SAMPLING STREAM GRAVELS FOR TIN,

NEAR YORK, SEWARD PENINSULA, ALASKA

BY JOHN J. MULLIGAN

* * * * * * * * Report of Investigations 5520

UNITED STATES DEPARTMENT OF THE INTERIOR

Fred A. Seaton, Secretary

BUREAU OF MINES

Marling J. Ankeny, Director

1959
This publication has been cataloged as follows:

Mulligan, John J

Sampling stream gravels for tin, near York, Seward Peninsula,

Alaska. [Washington] U. S. Dept. of the Interior, Bureau of

Mines, 1959.

ii, 25 p. illus.,maps, tables. 27 cm. (U. S. Bureau of Mines. Report

of investigations, 5520)

Bibliography: p. 24-25.

1. Tin ores-Alaska-Seward Peninsula. 2. Tin mines and mining-Alaska-Seward Peninsula. I. Title. (Series)

LTN23.U7 no. 55201 622.06173

U. S. Dept. of the Int. Library
CONTENTS

Page

Summary ..... o........o......O.O.....O....¢.... 0 0 0..O...... I

Introduction . .o o. 2

Acknowledgments........ ..-. .. .. ... ... ............ 2

Location and accessibility. .......... ............ 2

History and production of tin placers.........-....o... 5

Physical features and climate........... o-o .... - ... 7

Labor..........9-o-.-.............. o.. -.-......... 9

Property and ownership ...... ... .... ........... 10

General geology ..... -- . .......--.-....... 10

Work by Bureau of Mines .... 10

Nature and extent......- ........ o oo....... o. 10

Sampling procedure o ...... 11

Definition of terms. 11

Method of evaluation........ .. o ..... ..... ....... 12

Summary of results......................... o..... 12

Lost and Rapid Rivers....... .... ... 12

York Creek.......oo0 ... *--* o... ....... 15

Anikovik River Valley......... oo .. 15

Kigezruk and Baituk Creeks...o.-kr e ek. ......... 17

Conclusions.......*....... ....... .o- 23

Bibliography.................. -... .... 24

ILLUSTRATIONS

Fig.

1. Index map of Alaska................................ 3

2. Geologic and location map, Brooks Mountain and

York areas..... o......- ..... , 4.......... 4

3. Placer sample locations, Lost River. 6

4. Placer sample locations, York Creek............... 6

5. Placer sample locations, York area....8..... 8

TABLES

1. Weather summary, Wales, Alaska.-... ........... 9

2. Summary of churn-drilling results, Lost and Rapid

Rivers............ .- o......... . 13

3. Spectrographic and radiometric analyses, churn-drill

concentrates, Lost and Rapid Rivers................ 14
TABLES (Con.)

Page

4. Identification of bedrock samples, Lost River....... 15

5. Summary of churn-drilling results, York Creek....,.. 16

6. Petrographic and radiometric analyses of churn-drill

concentrates, York Creek .. .............. 16

7. Identification of bedrock samples, York Creek...... 17

8. Summary of churn-drilling results, Anikovik River

Valley..................................... ... 18

9. Petrographic and radiometric analyses of churn-drill

concentrates, Anikovik River Valley .19

10. Identification of bedrock samples, Anikovik River

Valley..................*o......................o 20

11. Summary of churn-drilling results, Kigezruk and

Baituk Creeks ............................... ... 21

12. Analyses of miscellaneous concentrates, Baituk

Valley. ......... oo.......o........ .... 22

13. Petrographic and radiometric analyses of churn-drill

concentrates, Kigezruk and Baituk Creeks .......... 22

14. Identification of bedrock samples, Kigezruk and

Baituk Creeks. . ...... o......o .......... ... . 23
SAMPLING STREAM GRAVELS FOR TIN, NEAR YORK,

SEWARD PENINSULA, ALASKA2/

by

John J. Mulligan23

SUMMARY

Since 1941 the Federal Bureau of Mines has been conducting an intermittent program of placer and lode investigations to evaluate the potential tin

resources of the western Seward Peninsula tin belt. Previous investigations

were made in the Potato, Cape, Brooks (Lost River), and Ear Mountain areas.

As part of this program the Bureau made a reconnaissance of reportedly tinbearing stream gravels in areas adjacent to the previously worked tin deposits at Lost River and Potato Mountain. The objective of the reconnaissance

was to determine if additional areas might be favorable for lode or placer

exploration. The work was begun late in the fall of 1956 and completed

during the following summer.

The streams sampled were the Lost River and York Creek in the Brooks

Mountain area and the Anikovik River and Kigezruk and Baituk Creeks in the

York area. Samples were obtained by churn-drilling methods employing conventional placer-evaluation procedures. Holes were drilled at wide intervals

at sites chosen as being representative of drainage areas rather than of

individual gravel deposits. Minor to trace amounts of tin were found in the

gravels of all these streams, but the highest grade was 0.35 pound of tin

per cubic yard in the gravels of Lost River below the mouth of Tin Creek.

Small amounts of gold were found on Baituk Creek and in one hole on the

Anikovik River; the highest grade did not exceed 10 cents per cubic yard.

Traces of scheelite and barite were found on York Creek, chromite was

encountered in one hole on the Anikovik River, and minor amounts of titanium

minerals (probably derived from basaltic intrusives) were found in the York

area.

The reconnaissance did not eliminate the possibility that valuable lode

or placer deposits may be found in the area, but the sampling data strongly

indicate that the cassiterite and other heavy minerals in the stream gravels

are too widely and sparsely distributed to encourage further investigations

except in the Lost River drainage basin, where substantial tin lode and

placer deposits are known.

1/ Work on manuscript completed May 1959.

2/ Mine examination and exploration engineer, Bureau of Mines, Region I,

Alaska.
2

INTRODUCTION

Since 1941 the Bureau of Mines has been conducting intermittent investigations of lode and placer tin deposits in the western part of the Seward

Peninsula, Alaska, with the ultimate objective of evaluating the potential

tin resources of the entire area. Previous work was concentrated in the

Brooks (Lost River), Ear, Cape, and Potato Mountain areas. The results of

these investigations have been published, and the publications are listed

in the bibliography at the end of this report.

As part of this long-range program, the Bureau conducted reconnaissance

churn-drill sampling of stream gravels in the areas adjacent to the known

tin deposits in the vicinity of the Brooks and Potato Mountains. The project

was started in the fall of 1956 and completed during the following summer.

The objective was to determine the relative abundance of tin and other heavy

minerals in the stream gravels as a possible guide to areas in which more

detailed lode or placer investigations might be justified. Because of the

heavy overburden (usually frozen) and scarcity of outcrops that characterize

much of the Seward Peninsula, the examination of stream gravels provides the

only quick and comparatively inexpensive method of indicating the character

and distribution of metallic minerals. Sampling was confined to stream

gravels known to contain some tin but for which no sampling data had been

recorded. This report describes the sampling procedures and presents sample

analysis data in detail.

