Bulletin No. 229 Series A, Economic Geology, 36

DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

. CHARLES D. WALCOTT, DIRECTOR

THE

BY

ARTHUR, J. COLLIER

WASHINGTON

GOVERNMENT PRINTING OFFICE 

1904
o
CONTENTS.

Page.

Letter of transmittal .............................^........................ 7

Introduction .............................................. ...^.......... 9

Geographic position .............................................. 9

History of recent exploration and development..................'... 10

Purpose of this bulletin ........................................... 12

General geology.......................................................... 12

Sedimentary rocks ..........-....-------...-..---.-.--.-.--.--...-..- 12

Surficial deposits...................'..........................-... 14

** Igneous rocks........................--..-...-......-.----.....------ 15

^ Economic geology.....................--...---...-.-.-.-...---.-.-....... 16

General statement ...................................................... 16

I Localities where lode tin has been fouhd............................... 17

Lost Eiver........................................................ 17

Cape Mountain .................................................. 23

Localities from which lode tin has been reported ....................... 25

* Diomede Islands................................................. 25

Brooks Mountain................................................. 26

* Don River....................................................... 26

, Ear Mountain.................................................... 26

Hot Springs...................................................... 28

^ Asses Ears...............................--..........-..........'. 28

Localities where stream tin has been found ............................ 29

* Buck Creek...................................................... 29

* . Anikovik Creek and Buhner Creek-................................ 35

* . Localities from which stream tin has been reported......... J........... 36

Summary of economic geology ........................................ 36

Transportation and fuel supply............................................ 37

_ Tin ores and associated minerals .......................................... 39

Physical characteristics of tin ore........................:..... 39

^ Associated minerals ......................'............................ 40

Tourmaline.................................................. 40

^ Garnet ...................................................... 40

Butile. ..................................................... 40

* Wolframite.................................................. 41

Epidote -...................................._............... 41

* Magnetite and limonite........................................ 41

Fluorite ...................................................... 41

Quartz............................................. .......... 41

Methods of assaying tin ore ........................................... 41

Occurrences of tin ore in the United States.............................. 44

3
4: CONTENTS.

Tin ores and associated minerals Continued. . Page.

Conditions and methods in the large tin mines of the world ............. 46

Malay Peninsula ................................................. 46

Banca...................:....................................... 48

Billiton...................................1...................... 48

Australia........................................................ 49

Cornwall........................................................ 50

Bolivia ...........-............................................".. 52

Reduction of tin ores .................................................. 52

Production and value of tin in 1902-3 ...................... i............ 54

Value of. tungsten as a by-product..................................... 54

Bibliography......................................................... 55

Index .................................................................... 59
ILLUSTRATIONS

. ' . Page. 

PLATE I. Outline map of Seward Peninsula, showing position of York region,

Alaska........................................................ 8

II. Topographic map of York region................................. . 12

III. Valley of Lost River from the coast.............................. 20

IV. Cape Mountain ................................................. 22

V. A and B, Thin sections of altered porphyritic dike near Tin Creek.. 24

VI. A and B, Thin sections of porphyritic dike on Ear Mountain....... 26

VII. A, Thin section of luxulianite from Ear Mountain; B, Polished surface of tin ore from Lost River .:.............................,. 28

FIG. 1. Sketch of the coast from Cape York to Cape Prince of Wales......... 9

2. Geologic sketch map of York region................................ 13

3. Sketch map of Lost River.......................................I.. 18

4. Sluice boxes used in washing placer tin in York region .............. 33

5. Box used in washing stream-tin concentrates........................ 34

LETTER OF TRANSMITTAL.

DEPARTMENT OF THE INTERIOR, 

UNITED STATES GEOLOGICAL SURVEY,

Washington, D. C., March 0, 1904.

SIR: I have the honor to transmit herewith a report entitled "The 

Tin Deposits of the York Region, Alaska," by Mr. Arthur J. Collier, 

and to recommend its publication as a bulletin.

Placer tin was discovered in this region in 1900, and since that time 

active prospecting has been going on to determine the extent and distribution of the stream tin, and also to locate its source in bed rock. 

Though the occurrence of tin-bearing .lodes had been previously 

reported, the first authentic discovery of this kind was made by Mr. 

Collier during the last season, and this find has awakened great interest in the district. The demand for authentic information regarding 

these occurrences has led to the preparation of this report, which is 

based on a very hasty field examination. The aim has been to summarize all the information in regard to the occurrence of tin which 

might be of value to the prospector, and for this reason a brief description of the better known tin deposits of the world has been included. 

The publication of the geologic results of these investigations is deferred 

until a more complete study of the notes and specimens has been made. 

Veiy respectfully,

ALFRED H. BROOKS, 

G-eolo'gist in Charge of Division Alaskan Mineral Resources.

Hon. CHARLES D. WALCOTT,

Director 'United States (Geological Surve-y.

OUTLINE MAP OF SEWARD PENINSULA, ALASKA, SHOWING POSITION OF YORK REGION.
THE TIN DEPOSITS OF THE YORK REGION, ALASKA.

By ARTHUR J. COLLIER.

INTRODUCTION.

The known occurrences of tin in Alaska are close to the westernmost 

point of the American continent, in the York region of Seward Peninsula, the land mass which projects from the west coast of Alaska to 

within 60 miles of the coast of Asia. The peninsula as a whole has 

become famous in recent years on account of its gold placers, and every 

summer it is the objective point of a fleet of vessels loaded with prospectors following the ice pack in its northward retreat. The city of 

Nome, its most important mining camp, is the metropolis of Alaska. 

North of Seward Peninsula the Arctic Ocean stretches away toward 

the pole, while ,on the south Bering Sea, icebound for half the year, 

extends for 700 miles to the open water of the Pacific Ocean.

"Pie. 1. Sketch of the coast from. Cape York to Cape Prince of Wales.

Geographic position of the York region. The Yprk region, which 

derives its name from Cape York, an ill-defined promontory on Bering 

Sea, about 100 miles northwest of Nome, comprises that portion of .the 

peninsula west of the entrance to Port Clarence, thus including Cape 

Prince of Wales, the westernmost point of the American continent. 

Its general geographic position is shown in the outline map, PL I.

Reference to the topographic map, PL II, will show that the region 

has the general form of an isosceles triangle, with its apex at Cape 

Prince of Wales and its two sides formed by the 'shore lines of the 

Arctic Ocean and of Bering Sea. The southern coast line is, in the 

main, inhospitable and unbroken by inlets or harbors. The land usually 

presents abrupt escarpments rising from narrow rocky beaches and 

giving it a forbidding character, well shown by the sketch reproduced

9
10 TIN DEPOSITS OF THE YOEK BEGION, ALASKA. [NO. 229.

in fig. 1. On the north the slopes toward the Arctic Ocean are more 

gentle, and the coast is characterized by barrier beaches that cut off 

broad lagoons from the open sea. Such a one is Lopp Lagoon, a large 

body of water that is unfortunately too shallow for any but light-draft 

boats. The large bay known as Port Clarence, 20 miles southeast of 

York, is the only good harbor in the region.

. The York Mountains occupy the southeastern part of the triangle 

and culminate in Brooks Mountain, 2,900 feet in altitude, the highest 

point in this part of the peninsula. These mountains have rugged 

crest lines, their continuity being broken by several broad streams and 

river valleys, but when seen from a distance their summits have an 

even sky line from 2,000 to 2,900 feet above the sea. To the north 

and west of this mountain group stretches the so-called York Plateau, 

a comparatively smooth upland surface 200 to 600 feet above sea level 

that comprises the greater part of the region under discussion. The 

smaller streams crossing this plateau flow in sharply cut V-shaped 

canyons, while the larger streams occupy comparatively broad valleys 

containing large accumulations of gravel. On the south the plateau 

presents an escarpment to Bering Sea, but on the north it slopes 

gently downward to a coastal plain dotted with lakes, through which 

the rivers and streams meander to the Arctic Ocean.

The drainage of the region runs either northward or southward, but 

the watershed lies much nearer Bering Sea than the Arctic Ocean.

History of recent exploration and development. The chief settlement of the region is York, a collection of cabins and tents on the open 

coast of Bering Sea at the mouth of Anikovik River, about 10 miles 

east of Cape Prince of Wales and 5 miles west of Cape York.

Previous to the discovery of gold at Cape Nome very little was known

regarding the York region. A mission had been established for a

number of years at Cape Prince of Wales, where one of the Government reindeer herds was maintained. After the first rush to Nome 

prospectors rapidly extended their search to all parts of the peninsula, 

and as early as the fall of 1899 some placer gold had been found.in the 

Anikovik River Basin/'

In 1900, A. H. Brooks, of the United States Geological Survey, during his investigation of the southern part of the Seward Peninsula, 

spent several days in the York region and brought from the placers of 

Anikovik River and Buhner Creek, one of its tributaries, some concentrates, which proved to contain stream tin. 6

In July, 1901, the writer spent a number of days in the York district,

oSchrader, F. C., and Brooks, A. H., Preliminary report on Cape Nome gold region, Alaska: Special 

report on Alaska, U. S. Geol. Survey, 1900, pp. 25-26.

b Brooks, A. H., An occurrence of stream tin in the York region, Alaska: Mineral Resources U. S. 

for 1900. U. S. Geol. Survey, 1901, pp. 267-271. A new occurrence of cassiterite in Alaska: Science, 

new s»r., vol. 13, No. 328,1901, p. 593. A reconnaissance of the Cape Nome and adjacent gold fields of 

Seward Peninsula, Alaska, in 1900; special report on Alaska, U. S. Geol. Survey, 1901, pp. 132-139.
COLLIER.] . RECENT EXPLORATION. 11

before the news of the discovery had been disseminated among the 

miners, and it was possible only to verify the facts regarding1 tin ore . 

reported by Mr. Brooks. A reconnaissance geologic map of the region 

was prepared and published in the report of the season's work, together 

with some suggestions in regard to the possible occurrence of tin 

ore." In the latter part of the season, a great many prospectors 

searched the York region for tin, and before winter they had located 

promising deposits of stream tin on Buck Creek, a tributary of Mint 

River, about 20 miles north of the town of York.

In 1902 the search was continued and the first real attempts to mine 

the tin-bearing gravels were made on Buck Creek. The nature of this 

occurrence and the mining conditions which existed there at that time 

have been described by Mr. Rickard.*

In 1903 the writer was detailed to continue investigations of the

mineral resources of the Seward Peninsula, and Mr. P. L. Hess was 

assigned to his party as field assistant. The party also included two 

experienced camp hands, and was equipped for traveling inland with 

a pack train of five animals. Nearly all the important placer mining 

camps of the peninsula were examined during the course of the work. 

Though a visit to the York region had not been contemplated, it was 

found upon arrival in the field that the interest in the tin deposits at 

York had not subsided, and that developments since 1901 justified 

further investigations, though there was little time available for this 

purpose. The party reached Teller in the latter part of July and there 

met a number of prospectors who had been searching for tin in the 

York region, and who desired to have their specimens examined, since 

they were unable to identify tin ore. Among these specimens only 

one piece of tin ore was found, but it had been obtained in a new 

locality and consisted of cassiterite crystals still in the matrix, indicating that its original source might easily be found.

On the following day Mr. Hess and the writer, accompanied by two 

prospectors, started from Teller in a small sailboat en route to the 

scene of the tin prospecting operations in the York region. During 

the following week Lost River, Buck Creek, and Cape Mountain were 

visited and the tin deposits at these places were examined. This work 

had to be done witli such haste as to make the results in many respects 

unsatisfactory, since the work in other districts comprehended in the 

writer's instructions was sufficient to consume the whole season. The 

examination of the Lost River locality was made by Mr. Hess and the 

writer jointly, while Buck Creek was visited by Mr. -Hess and Cape 

Mountain was visited by the writer.

a Collier, A..!., Reconnaissance of the northwestern portion of' Seward Peninsula, Alaska: Prof. 

Paper U. S. Geol. Survey No. 2,1902, p. 49.

ftRickard, Edgar, Tin deposits of the York region, Alaska: Eng. and Min. Jour., Vol. 75, 1903, pp. 

30-31.
12 TIJST DEPOSITS OP THE YORK REGION, ALASKA. [NO. 229.

