver per ton was secured. This tunnel 

was extended 15 feet beyond this shear zone without encountering the freemilling quartz vein which it was driven to intersect. A crosscut was then 

driven 12 feet to the right of the tunnel along the shear zone, at the end of 

which the quartz vein was encountered. It was discovered that the vein had 

been faulted and displaced to the left and that the tunnel had been driven 

through the fault. The tunnel is 4 feet by 6 feet in the clear and is timbered 

for the first 25 feet.

GLEN CREEK

Glen Creek is one of the streams that has yielded a considerable 

amount of the placer gold produced from the district. The largest 

nugget was found in this creek, and many nuggets weighing from 1 

to 7 ounces have been recovered there. Galena, stibnite, and pyrite 

are abundant in the concentrates. Boulders of rhodonite are found, 

and crystals of cassiterite reported to have come from the concentrates have been seen by the writer. Though these facts as well as 

the croppings indicate that the basin of Glen Creek is a favorable 

area for prospecting, little work has been done in the headwater 

region, and during the last few years the old workings have all 

caved.

33 Davis, J. A., op. cit., p. 131..
LODE DEPOSITS OF EUKEKA AND VICINITY 373

On the ridge between the West Fork of Glen Creek and Kainy 

Creek are several caved prospect pits and trenches. The country 

rock is a thinly foliated schist which strikes N. 50°-75° E. and dips at 

varying angles southeastward. It seems from the distribution of 

the trenches that the veins are parallel in strike to the schistosity. 

The material lying on the surface is generally iron-stained quartz, 

usually with numerous cavities and containing crystals of pyritii, 

but in some specimens coarse crystals of pyrite predominate over 

the quartz. Some of the quartz contains a little galena.

GLEN

The Glen prospect is on the west slope of Glacier Peak. Development work on it consists of two tunnels, the lower one at an 

elevation of about 4,050 feet and the upper about 200 feet higher. 

The prospect, now the property of Lee Swisher, was formerly owned 

by a small group, Tom Lloyd having the controlling interest, and 

the tunnels were driven between 1906 and 1909. Since then no work 

has been done, and the workings are now caved and filled with ice.

The country rock is a quartzose quartz-muscovite schist showing 

but little foliation, in which the trend of the schistosity is N. 20° E. 

According to John Stendhal the lower tunnel is about 300 feet long 

and was driven along a vein that trends northeast. The vein is 

reported to consist of a quartz ledge about 4 feet wide and a zone of 

shattered decomposed rock, with bunches of galena scattered through 

the quartz. The upper tunnel is on the same vein, which can be 

traced by the float for about 300 feet westward. The material on 

the dump is mostly quartz, showing only small quantities of scattered sulphide; pyrite, galena, and sphalerite, stated in the order 

of their relative abundance, were recognized.

GLEN RIDGE NO. 1

C. A. Trundy has staked a claim, named Glen Ridge No. 1, on the 

crest of the ridge to the east of the West Fork of Glen Creek. Here 

the schist is much deformed. The top of the ridge is covered with 

quartz float, and large masses of quartz apparently in place crop 

out. Owing to the covering of surface material and the complexity 

of the structure, it was impossible to determine definitely the thickness, strike, and dip, but the vein appears to be about 20 feet thick, 

to strike N. 65° W., and to dip southwestward. The vein material 

is rusty quartz with numerous cavities, carrying some scattered finegrained galena and a little pyrite. Moffit S4 reports free gold. The 

development work consists of a pit now 6 feet deep.

81 Moffit, F. H., The Kantishna district, Alaska: U.S. GeOl. Survey Bull. 836, p. 334, 

1932.
374 INVESTIGATIONS IN ALASKA KAILROAD BELT, 1931

All openings on the Arkansas and Pension claims, situated near 

the head of the West Fork of Glen Creek, were completely caved in. 

1931. Davis 35 states that the discovery open cut at the Arkansas 

claim exposed

a mineralized zone about 14 feet wide, consisting of three bands of quarts 

separated by two bands of schist from right to left as follows: Five feet of 

quartz, 2y2 feet of schist, iy2 feet of quartz, 2% feet of schist, iy2 feet of 

quartz. A grab sample taken by the writer across the 5-foot quartz band, 

showed 90 ounces of silver per ton. The ore is chiefly sulphides of lead and 

antimony with some sphalerite.