ACKNOWLEDGMENTS

Harvard Brown, caretaker of the Lost River mine, materially assisted

the field party on several occasions; his cooperation and hospitality are

gratefully acknowledged.

The base maps, historical notes, and geological data were compiled principally from the Federal Geological Survey publications listed in the

bibliography.

LOCATION AND ACCESSIBILITY

The Brooks Mountain and York areas are 80 to 100 miles northwest of

Nome in the western part of the Seward Peninsula, Alaska (figs. 1 and 2).

At the time of the investigation the area was uninhabited, except for a

caretaker and his family living at the Lost River tin mine. The nearest

permanently inhabited villages are Wales, about 25 miles to the west, and

Teller Mission and Teller, about 30 miles to the east. York, the shipping

point for the Potato Mountain tin-mining area, is uninhabited and the few

buildings have fallen into disrepair.

The usual means of access to the Brooks Mountain and York areas is by

bush-planes based in Nome, the distribution center for the Seward Peninsula.

Four airfields were used during the investigation. The principal airfield

is about 1-1/2 miles northwest of the mouth of Lost River and has been used

by planes as large as the DC-3. The other fields, used only by bush-planes
600 §> ~~~174° 162° 15 0° 138° 1260 114°

'A~~~~~~~~ k

FIGURE~~~~~~9 1.-Ide a f lsa
168100

ARCTIC 167 00

DLAGOOD LEG EN D

LLI Granite

Limestone

Basalt and gabbro

6 5' 45' Black slate 65'45'