Purpose of this "bulletin. It is the purpose of this bulletin to combine the results obtained by the United States Geological Survey parties 

that have visited the region, together with the information derived 

from a study of specimens of tin ores and associated minerals recently 

brought from the York region by outside parties, and to present such 

facts in regard to the occurrences and value of the metal as may be of 

assistance to those interested in the development of the field. Throughout the field and office work the writer has had the efficient aid of 

Mr. Hess, who has devoted special attention to the compilation of 

the literature referring to tin deposits. The work of Mr. Eugene 

C. Sullivan, chemist of the Survey, who elaborated a method of 

analyses b}* which minute traces of tin could be detected, and who also 

made assays of the material from the York region, has added greatly 

to the value of the report.

GENERAL GEOLOGY.

The geology of the York region, as has been shown, has been subject to investigations during the years 1900, 1901, and 1903, but all 

of this work was of a reconnaissance character, and the results have 

not yet been correlated with the latest work in other parts of the peninsula; hence it has been thought best to defer their publication for the 

present.

.A sketch map (fig. 2) is here introduced to show the relative distribution of the more prominent rock types, without attempting, however, 

to subdivide them into formations or to indicate their stratigraphic and 

structural relations. In this map the horizontal distribution of four 

different rock types is indicated. These include slates and limestones, 

probably of Paleozoic age, and some granular intrusives, chiefly of a 

siliceous character. The slates and limestones form belts of irregular 

outline extending north and south, while the igneous rocks are found in 

intrusive stocks and dikes, the former outcropping in more or less 

circular areas. Besides these hard rocks, Pleistocene and Recent sands 

and gravels form the surface deposits of the northern coastal plain, 

and are also found in the valleys of many of the streams.

SEDIMENTARY ROCKS.

It is seen in fig. 2 that the larger part of the area surrounding the 

York Mountains is occupied by limestone. This limestone has an 

ash-gray color and exhibits little evidence of nietamorphism. It is 

characterized by low dips and comparatively simple structure. This 

formation has been called the Port Clarence limestone, a and has been 

definitely traced over an area of about 1,400 square miles, extending

« Collier, A. J., Reconnaissance of the northwestern portion of Seward Peninsula, Alaska: Prof. 

Paper U. S. Geol. Survey No. 2,1902, p. 18.
U.S.GEOLOGICAL SURVEY BULLETIN NO.229 PLII

TOPOGRAPHIC MAP

OF THE

YORK RJ-XIION

VLA S K A

Contour interval 200 loot

.sett t.f

T. (i. Gerdine,Topographer in elmrgo 

Show line of Port Clmvneo and Grimlley lliirbor 

l>y I'nitert States Coast invd Geodetic Survey 

l'o(ioC'fa|ihy l>y T. (V(.reriline, RC'. UllhorKpooii, niid A.Il.lSronks

ill l! 

CoiTcclioiis tind additions liv A.-I. Collier nnd I 1' I,.Hess

too:.;

'ill

Tin ofc found in lodes 

Tin oro- fbiind in 

Wnaon irails

ULIUSBIENACO. N.Y.
COLLIER.] GENEBAL GEOLOGY. 13

V

V 

A

eastward from Cape York. The Port Clarence limestone is known to

be of. upper Silurian age, and it is safe to presume that a large part

of the sedimentary rocks of the York region are also upper Silurian.

The continuity of this limestone.is interrupted by several small

Slates 

Port Clarence limestone

FIG. 2. Geological sketch map of the York regloii.

slate areas of irregular outline, and a large belt of these -rocks lies to 

to the west of the York Mountains, forming the mass from which the 

greater part of the York Plateau is cut. These rocks, often so altered 

that they might more properly be called schists, are of a graphitic,
14 TIN DEPOSITS OF THE YORK EEQION, ALASKA. [NO. 229.

arenaceous, and sometimes calcareous character, and are of very fine 

texture. They are much jointed and broken by lines of'cleavage into 

rhombohedral blocks and pencil-shaped fragments. The bedding is 

often obscured and sometimes obliterated by the highly developed 

joint structures. The age of these slates has not been determined. In 

1900 they were correlated by Brooks" with the so-called Kuzitrin 

slates, which outcrop along the northern base of the Kigluaik Mountains. The work of the writer in 1901 pointed to the conclusion that 

they are older than the Port Clarence limestone, but this fact has 

not yet been definitely established. There is some indication of 

faulting along the contact of this slate belt and the limestones to the 

southeast.

West of the slates there is a narrow belt of highly altered limestone 

or marble more or less interbedded with micaceous schists. This belt, 

about 4 miles in width, lies between the slates on the east and a large 

mass of granite on the west, the latter forming the peak known as 

Cape Mountain. Some obscure fossils collected during the past season 

indicate that these limestones are either of Devonian or Carboniferous 

age. The stratigraphic relations of this limestone to the slates on the 

east have not been definitely determined:

STJRFICIAL DEPOSITS.

The unconsolidated gravels and silts form the youngest group of 

sediments of the region. On the sketch map these deposits are shown 

mantling an area bordering the Arctic coast. This is the western end 

of a very extensive gravel deposit which covers the low Arctic coastal 

plain of Seward Peninsula from Cape Espenberg to Cape Prince of 

Wales. 6 These deposits extend to the base of the hills and in the 

valleys merge with the stream gravels with which they probably have 

common origin. In the southern part of the York region these surficial deposits are confined to the creek beds and narrow strips along 

the coast, and are usually too small to be shown on the map. All of 

these gravels are water-laid deposits, there being no evidence of glaciation. The}r form a part of the great Quaternary mantle that is so 

extensively developed in Seward Peninsula and adjacent portions of 

Alaska. The gravels, which are of economic interest because the}'' 

locally contain concentrations of stream tin, will be described in 

another part of this paper.

a Brooks, A. H., Kichardson, G. B., and Collier, A. J., A reconnaissance of the Cape Nome and 

adjacent gold fields of Seward Peninsula, Alaska, in 1900: Special report on Alaska, U. S. Geol. Survey 

1901, p. 133. . '

6Collier, A. J., Reconnaissance of the northwestern portion of Seward Peninsula, Alaska: Prof. 

Paper U. S. Geol. Survey No. 2,1902, p. 25.
 COLLIER.] GENERAL GEOLOGY. 15

v -

IGNEOUS ROCKS.

*. Two distinct types of igneous rocks are present, one of which is basic 

while the other is acidic. The first group includes basic dikes and sills,

* all more or less altered and sometimes schistose, which maybe grouped 

together under the general name of greenstones. The greenstones and 

greenstone-schists include a number of more or less altered intrusive 

masses, and occur most frequently in the slates near the contact with the 

limestone which forms the York Mountains. Bowlders of this rock 

are Avidely distributed in the gravels of the region. Under the microscope they appear, for the most part, to be altered gabbros. They 

are often called granite by the miners, but can readily be distinguished 

from the true granite by a general green color and the absence of 

quartz. This distinction is of importance, for. so far as known, no 

tin deposits have been found in association with the greenstone.

The second group consists of more acid rocks and includes a number 

of large masses of granite together with dikes of a fine-grained, pqrphyritic rock containing prominent quartz crystals. These dikes often 

form a fringe surrounding the larger granite masses, of which they are 

probabl}* offshoots. Granite masses of the same type occur in occasional outcrops from Cape Prince of Wales northeastward for over 

100 miles, and form a zone which also finds a western extension in the 

Diomede Islands and possibly in the granites on the Siberian coast.

In the York region these rocks find their greatest development in 

Cape Mountain, where a great stock of granite is intruded into the 

limestone. The Cape Mountain granite is coarsely crystalline, somewhat porplryritic, and consists essentially of quartz, microcline, and 

biotite, but contains as accessory minerals, albite, muscovite, zircon, 

apatite, tourmaline, p}rrite, and fluorite.

At Brooks Mountain, which is largely made up of slates, a number 

of dikes of granitic and rhyolitic rocks were observed, but these have 

not yet been studied microscopically. A few miles to the south, near 

Lost River, a number of'granite and rhyolite intrusions in the limestone have been examined and will be described in some detail in connection with the Lost River tin deposits. The granites of this region, 

and especially those at Lost River, have been considerably altered and 

have taken various forms to which the name "greisen" has been 

applied because of their similarity to the vein rocks of the tin deposits 

of Cornwall and Saxony. The typical greisen of Saxony is a granite 

made up of quartz and lepidolite, or lithia mica, with fluorite, tourmaline, topaz, and cassiterite in small amounts.

The distribution of the granite intrusives is of the greatest economic 

importance, since man}r of the known lode deposits of tin occur in 

granite dikes. The prospectors of the region have readily recognized 

this and have made careful search along these contacts.
16 TIN DEPOSITS OF THE YOKK EEGION, ALASKA. [NO. 229.

ECONOMIC GEOLOGY.

GENERAL STATEMENT.

Tin is known to be irregularly distributed in the York region over 

an area of about 450 square miles, embracing the western end of the 

peninsula. Its occurrence in alluvial deposits has been verified by the 

United States Geological Survey at three localities, and the existence 

of tin-bearing lodes has been observed at two points. The extreme 

points known are 25 miles apart. . In addition to these, prospectors 

report the occurrence of tin at a great many other places, either in 

lode or placer form, and though it has not been possible to confirm 

these reports, there is reason to believe that they indicate a more 

extensive distribution of the tin ores. Many of the reported discoveries lie beyond the limits of the York region and indicate that the 

tin districts extend 100 miles or more to the northeast.

The tin ore is almost all cassiterite (tin oxide)., though, some stannite (sulphide of tin, copper, and iron) has been found. In the bed 

rock two essentially different types of deposits are represented. The 

ore occurs in veins cutting phjdlites or metamorphic slates, and is disseminated through more or less altered granitic dikes. The lode 

deposits of the latter type give promise of commercial importance. 

Lode deposits of the former type have not been discovered in place, 

but the occurrence of tin-bearing quartz veins in slates is inferred 

from the distribution of the placer tin and from pebbles of slate containing small tin-bearing quartz veins, which have been observed in. 

the gravels. It should be noted that no granite has been found in the 

slate area, and there is- no positive evidence that the tin there has 

any genetic relation to granite intrusives.

No discussion of the genesis of these various ore bodies will be presented in this report, since the fieldwork has all been of a reconnaissance character. From a comparison of the evidence at hand with 

the facts known with regard to the older tin-bearing districts, it seems 

to be at least possible that the tin lodes of both types are connected 

with intrusive granite bodies, some of which have been exposed by 

erosion, while others are still deeply buried. These granites, which 

probably were all intruded at about the same time, mark a zone of 

plutonic activit}7 extending from the Diomede Islands northeastward, 

parallel with the Arctic coast, for 100 miles or more. The localities 

from which tin ore has actually been obtained by United States'Geological Survey parties and which have been examined in some detail 

will be described under the headings "Lost River," "Cape Mountain," "Buck Creek," "Buhner Creek," and "Anikovik River." The 

streams from which placer tin is reported by prospectors will be mentioned under the heading "Reported occurrences of stream tin," and
COLLIER.] LODES ON LOST EIVER. 17

the localites from which prospectors have reported "ledge tin" will 

be described under the headings " Brooks Mountain," " Ear Mountain," "Hot Springs," "Asses Ears," and two other localities worthy 

of investigation will be mentioned under the headings "Diomede 

Islands" and " Don River."

LOCALITIES WHERE LODE TIN HAS BEEN FOUND. 

LOST EIVER.

Lost River enters Bering Sea at a point about 15 miles southeast of 

York, 25 miles west of Teller, a town on Port Clarence, and 10 miles 

northwest of Point Spencer, at the entrance to Port Clarence. A view 

of the valley of this river, taken from the coast, is shown on -PI. III. 

The river has a length of about 10 miles and drains the central part of 

the York Mountains. The mountains constitute a nearly circular area 

of rugged land forms, about 15 miles in diameter. The summits rise 

to a general level of about 2,500 feet, and, as noted, reach a culmination 

of 2,900 feet in Brooks Mountain, near the north side of the area, 

which is the highest point in the northern part of Seward Peninsula. 

Along the southern edge of this mountain mass there is a well-defined 

bench from one-half mile to 4 miles wide. This bench was cut from 

the rocks by wave action and then raised, but so unequally that at the 

mouth of Lost River it has an elevation of 600 feet, while eastward it 

gradually declines until at Port Clarence it is practically at sea level.

The writer has referred to this feature in a previous paper as the 

Cape York bench." It was produced during the same period of erosion 

as the York Plateau.

On the seaward side the Cape York bench is bounded by steep 

bluffs, which at places front directly on Bering Sea (see fig. 1) and at 

other points rise from a lower and younger bench nearly at sea level. 