HUMBOLDT

The following description of the Humboldt prospect, the property of John Stendhal, is in the main an abstract of the earlier 

published statement by Capps.86 The Humboldt prospect lies at 

the head of the East Fork of Glen Creek, on the high ridge that 

forms the crest of the Kantishna Hills, at an elevation of 4,250 feet. 

The schist here strikes N. 37° W. and dips 27° S.W. A tunnel said 

to be 48 feet long, driven westward, was so caved at the time of visit 

that it could not be examined. This tunnel was apparently started on 

the cropping of a vertical quartz vein that strikes N. 55° E., but it 

is said that the tunnel diverged from the vein and that no quartz, 

showed at the breast. The main vein is 3 to 4 feet wide and consists 

principally of milky-white quartz, but with somewhat stained and 

rusty quartz also present. It is massive and shows no noticeable 

banding but contains some small schist inclusions. Associated with 

the main vein are two or three smaller parallel veins, all lying 

within a zone that measures about 30 feet across. Numerous large 

pieces of vein quartz, broken from the cropping, lie on the surface 

near the mouth of the tunnel. This material contains small bunches 

and crystals of sulphide minerals scattered through it, and bunches 

of sphalerite and galena are reported to have occurred in the vein. 

No work has been done on the property for several years.

SPRUCE CREEK

Several prospect pits have been dug on the ridges forming the 

basin of Spruce Creek, but most of these have been abandoned. 

From the few pieces of iron-stained quartz lying on the surface near 

the caved pits it would seem that the pits were sunk on quartz veins 

or stringers, the quartz usually containing some arsenopyrite or pyrite. The Spruce Creek No. 1 claim of C. A. Trundy, on the saddle 

between Spruce and Crevice Creeks, is on a vein of this type. The

85 Davis, J. A., op. cit., p. 132.

88 Capps, S. R., op. cit. (Bull. 687), p. 99.
LODE DEPOSITS OF EUREKA AND VICINITY 375

vein, which is about 12 feet wide and strikes about N. 20° E., is ironstained and shows a little pyrite mineralization. Two shallow pits 

have been dug on the vein, b,ut they are both caved.

LENA AND SILVER WIRE

The Lena and Silver Wire claims both lie on the west slope of 

Spruce Peak, within the basin of Spruce Creek (see pi. 28), and both 

are owned by C. A. Trundy. The vein has been opened up by a series 

of trenches crosscutting the vein at intervals along the strike. Unfortunately all the trenches had caved, so the vein could not be seen 

in place. The country rock, a quartz-muscovite schist, strikes N. 

60°-70° E., and according to Moffit 3T the vein parallels the schistosity 

but dips at a high angle to the south, thus cutting the northwarddipping foliation of the schist. The vein as exposed in one open 

cut is 5 feet wide, and about one third is high-grade galena ore. The 

galena content becomes less to the east along the strike. According 

to Mr. Trundy, a sample of the ore assayed half an ounce in gold to 

the ton and had a total value in gold, silver, and lead of $90 a ton 

during the time of high prices for silver following the World War.

NORTH STAR

The North Star claim held by Mr. C. A. Trundy, is on the north 

slope of Spruce Peak within the drainage basin of Crevice Creek. 

The slope is strewn with talus, but at one place a stream has cut a 

small trench about 6 feet deep. In the bank of the stream a vein 2 

feet wide, composed of quartz, galena, sphalerite, and pyrite crops 

out. The country rock is a thinly laminated chloritic schist, the 

schistosity of which strikes N. 25° E. and dips 65° SE. The vein, 

however, dips 65° SE. Much coarsely crystalline galena float is 

scattered in the talus to the southwest, and Mr. Trundy said that at 

one place where he cleared away the talus he found a 6-foot vein of 

galena. This was covered when visited by the writer. The large 

amount of coarse talus on this slope shows that there has been considerable sliding, so it is possible that rock apparently in place is 

part of a large block which has suffered some movement.

ELDORADO CREEK

ALPHA

In the summer of 1931 all the workings of the Alpha claim were 

caved. Lawrence Ferrara, who now owns the claim, had dug out 

the vein at one point from which it was possible to obtain a few 

specimens. Here the vein consists of 1 foot of hard iron-stained 

galena with cavities. The material on the dump was largely jame3T Mofflt, F. H., The Kantishna district, Alaska: U.S. Geol. Survey Bull. 836, p. 333, 

1932.