swamp

* ~~~~~~TrailI

mt..

w ales >- _ _ _ _ _ _ _ _ _ _ _ _ _ _

65-30' 65__30

168 00 F G Modified after Maps of the Federal Geolo gcal Survey. 6

FIGURE 2. - Geologic and Location Map, Brooks Mountain and York Areas.
5

carrying payloads of less than 1 ton, are at the mouth of Lost River, in Lost

River Valley below the mouth of Cassiterite Creek, and in Grouse Creek Valley

at the mouth of Buck Creek.

Freight too heavy or too bulky for air transport is shipped by barge

from Nome or lightered ashore from steamships. The more commonly used landing places are near the mouths of Lost River and the Anikovik River. No

docks or freight-handling facilities are available; barges or other landing

craft are beached and unloaded on the sand. Obviously, such operations are

limited to periods of good weather.

There are few roads or trails in the area investigated. The principal

means of transportation is by tracked vehicles; crawler-type tractors towing

sleds or trailers are used most commonly. However, trucks have been used on

short roads serving mining operations at Lost River and Buck Creek.

HISTORY AND PRODUCTION OF TIN PLACERS

The first prospectors to enter the western Seward Peninsula tin belt are

believed to have been a group returning from the Kobuk area of northwestern

Alaska in 1898. They were shipwrecked and spent the winter a few miles east

of the mouth of Lost River; the stream probably derives its name from the

mishap. Members of this party, and others who arrived the following spring,

rapidly spread over the area and discovered gold on Buckner (Buhner) Creek,

a tributary of the Anikovik River, during the summer of 1899. Other discoveries soon followed. In 1900 samples of sluicebox concentrates containing a

heavy mineral were submitted to A. H. Brooks of the Federal Geological Survey

by prospectors working on Buckner Creek-and the Anikovik River. Subsequently,

the heavy mineral was identified as cassiterite. Publicity resulting from

the discovery intensified interest in the area and within the next few years

prospecting had outlined, roughly, the western Seward Peninsula tin belt as

it is now known.

Attempts to mine the gravels of the Anikovik River Valley by hand methods met with little success and were abandoned when prospecting disclosed the

more attractive deposits on Buck Creek in the Potato Mountain area, a few

miles to the north. In 1914 the American Gold Dredging Co., after prospecting with churn drills the previous season, put two floating dredges on the

Anikovik River. One dredge was towed along the shore of the Bering Sea from

near Nome to York, where it dug its own way across the bar and into the river.

The other dredge was erected on the river about a quarter of a mile from the

beach. Dredging was begun August 1, 1914, and was discontinued at the end of

the 1915 season. Only one dredge was operated. It was worked a total of 123

days; 156,000 cubic yards of gravel was handled, and 1,217 ounces of crude

gold and 1,600 pounds of concentrate containing 31 percent tin were produced.

There has been no recorded production of tin or other metals from the Anikovik

River since that time, although a number of prospect pits and trenches were

noted during this reconnaissance.

The Lost River tin mine on Cassiterite Creek, a tributary of Lost River

(fig. 3), was discovered in 1903 and has been the most extensively developed
?+ Lost River tin mine

\" 3 .6 0 ,_- 6 eek 0~~~~~~~~~~~~~~

Churn - d ri ll holes . | | ¢ A

\t_ v % Scale in Mi les 6-2

% >'N )sX ^rooks Mt. - t 0 """""'|"' L 0 E G E N D--t '

Cu r n- d rilI h oles 0~~~~~~~~~~~~~~~~~~~~~~~~~~ 2 -3

\~~~~~~~~~~ A ~~~~~~~~~~~~Scale in Miles

5 1.05'

FIGURE 3. -Placer Sample Locations, Lost River. FIGURE 4. -Placer Sample Locations, York Creek.
7

lode mine in the Seward Peninsula tin belt. At various times during the operation of the Lost River mine, placer tin was recovered from the gravels of

Cassiterite Creek. The principal production from the Cassiterite Creek

placer deposit was from 1949 through 1951, when the United States Tin Corp.

recovered 186,710 pounds of tin from 52,000 cubic yards of gravel. There

has been no recorded production from Lost River itself or from its other

tributaries.

Tin was reported in York Creek (fig. 4) in 1901 and again in 1904.

Samples, reportedly from York Creek, were described as containing "cassiterite

in fine grains associated with small amounts of magnetite, garnet, tourmaline

and quartz." Apparently no further work was done, and no signs of mining

activity were found when the stream was sampled in 1957.

During the same period prospectors discovered tin on both Kigezruk and

Baituk Creeks (fig. 5). Remnants of abandoned cabins and placer-mining

equipment found at various places along both streams indicate that mining

had been attempted, but there has been no recorded tin production from

either creek.

PHYSICAL FEATURES AND CLIMATE

The York Mountains, the principal physical feature of the area, are

steep, barren, dominantly limestone hills that rise to altitudes of 2,000 to

2,500 feet. Brooks Mountain, the highest of the group, has an altitude of

2,900 feet and differs from the others in that it consists of an exposed

granitic core surrounded by metasediments. Lost River rises on the south

side of Brooks Mountain; with its tributaries, it drains the east-central

part of the York Mountains and flows southward into the Bering Sea. York

Creek rises on the north slopes of Brooks Mountain and flows northward into

the Pinguk River, which in turn flows into the Arctic Lagoon and the Arctic

Ocean. Except for the extreme headwaters, York Creek and the Pinguk River

traverse an area of low, rounded hills that gradually merge into the Arctic

coastal plain. A scant growth of tundra vegetation partially covers the

claylike soil and broken rock on the hills; a heavier growth covers the

valleys and the coastal plain.

The Anikovik River and the Kigezruk and Baituk Creeks rise on the

plateau area extending westward from the York Mountains and flow southward

into the Bering Sea. Their drainage basins are characterized by wide valleys

and gently rounded hills varying in elevation from 600 to 800 feet. Unlike

the barren York Mountains, the entire area is mantled by a thick cover of

tundra vegetation and a scattered growth of willow brush.

The ground remains frozen throughout the area except for the top few

feet, which thaws during the summer months. The depth of the summer thaw

varies from 1 to 3 feet where the ground is insulated by a cover of moss;

where it is not insulated the thaw may extend to much greater depths.

The only timber available locally is driftwood, which collects on the

exposed beaches. The tundra mosses have furnished sustenance to reindeer,

but no herds have been in the area in recent years.
00

o~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~~~~~s

84~~~~~~~~~~~~~~~ I~ ~ ~ ~~~1

4' , I , -,' 86 

13'1

3) 33 @e X, "82~~~~~~~~~~2 0 0~~~~~~~~~~~~~~~1

0.~~~~~~~~~~~~~~~~24

/T I

t < ~~~~York 26 Churn-drill holes 0

6- \Pit samples x

|167)4 ' \Scale in Miles

W Pl67o45' A