This lower'and newer plane is well developed from the mouth of Lost 

River eastward to Port Clarence, and has a width varying from onehalf mile to 3 or 4 miles. It is, in part, a rock bench similar to the 

Cape York bench, and, in part, a gravel-built coastal plane. Immediately north of Port Clarence the lower coastal plane is fringed by a 

wide lagoon, cut off from Port Clarence by a sand spit.

The York Mountains are' generally devoid of the tundra vegetation which covers so much of the Seward Peninsula; and along Lost 

River., from the coast to the tin deposits, can be found an exceptionally good roadbed for this part of Alaska. For one traveling on foot 

it is as firm as an ordinary macadamized road, and owing to the ea?e 

with which the trip up the river is made the distances are likely to be 

underestimated by persons who have traveled in other parts of Seward

"Collier, A. J., A reconnaissance of the northwestern portion of Seward Peninsula, Alaska: Prof. 

Paper U. S. Geol. Survey No. 2,1902, p. 37.

Bull. 229 04 2
18 TIN DEPOSITS OF THE YORK REGION, ALASKA. [NO. 229.

Peninsula. Lost River forks about li miles from the coast, one 

branch continuing in a nearly due north direction, while the other 

drains a country to the west that has not be examined by geologists.

FIG. 3. Sketch map of Lost River. Scale, J inch=l mile.

About 4 miles froni the coast the north fork of Lost River divides. 

The eastern branch is Cassiterite Creek; the western, which is somewhat larger, rises about 3 miles to the north, in the slopes of Brooks 

Mountain.
COLLIER.] LODES ON LOST RIVER. 19

The Lost River tin deposits are located on the east side of the north 

fork of Lost River. (See fig. 3.) The ore has been found on Cassiterite Creek and on another eastern tributary, known as Tin Creek, which 

enters Lost River about a mile below the mouth of Cassiterite Creek. 

The latter stream has a length of about 3 miles; its head is within 1 

mile of Cassiterite Creek, and after flowing parallel with Cassiterite 

Creek for about 1 mile it turns westward and enters Lost River from 

a deep canyon cut in the limestone of the York Mountains. At its 

mouth Cassiterite Creek is about 100 feet above the sea. In the latter 

part of July, 1903, Lost River carried approximately 1,000 miner's 

inches of water.

The York Mountains, in which the Lost River Basin lies, are composed almost wholly of ash-gniy limestone of Silurian age, the Port 

Clarence limestone. Along Lost River the limestone shows little general metarnorphism, and as a rule dips at low angles. From the 

coast to Tin Creek the strata generally dip to the north, and unless 

there are faults, which were not detected, a thickness of over 5,000 

feet of limestone must be exposed. Near the mouth of Lost River a 

section of these limestones lying nearly horizontal is exposed in a 

mountain, called by prospectors Saddleback, which has an elevation 

of more than 2,000 feet above sea level. Dikes of igneous rock out 

this limestone at several places along Lost River, and a number of 

these were readily traced across the limestone by a growth of moss 

and other vegetation which formed over them, the limestone itself 

being utterly devoid of vegetation. Microscopic examination shows 

that these dikes are of rhyolitic nature.

On Tin Creek,, which'enters Lost River from the east about 4i miles 

from the coast, a large body of granite was found intruded in the limestone. This granite outcrop is believed to be nearly' circular in outline and probably one-half mile in diameter. Around its margin the 

limestone was found to be considerably altered, and some small dikes 

of fine-grained pegmatite, probably apophyses from the main mass, 

were found cutting the limestone, apparently parallel with the contact 

of the limestone and granite. , Under the microscope the granite from the main mass is found to 

consist essentially of quartz, biotite, hornblende, orthoclase and acidic 

plagioclase feldspars with fluorspar, either accessoiy or secondary, 

and a few small grains of a mineral resembling zircon and believed to 

be cassiterite. Apparently the rock has been slightly crushed or 

sheared, producing streaks of fine-grained fragmental material of the 

same character as the original grains.

In Tin Creek, which flows for some distance along this contact, many 

bowlders and pebbles, some of considerable size, were found to contain minerals, which are the result of contact metamorphism.

The main tin-bearing ledge outcrops nearly half a mile north of this
20 TIN DEPOSITS OF THE YORK REGION, ALASKA. [NO. 229.

granite boss. It is a white,-porphyritic dike, cutting the Port Clarence limestone, and striking nearly east and west. It has been traced 

from Tin Creek westward across the mountain to Cassiterite Creek, a 

distance of about 1 mile, but has not been found beyond these streams 

in either direction. All of this rock has been more or less altered, so 

that it is practically a greisen having crystals of cassiterite disseminated through it. Specimens collected near Tin Creek appear, in the 

hand specimen, to be a white aplite or porphyry with some small spots 

and large patches of purple. Under the microscope many of the original minerals are seen to have been replaced by fluorite, to which the 

purple color is due. Pseudomorphs of fluorite take the place of most 

of the feldspar crystals and of some of the quartz grains. (See PI. V.) 

In specimens which are still more altered, collected from the same dike, 

near Cassiterite Creek, -probably very few of the original minerals 

remain. The rock here is found to consist of calcite, fluorite, lithia 

mica, and quartz, proportioned in the order named. The limestone, 

on the south side of the dike, is altered for several hundred feet, and 

contains many greenish minerals, among which epidote and garnet have 

been identified. The limestones north of this dike are reported to 

contain many small stringers of tin ore for several hundred feet. The 

ore obtained from the main ledge varies considerably in general appearance and character. Some of the weathered ore from the croppings is 

highly siliceous, and has the appearance of weathered, iron-stained vein 

quartz with small black cassiterite crystals disseminated, through it, 

while other specimens show clearly their granitic origin and contain 

comparatively little vein. quartz. In the ore of the latter type the 

cassiterite occurs both as disseminated crystals varying in size from 

that of a pin head to that of a walnut and as veinlets and irregular

masses. (SeePl.YII,j5.) The granitic ore consists principally of calcite,

fluorite, quartz, and large crystals of lithia mica; and in addition to the 

cassiterite, tourmaline, topaz, pyrite, garnet, and galena were observed 

in small amounts. Quantitative analyses of the lithia mica present 

made by W. T. Schaller, of the United States Geological Survey, show 

that it has the composition of zinnwaldite. In the float of this dike 

large specimens of galena, wolframite, and some malachite were collected, and in the altered limestone near the contact some large specimens of garnet were obtained. The siliceous ore mentioned above, 

when examined with the hand lens, sometimes showed spangles of 

free gold. A sample of this ore assayed a for gold and silver gave 

0.36 ounce of gold per ton and a trace of silver. The piece assayed 

was a picked specimen, and not a commercial sample. Assa37 s made 

for other parties are reported to show smaller amounts of gold in all 

cases. The occurrence of so much gold associated with the cassiterite 

seems to be unusual in tin ores, and merits further investigation.

"Assay by E. E. Burlingame & Co., Denver, Colo.
U. S. GEOLOGICAL SURVEY 

LEY 1,1 :.ObT RIVER, FROM THE COA
COLLIER.] LODES ON LOST RIVER. 21

Among the loose material from the croppings of the ledge a large 

piece of galena coated with yellowish alteration products was found. 

This may have come either from the ledge or from the altered limestone near the contact. An assay shows that it contains 0.08 ounce of 

gold and 7.76 ounces of silver per ton. Both on Tin Creek and on 

Cassiterite Creek tin ore in angular, unworn crystals is reported to 

have been found in the gravels of the stream beds. One specimen of 

placer tin of this kind obtained near the cropping of the large dike on 

Cassiterite Creek consists principally of crystals of cassiterite, but 

contains also wolframite and garnet.

The tin-bearing dike is readily followed from Cassiterite Creek eastward over a mountain having an elevation of about 1,000 feet to Tin 

Creek, a distance of about 1 mile. At the time the ledge was examined, in the latter part of July, 1903, no excavation had been made on 

it, and it was impossible to measure the exact width at any point, but

surface debris indicated a width of about 100 feet. Since that time 

crosscut trenches have been made on the ledge near Cassiterite Creek, 

and the above estimate is reported to represent the facts." The cassiterite was found to be distributed through the whole width of the 

dike.

No attempt will be made to give an estimate of the value of the 

deposit. The development on the ledge has not, as yet, gone far 

enough to allow systematic sampling, and until further excavations 

have been made the grade of the ore and the size of the deposit can 

not be determined. Picked specimens showing as high as 17 per 

cent metallic tin have been assayed, and still higher assays could be 

obtained by careful sorting. From the tests thus far made an average 

of 6 per cent for the whole width of the ledge is claimed.

The following assaysx of ore collected on this lode by Governor 

Hutchinson were made by Ledoux & Co., of New York:

Assay of tin ore from Lost River.,

Per cent tin. 

Sample of ore marked "Dyke"................ ............................ 5.08

Sample of ore marked "Float"............................................ 15. 70

Sample of ore marked " Greisen" ......................................... 4.13

A partial analysis of one sample of the ore is as follows (No. 7451):

Partial analysis of tin ore from Lost River.

Per.cent.

Gold and silver ......................................................... None.

Lead oxide (lead, 0.028 per cent)......................................... 0.030

Copper oxide (copper, 0.085 per cent) .................................... . 106

Arsenic oxide (arsenic, 0.38 per cent)..................................... . 580

'Tin oxide (tin, 4. 46 per cent) ............................................. 5. 74

a For information regarding developments subsequent to July 31,1903, the writer is indebted to Gov. 

J. H. Hutchinson, a mine operator, who bonded several of the claims here in September, 1903. The 

facts as given by him are corroborated by others who have visited the locality.
22 TIN DEPOSITS OF THE YORK BEGION, ALASKA. [NO. 229.

Per cent.

Manganous oxide (manganese, 0.424 per cent) ............................ . 548

Zinc oxide (zinc, 0.257 per cent) ......................................... . 320

Nickel and cobalt oxides................................................. Traces.

Silica................................................................... 28.52

Alumina..^............................................................. 33. 55

Ferric oxide ...............................^............................ 8. 31

Lime................................................................... 6. 75

Magnesia............................................................... .25

Lithium oxide ........................................i................. .09

Potassium oxide ........................................................ .91

Sodium oxide. ........... ^...........................:.................. .36

Water, carbonic acid, etc ................................................ 6.48

Sulphuric oxide (sulphur, 0.04 per cent).................................. .10

The alumina, etc., may contain titanic acid. The magnesia and alkalies require confirmatory determinations.

Tin ore in the form of stannite or tin pyrites has been found on Tin 

Creek at the upper contact of the large granite area which has been 

described, and about half a mile below the cassiterite ledge. Specimens of mineralized granite were collected at this place, which, on 

examination in the laboratory of the Survej^, are found to contain a 

small amount of tin in the form of stannite, together with other sulphide minerals. A sample of this ore assayed by Mr. E. C. Sullivan 

contained 0.3 per cent tin. Mineralized granite of this character 

appears to cover a considerable area, but the ore is probably of little 

value, except as showing the distribution of tin through the granites 

of the region.

In 1898 a party of disappointed prospectors, returning from Kotzebue Sound, were shipwrecked a few miles east of the mouth of Lost 

River, and were obliged to camp at that point during the winter. A 

cabin built largely from wreckage of their schooner is still standing, 

and is known as the Kotzebue cabin. These prospectors probably 

first applied the name Lost River to this stream.

In the succeeding summer a mining district was organized by survivors of this expedition, with headquarters located On King River, 

which enters Bering Sea between Lost River and Cape York. The 

Lost River region, was included at that time in the King River recording district. No discoveries of gold were made, however, and the 

region was abandoned by prospectors. In 1901 the writer, in company 

with Mr. D. C. Witherspoon, topographer, of the Geological Survey, 

made a hasty examination of Lost River, but did not discover any 

indications of tin ore.

In the winter of 1902 prospectors again turned their attention to this 

region in the search for tin ore. Granite-porphyry dikes, which occur in the limestones near the mouth of Lost River and also near King 

River, first attracted their attention, and many specimens of this 

material containing dark colored or smoky quartz phenocrysts, which
U. S. GEOLOGICAL SURVEY 

CAPE MOUNTAIN, FROM YORK.
COLLIER.] LODES AT CAPE MOUNTAIN. 23

were mistaken for "tin crystals," were sent to various assayers, from 

whom widely divergent reports were obtained.