179399 33 4
376 INVESTIGATIONS IN ALASKA RAILBOAD BELT, 1931

sonite with some sphalerite and crystalline quartz. . Considerable 

siderite is found with the ore. The galena from the vein assayed 

0.01 ounce of gold and 374.2 ounces o| silver to the ton and 5.46 

percent of lead. Davis 38 gives the following description of the 

Alpha claim:

The Alpha claim lies near the top of the hill on the Eldorado Creek side, 

about a mile from Moose Creek. The development work consists of a tunnel 

120 feet long, the first 100 feet of which is timbered, and a shaft 20 feet deep 

situated 60 feet S. 25° W. from the end of the timbering. The vein matter 

is highly iron-stained quartz and contains sulphides and oxides of lead and 

copper. The bottom of the shaft exposed a mineralized zone 8 or 9 feet wide 

containing three bands o'f highly mineralized iron-stained quartz, each about 

1 foot in width. Something over a ton of ore was sorted and sacked from the 

material excavated in sinking this shaft. A grab sample of this ore assayed 

by the Bureau of Mines showed 266.30 ounces of silver per ton.

NEVERSWEAT

The N.eversweat claim, the property of John Busia, is located on 

the south side of Eldorado Creek at the junction of Keinhart Creek. 

Here the side of the valley is covered by a talus of large blocks of 

quartz porphyry, and in this talus are found many large pieces, 

consisting principally of coarsely crystalline galena with some pyrite 

and chalcopyrite. A tunnel a few feet above the creek level was 

driven for more than 40 feet into an area of schist included in the 

porphyry but failed to encounter a vein, though a little mineralized 

schist was found. Two open cuts, one 100 feet and the other 150 

feet up the hill, failed to locate the vein in place. A sample of the 

ore ran 55 percent of lead and 74 ounces of silver and $10 in gold 

to the ton.

ANTIMONY PROSPECTS

Stibnite is found both in the placer concentrates and as large 

cobbles and boulders in all the creeks of the district that have been 

worked for placer gold, and owing to the conspicuous nature of 

the vein outcrops it was the first mineral to be mined from lodes 

(p. 353). Stibnite float is especially abundant in Glen, Eureka, and 

Eldorado Creeks. No lodes of stibnite have been worked in the 

drainage basin of Glen Creek. Mr. Quigley states that two lodes 

of stibnite on the south bank of Eureka Creek were opened up by 

trenches, but in the summer of 1931 no trace of the lodes could be 

found. Mr. Quigley likewise reported ,a stibnite lode on the north 

slope of Eldorado Creek, but neither he nor the writer was able 

to locate it even after much searching.

SLATE CREEK

The workings at the antimony prospect on Slate Creek were completely caved when visited in 1931, so the vein could not be examined.

48 Davis, J. A., op. cit, p. 131.
LODE DEPOSITS OF EUEEKA AND VICINITY 377

There was several tons of ore on the dump. The ore is almost pure 

stibnite, but some pieces show quartz gangue. Capps,39 who visited 

the prospect in 1916, gives the following description in his report:

The Taylor mine, or, as it is commonly called, the Antimony mine, lies 

near the head of Slate Creek, a headward tributary of Eldorado Creek. The 

property was first staked in 1907, but the title lapsed and the ground was 

restaked by the present owner. It is said to include a group of claims, but 

the work done has been confined to the driving of a tunnel 97 feet long, with 

22 feet of crosscuts, and to the excavation of an open cut immediately above 

the tunnel. The open cut and the tunnel show a strong fissure along which 

movement has taken place. This fissure strikes N. 50° E. and dips 82° SE. 

and forms the southeast wall of the main ore body, though a little ore is 

seen on its southeast side. The ore body has a maximum width of 15 feet 

and constitutes a reticulated stockwork of quartz and stibnite, with irregular 

bunches and horses of decomposed clayey schist, all much broken and confused. The enclosing quartzite schist strikes north and dips 29° E.