FIGURE 5. - Placer Sample Locations, York Area.
9

The climate is subarctic and is influenced by the area's position between

the Arctic Ocean and the Bering Sea. As a consequence, high winds, fog, and

mist are unpleasantly prevalent, although the total rainfall is low. A summary of weather data, collected at Wales by the U.S. Weather Bureau follows:

TABLE 1. - Weather summary, Wales, Alaska

Average Average Average

temperature, precipitation, snowfall,

"F. inches inches

January ..................... 0.8 0.67 10.0

February .................... -1.7 .83 7.5

March ....................... -2.7 .55 6.7

April ....................... 12.8 .30 4.0

May ......................... 26.6 .43 2.5

June ........................ 38.7 .58 .2

July ........................ 46.0 1.43

August..............45.9 2.74 Trace

September ................... 40.3 1.98 .7

October ..................... 30.6 1.20 5.0

November .................... 20.0 .63 6.9

December .................... 4.4 .64 8.2

Annual average .............. 21.8 11.98 51.7

The average date for the winter ice to break up in the Bering Strait is

June 7, and the average date of the freezeup is November 29, although some

harbors freeze about 2 weeks earlier.

The highest recorded temperature at Wales was 750 F. in July 1926 and

the lowest -41° F. on February 5, 1947.

LABOR

Supervisory personnel and specialized technicians usually must be brought

from other localities, but unskilled, semiskilled, and some skilled labor can

be obtained from the native Eskimo and resident--white population of the

Seward Peninsula. A high percentage of the population is available for

employment because of the lack of industrial development. The population of

the western part of the Seward Peninsula as recorded in the 1950 census is

listed below.

Diomede . . ....... 103

Igloo................................ 64

Nome ..................... 1,930

Shishmaref ... 194

Teller ... 140

Teller Mission....................... 109

Wales................................. 141

Total ... 2,681
10

PROPERTY AND OWNERSHIP

The investigation was a preliminary reconnaissance; therefore property

records were not examined. Numerous old claim stakes were seen, but the

claims appeared to have been abandoned, and there were no signs of recent

activity. It is believed that the Bureau work was performed on the public

domain.

GENERAL GEOLOGY

The predominant types of bedrock in the area investigated are a series

of schists, shales, and phyllites generally referred to as "black-slates" and

a series of limestone beds (fig. 2). The black slates are believed to be of

Cambrian or pre-Cambrian age. The limestones overlie the black-slates and

are believed to be principally of Ordovician or Silurian age, although the

upper beds may be Mississippian.

Two distinct periods of igneous activity are evident. The earliest

period is represented by stocks, sills, and dikes of basalt and gabbro,

which intrude the slates and probably antedate the limestones. These basic

intrusives (often termed "greenstones") are a pervasive feature of the slate

areas, but only the more prominent outcrops have been mapped. The second

period of igneous activity followed the deposition of the limestones.

Granitic stocks and acidic dikes of generally similar composition intruded

both the slates and the limestones. The stocks and their associated halo

of dikes and contact-metamorphosed sedimentary rocks are more resistant to

erosion than the surrounding metasediments and tend to form mountains, of

which Brooks Mountain is a prominent example.

Tin mineralization followed the granitic intrusion and appears to have

been localized in and near the granitic stocks. Tin minerals occur in the

granite, in the contact zones, and in dikes and veins in the surrounding

metasediments.

A long period of erosion and several periods of uplift, the details of

which have not been worked out, followed the latter period of igneous activity and subsequent mineralization. However, the gravel deposits were found

to be shallower than the broad, open nature and gentle gradient of the valleys

would indicate. This is particularly evident along the Anikovik River, where

bedrock is exposed in the stream bottom within a few hundred feet of its

mouth and at intervals along its course.

WORK BY BUREAU OF MINES

Nature and Extent

The objective of the reconnaissance sampling was to determine the character, relative abundance, and distribution of heavy minerals (particularly

tin and radioactive minerals) in the stream gravels as a guide to drainage

areas that might be favorable for the discovery of lode deposits. The indication of areas favorable for more detailed placer exploration was incidental
to the lode investigation. The reconnaissance was based upon reports of early

prospecting and mining activity in the Brooks Mountain and York areas; sampling

was confined to streams in which placer tin had been reported but no sampling

data recorded. In the Brooks Mountain area (figs. 2, 3, 4), samples were

taken from the Lost and Rapid Rivers and York Creek. In the York area (fig.

5), samples were taken from the Anikovik River and its principal tributaries,

from Kigezruk Creek, and from Baituk Creek and its principal tributaries.

The reconnaissance sampling of placer deposits was planned to produce

data directly comparable with the results of the more extensive placer sampling programs conducted in the Potato, Cape, and Ear Mountain areas where

lode-tin outcrops are known. Previous experience indicated that the type and

amount of heavy minerals in the stream gravels would be roughly representative

of the heavy mineral content of lode outcroppings in the drainage basin from

which the gravels were derived. Thus the placer samples would indicate where

additional investigation might be justified. This indirect method of determining the distribution of lode minerals was resorted to because most of the

area is covered by a permanently frozen mantle of detritus and tundra vegetation. The samples from Lost River (H-3 through H-8) were taken, primarily,

to serve as a standard for comparison, since lode-tin deposits are known in

the valleys of the Cassiterite and Tin Creeks--both tributaries of the Lost

River.

Sampling Procedure

Heavy mineral concentrates were obtained from the streams by churn drilling; the samples were taken at sites considered to be representative of the

average grade of the stream gravels. Conventional placer-sampling methods

adapted to permafrost areas were used. Holes were drilled with a skid-mounted,

Fairbanks-type churn drill, using 5-inch (nominal inside diameter) casing; the

outside diameter of the casing shoe was 6-1/2 inches. In thawed ground samples were obtained from cased holes; in frozen ground, from uncased holes.

Sampling data were recorded on special drill-log forms developed for use in

permafrost areas. The samples were panned to a rough concentrate, dried,

sacked, and shipped to the Bureau experiment station in Juneau, Alaska. At

Juneau the samples were weighed, assayed for tin, checked for radioactivity,