Earty in the summer of 1903 Charles Randt, Leslie Grim, and W. J. 

O'Brien discovered the interesting minerals above referred to in float 

bowlders in Tin Creek, a tributary of Lost River, and made a thorough' 

search for tin ore in that vicinity. They made a large collection of 

minerals, which was referred to the writer when he arrived in Teller in 

July, 1903. Metallic tin was readily obtained from one small specimen by aid of a blowpipe, while the larger part of the collection" was 

shoAvn to contain minerals of no value. The collection was of sufficient 

interest to tempt the writer to examine the locality in detail. Mr. 

Hess and the writer proceeded to Lost River and were there able to 

trace the tin ore which had been seen in Teller to the granitic dike on 

Cassiterite Creek8, and also to obtain specimens of stanmte ore from 

Tin Creek.

Since this examination the dike described has been called "Cassiterite ledge" in location notices, and it has been definitely traced 

through a group of four claims. A crosscut trench has been made 

near the Cassiterite Creek end of the ledge, which, it is reported, 

shows that the ledge has a width of 100 feet and that cassiterite is O

disseminated throughout the rock. It is also reported that other discoveries of tin-bearing ledges in this neighborhood have been made 

since July, 1903. The claims located on Cassiterite ledge have been 

purchased by an experienced mine operator and will be developed 

next summer.

CAPE MOUNTAIN.

Cape Prince of Wales, the most western point of Seward Peninsula, 

is marked by a high peak known as Cape Mountain. At the southeast base of this mountain a settlement called Tin City has grown up 

within the last year. The Eskimo village of Kingegan, the. Congregational Mission, and Wales post-office are located on the north side, 

facing Bering Strait. From the summit of the mountain East Cape 

and other points on the Asiatic coast, only 60 miles distant, are plainly 

visible on clear days. On its west and south sides this mountain 

slopes down to.bluff's that drop perpendicularly into the sea. On its 

southeast side, near Tin City, the coast recedes northward, making a 

bight, which affords some protection from west winds, but for the prevailing south winds of summer it is practically an open roadstead with 

landing facilities, little, if any, better than those at Nome or York. 

The nearest good anchorage is about 40 miles distant, on Port Clarence, from which there are several practicable railroad routes. A 

view of this mountain as seen from York, about 12 miles distant, is 

shown in PL IV.

"A chemical analysis of one of these samples made by Mr. E. C. Sullivan, of the United States Geological Survey, shows no trace of tin. This sample consists mainly of tourmaline.
24 TIN DEPOSITS OF THE YOKE REGION, ALASKA. [NO. 229.

The greater part of the York region is occupied by the York Plateau, which is from 200 to 600 feet above the sea and is a result of 

erosion occurring during the period in which was produced the bench 

described in connection with the Lost River deposits. 0

This plateau is trenched by the streams which drain the region, and. 

the valleys have V-shaped cross sections, characteristic of newly established drainage. At the base of Cape Mountain, which rises to an 

elevation of 2,300 feet, the York Plateau has an elevation of about 300 

feet above the sea. The interbedded schists and limestones above 

described form the bed rock of the plateau surface surrounding Cape 

Mountain, but the mountain itself is composed almost entirely of a 

granite boss intrusive in the limestone. The contact relations of the 

granite and limestone have not been studied in detail, but from data 

gathered in the hast}^ reconnaissances it appears that the granite cuts 

across the bedding of the limestone. This granite has already been 

described under the heading "Igneous rocks."

The writer's visit to this locality was of necessity a very hasty one, 

and work was hampered by exceedingly rainy weather, so that his 

observations were limited. Specimens of tin ore,- however, were 

obtained from surface debris, which undoubtedly came from the granite 

of the mountain, though the ore was not definitely traced to its position in the solid rock. It is reported that tin ore has been found in 

at least three distinct places on this mountain, and that it occurs in 

somewhat irregular deposits which have an east-west trend. Several 

short tunnels have been driven into the mountain, but are reported 

not to have reached any ore bodies. The granite from some of-these 

tunnels is partially altered to greisen and justifies the belief that the 

ore bodies may be not far distant. A sample of this granite, analyzed 

by Mr. Sullivan, of the Survev. was found to contain a few hundredths 

of 1 per cent tin.

The ore obtained at Cape Mountain differs in general appearance 

from that seen at Lost River. Large pieces of nearly pure cassiterite, 

one of which weighed fully 9 pounds, are said to have been found on 

the surface of the mountain. A specimen which the writer obtained 

weighs approximately 2 pounds and is nearly pure cassiterite, showing few crystal faces, but embedded in it and surrounding it are long, 

slender needles of tourmaline. While in this vicinity the writer saw 

a number of large, nearly colorless ciystals of cassiterite which were 

practically transparent. Near the end of the season a large amount 

of supposed tin ore was collected on the flanks of Cape Mountain and 

shipped to Seattle, where it was examined by the writer and from it 

samples were selected for study in the laboratory. This supposed ore 

contains very little tin, but several dark crystalline minerals which

 aCollier, A. J., A reconnaissance of the northwestern portion of Seward Peninsula, Alaska: Prof. 

Paper U. S. Geol. Survey No. 2, 1902, pp. 36-39.
U. S. GEOLOGICAL SURVEY BULLETIN NO. 229 PL. V

THIN SECTIONS OF ALTERED PORPHYRITIC DIKE NEAR TIN CREEK,

Magnified 80 diameters: ft, feldspar; &, fluorite; C, fine-grained sericitic minerals; d, groundmass of

fine-grained quartz, fluorite, seridte, and calcite.

Magnified 54 diameters: (t, quartz phenocryst; b, groundmass, consisting mainly of fluorite and secondary quartz; C, zinnwaldite mica.
COLLIER.] REPOBTED LODE DEPOSITS. 25

have been mistaken for cassiterite. A sample assayed for tin by Mr. 

Sullivan, of the Survey, contained a trace of tin, a few hundredths of 

1 per cent. The principal constituent is tourmaline, in slender black 

or brown needles, and wolf ramite or scheelite are probably present, 

if, as reported, a considerable amount of tungsten was found.

Tin ore was discovered on Cape Mountain in July, 1902V by Mr. 

W. C. J. Bartels. In the fall of 1902 he brought out a large collection 

of specimens, which on examination by chemists and assayers, was 

found to include some tin ore. Extensive developments were planned 

for the season of 1903, and a well-equipped prospecting plant was sent 

to Cape Mountain. A large dynamo driven by a gasoline engine was 

to be placed near the beach at the point now known as Tin City, and 

from this dynamo wires to several points on the mountain were to 

supply power for electric drills. By the use of these drills it was 

expected that tunnels could readily be extended into the heart of 

the mountain and crosscut the ledges from which has come the float 

ore.

After spending nearly the whole of the season of 1903 in getting 

the machinery in place and establishing the winter camp it was found 

that the engine for driving the dynamo was defective, and the plan 

for development work during the winter of 1903-4 was necessarily 

suspended..

No work is now in progress on Cape Mountain, so far as is known, 

and very little advance has been made in revealing the nature of the 

ore deposits since the float ore was first discovered. This work, however, will undoubtedly be resumed in the summer of 1904, and it is to 

be expected that by the end of that season more definite information 

will have been obtained.

LOCALITIES FROM WHICH LODE TIN HAS BEEN REPORTED.

The discovery of tin ore in ledges has been reported by prospectors 

from m&ny other localities in Seward Peninsula, some of which deserve 

notice, since the geologic conditions are known to be promising, and 

they will be described in some detail.

DIOMEDE ISLANDS.

These islands, which lie in Bering Strait, midway between Alaska 

and Siberia, are reported to be composed of granite, though they have 

not been examined by geologists. It is probable that they represent 

an intrusion similar to that at Cape Mountain. It is reported that 

copper ore has been found on them, and should the tin ore found on 

Cape Mountain develop commercial importance they may merit 

investigation.
26 TIN DEPOSITS OF THE YOBK BEGION, ALASKA. [NO. 229.

BKOOKS MOUNTAIN.

This mountain lies about 11 miles north of the mouth of Lost River. 

The localit}7 can easily be reached by a road up Lost River from the 

beach, or by a road following up Don River from Port Clarence. 

Wagons have been driven over, both these routes." By the latter route 

the mountain is probably 20 miles from deep water of Port Clarence. 

The bed rock exposed on the mountain consists of highly altered limestones, and black slates which resemble the slates near York/*

The sedimentarjr rocks are cut by a number of granite and rhyolite 

dikes, which are believed to strike approximately east and west. All 

of the streams which head in Brooks Mountain, namely Lost River, 

Don River, York River, and Mint River, carry granite bowlders that 

have been derived from the mountain.

In 1901 the writer observed in this vicinity some of the minerals 

that have been found associated with tin in the ledges seen within the 

past season, and in the winter of 1901 a prospector, who had spent 

considerable time in this same region, sent a collection of these minerals to the Geological Survey Office. This collection contains a great 

deal of tourmaline and garnet, both of which are associated with tin 

ore on Tin and Cassiterite creeks, about4 miles south of Brooks Mountain. This locality seems promising for the occurrence of tin-bearing 

veins, though so far as is known to the writer no tin ore has yet been 

identified. N

DON RIVEK.

On the west side of Don River there is a ridge of high hills composed, in part, of slates like those found near York. b - These slates are cut by intrusive dikes of quartz-porphyry and 

granite resembling the intrusives of Brooks Mountain and Lost River. 

Some of the minerals often associated with tin ore have been found 

here, and the region is worthy of some investigation. This region 

lies about 10 miles east of Lost River and 9 miles north of Port 

Clarence.

EAR MOUNTAIN.

Ear Mountain is 50 miles north of Teller and 10 miles southwest 

from Shishmaref Inlet, a large, shallow body of water, not navigable 

for ocean vessels. Should the reported discoveries of tin be verified, 

and the ore occur in commercial quantities, a railroad riot over 50 miles 

in length could be built to Port Clarence.

This mountain is an isolated upland mass that has an altitude of

"Collier, A. J., A reconnaissance of the northwestern portion of Seward Peninsula, Alaska: Prof. 

Paper U. S. Geol. Survey No. 2, 1902, p. 30, PI. III. 

b Collier, A. J., Idem, pp. 46-47.
U. S. GEOLOGICAL SURVEY BULLETIN NO. 229 PL. VI

THIN SECTIONS OF PORPHYRITIC DIKE ON EAR MOUNTAIN.

A. Magnified 23 diameters: a, pyrrhotite; ?>, tourmaline; ('. quartz; (?, feldspar; e, groundmass of quartz and

feldspar.

B. Magnified 23 diameters: n, pyrrhotitej b, lourmaline; <\ kaolin and calcite pseudomorph after feldspar; 

(/, groundmass of secondary calcite.
COUJEK.] REPORTED LODE DEPOSITS. . 2V

2,308 feet above the sea. It stands on a well-marked plateau surface 

that has an elevation of 1,000 feet. This plateau has been correlated 

with the Kugruk Plateau, and is due to an earlier era of erosion than 

that which produced the York Plateau. a

The sedimentary rocks surrounding Ear Mountain consist mainly 

of quartzites and dark slates, which resemble the slates near York and 

have been correlated with them. The core of the'mountain is a granite boss or stock intruded in these slates. Radiating from the main 

granite mass there is a fringe of intrusive quartz-porphyry and rhyolite 

dikes which are regarded as offshoots from the main intrusion. b

The granites of the main mass are coarsely crystalline and consist 

essentially of quartz, orthoclase, and biotite. A specimen from one of 

the smaller bodies, examined microscopically, is made up essentially 

of quartz and of orthoclase and plagioclase feldspars. A narrow dike 

from the same region was found to consist essentially of quartz and 

feldspar, with muscovite, largely secondary, and a secondary growth 

of feldspar surrounding the larger orthoclase crystals. In Ear Mountain a platy structure brought out by the weathering gives the rock a 

stratified appearance.

Tin ore has been reported to occur in this region, and it is probably 

tr.ue that some ^cassiterite has been brought out by prospectors. The 

specimens of supposed ore which were submitted to the writer contained, however, only traces of tin, though some of the minerals often 

associated with its ores were present. On the north side of the mountain quartz-porphyry dikes can be traced for considerable distances. 