Almost pure stibnite occurs here in veinlets and in veins, the largest 2 

feet thick, and in irregular lenses and bunches. In some places it is solid 

and unaltered, but in others it is crushed and broken and consists of small 

fragments of quartz and stibnite recemented by yellow and reddish secondary 

oxidation products, which on analysis are found to consist of the antimony 

ochers, stibiconite and kermesite. The principal ore bodies, which occur within 

6 or 8 feet of the main fissure, seem to lie in the stockwork with their longest 

diameter oblique to the main fissure, the ore lenses and veinlets in general 

dipping 60° NW. The stibnite occurs predominantly as aggregates of acicular 

crystals but includes also masses of fine-grained material. About 125 tons of 

hand-sorted stibnite has been mined, most of which was taken from the open 

cut. That taken from the tunnel was of lower grade, as the pure stibnite 

occurred there in smaller bunches, and the ore contained more quartz and 

schist. In the absence of facilities for machine concentration much stibnite 

that could not be separated from the gangue by hand sorting was thrown 

on the dump.

HOME LODE

W. M. Julian has staked a claim called the Home Lode on the 

west bank of Crevice Creek about 1 mile above its mouth. Some 

work had been done on the lode, but it was sloughed when visited, so 

the vein could not be seen in place. The country rock is a quartzmuscovite schist. Small showings of quartz stained by iron oxide 

and yellow oxidation products of stibnite and containing a little 

stibnite were seen. The quartz has been brecciated and cemented by

later quartz.

CARIBOU

Capps 40 describes the Caribou lode as follows:

Caribou lode, in the basin of Caribou Creek, near the mouth of Last Chance 

Creek, a tributary from the southeast, is a stibnite-bearing lode on which some 

development work has been done. This property was visited by Prindie 

in 1906, and the following description is written from information gathered by 

Prindle and by the writer. Little work has been done on the property since

80 Capps, S. R., op. cit. (Bull. 687), pp. 107-108.

40 >Iclem, Trloin pp. nn 108-109. 1 nS_1 flfl
378 INVESTIGATIONS IN ALASKA EAILEOAD BELT, 1931

1906, and at the time it was visited in 1916 the shafts were full of watet 

and inaccessible. The property consists of two lode claims, the Pioneer and 

the Caribou, which lie across the lower valley of Last Chance Creek. Two 

shafts have been sunk one, 40 feet deep, on the west bank of Last Chance 

Creek, and another, 30 feet deep, on the east bank. The vein strikes N. 40° E. 

and dips about 67° SE., is about 4 feet wide, and consists of a mixture of 

quartz and stibnite. In the western shaft a vein of pure stibnite 1 foot wide 

is said to lie along the northwest wall and to become narrower toward the 

bottom of the shaft. The quartz is massive to crystalline and is intimately 

intergrown with the stibnite, which occurs as a mixed aggregate of finegrained massive sulphide intermingled with acicular crystals, the largest 2 

inches or more in length. Within the coarsely crystalline stibnite there are 

mingled many long prisms of quartz, which lie parallel with and are surrounded 

by the stibnite. The country rock enclosing the vein is much contorted hornblende schist, the general strike of which is N. 65° E. and the general dip 

35° NW. On Caribou Creek, several hundred feet northeast of the shafts, is 

an outcrop of a fissure that strikes N. 45° E. and .dips 75° SE. It is believed 

to be the continuation of the antimony lode but shows only a little quartz.

Three samples of antimony ore collected from this property in 1906 were 

assayed. One yielded 4 ounces of silver to the ton, one 2.76 ounces of silver 

and 0.12 ounce of gold, and the third 0.12 ounce of gold but no silver. Another 

sample, assayed for gold only, yielded 0.02 ounce to the ton. No ore from this 

lode has been marketed.

SUMMARY

To sum up the conclusions reached as to the mineral resources of 

the Eureka and vicinity area, it may be said the area warrants further prospecting. Much of it is practically untouched, and none of it 

has been thoroughly prospected. Exploration along the strike and 

down the dip of the known veins would probably reveal additional 

ore, and further prospecting would probably uncover new lodes. 

From what is now known concerning the nature of the mineralization and the relation of the different types of veins to one another 

it is clear that sulphide-bearing quartz veins, though carrying only 

small quantities of metals where exposed, may elsewhere contain 

shoots of gold ore or large lenses of silver-bearing galena and sphalerite. Many such veins have been staked in the past and are now 

abandoned. The small amount of trenching and drifting done on 

these veins was not sufficient to explore them thoroughly. 