and submitted for petrographic and/or spectrographic analyses.

Bedrock samples also were obtained from the drill holes, and a small

bedrock sample was submitted separately for petrographic analyses.

A few small tributaries of Baituk Creek were sampled by test pitting;

sample results are included, but these data are less accurate than those

obtained by churn drilling.

Definition of Terms

Terms used in recording and evaluating sampling data are defined as

follows:

Overburden (O B.) is a mixture of varying proportions of

organic material, rock decomposition products, and ice (called
12

muck by the Alaskan placer miners). Usually a dense mat of moss

and tundra vegetation, varying in thickness from 1 to 3 feet,

covers the overburden and serves as insulation, which prevents

thawing.

Pay horizon (P.H.) is the section of hole from which a heavy

mineral concentrate was obtained. In cased holes the sample

volume is the area encompassed by the cutting edge of the casing

shoe, multiplied by the depth of the pay horizon. In uncased

holes the sample volume is the volume of water required to refill

the pay horizon.

Mining section (M.S.) is the total depth of gravel and bedrock that would be excavated during mining; usually, it includes

1 foot of bedrock.

Method of Evaluation

The volume of the mining section, the amount of concentrate per cubic

yard, and the amount of tin per cubic yard were calculated as follows:

(Volume of P.H., cubic yards) depth of M.S.

depth of P.H.

= volume of M.S., cubic yards.

Weight of concentrate, pounds

Volume of M.S., cubic yards

= concentrate/cubic yard, pounds.

(Concentrate/cubic yard, pounds) (tin in concentrate, percent)

tin/cubic yard, pounds.

Summary of Results

Drilling and sampling data for the various streams are summarized as

follows:

Lost and Rapid Rivers

Six holes were drilled along Lost River (fig. 3), and tin was found in

all samples. The best hole indicated 11 feet of mining section containing

0.35 pound of tin per cubic yard; the remaining holes indicated depths of

mining section varying from 6 to 10 feet containing 0.04 to 0.27 pound of

tin per cubic yard.

Two holes were drilled along Rapid River (fig. 3), but only one reached

bedrock. The two holes indicated a depth of mining section varying from 24

to more than 30 feet and containing only traces of tin. The depth of gravel

decreases to only a few feet a short distance upstream from the drill holes.
13

Cassiterite Creek was not sampled, but production data indicated that the

gravels in the section mined averaged 3 to 4 pounds of tin per cubic yard.

This productive section extended about 2,000 feet downstream from the Lost

River lode-tin mine (fig. 3). Samples taken from Lost River a short distance

below the mouth of Cassiterite Creek (samples H-3, H-4, and H-5) indicated a

grade of about 0.05 pound of tin per cubic yard.

Tungsten was not detected in the samples from Lost River or Rapid River,

although the production records indicate that, in addition to tin, the gravels mined from Cassiterite Creek contained 0.6 to 0.7 pound of tungstentrioxide (W03) per cubic yard.

Gold was not detected in any of the drill-hole concentrates; traces of

silver were found in holes H-6 and H-7, which also contained more lead

(galena) than the other samples.

The gravels of Lost River are medium coarse and unconsolidated. Permafrost was encountered in hole H-6 at a depth of 6 feet; the other holes were

in thawed gravel. The stream drains an area barren of vegetation and consequently subject to flash floods. Flood action on loose gravels may tend

to disperse the placer minerals to a greater extent than in the other streams

sampled, where flood action is moderated by a cover of tundra vegetation.

Churn-drill sampling data resulting from holes drilled along the Lost

and Rapid Rivers are summarized in tables 2, 3, and 4.

TABLE 2. - Summary of churn-drilling results, Lost and Rapid Rivers

Pay horizon _

Drill-hole data Interval

Hole Depths, ft. From, To, Depth, Volume,

No. Total O.B. Gravel Bedrock Cased ft. ft. ft. cu. yd.

H-1....... 30.5 - 30.5 None 29.0 - -_ _ 

H-2... 25.0 - 23.0 2.0 25.0 - - - -

H-3 10.5 - 9.0 1.5 10.5 4.0 9.5 5.5 0.0469

H-4.... 10.0 - 8.0 2.0 10.0 6.5 10.0 3.5 .0299

H-5 ....... 6.5 - 5.0 1.5 6.5 .0 6.0 6.0 .0512

H-61/ ..... 12.5 - 9.0 3.5 8.5 3.0 9.5 6.5 .0516

H-71/ ... 11.0 - 10.0 1.0 10.5 5.0 10.0 5.0 .0427

H-8 ....... 7.5 - 5.5 2.0. 7.5 4.0 5.5 1.5 .0128

Concentrate Mining section

Hole Weight, Tin, Depth, Concentrate, Tin,

No. lb. percent ft. lb. per cu. yd. lb. per cu. yd.

H-....... 1.74 Trace _ Trace

H-2 .2.05 . 0.06 - _ Do.

H-3....... .90 .40 10.0 10.55 0.04

H-4....... .66 .70 10.0 7.68 .05

H-5 ....... .29 .90 6.0 5.64 .05

H-61/ ..... .92 2.50 10.0 11.55 .29

H-71/..... 1.22 2.70 11.0 13.00 2/.35

H-8 ........ 1.61 .30 6.5 29.04 .09

1/ No gold detected in any samples; trace amounts of silver found in samples

H-6 and H-7.

2/ H-7 also contains 0.04 pound per cubic yard of lead; other samples contain

traces of lead.
14

TABLE 3. - Spectrographic and radiometric analyses,'!

churn-drill concentrates,

Lost and Rapid Rivers

Letters indicate estimates from Radiometric uranium

qualitative analysis: equivalent

A - Over 10 percent. E - 0.01 to 001 percent. Sample No.

B - 5 to 10 percent. F - 0.001 to 0.01 percent. HI11 .Nil

C - 1 to 5 percent. G - Under 0.001 percent. H2.......... 0.002

D - 0.1 to 1 percent. - - Not detected. H3........ Nil

H4.......... 0.008

H5......... Nil

H6... ...... 0.002

H7 ... Nil

118 .@@ov^^"0.005

Composite Composite Composite

Hl-H2 H3-H5 H6-H7 Sample 8

Ag..-............ _ -. F _

Al................ C B B CAs..................... D

Au ..................... B................... F E E F

Ba a... .......... E E E E

Be ............ G F F F

Bi ..................... Ca .... A A A A

Cd.................

Co ...........

Cr ............. _._.

Cu .......... . F F E F

Fe ... ....... C B A C

Ga.. _ _ -....... 

Ge ..... _.. ........... _ _ 

In .. _ _ 

Li................... _ _

Mg .. ...... C B B C

Mn . E E D E

Mo ....... _._.

Na a.. D D D D

Nb.............. -......

Ni . E E E E P................ .....

Pb.................. D D D E

Pd ... ..................

Sb .....................

Si .O.. C C C C

Sn . D C C D

Sr ..................... E E F F

Ta ............

Te ............ _._.

Ti............... E E E E

V .... F E E E

W ...... . Zn ....

Zr .. F F E F

1/ Samples H1 and H2 are from Rapid River; samples H3 through H8 are from

Lost River.
15

TABLE 4. - Identification of bedrock samples, Lost River

Hole No. Stream Type of bedrock

H-4 ... Lost River Impure limestone.

H-7 ....... do. Dolomite with chlorite, fluorite, and a

trace of pyrite. Traces of lead and

zinc are present, but the minerals

could not be identified.

H-8 . .do. Limestone.

York Creek

Nine holes were drilled in the gravels of York Creek (fig. 4). Holes 1,

2, and 3 were drilled in a line near the head of the east fork of York Creek.

Traces of cassiterite were found, and consequently another line (holes 4, 5,

and 6) was drilled about 1 mile downstream. Holes 7, 8, and 9 were drilled