Several specimens of these rocks have been carefully examined in the 

laboratories of the U. S. Geological Survey. Apparently they were 

originally rhyolites or quartz-porphyries, but in thin sections they 

show considerable alteration. In one case the porphyritic texture of 

rhyolite remains, but the minerals, especially the feldspar phenocrysts, 

are partly replaced by tourmaline and pyrrhotite or magnetic pyrite, 

as shown on PI. VI. In this case the tourmaline was probably first 

introduced and was followed by the pyrrhotite. No cassiterite has 

been identified in the section. In another section the original texture 

is completely obliterated and the rock consists essentially of tourmaline in radiating groups of crystals surrounded by a groundmass made 

up principally of calcite with some quartz (PI. VII, A). Magnetite 

and biotite seem to be present in small amounts, and probably also 

cassiterite, though it has not been detected in the thin sections. This 

specimen resembles in texture the luxullianite c from Cornwall, but 

differs from it in composition, since the groundmass of the typical

"Collier, A. 3., Prof. Paper U. S. Geol. Survey No. 2, p. 35.

b Collier, A. 3., op. cit., p. 30.

cHarker, Alfred, Quart. Jour. Geol. Soc. London, 1895, vol. 51, p. 141. Rosenbush, H., MikroskopIsche Physiographie der Massigen Gesteine, vol. 2, pt. 1, p. 50. Kemp, James Funnan, Handbook of 

Rocks, p. 32.
28 . TIN DEPOSITS OF THE YOEK REGION, ALASKA. [NO. 229.

luxiilliariite consists largely of feldspar and quartz, while in this rock it 

is largely calcite.

Four samples of rock from the north side of Ear Mountain were 

assayed for traces of tin by Mr. Sullivan of the Survey. While none 

of them carry tin in commercial quantities, traces of tin, estimated at 

a few hundredths of 1 per cent, were found in all of them. A prospecting shaft, it is^ reported, was sunk on one of these dikes, and 

samples obtained from considerable distance below the surface were 

found to be largely made up of dark mica and tourmaline. It is also 

reported that stream tin has been found in several of the creeks that 

head in Ear Mountain.

HOT SPRINGS. a '

This locality is 70 miles northeast from Port Clarence, about 30 

miles southeast from the head of Shishmaref Inlet, and 30 miles from 

deep water on Goodhope Bay. It takes its name from a group of hot 

sulphur springs, well known to prospectors and miners, around which 

there is usually a small village of tents.

In summer time the usual route of travel to this locality is by way 

of Imuruk Basin and the Kuzitrin and Kugruk rivers'. If tin deposits 

of value should be discovered in this vicinity a road would probably 

be constructed to Goodhope Bay. The general bed rock of this 

vicinity is graphitic mica-schist, but at Hot Springs this schist is 

intruded by a large body of granite several miles across. The granite 

is of the same general type as that of Ear Mountain, but it has not 

been examined microscopically. In Professional Paper No. 2 two 

characteristic landscapes within this granite area are shown on Pis. 

VIII and IX.

Since the discoveries of tin ore were made in the granites of the 

York region, prospectors have turned their attention to this area, and 

samples of tin ore purporting to come from it were brought to Nome 

late in the season of 1902.

ASSES EARS. 6

Near the headwaters of the western tributaries of Pinnell River, in 

the region south of the eastern extension of Kotzebue Sound, are a 

number of small isolated areas of granite, .surrounded by massive 

crystalline limestones. These granites have been more resistant to 

weathering than the limestones, and, stand out as prominent hills or 

buttes. One of these forms the well-known landmark called the 

Asses Ears, which was so named by Kotzebue in 1816, because "its 

summit is in the form of two asses' ears." A few miles to the north-

« Collier, A. J., A reconnaissance of the northwestern portion of Seward Peninsula, Alaska: Prof. 

Paper U. S. Geol. Survey No. 2, 1902, p. 55.

bThis note is furnished hy Mr. Fred H. Moffit, in advance of his report on "A reconnaissance of 

the northeastern portion of Seward Peninsula."
U. 6. GEOLOGICAL SURVEY BULLETIN NO. 229 PL. VII

A. THIN SECTION OF LUXUL1ANITE FROM EAR MOUNTAIN. 

Magnified 80 diameters: a, tourmaline; b, groundmass of secondary calcite.

 'V

«.. *

^. POLISHED SURFACE OF TIN ORE FROM LOST RIVER.

a, Cassiterite; b, gray pyrite; c, zinnwaldite mica; d. fluorite; e, groundmass of fluorite and calcite; /, groundmass, chiefly kaolin.
COLMER.] STREAM TIN" ON BUCK CREEK.. ' 29

west is another granite area, smaller and much less prominent than 

that forming the Asses Ears. These two localities are situated south of 

the Sound and, since they are not favorable places for placer gold, 

have been rarely visited. A third granite area makes up the central 

mass of the elevated watershed between Kiwalik and Buckland rivers. 

This range extends from Kotzebue Sound to within a few miles of 

Koyuk River, a distance of about 40 miles. Here the granites are 

found only in the higher central part of the mass, and are surrounded 

by later eruptives, including andesitic rocks and lavas which form the 

lower hills. -

These granites are all variable in their texture, and often have an 

extremely coarse, pegmatitic appearance. Twinned orthoclase feldspars, 2 or 3 inches in length and three-fourths of an inch thick, are 

not uncommon, and hornblende crystals of large size are found in 

places. Locally, quartz seems to be absent and the rock becomes

Syenitic in character. Fluorite was seen in joint planes in the granites 

northwest of the Asses Ears, suggesting the possible presence of tin 

ores such as occur with this mineral in the western part of Seward 

Peninsula.

Dr. Cabell Whitehead, of the Alaska Banking and Safe Deposit 

Company, reports the presence of cassiterite in the form of fine sand 

in gold taken from Old Glory Creek, which heads up toward the limestone area in which the previously mentioned granite masses of the 

Asses Ears region occur.

LOCALITIES WHERE STREAM TIN HAS BEEN FOUND. 

BUCK CREEK. a

Buck Creek was the scene of the first actual mining of tin ore in 

Alaska, and is the present center for tin-placer mining activities. This 

settlement is on the Arctic slope of Seward Peninsula, about 20 miles 

northeast from York, and 4 miles from tide water on Lopp Lagoon, 

an inlet from the Arctic Ocean. It is reached by a wagon road from 

York, which follows the bed of Anikovik River for 10 miles, then 

crosses a low divide to Grouse Creek and follows Grouse Creek to its 

junction with Buck Creek. This road is fairly good, except for 1£ 

miles of soft tundra 6 on the divide between Anikovik River and Grouse 

Creek, where it is almost impassable for heavy Avagons. A good roadbed could easily be built here lay bringing gravel from Anikovik 

River. Lopp Lagoon is not navigable for seagoing vessels and affords 

no harbor for such craft. It is a large, shallow body of water, sepaaThis description of the tin placers of Buck Creek is based on the work of Mr. Frank L. Hess.

l> The Standard Dictionary gives the following definition of "tundra:" "A rolling plain of Russia 

and Siberia, covered with moss and at times very moist and marshy." "The ' tundras' of northern 

latitudes are frozen plains of which the surface is covered with arctic mosses and other plants." 

Archibald Geikie, Text-Book of Geology.
30 TIN DEPOSITS OF THE YORK REGION, ALASKA. [NO. 229.

rated from the Arctic Ocean by a low sand spit, on the seaward side 

of which the shallow water is reported to extend out about 2 miles 

from the coast, so that landing is difficult. For small, flat-bottomed 

boats, however, this lagoon is navigable, and it is possible that such 

boats might, but not probable that they ever will, convey tin ore from 

the Buck Creek mines, out through the inlet, to vessels lying offshore 

.in the Arctic Ocean. It. is reported that small boats can be brought 

up Mint River and Grouse Creek to within 1 mile of the mouth of 

Buck Creek. These streams, however, are shallow and crooked, jind 

it is not probable that they can be used successfully for conveying ore 

from Buck Creek to the sea. '

The plateau already described extends northward from the town' 

of York on the coast of Bering Sea to the Arctic Ocean. It has an 

elevation of about 600 feet near York, and slopes to sea level a few 

miles from the Arctic coast. Buck Creek and the other streams in 

its vicinity flow in comparatively new valleys cut in this plateau. 

Above the surface of the plateau there are several buttes, of which 

Cape Mountain and Potato Mountain a are the most prominent. Potato 

Mountain is a large, cone-shaped mountain, having an elevation of 

1,370 feet. From this mountain a range of low hills extends northward for a distance of 3 or 4 miles toward Lopp Lagoon.

Buck Creek is a small stream, about 5 miles.in length, which rises 

in this range of hills and flows southeastward to Grouse Creek. Its 

waters are then carried northward through Mint River and Lopp 

Lagoon to the Arctic Ocean. About 1 mile from its mouth Buck 

Creek receives a large tributary from the south, called Sutter Creek, 

and about 4 miles above its mouth it again forks, the two branches 

being known, respective!}^ as Right and Left forks. Several smaller 

tributaries are received between Sutter Greek and these upper forks.

The bed rock on which the York Plateau is developed, and in which 

Buck Creek Valley is incised, is a dark, slaty schist, which has been 

already described. Along Buck Creek it has the characteristic jointing described in the general discussion of the geology of this region.

The mountains west of Buck Creek, including Potato Mountain, are 

composed of similar slates. They apparently contain no intrusive, 

igneous rocks, either of the greenstone or granite type.

Near the mouth of Buck Creek bowlders and pebbles of greenstone 

occur in the gravel deposits. These have not been traced to their 

source, but the}^ probably came from a group of hills on the east side 

of Grouse Creek before the present drainage was established. At a 

number of places along Buck Creek small quartz veins were found 

cutting across the bedding or running parallel with it through the 

slate. Some of these quartz veins are as much as 3 or 4 feet thick,

«The name Conical Hill was applied to this mountain by Captain Beechey in 1826. It is said'to 

have been called " Potato Mountain" by the Russians. On the topographic map, Prof. Paper No. 2, 

PI. XII, the mountain is called "Cone Hill." -
COLLIER.] STREAM TIN ON BUCK CKEEK. ' 31

and two of them can be traced for a quarter of a mile or more. Most 

of the veins are mere stringers, 1 or 2 inches thick and only a few 

feet long. In one instance a vein of nearly pure pyrite 6 or 8 feet 

wide was seen. Pebbles of pyrite 2 or 3 inches in diameter, oxidized 

on the outside, are found in the gravels below this vein. 

Mr. Edgar Rickard" reports on this deposit as follows:

The source of the cassiterite can be readily traced to the slate of the [Potato Mountain] range, where it undoubtedly occurs in countless small veins and vugs, sometimes associated with quart/ and so thoroughly scattered through the mass that the 

action of the elements has washed it from the hillsides and concentrated it in the 

streams below in appreciable deposits.

Though,specimens obtained from the gravel show that this is true, 

no veins of this kind were seen by Mr. Hess nor by the number of 

prospectors who were actively engaged in a search for tin-bearing 

veins. It is of interest to note that no granitic rocks or acid intrusives of any kind have been found associated with the phyllites, nor 

have any pebbles of such rocks been found in the gravels. So far as 

the surface indications show, it appears that the tin ore has its source 

in veins which are of distinct origin from those found in association 

with granitic rocks.

The gravel deposits in the bed of Buck Creek are from 10 to 150 feet 

wide, varying greatly in different parts of the creek.

Cassiterite, in the form of stream tin, is distributed from the mouth 

of the creek to within a mile of its head, above which point little more 

than traces have been found. The ore varies in size from line sand to 

pebbles weighing 13 or 14 pounds. Several pieces from 5 to 8 pounds 

in weight were seen by Mr. Hess, though the average size is much 

smaller. A few of the pebbles are perfectly rounded, but most of 

them are subangular. The ore from the claims near the mouth of 

Buck Creek is general!}'- well rounded, while that from near the head 

is sharp and angular. In general the stream tin grows more angular 

as the head of the creek is approached.

The color of the cassiterite varies from almost black to a light resin 

or amber; when crushed, however, it makes a light-colored resinous 

powder, by which it is readily distinguished from hematite or other 

iron minerals that are frequently mistaken for it, since they invariably 

 give a distinctly red, brown, or black powder. A number of specimens were obtained with pieces of quartz and slate still attached to 

them, leaving no doubt as to the localorigin of the fragments. Sometimes small pieces of cassiterite are found inclosed between fragments 

of slate, showing that the ore sometimes occurs as veinlets in the bed 

rock.