., Many facts clearly indicate that the most highly mineralized area 

and the one in which prospecting seems most justified is a tract about 

2 miles wide that runs from Slate Creek to Spruce Peak and includes 

the drainage basins of Eldorado, Eureka, and Friday Creeks, upper 

Glacier Creek and its tributaries, Twenty-two Gulch and Yellow 

Creek, and Glen Creek. These creeks have furnished all the placer 

gold, and boulders and pebbles of galena and stibnite are found 

there. The axis of an anticlinal fold of the schistosity as well as 

the outcrops of the igneous dikes follow this line. Furthermore, the 

belt of outcrop of the limestone and chlorite schist occupies the 

central part of this area.
INDEX

Page

Abstract of report __ _ 335-336 

Accessibility of the area 336-337 

Acknowledgments for aid______ 338-339 

Alpha claim______________ 375-376 

Antimony prospects.- 376-378 

Arkansas claim__ 374 

Assays of ore _- 363, 364, 365, 367, 368, 

369, 370, 372, 374, 375, 376, 378

Banjo claim________ __ 370-371 

Birch Creek schist, age and correlation of _______ 346-347 

character and subdivisions of- 343-346 

thickness and origin of 346

Capps, S. R., quoted__ __ 369, 377-378 

Caribou antimony locle__ __ 377-378 

Chlorite schist, occurrence of, in

Birch Creek schist__ 346 

Climate_________________ 340-341

Damon and Pythias claim _ 371 

Davis, J. A., quoted- 367, 370, 372, 374, 376 

Diabase, occurrence and character of_ 348 

Drainage_______-_______ 339-340

Eldorado Creek, prospects on 375-376 

Eureka and vicinity, geologic map

of___ _ pi. 28 (in pocket) 

Eureka Creek, sketch map of lode

claims in vicinity of_ pi. 29

Field work_________ _____ 338 

Foreword, by Philip S. Smith v-vm 

Francis claim___ 368 

Friday Creek, sketch map of lode

claims in vicinity of-_ pi. 29

Galena claim_____________ 367-368 

Galena-sphalerite veins, features of__ 358 

Gangue minerals, character of__ 355-356 

Geologic history________ 351-352 

Geologic map of Eureka and vicinity, pi. 28

(in pocket)

Geology, principal features of_ __ 343 

Glaciation and glacial deposits-__ 349-350 

Glacier Creek, prospects on ___ 371-372 

Glen Creek, prospects on __ 372-374 

Glen prospect_____________ 373 

Glen Ridge No. 1 claim________ 373 

Gold Dollar and Golden Eagle

claims_________ 366-367 

Gold quartz veins, features of__ 357-358 

Gravel deposits, postglacial 350-351

Home Lode claim. 

Humboldt clalm_.

377

374

Page

Igneous rocks, occurrence and character of____-__- 347-348

Keystone claim. _ _____ 370

Lena claim_ _ _ _ 375 

Limestone, occurrence of, in Birch

Creek schist______ 345 

Little Annie claim___ 364-366, pis. 31, 32 

Little Maud claim__________ 368-369 

Location of the area________ 336 

Lucky Strike claim__________ 367

McGonogill claims- _ __ 372 

Merry Widow claim__________ 371 

Metallic minerals, occurrence of, In

veins _ ____ 356-357

Mining, economic factors affecting_ 360

history of _ _____ 352-354

Neversweat claimNorth Star claim.

376

375

Ore, genesis of__-_ ____ 359-360

Ore deposits, mineralogy of____ 355-358

oxidation and enrichment of_ 358-359

structural features of_____ 354-355

Pennsylvania claim- _ ______ 370 

Pension claim _ __ 374 

Polly Wonder claim__________ 364 

Population of the area_______ 342-343

Quartz-muscovite schist, character

and distribution of__ 343-344 

structure of ________ 344-345 

Quartz porphyry, occurrence and

character of_____ 347-348 

Quaternary deposits, occurrence and

character of______349-350 

Quigley Hill, mines and prospects

on_____________ 360-371

Red Top claim-__ ____ 361-364, pi. 30 

Relief in the area____________ 340

Silver Pick claim___________ 368-369 

Silver Wire claim___________ 375 

Slate Creek, antimony prospect on_ 376-377 

Spruce Creek, prospects on_____ 374-375 

Stibnite veins, features of______ 358 

Summary of conclusions __ 378 

Surveys of the area, previous 337-338

Vegetation __-__ ________ 341-342 

379

O