near the head of the west fork of York Creek.

Trace amounts of tin were found in all samples from York Creek, but

cassiterite was identified only in samples from holes 1, 2, and 3. Gold and

silver were not detected. Minor to trace amounts of scheelite and barite were

found in most of the samples, and traces of powellite were found in samples

from the west fork.

The gravels of York Creek vary in depth from 6.0 to 12.5 feet and consist

principally of fragments of schist and shale. The bedrock is dominantly shale

and limey shale containing some quartz and disseminated pyrite. The stream

was drilled in early July; the gravels underlying the stream were not frozen,

but those overlain by vegetation were frozen.

Sampling data from York Creek are summarized in tables 5, 6, and 7.

Anikovik River Valley

Twenty holes were drilled in the gravels of the Anikovik River and its

principal tributaries (fig. 5). Traces of tin were found in all holes, but

in most instances the tin mineral was not identified. Cassiterite was recognized in the gravels of Buckner Creek (hole 17), Banner Creek (hole 21), and

the Anikovik River (hole 24).

The only gold noted occurred as bright, thin flakes, one-thirty-second

of an inch in diameter and smaller, in hole 24. Based upon the number and

size of "colors," the gold value of this hole was estimated at 8 cents per

cubic yard.

Angular fragments of chromite were found in samples from hole 23 on the

Anikovik River; chemical analyses indicated slightly less than one-fourth

pound of chromite per cubic yard. Samples from adjacent holes contained no

chromite.
16

TABLE 5. - Summary of churn-drilling results. York Creek

Pay horizon

Drill-hole data Interval

Hole Depths, ft. | From, To, Depth, Volume,

No. Total TO.B. Gravel Bedrock Cased ft. ft. ft. cu. yd.

1 -..... 11.5 - 10.0 1.5 10.5 - - - -

2 . .16.0 2.0 11.0 3.0 12.0 - - - -

3 . .12.0 - 10.0 2.0 10.0 - - - -

4 . .4.5 - 12.5 2.0 10.0 - - - -

5 . .10.8 - 8.0 2.8 10.0 - - - -

6 . .8.5 - 6.0 2.5 6.0 - - - -

7. 10.5 - 7.5 3.0 8.5 _ _ _ _

8. 14.5 4.0 8.0 2.5 3.0 _ _ _ _

9 . . 15.0 - 12.0 3.0 10.0 _ _ _ _

Concentrate Mining section

Hole Weight, Tin, Depth, Concentrate, Tin,

No. lb. percent ft. lb. per cu. yd. lb. per cu. yd.

1 .. 1.58 Trace - - Trace

2 . .1.77 do. - - Do.

3. 2.20 do. - - Do.

4. 2.16 do. - - Do.

5. 1.86 do. - - Do.

6 .. 1.92 do. - - Do.

7 . .1.82 do. - - Do.

8 . .1.56 do. - - Do.

9....... 2.09 do. _ Do.

TABLE 6. - Petrographic and radiometric analyses of

churn-drill concentrates, York Creek

Hole

Nos. Light minerals and rocks Heavy minerals

1, 2, 3 Dolomite, calcite, quartz, an Pyrite, limonite pseudomorph after

unidentified clay mineral, and pyrite, garnet, tourmaline,

small amounts of chlorite, epi- apatite, barite, augite, tracesdote, diopside, and vesuvianite. of cassiterite, and scheelite.

4, 5, 6 Carbonaceous shale, schistose Pyrite, limonite pseudomorph after

limestone, dolomite, calcite, pyrite, barite, tourmaline,

quartz, epidote, and actinolite. garnet, and zircon.

7, 8, 9 Carbonaceous shale, schistose Pyrite, limonite pseudomorph after

limestone, dolomite, quartz, pyrite, garnet, barite, tourmacalcite, epidote, chlorite, line, scheelite, and powellite.

and biotite.

Radiometric-equivalent uranium

No significant radioactivity

_ detected in any samples. I
17

TABLE 7. - Identification of bedrock samples, York Creek

Hole

No. Stream Type of bedrock

4. . East Fork Limey shale with quartz and pyrite.

9............... West Fork Shale and quartz, with calcite and

traces of limonite and pyrite.

The gravels of the Anikovik Valley vary in depth from a few inches to 5

feet and are composed principally of angular fragments of shale with lesser

amounts of basalt and quartz. When the deposits were drilled in July the

bare gravels were thawed to bedrock, but those covered by soil or vegetation

were frozen.

The bedrock is dominantly carbonaceous or limey shales. Abundant disseminated pyrite and limonite pseudomorph after pyrite occurs in some beds.

An andesine dike or sill (sample 26-A) forms a prominent outcrop across the

bed of the Anikovik River a few feet upstream from holes 26 and 27. A dike

or sill, lighter in color than the greenstones common throughout the area

and composed largely of plagioclase feldspar and quartz with minor amounts

of sulfide minerals (sample 20-A), is exposed on the north bank of Banner

Creek about 15 feet downstream from hole 20. The relationship of these

intrusives to the more prominent basaltic greenstones of the area is not

known.

Sampling data from the Anikovik River Valley are summarized in tables

8, 9, and 10.

Kigezruk and Baituk Creeks

Two holes were drilled in Kigezruk Creek, and eight holes in Baituk

Creek (fig. 5). In addition, six panned concentrates were taken from the

principal tributaries of Baituk Creek. Minor to trace amounts of tin were

found in all drill holes; cassiterite was most abundant in hole 35 on Baituk

Creek, but the tin content of the gravels did not exceed a few hundredths of

a pound per cubic yard.

Gold, in amounts estimated to range from traces to 10 cents per cubic

yard, was found in holes 31, 32, 34, and 37 on Baituk Creek and in sample

pit B6 on the East Fork of Baituk Creek. The gold occurs as thin flakes

one-thirty-second of an inch and less in diameter on bedrock and in bedrock

crevices.

The gravel on Kigezruk Creek is composed largely of fragments of shale

and phyllite with some quartz. When the holes were drilled August 1 the bare

gravel was thawed to bedrock, but the gravel overlain by soil and vegetation

was frozen.

The gravel on Baituk Creek varies in depth from 4 to 15 or more feet and

is composed largely of fragments of shale, phyllite, and basalt, with lesser

amounts of quartz. During the first week in August when the stream was

drilled, the gravel was frozen everywhere except under the stream channels.
TABLE 8. - Summary of churn-drilling results, Anikovik River Valley

Pay horizon

Drill-hole data Interval Concentrate Mining section

Hole Depths, ft. From, To, Depth, Volume, Weight, Tin, Depth, Concentrate, Tin,

No. Total O.B. Gravel Bedrock Cased ft. ft. ft. cu. yd. lb. percent ft. lb. per cu. yd. lb. per cu. yd.

10 9.5 - 5.0 4.5 8.5 - - - - 2.13 Trace _ _ Trace

11 8.0 - 4.0 4.0 5.7 - - - - 2.97 do. _ _ Do.

12 8.5 - 5.0 3.5 1.5 - - - - 2.89 do. _ _ Do.

13 8.8 3.5 3.0 2.3 .0 - - - - 1.77 do. _ _ Do.

14 11.0 3.5 4.5 3.0 3.0 - - - - 1.29 do. _ _ Do.

39 8.0 3.0 3.0 2.0 6.5 - - - - .52 do. _ _ Do.

40 6.0 - 4.0 2.0 4.6 - - - - .67 do. _ _ Do.

15 6.5 - 4.0 2.5 5.5 - - - - 1.60 do. _ Do.

16 6.1 - 3.0 3.1 5.0 - - - - .78 do. _ _ Do.

17 8.0 - 3.5 4.5 5.5 - - - - .96 do. - _ Do.

18 9.0 - 4.0 5.0 3.0 - - - - .80 do. _ _ Do.

19 7.5 - 4.0 3.5 4.0 - - - - 1.48 do. _ _ Do.

20 8.0 - 5.0 3.0 5.5 - - - - 1.75 do. _ _ Do.

21 9.0 - 5.0 4.0 5.0 - - - - 1.81 do. _ _ Do.

22 10.5 2.5 4.5 3.5 .0 - - - - .88 do. _ _ Do.

23 8.2 - 5.0 3.2 .0 - - - - 1.85 do. _ _ Do.

24 7.0 - 4.0 3.0 5.0 - - - - .97 do. _ _ Do.

25 5.0 - 1.5 3.5 3.0 - - - - 1.60 do. _ _ Do.

26 5.7 - 4.0 1.7 4.2 - - - - 1.03 do. _ _ Do.

27 6.5 - 3.0 3.0 5.8 - - - - 1.27 do. _ _ Do.