Near the head of Buck Creek Mr. Edgar Rickard," in 1902, tested

aRickard, Edgar, Tin deposits of the York region, Alaska: Eng. and Min. Jour., vol. 75,1903, p. 30.
32 TIN DEPOSITS OF THE YORK REGION, ALASKA. [NO. 229.

the gravels systematically and found that they contain about 8 pounds 

of 60 per cent ore to the cubic }^ard. The value per yard on this basis, 

with tin at 28 cents per pound, would be $1.34, out of which charges 

for shipping and treatment would have to be paid.

Mr. Hess saw pannings made at a number of places along Buck 

Creek, but not enough to test thoroughly the richness of the gravels. 

The best that were seen came from immediately above the mouth of 

Sutter Creek, where a drain ditch from 2 to 2£ feet deep was under ^ 

construction. Seven pans taken from various parts of the gravel 

thrown out of this ditch gave about 1 pound 6 ounces of concentrates. 

Estimating 20 pounds of gravel to the pan, this would give approximately 27 pounds of, say, 60 per cent ore to the cubic yard of gravel. 

Bed rock was here 5i feet below the surface, and the gravel approximately 100 feet wide. A few good colors of gold were found in the 

concentrates. At this point there seemed to be no difference in the 

distribution of the tin ore through the gravels below the surface. It 

seemed from the evidence of prospectors that this uniform distribution through the gravels prevailed generally along the creek, though 

at one place it was found to be richer on bed rock.

It is reported that cassiterite has been found in a bench near the 

upper forks of Buck Creek, but no definite data were obtained concerning the nature of the occurrence.

On Grouse Creek, below the mouth of Buck, the amount of tin ore 

is reported to-be very small, and while Mr. Hess found no evidence of ; 

prospecting in this section, and is of the opinion that practically none 

has been done there, the gravel deposits are more extensive than those 

on Buck Creek and seem to be worthy of attention. No large amounts ^ 

of cassiterite have been reported from either Gold Creek, a tributary 

of Grouse above Buck, or from Sutter Creek, the large southern ti'ibutaiy of Buck, nor has much gold been found there.

To summarize the evidence with regard to the Buck Creek region, 

tin ore has been found in the gravels of the creek from its mouth to 

within 1 mile of its head. The pay streak appears to be confined to 

the present stream-bed and flood-plain deposits. lii the present creek 

bed the ore is found from the surface to the bottom of the gravels. 

Outside the creek bed, in the flood plain, there is a covering of moss 

and muck above the pay gravel. No cassiterite is known to have been 

found on the hillsides surrounding Buck Creek or on the plateau 

surface in which Buck Creek Valley is incised, though such an occur- j. 

rence is to be expected. The known pay streak varies in width 

from 10 to 150 feet, and in thickness from a few inches to 5 feet. 

Estimates of the amount of tin ore in the gravels vary from 8 to 27 > 

pounds per cubic yard, but very few comprehensive tests have been 

made.

At the time of Mr. Hess's visit to Buck Creek, near the end of f
COLLIER.] STKEAM TIN ON BUCK CREEK. 33

July, sluicing for tin ore was in progress at only one place. The 

creek valley still contained great drifts of snow, and mining operations generally were retarded by the lateness of the season.

Stream tin is harder to separate from the gravel than is gold on 

account of its lower specific gravity, but the methods employed in 

washing it out were modifications of somewhat primitive processes of 

gold placer mining. Ten men were shoveling into the one "string"

T

 22 H

SLUICE BOX

J_

FIG. 4. Sluice boxes used in washing placer tin in York region.

of sluice boxes and a clean up was made four times a day, so that the 

work was frequently interrupted. The sluice boxes used were 16 

feet long, 24 inches wide at the upper end and 22 inches wide at 

the lower end, and 7 boxes were used in a " string," making a total 

length of 150 feet. A "dove box 3 ' 8 feet long, 4 feet wide at the 

upper end and 22 inches wide at the lower end, with riffles, was 

Bull. 229 04 3
34 TIN DEPOSITS OF THE YOJRK EEGION, ALASKA. [NO. 229.

introduced between the fourth arid fifth boxes from the upper end 

(see fig. 4). Ordinary patterns of Pole and Hungarian riffles were 

used, except that they were made of 2£ by li inch material, which is 

larger and heavier than that ordinarily used in sluicing for gold. 

About 100 miner's inches of water constituted a sluice head for this 

apparatus. It is reported that the concentrates obtained averaged 

about 40 pounds per day to the shovel. The concentrates from the 

sluice boxes were further concentrated by hand by panning in a box 

5 feet long by 3 feet wide and 8 inches deep, into which water flowed

3'

FIG. 5. Box used in washing stream tin concentrates.

through a canvas hose and flowed out over an apron 4 feet long in a 

stream about three-quarters of an inch deep, as shown in fig. 5. The 

concentrated gravel was gradually worked up over the edge of the pan, 

which was kept just submerged at the upper end of the apron, where 

the stream of water carried away the lighter portion, while the heavier 

particles sank in the box. It is reported that concentrates treated in 

this way averaged about 50 per cent tin. The larger pieces of foreign 

matter were picked out by hand. The impurities in the concentrates 

are mainly hematite, magnetite, quartz, and slate.

Later in the season some sluicing for tin ore was done at several
COLLIER.] STREAM TIN ON BUHNER CREEK. 35

other points on Buck Creek, and altogether a considerable amount of 

tin ore, estimated at from 30 to 40 tons, was obtained and hauled to 

York for shipment.

Should further prospecting demonstrate that there are large amounts 

of stream, tin in Buck Creek or any of the neighboring streams, practical mining will require the introduction of more economical methods, 

to overcome the handicap of short seasons and high wages. In other 

parts of Seward Peninsula hydraulic mining has been practiced with 

marked success in the gold placers, and the same method can probably 

be adapted to the tin placers as well. Water for this purpose can be 

obtained from the streams rising in the York Mountains. The feasibility of collecting water from these streams for working the tin 

placers of Buck Creek and vicinity will be readily seen from the topographic map of the region (PI. II), but the question whether or not 

the deposits will warrant the necessaiy expenditure can not be settled 

without further development.

ANIKOVIK RIVER AND BUIINER CREEK.

The localities on Anikovik River and Banner Creek, where tin ore 

was discovered in 1900, are 2 and 3 miles, respectively, from York. 

Buhner Creek flows into Anikovik River from the west, a short distance north of the point where Banner Creek enters the Anikovik. 

The following description of these deposits is quoted from Mr. 

Brooks:"

On Buhner Creek 2 or 3 feet of gravel overlies the bed rock, which consists of 

arenaceous schists, often graphitic, together with some graphitic slates. This is part 

of the schist series which has been described. The bed rock is much jointed, the 

schists being broken up into pencil-shaped fragments. They strike, nearly at right 

angles to the course of the stream and offer natural riffles for the concentration of 

heavier material. A hasty reconnaissance of the drainage basin of this stream, 

which includes not more than a square mile of area, showed the same series of rocks 

throughout its extent. At a few localities some deeply weathered, dark-green intrusives were found, which, on examination by the microscope, were found to consist 

almost entirely of secondary 'minerals. In some cases, however, a little plagioclase was still unaltered and a. suggestion of ophitic structure remained, so that 

these are probably of a diabasic character. The slates and schists are everywhere 

penetrated by small veins, consisting usually .of quartz with some calcite, and frequently carrying pyrite and sometimes gold. These veins are very irregular, often 

widening out to form blebs, and again contracting so as not to be easily traceable.

The stream tin is concentrated on the bed rock with other heavy minerals, and 

was found by the miners in the sluice boxes. A sample of the concentrate & in one 

of the sluice boxes was examined by Mr. Arthur J. Collier, and yielded the following minerals: Cassiterite, magnetite, ilmenite, limonite, pyrite, fluorite, garnets, and

gold. The determination of percentage by weight was as follows: 90 per cent tin- 

 : 

a Brooks, A. H., An occurrence of stream tin in the York region, Alaska: Mineral Resources U. S. 

for 1900, U. S. Geol. Survey, 1901, p. 270.

6 The sample of these concentrates from which the first determination of tin ore in Alaska was 

made was obtained from C. B. Kittredgc, who was mining on Buhner Creek. Another sample was 

obtained from Mr. Trumble, a miner on Anikovik River.
36 TIN DEPOSITS OF THE YOEK REGION, ALASKA. [NO. 229.

stone; 5 per cent magnetite; other minerals, 5 per cent. The cassiterite occurs in 

grains and pebbles, from those microscopic in size to those half an inch in diameter; 

they have subrounded and rounded forms. In some cases there is a suggestion of 

pyramidal and prismatic crystal forms. The cassiterite varies in color from a light 

brown to a lustrous black.

A second locality of this mineral was found on the Anikovik River, about half a 

mile below the mouth of Buhner Creek. Here the cassiterite Avas also found with 

the concentrates from the mining operations. One pebble of stream tin obtained 

from this locality was about 2 inches in diameter.

It will be necessary to make a more detailed examination of this region to determine where this mineral occurs in the bed rock. The facts obtained by the writer 

point toward the conclusion that its source was in the quartz and calcite veins in 

which the gold was found. No cassiterite was, however, found in this vein material.

Since 1901 these workings have been abandoned by miners, neither 

gold or cassiterite having been found in paying quantities. On Anikovik River there are extensive gravel deposits, which may possibly 

be made to yield fair returns either in gold or tin if economically 

worked on an extensive scale by hydraulic methods. Sufficient water 

for this purpose can probably be obtained. either from the head of 

Anikovik River or from Kanauguk River.

LOCALITIES FROM WHICH STREAM TIN HAS BEEN REPORTED.

It is reported by prospectors familiar with the Buck Creek deposits 

that some tin ore has been found in alluvial deposits on Baituk and 

Kigezruk creeks, flowing into Bering Sea; in Banner Creek, tributary 

to the Anikovik; several small streams flowing into Lopp Lagoon; 

Clara Creek, a tributary of Mint River; and in York Creek, a tributary of Pinguk Ri\7 er, all in the York region. Stream tin has also 

been reported from all parts of Seward Peninsula where gold mining 

is in progress, but outside of the York region these reports have generally been without foundation. Last summer, however, Mr. Hess 

obtained from a miner a specimen of stream tin said to have been 

found on Gold Bottom Creek, a tributary of Snake River, in the Nome 

district. If this find was genuine it indicates a wider distribution of 

the tin ore than has heretofore been supposed, and is the only case 

known in which stream tin has been found in the gold placers near 

Nome. There is probably not- enough tin ore there to have economic 

value.

The bed rock of Gold Bottom Creek consists of limestones and schists 

of the Nome series.

SUMMARY OF ECONOMIC GEOLOGY.

Tin ore in considerable quantities has been found in the York region 

at a number of widely separated localities, the extreme points known 

being 25 miles apart. While the existence of -tin ore in sufficient 

quantities to be worked on a profitable scale has not yet been demonstrated because of the remoteness of the region, the inhospitable
COLMKR.] SUMMARY .OF ECONOMIC GEOLOGY. 37

climate and the cost of labor, the probabilities are that further development will prove some of the deposits to have commercial value.

The ore occurs in both alluvial deposits and in ledges. The ore of 

the alluvial deposits has been traced in some cases to small veinlets 

and vugs in the slate country rock, where it has no visible connection 

with intrusions of granite or other igneous rock, and in others to welldefined dikes or veins of greisen. This lode ore is associated with 

granite or other siliceous, igneous, intrusive rocks, that have been 

altered to true greisen like that occurring in nearly all productive tin 

regions.

In one case the cassiterite occurs disseminated through a greisen 

composed of quartz, calcite, fluorite, and lithia mica. In another case 

the tinstone is intimately associated with tourmaline contained in veins 

in the granite.

The granites in which tin ore has been found.are intruded in limestones of Silurian age in one case and probably of Carboniferous age 

in another. Similar bodies occur northeastward from York for a 

distance of 100 miles. Minerals associated with the tin ore in the 

York region, such as fluorite and tourmaline, have been found in several of these granite areas, and .tin ore has been reported from some 

of them, but its existence outside of the York region has riot yet been 

proved.