1/ The only heavy mineral occurring in greater than trace amounts in this hole was chromite. For analysis see

table 11.

2/ The only hole in which gold was observed; no assay was made. Based upon the size and the number of "colors,"

the gold content of the mining section is estimated to be 8 cents per cubic yard.
19

TABLE 9. - Petrographic and radiometric analyses of churn-drill

concentrates, Anikovik River Valley

Hole

Nos. Light minerals and rocks Heavy minerals

10, 11 Shale, phyllite, about 5 percent Pyrite, limonite pseudomorph after

quartz, smaller amounts of dolo- pyrite, augite, ankerite, and

mite, calcite, and chlorite. zircon.

12, 13, Shale, about 5 percent quartz, lesser Pyrite, limonite pseudomorph after

14 amounts of basalt fragments contain- pyrite, augite, ankerite, and

ing augite, phyllite fragments, zircon.

chlorite, dolomite, oligoclase, and

magnesite.

39, 40 Phyllite, quartz, chlorite, limestone, Pyrite, limonite pseudomorph after

and calcite. pyrite, magnetite, apatite,

tourmaline, zircon, and traces

of scheelite. Titanium was

present but was not identified.

15, 16 Shale, phyllite, about 10 percent Pyrite, limonite pseudomorph after

quartz, lesser amounts of lime- pyrite, augite, zircon, and

stone, dolomite, calcite, garnet.

chlorite, and biotite.

17 Shale, phyllite, minor amounts of Pyrite, limonite pseudomorph after

quartz, limestone, dolomite, pyrite, hematite, augite,

calcite, and chlorite. zircon, and cassiterite.

18, 19 Shale, phyllite, a basic igneous rock Pyrite, limonite pseudomorph after

containing ilmenite, altered plagi- pyrite, augite, ankerite, and

oclase, quartz, chert, calcite, magnesite.

and chlorite.

20, 21, Shale, phyllite, quartz, limestone, Pyrite, limonite pseudomorph after

22 dolomite, calcite, and chlorite. pyrite, ilmenite, tourmaline,

zircon, augite, hematite,

hypersthene, and cassiterite.

23, 24, Shale, phyllite, about 5 percent Chromite (hole 23 only), pyrite,

25 quartz, and smaller amounts of limonite pseudomorph after pyrite,

limestone, calcite, and chlorite. olivine, augite, apatite, cassiterite, and gold. Analysis of sample

from hole 23 indicated 0.23 pound

of chromite per cubic yard containing 48 percent Cr2 03.

26, 27 Shale, about 5 percent quartz, Pyrite, limonite pseudomorph after

limestone, and chlorite. pyrite, augite, ilmenite, magnetite, ankerite, and zircon.

Radiometric equivalent uranium

No significant radioactivity detected

in any samples.
20

TABLE 10. - Identification of bedrock samples, Anikovik River Valley

Hole No. Stream Type of bedrock

10 ....... Anikovik River Dolomitic shale with pyrite and limonite.

11 ......... do. Shale with pyrite, quartz, a trace of calcite, chlorite,

and biotite.

12 .. Ishut Creek Shale with traces of hematite, limonite, and calcite.

13....... do. Shale with fine quartz and traces of calcite, pyrite,

limonite, and chlorite.

14 ........ do. Shale and quartz with ankerite and traces of limonite,

pyrite, and siderite.

39...... do. Shale with limonite and quartz.

40 . do. Shale with chlorite and a trace of limonite.

15 .. Anikovik River Shale with traces of calcite, quartz, pyrite, and

limonite.

16 do. Shale with traces of quartz and pyrite.

17 .. Buckner Creek Shale with traces of limonite, calcite, and quartz.

18 .. Jarvis Creek Shale with traces of calcite, pyrite, and quartz.

20 .. Banner Creek Limey shale with pyrite.

21 do......... Shale with traces of pyrite, quartz, and calcite.

22 do......... Carbonaceous shale with traces of quartz, calcite, and

limonite.

23 .. Anikovik River Limey shale with quartz.

24 ... do. Carbonaceous shale.

25 do. Carbonaceous shale with pyrite and quartz.

26 do. Carbonaceous shale with ankerite, quartz, and traces

of chlorite and tourmaline.

27 ...... do. Limey shale.

Sample No. Stream Miscellaneous bedrock samples

20-A . Banner Creek Typical sample of outcrop exposed on north bank of

Banner Creek 15 feet downstream from drill hole 20.

Outcrop has vertical or near-vertical dip and apparent strike of N. 200 E. Sample composed chiefly of

altered plagioclase, quartz, calcite, ankerite,

pyrite, apatite, and limonite. Semiquantitative

spectrographic analyses data follow:

Spectrographic analyses, sample 20-A

As Al As Au B Ba Be Bi Ca Cd Co Cr Cu Fe

G B - - F - - - B - F E E A

Ga Ge g In Li Mp Mn Mo Na Nb Ni P Pb Pd

E C D E C - E - -

Pt Sb Si Sn Sr Ta Te Ti V W Zn Zr

- - A - E - - C D - - E

Legend: A - More than 10 percent. E - 0.01 to 0.1 percent.

B - 5 to 10 percent. F - 0.001 to 0.01 percent.

C - 1 to 5 percent. G - Less than 0.001 percent.

_ D - 0.1 to 1 ercent. - - Not detected.

Sample No. Stream Miscellaneous bedrock samples

26-A . Anikovik River Typical sample of dike or sill that outcrops in bed of

Anikovik River a few feet upstream from holes 26 and 27.

Intrusive has apparent strike of N. 50° W., but dip

could not be determined. Sample composed chiefly of

andesite with phenocrysts of andesine and biotite, some

chlorite, and a trace of hornblende.
21

The bedrock of both streams is dominantly shale with quartz inclusions

and usually contains disseminated pyrite and limonite pseudomorph after

pyrite. One hole (33) encountered a basic rock composed of plagioclase

feldspar with augite, chlorite, hornblende, and apatite.

Sampling data from Kigezruk and Baituk Creeks are summarized in tables

11, 12, 13, and 14.

TABLE 11. - Summary of churn-drilling results, Kigezruk and Baituk Creeks

Pay horizon

Drill-hole data Interval

Hole Depths, ft. From, To, Depth, Volume,

No. Total O.B. Gravel Bedrock Cased ft. ft. ft. cu. yd.

29 ....... 6.0 - 4.5 1.5 5.0 - - - -

30 ....... 4.5 - 3.0 1.5 4.2 2.5 4.0 1.5 0.0128

31 ....... 20.7 - 15.3 5.4 15.3 - - - -

32 . .... 7.5 - 5.0 2.5 5.5 - - - -

33 ....... 12.0 0.5 8.5 3.0 2.5 - - - -

34 ....... 13.0 4.5 5.5 3.0 2.5 - - - -

35 . .... 8.5 - 5.5 3.0 7.0 4.0 5.5 1.5 .0128

36 ....... 8.5 .5 5.0 3.0 2.3 - - - -

37 . .... 11.2 1.0 5.0 5.2 4.5 _ _ _ _ 

38 . .... 8.8 2.0 4.3 2.5 6.3 _ -_ _ 

Mining section

Concentrate Concentrate, Tin, Gold,-!/

Hole Weight, Tin, Depth, lb. per lb. per cents per

No. lb. percent ft. cu. yd. cu. yd. cu. yd.

29 ....... 0.74 Trace - - Trace _

30 ....... .99 0.05 4.0 28.94 0.01 -

31 ....... .74 Trace - - Trace 1

32. .. .80 do. - _ do. 5

33 ....... .72 do. - _ do. -

34 . .... 1.06 do. - _ do. 10

35 ....... 1.80 .06 6.5 32.43 .02 -

36 ....... 1.70 Trace - - Trace _

37 . ...... 1.12 do. _ do. Trace

38 . .... 1.10 do. _ _ do. _

1/ Estimate based upon number and size of "colors" observed.
22

TABLE 12. - Analyses of miscellaneous concentrates l/ Baituk Valley

Gravel Gold,2/

Sample depth, Assay, percent cents per

No. Creek ft. Sn Eu cu. yd.

B-l........... Carmen . . 3 <0.05 Trace Nil

B-2...... . Eureka . ............... 3 < .05 Nil Nil

B-3....... Boulder ............... 3/4 < .05 Nil Nil

B-4 . ...... Fremont . ........ 3/3 < .05 Nil Nil

B-5 .... . Baituk:

Center Fork ......... 3/4 < .05 Nil Nil

B-6 . .East Fork ......... 4 < .05 0.003 A/l0

1/ Samples were panned concentrates taken from bulldozer pits in stream

channel.

2/ Estimate based upon size and number of "colors" present.

3/ No bedrock encountered.

4/ Sample taken near bedrock; entire gravel section may average considerably

less.

TABLE 13. - Petrographic and radiometric analyses of churn-drill

concentrates, Kigezruk and Baituk Creeks

Hole Nos. Light minerals and rocks Heavy minerals

29, 30 Shale, quartz, phyllite, and Pyrite, limonite pseudomorph after

chlorite. pyrite, magnetite, ilmenite, and

tourmaline.

31 Shale, phyllite, quartz, Garnet, limonite pseudomorph after

feldspar, dolomite, pyrite, pyrite, ilmenite,

andesine, and calcite. magnetite, augite, tourmaline,

hornblende, zircon, epidote,

sphene, hypersthene, staurolite,

cassiterite, and gold.

32, 33 Shale, basalt, phyllite, Pyrite, limonite pseudomorph after

quartz, sericite (with pyrite, augite, magnetite,

phyllite), and chlorite. ilmenite, apatite, hornblende,

and cassiterite.

34, 35 Shale, quartz, phyllite, Pyrite, limonite pseudomorph after

sericite, and chlorite. pyrite, augite, magnetite,

ilmenite, apatite, zircon, tourmaline, cassiterite, and gold.

36, 37 Shale, phyllite, basalt, Pyrite, limonite pseudomorph after

quartz, sericite, chlo- pyrite, augite, cassiterite, and

rite, ankerite, and gold.

epidote.

Radiometric equivalent uranium

No significant radioactivity

detected in any samples.
23

TABLE 14. - Identification of bedrock samples, Kigezruk and Baituk Creeks

Hole No. Creek Type of bedrock

29............. Kigezruk Shale.

30............ do. Shale and sandstone with pyrite and limonite.

31..... ....... Baituk Do.

32 ............... do. Carbonaceous shale with pyrite and traces of

hematite, limonite, and chlorite.

33...... ..... do. Dominantly carbonaceous shale with ankerite,

limonite after pyrite, pyrite, and a trace

of chlorite. One fragment is a basalt composed of plagioclase with augite, chlorite,

and traces of hornblende and apatite.

34 .. . do. Shale with quartz and traces of limonite and

pyrite.

35 . . do. Shale with traces of limonite, chlorite, and

ankerite.

36 . .............. do. Shale with pyrite, quartz, and limonite.

37 . .............. do. Shale and quartz with chlorite and ankerite.

38 . .............. do. Shale and quartz with calcite and ankerite.

Conclusions

The samples from Lost River contained more tin than the samples from the

other streams investigated during this reconnaissance. The tin in Lost River

gravels undoubtedly was derived largely from the known tin-bearing outcrops

on the Tin and Cassiterite Creeks. Except for the small deposit in the gravels of Cassiterite Creek, there was no indication of placer deposits of a

size and grade comparable with the placer deposits that have been mined or

explored in the Potato and Cape Mountain areas. The lack of organic cover

and the consequent flash floods, which frequently disturb the gravels of

Lost River, make this stream less favorable for the accumulation of placer

deposits than the streams of the Potato and Cape Mountain areas. The gravel

samples from Lost River therefore do not constitute a reliable indication of

the relative abundance of lode outcrops in the Lost River area as compared

with the Potato and Cape Mountain areas. However, these samples do indicate

that, even under unfavorable conditions, measurable amounts of tin will be

found in placer gravels derived from areas containing significant lode tin

outcroppings such as those in the Lost River drainage basin.

The samples from gravels of the Anikovik River, and of the Kigezruk, York,

and Baituk Creeks all contained traces of tin, but none more than trace

amounts. Insofar as was determinable by Bureau reconnaissance, the conditions for the formation of placer deposits in these streams are substantially

similar to the conditions at the Potato and Cape Mountains; therefore, it is

believed that the widespread distribution of sparse amounts of tin indicates

that it was derived from scattered or low-grade sources.

None of the samples contained enough gold or valuable heavy minerals

other than tin to encourage additional exploration with the objective of

developing placer reserves. In this respect Baituk Creek, which contained

some gold in every line of drill holes, appeared to be the most favorable

of the streams sampled.
24

BIBLIOGRAPHY-2/

1. SCHRADER, F. C-., AND BROOKS, A. H. Preliminary Report on the Cape Nome

Gold Region, Alaska. Geol. Survey Spec. Pub., 1900, pp. 25-26.

2. BROOKS, A. H. An Occurrence of Stream Tin in the York Region, Alaska.

Geol. Survey Mineral Resources of the United States, calendar year

1900, 1901, p. 270.

3. COLLIER, A. J. A Reconnaissance of the Northwestern Portion of Seward

Peninsula, Alaska. Geol. Survey Prof. Paper 2, 1902, 70 pp.

4. . Tin Deposits of the York Region, Alaska. Geol. Survey Bull.

229, 1904, 61 pp.

5. . Recent Development of Alaskan Tin Deposits. Ch. in Report on

Progress of Investigations of Mineral Resources of Alaska in 1904.

Geol. Survey Bull. 259, 1905, pp. 120-127.

6. HESS, F. L. The York Tin Region. Ch. in Report on Progress of

Investigations of Mineral Resources of Alaska in 1905. Geol. Survey

Bull. 284, 1906, pp. 145-157.

7. COLLIER, A. J., HESS, F. L., SMITH, P. S., AND BROOKS, A. H. The

Gold Placers of Parts of Seward Peninsula, Alaska. Geol. Survey Bull.

328, 1908, pp. 268-282.

8. KNOPF, ADOLPH. Geology of the Seward Peninsula Tin Deposits, Alaska.

Geol. Survey Bull. 358, 1908, 71 pp.

9. HESS, F. L. Tin Resources of Alaska. Ch. in Mineral Resources of

Alaska, Report on Progress of Investigations in 1911. Geol. Survey

Bull. 520, 1912, pp. 89-92.

10. CHAPIN, THEODORE. Placer Mining on Seward Peninsula, Alaska. Ch. in

Mineral Resources of Alaska. Report on Progress of Investigations in

1913. Geol. Survey Bull. 592, 1914, p. 393.

11. EAKIN, H. M. Tin Mining in Alaska. Ch. in Mineral Resources of Alaska,

Report on Progress of Investigation in 1914. Geol. Survey Bull 622,

1915, pp. 81-94.

12. MERTIE, J. B., Jr. Lode Mining and Prospecting on Seward Peninsula;

Placer Mining on Seward Peninsula. Ch. in Mineral Resources of Alaska,

Report on Progress of Investigations in 1916.

13. HARRINGTON, G. L. Tin Mining in Seward Peninsula. Ch. in Mineral

Resources of Alaska. Report on Progress of Investigations in 1917.

Geol. Survey Bull. 692, 1919, pp. 353-361.

3/ Arranged by years.
25

14. STEIDTMANN, E. AND CATHCART, S. H. Geology of the York Tin Deposits,

Alaska. Geol. Survey Bull. 733, 1922, 130 pp.

15. HEIDE, H. E. Investigation of the Lost River Tin Deposit, Seward

Peninsula, Alaska. Bureau of Mines Rept. of Investigations 3902,

1946, 57 pp.

16. , WRIGHT, WILFORD S., AND SANFORD, ROBERT S. Exploration of Cape

Mountain Lode-Tin Deposits, Seward Peninsula, Alaska. Bureau of Mines

Rept. of Investigations 3978, 1946, 16 pp.

17. __ , AND SANFORD, ROBERT S. Churn Drilling at Cape Mountain Tin

Placer Deposits, Seward Peninsula, Alaska. Bureau of Mines Rept. of

Investigations 4345, 1948, 14 pp.

18. , AND RUTLEDGE, F. A. Investigation of Potato Mountain Tin Placer

Deposits, Seward Peninsula, Northwestern Alaska. Bureau of Mines Rept.

of Investigations 4418, 1949, 21 pp.

INT. - BU. OF MINES PGH. .PA. 587