Some of the promoters of mining enterprises have expressed a 

desire to install immediately a complete outfit for milling and smelting 

tin ore at some point in the York region. The many fiascos resulting 

from the building of mills and smelters before the extent of ore bodies 

had been determined are well known to anyone familiar with the history of mining in the United States, so that the folly of this plan is 

evident. Even after the ore is proved to exist in sufficient quantities 

for mining a careful study must be made of the ore itself, and of the 

conditions as affected by climate, wages, fuel supply, and transportation, before either the proper place or method of treating the ores can 

be determined. The erection of a smelter at present Avould seem to 

be ill advised, if for no other reason than because no estimable supply 

of ore exists. In estimating the value of tin ores in this northern 

region several facts must be borne in mind. The region is devoid of 

timber and is accessible-by ocean steamers, at the longest, or\\y from 

the first of June to the end of October. Harbor facilities are poor, 

and all supplies and wages are high. On the other hand, the construction of railroads and wagon roads would not be difficult, and, if 

demanded, would require comparatively little outlay of capital.

TRAlSTSPOKTATIOiN AND FUEL SUPPLY.

In view of the possible developments of tin mining in this region 

the questions of transportation and harbor facilities become important.
38 TIN" DEPOSITS OF THE YORK REGION, ALASKA. [NO. 229.

The coast line of the York region is not broken by any inlet or harbor 

suitable for seagoing vessels. Such craft are obliged to lie a safe 

distance offshore, while landings of freight or passengers are made 

with lighters or small boats through the surf, as at Nome. .During 

much of the time the sea is smooth and such landings are easy, but 

frequently violent storms continue for several days, which would 

destroy lighters and endanger the ships themselves. In fair weather 

vessels could be loaded in safety from piers, but the possibility of 

maintaining docking or other loading facilities along this coast is 

questionable on account of the movement of great ice floes that cover 

Bering Sea during the long winter.

Port Clarence, the only harbor and safe anchorage for large vessels 

in Seward Peninsula, is a bay 25 miles southeast of York, and, should 

the tin deposits be worked on an extensive scale, this harbor is easily 

accessible. It is a large body of comparatively deep water, nearly 

circular in outline, and cut off from the sea by a long, low sand spit, 

which terminates in Point Spencer at the entrance to the bay.

Along the north side of Port Clarence there is a shallow lagoon, 

separated from the bay by a narrow sand spit. This lagoon extends 

several miles west, of the entrance to Port Clarence. It can be made 

use of for transporting ore in lighters and small boats. The Coast 

Survey charts show deep water suitable for large vessels along the 

north shore near the entrance to the bay, and docks and wharves 

would naturally be built there. On the south side of the entrance, 

at Point Spencer, a safe anchorage near shore is made use of as a 

coaling station by whalers en route to the Arctic Ocean. It is 

reported that the ice leaves this part of Port Clarence first, at the 

opening of summer, and that vessels have made use of this anchorage before they were able to approach the coast at Nome. It is 

therefore possible that Point Spencer might be the most convenient 

shipping point for the York region. The product of the mines could 

be brought to the coast of Bering Sea by tramroads or wagons, 

and, in the summer time, ferried across to Point Spencer, or in 

the winter hauled over the ice either by traction engines or by 

horses. Should production be sufficient to warrant it a railroad can 

easily be built from some point on the north shore of Port Clarence to 

Lost River and up its valley. Should the mines on Buck Creek warrant the building of a railroad the Lost River line could be extended 

across the divide at the head of Lost River to Mint River, and thence 

follow around the northern foothills of the York Mountains to Buck 

Creek. This road could again be extended from Buck Creek to the 

locality at Cape Mountain. It would probably not be practicable to 

build a road along the coast from the month of Lost River to York.

During the summer season there is sufficient water in the streams of 

the region to furnish power for all the machinery required in mining
COLLIER.] CHARACTERISTICS OF TIN ORE. 39

and concentrating, but, obviously, during the winter this source of 

power is cut off, and coal or other fuel must be used. In Alaska there 

are two possible sources of coal for the York region. One of these 

is near Cape Lisburne/8 about 200 miles northeast of York, on the 

shore of the Arctic Ocean. There is reported to be an abundance of 

coal suitable for steaming purposes at this place, but there are absolutely no' harbor facilities and there is no wood available for timbering 

the mines, and, further, navigation on the Arctic Ocean is possible 

for only two months of the year; so that these coal beds can not be 

depended on to furnish a coal supply.

The other source of coal is at Herendeen Bay and Port Moller, 

about 700 miles to the south, on the Alaskan Peninsula, but this coal 

has not been sufficiently developed to determine whether it exists in 

commercial quantities. At the present writing it seems that the only 

certain sources of fuel for the Seward Peninsula are the coals of 

the State of Washington and those of British Columbia. On account 

of the difficulty in obtaining fuel and the cost of labor and subsistence 

in the Seward Peninsula it does not seem possible that the smelting of 

tin ore in the York region will ever be successfully accomplished. 

The ore from this region will necessarily be shipped either to the coal 

mines in other parts of Alaska, to Puget Sound, or to other points for 

smelting. The freight on ore shipped from' Port Clarence to Seattle 

would probably be very low, since the large number of vessels carrying freight to Seward Peninsula and St. Michael would desire return 

cargoes.

In the summer of 1902, 98,822 tons of freight were carried to these 

points.

TIN ORES AND ASSOCIATED MINERALS.

Physical characteristics of tin ore. Cassiterite, tinstone, or tin ore, 

the dioxide of tin, is the most common form in which tin occurs in 

nature. It crystallizes in four-sided prisms and octahedrons, but 

twinning is so common that simple crystals are rarely found. The 

stream tin of the York region usually occurs in rounded pebbles, its 

color varying from light brown to black; the color of the streak 

that is, of the powdered mineral is pale gray to brownish. Wood tin 

is cassiterite that occurs in botryoidal and renifcrm shapes, with concentric and radiated fibrous internal structure, though very compact. 

Its color is brownish in varying shades, which give it somewhat the 

appearance of dry wood. A few specimens of wood tin have been 

found on Buck Creek. Cassitei'ite has no distinct cleaA^age visible to 

the naked eye. It has about the same hardness as quartz, but is very 

much heavier, having a specific gravity, when pure, of from 6.4 to Y.02.

" Schradcr, F. C., A reconnaissance in northern Alaska in 1901: Prof. Paper U. S. Geol. Survey No. 

20,1904, pp. 109-114.
40 ,fnJ DEPOSITS OF THE YORK REGION, ALASKA. [NO. 229.

Specimens of the ore mined in the York region, which were tested in 

this office, gave specific gravities from 5.1.5 to 6.06. Since cassiterite 

is heavier than most of its associated minerals, it can usually be separated from them by crushing and panning. The most satisfactory 

test'for cassiterite that can be made in the field is with the blowpipe, 

as follows: The mineral, crushed and finely powdered, is mixed with 

about equal amounts of powdered charcoal and soda, and heated gently 

in the reducing flame. Metallic tin is readily obtained in small globules 

scattered through the assay, but it is more difficult to collect the metal 

into one globule, and in attempting it an unskilled operator will 

usually reoxidize the tin.

Stannite, or tin pyrites, is sulphide of tin, copper, and iron with 

some zinc. Some varieties contain silver, lead, or antimony. Stannite resembles pyrites and other metallic sulphides, and is not easily 

distinguished in the field. The blowpipe tests are unsatisfactory, since 

it is impossible to obtain a tin globule from it. This ore, when pure, 

contains only 27 per cent tin, and is not mined except in conjunction 

with other ores." It has been found on Tin Creek in the York region.

ASSOCIATED MINERALS.

In the York region the most common minerals accompanying tin 

are quartz, tourmaline, epidote, garnet, rutile, fluorite, wolframite, 

magnetite, hematite, limonite, and ilmenite. Of these, tourmaline, 

garnet, rutile, wolframite, magnetite, limonite, and quartz have often 

been mistaken for tin ore.

Tourmaline. ^This is a complex silicate of boron and aluminum. 

In the York region it Occurs in slender three, six, or nine sided prisms, 

brownish black and bluish black in color. These prisms are often 

arranged in radiating groups. Tourmaline is distinguished from 

Cassiterite by its crystallization and by its specific gravity, which 

varies from 2.98 to 3.20. Before the blowpipe the tourmaline of the 

York region is fusible without fluxing, while cassiterite is infusible.

Garnet. In the York region garnet often occurs in massive, granular aggregates, which greatly resemble tinstone. To the experienced 

eye they are readily distinguishable by slight differences in color. 

Garnet has a "specific gravity from 3.15 to 4.30; in other words, it is 

a little more than half as heavy as tinstone,. It crystallizes in the 

isometric system, and never forms elongated prisms. Like tourmaline, 

it fuses before the blowpipe.

Rutile. Titanium dioxide, or rutile, occurs in crystals, which in 

hardness, specific gravity, and crystallization resemble cassiterite. 

The crystals, however, are usually slender prisms, striated or furrowed 

lengthwise. The streak is pale brown. This mineral has not been 

found in the ledges, but in alluvial deposits it has often been mistaken 

for tinstone.
COLUKH.] MINERALS ASSOCIATED WITH TIN OEE. 41

Wolframite. This is an ore of the metal tungsten, a tungstate of 

iron and manganese. It has a submetallic luster, a grayish or brownishblack color, and a black streak. Its specific gravity is 7.2 to 7.5, a 

little higher than that of cassiterite, but it is readily distinguished 

from the latter mineral by possessing a perfect cleavage.

Epidote. This complex silicate of calcium, aluminum, and iron is 

usually .of a yellowish-green color. On Tin Creek it.is found in 

prismatic crystals forming divergent groups resembling the tourmaline, which is also found there. In luster, streak, and hardness it 

resembles cassiterite, but its specific gravity is 3.25 to 3.50, only a 

little more than half as heavy as cassiterite. Before the blowpipe it 

fuses easily, and in the closed tube gives water.

Magnetite and linwnite.- These ores of iron are found in the placers 

associated'with stream tin. They are often mistaken for tin ore, but 

 are readily distinguished by the practiced eye. Magnetite can be distinguished by the use of a magnet, while the red or brown streak of 

limonite serves to separate it from the tin ore.

Fluorite. This mineral, commonly known as fluorspar, occurs in 

the bed rock associated with the tin ore wherever found in the York 

region. It is a simple chemical combination of fluorine arid calcium, 

crystallizing in cubes and having a vitreous luster and usually a white, 

wine-yellow, greenish-blue, or violet-blue color. Its specific gravity 

is from 3.01 to 3.18. It is easily scratched with a knife, its hardness 

being about equal to that of calcite, from which it is distinguished by 

its cubic crystallization and failure to effervesce with hydrochloric 

acid.

Quartz. In varying amounts quartz is also associated in the bed 

rock with the tin ore. Usually it is readily distinguished from the 

cassiterite, but instances were common last summer where prospectors 

had mistaken a dark-colored, smoky quartz in small grains for cassiterite. The specific gravity of quartz is 2.65 to 2.66, so that by the 

panning test the quartz can readily be separated. In powdered form 

smoky quartz and cassiterite resemble each other so much that the 

blowpipe test is often required to distinguish them.

METHODS OF ASSAYING TIN ORE.

Accurate assays of tin ore by ordinary methods are difficult on 

account of the readiness with which the tin combines with the various 

gangue minerals, forming silicates and stannites, which pass off with 

the slag.

Nearly all writers on the subject of tin assays recommend that only 

rich ores, practically almost pure cassiterite, be treated by fire assay.. 

Stream tin is ordinarily pure enough to give an approximately accurate " 

result without further concentration, but lode ore, associated as it is
42 TIN DEPOSITS OF THE YORK REGION, ALASKA. [NO. 229.

with gangueaninerals, must be concentrated. Without such treatment 

it is impossible to obtain even an approximate estimation by the dry 

method usually employed, and in an ore containing less than 10 per 

cent it is probably impossible to obtain any tin at all. A study of the 

literature regarding tin analyses has convinced the writer that the 

reports of dry assays of low-grade tin ores, in which the cassiterite can 

not be recognized by the naked eye or separated by hand panning, are 

of no value.

For assaying'** the ore is first pulverized and screened to uniform 

size, care being taken in the crushing to prevent "the formation of 

slimes, since cassiterite is very brittle. . The pulp is then roasted in 

a muffle to decompose any sulphides and arsenides that may be present. 

After roasting, and while still hot, it is thrown into cold water, which 

finely subdivides the ore and exposes a much larger surface .to the 

action of acids. The ore is then boiled with nitrohydro-chloric acid 

to remove all soluble metallic compounds. This boiling must be continued until iron ceases to dissolve. The ore is then washed with hot 

water, transferred to a gold pan, and washed free from visible impurities. The ore thus prepared for assay may be treated b}^ either of 

the two following methods, the first being preferred:

The finely pulverized ore is mixed with five times its weight of chemically pure 

potassium cyanide, then fused in a clay crucible in a bright fire. A steady fusion"" is 

kept up for from 10 to 15 minutes at the highest point to which potassium cyanide 

can be heated without showing heavy fumes.

Five grams of KCN are rammed into the bottom of the crucible. The charge, consisting of 10 grams of ore mixed with 40 grams of potassium cyanide, is then poured 

into the crucible, and 5 grams of KCN placed on top of the charge.

A "G" Battersea or Denver crucible may be used for pot-furnace work, and a 

"B" or 20-gram Colorado crucible will probably do for muffle work.

The following charge is said to be taken from Keii and Balling.*

Five grams' of ore are intimately mixed with 0.75 to 1 gram of charcoal dust and 

charged into a clay crucible. On top are placed 12.5 to 15'grams black flux c (or 

substitute) Avith 1 to 1.25 grams borax glass, then a salt cover, and finally a piece of 

charcoal. The crucible is covered, heated in a muffle or a pot furnace at a moderate 

gradually increasing temperature until the boiling has ceased, and then from onehalf to three-fourths of an hour at a white heat. The crucible is removed from the 

fire, broken when cool, and the tin button weighed.

The salt cover should be about one-fourth inch thick. It would seem 

that finer charcoal would cover the charge as well as a single piece, 

for the object is to keep the charge in a reducing atmosphere. These 

methods are found to give within 0.5 per cent of the results of wet 

assa}7 s when used with well-cleaned minerals.

aHofman, H. 0., The dry assay of tin ores: Trans. Am. Inst. Min. Eng., vol. 18, 1890, pp. 3-54.

Z>Kerl, Metallurgische Probirkunst, Leipzig, 1882, p. 412. Balling, Die Probirkunde, Brunswick, 

1879, p. .391.

e Black flux is 1'part niter (KN03 ) and 3 parts argol, deflagrated. Black flux substitute is 2 parts 

potassium carbonate or sodium bicarbonate and 1 part flour.
.COLLIEK.] METHODS OF ASSAY. 43

All ores must be crushed and carefully concentrated by sizing and 

panning. For a prospector's iield test of ore supposed to carry a small 

percentage of tin, a practical method would be to crush the supposed 

tin ore in a hand mortar and concentrate by panning, after which the 

concentrates can be roasted and cleaned with a magnet and the residue 

tested with a blowpipe, as has been described.

As small globules of tin, such as are obtained by the blowpipe, are 

sometimes unsatisfactory, more metal can be reduced by simple means. 

While at Teller this seemed desirable, and an old teacup was lined onefourth inch thick with a paste of powdered Wellington coal and baked. 

The finely pulverized ore was mixed with an equal bulk of powdered 

coal and twice as much ordinary baking soda; this charge was placed 

in the cup and covered one-half inch deep with powdered coal and 

heated for forty-five minutes in an ordinary cook stove with as hot a

fire as possible. Although the cup broke upon attempting to remove

it from the fire, good-sized buttons of tin, as large as a pea, were 

obtained. After determining the presence and the relative value of 

the washed cassiterite, pan assays will be found sufficient for further 

tests.

Greater accuracy in the assay of tin ores is obtained by wet analysis. 

Such analyses of eight samples of low-grade tin ores from the Seward 

Peninsula were recently made in the laboratory of the United States 

Geological Survey. These ore ; contained no visible crystals of cassiterite, and were treated without mechanical concentration. The following note in regard to the wet method of analysis is furnished by 

Mr. Eugene C. Sullivan, of the United States Geological Survey:

The method used in detecting traces of tin was as follows: Two grams were roasted 

in platinum crucible, fused with potassium biflnoride (KHF), and the melt was twice 

evaporated with concentrated sulphuric acid (H2S04 ) to insure absence of hydrofluoric acid (HF). The mass was taken up with dilute sulphuric acid (H2S04 ), in 

which practically all dissolved. The solution was decanted from any slight residue, 

which Avas fused as before with potassium bifluoride (KHF) and after driving off 

hydrofluoric acid (HF) by means of sulphuric acid (H2S04 ) added to the main solution. 

The solution was nearly neutralized with ammonium hydroxide (NH4OH), and 

hydrogen sulphide (H^S) was passed through it for several hours. The precipitate was 

digested for some time with yellow ammonium sulphide, being warmed slightly. The 

insoluble residue was filtered out, the filtrate acidified slightly with sulphuric acid 

(H2S04 ), and hydrogen sulphide (H2S) was passed to insure complete precipitation 

of stannic sulphide (SnS2 ). The precipitate was filtered out and ignited, again fused 

with potassium bifluoride (KHF), evaporated with concentrated sulphuric acid 

(H2S04 ), taken up with dilute sulphuric acid, stannic acid (H2Sn03 ) precipitated 

with ammonium hydroxide (NH4OH), the precipitate dissolved in hydrochloric acid, 

any residue filtered out, the solution neutralized with ammonium hydroxide (NH4OH) 

and hydrogen sulphide (H2S) passed for some hours.

Where the tin was present a yellow precipitate of stannic sulphide (SnS2 ) separated, 

apparent on allowing, the solution to stand for some time. To obtain an idea of the 

amount of tin present this precipitate, after thorough washing, was ignited and 

weighed as stannic oxide (Sn02 ).
44 TIN DEPOSITS OF THE YOEK REGION, ALASKA. [NO. 229. 

OCCURRENCES OF TIN ORE IN THE UNITED STATES.

The total amount of metallic tin produced from ore mined in the 

United States has not exceeded 200 tons, though small amounts have 

been found in no less than 17 States and Territories: Alabama, Alaska, 

California, Colorado, Connecticut, Georgia, Idaho, Maine, Massachusetts, Missouri, Montana, New Hampshire, North Carolina, South 

Dakota, Texas, Virginia, Wyoming.

In Alabama, cassiterite occurs in quartz veins in graphitic schists" 

near granite, and as disseminated grains in gneiss.

In California & small amounts of float cassiterite have been found in 

the gold placers at a number of widely separated localities. The ore 

is found in places at the Temescal mine, 5 miles southeast of Riverside. 

At this place there .is an area of. bornblendic biotite-granite over 2 

miles in diameter which is cut near its borders by dikes of highly 

quartzose and feldspathic fine-grained granite. The ore occurs in 

veinlets of tourmaline and quartz aggregates which run northeast and 

southwest through the granite. A great body of such vein matter, 

covering an area 300 by 250 feet, and 25 to 30 feet high, crops out in 

the Cajalco Hill. What is known as the Cajalco vein courses northeast from this outcrop, and the workings .extend for 1,100 feet along it. 

The vein is sinuous, and varies from a minimum of a clay seam to a 

maximum of 8 feet. There is alwa)^s a clay gouge on one and often 

on both walls. Two hundred and ninety-one and fourteen one-hundredths pounds of metallic tin were produced from ore mined at 

Temescal previous to 1892, when the mines were abandoned.

In the Carolinas a tin belt c extends in a northeast-southwest direction for about 31 miles, and lies partly in North Carolina and partty 

in South Carolina. Tin ore is not evenly distributed through this distance, though the tin-bearing formation, which consists of crystalline 

schists or gneisses containing pegmatitic dikes, is continuous. The 

rocks of the tin belt are very much decomposed, and the pegmatite 

dikes are very thoroughly kaolinized. The tin ore has been 'found 

loose in the soil, in the gravels, in bowlders of quartz and mica, and 

occasionally in the pegmatite dikes. The most promising deposit in the 

belt is at the Ross mine, near Gaffney, S. C., from which 38,471 

pounds of the ore were shipped in. 1903.

In Colorado tin ore has been reported near Golden, but little is 

known of its occurrence.

a Phillips, Wm. B., Geol. Survey of Alabama, Bull. No. 3,1892.

6Sixth Ann. Kept. California State Min. Bureau, Sacramento, 1880. Eleventh Ann. Kept. California 

State Min. Bureau, Sacramento, 1893. Fairbanks, Harold W., Tin deposits at Temescal: Am. Jour. 

Sci., 4th ser., vol. 4,1897, pp. 39-42. llolker, C. M., Production of tin in various parts of the world: 

Sixteenth Ann. Kept. U. S. Geol. Survey, pt. 3,1895, p. 536.

cThis note is furnished by Joseph Hyde Pratt in advance of -Economic Paper No. 8 of the North 

Carolina Geological Survey on " Carolina tin deposits."
COLLIER.] TIN OEES IN THE UNITED STATES. . 45

In Connecticut tin ore has been found at liaddatn, but only as a 

mineralogical curiosity.

In Georgia tin ore has been reported from Lumpkin County as 

occurring in granite and chlorite schists, with minute quantities from 

the gold Avashings.

In Idaho a few specimens of. stream tin have been found on Jordan Creek, in the southwestern part of the State, and in the Coeur 

d'Alene district.

In Maine" cussiterite occurs at Winslow in small veins, which traverse impure limestone, with purple fluorite, mica, quartz, and mispickel. These veins have been prospected to a depth of 100 feet, 

but have yielded no tin in commercial quantities. Similar occurrences 

are reported at Paris and liebron.

In Massachusetts a few crystals of cassiterite have been found with 

albite and tourmaline at Goshen and Chesterfield.

In Missouri 6 a small amount of cassiterite has been found replacing 

spheno in granite.

In Montana b stream tin has been found in Prickly Pear, French 

Bar, and Ten Mile creeks, in the " Basin " in Basin Gulch and in Peterson Creek. Light-brown, rounded pebbles of wood tin associated 

with topaz crystals have been found at one locality.

In New Hampshire cassiterite was found at Lynn and Jackson in 

ISiO by Doctor Jackson. It occurs with arsenical and copper pyrites, 

fluorspar, and phosphate of iron in small quartz veins, arid mica, slate, 

and granite near a trap dike.

In South Dakota 6' the Black Hills contain noteworthy deposits of tin 

ore, which, however, have not yet proved commercially productive. 

They occur in an area of coarse-grained granite in the central part 

of the hills. The Etta mine deposit, the only one that has produced 

any considerable quantity of tin, is a lenticular body of pegmatitic 

granite, which consists of quartz, feldspar (albite), lepidolite, and spodumene in individuals of great size, up to 8 or 9 feet in dimensions. 

Cassiterite occurs in association with lithia mica and is accompanied 

by columbite'and tan tali te, with which it is apt to be confused. The 

mine was sold to an English company, which erected a 250-stainp mill, 

but the ore did not prove profitable to work, and after the first run, 

which produced 9,385 pounds of tin, the work was closed.

In Texas'' tin has been discovered in quartz veins occurring in greisen 

granite in the Franklin Mountains near El Paso, and one small ciystal

"Jackson, C. T., On the discovery of a new locality for tin ore in Winslow,Me.: Proceedings Boston 

Soc. Nat. Hist., vol. 12,1S69, p. 267. Hunt. T. S., Remarks on the occurrence of tin ore at Winslow, 

Me.: Trans. Am. lust. Min. Eng.,vol. 1,1873, p. 373.

''Raymond, R. W., Trans. Am. Inst. Min. Eng., vol. 1, 1873, p. 374.

"The writer is indebted to Mr. S. F. Enimons for the note on tin in South Dakota. 

c.'E. T., Second Ann. Kept. Texas Geol. Survey, 1890, pp. 595, 690,.713.
46 TIN DEPOSITS OF THE YORK EEGION, ALASKA. [NO. 229.

has been found at another local it}7 . At El Paso,rt wolframite occurs 

with the ores, and feldspar is replaced by cassiterite.

In Virginia 6 good tin prospects have been found on the headwaters 

of Irish Creek, Kockbridge County, in quartz lenses and stringers in 

granite, which itself is intrusive in metamorphic schists. Associated 

minerals are wolframite, mispickel, iron pyrites, quartz, and beryl, 

with small amounts of siderite, liinonite, chlorite, muscovite, damourite, and fluorspar.

, In Wyoming, c at Nigger Hill, in the northwestern portion of the 

Black Hills, cassiterite has been found in a granitic area that is similar 

in geological association to that at the Etta mine.

CONDITIONS AND METHODS AT THE LARGE TIN MINES OF THE

WORLD.

Since the tin from newly discovered sources must come into competition with the product of established mining districts, a comparison 

with the mining conditions in the older districts will" be useful in estimating the value of the newer ones. For this purpose the following 

notes have been compiled from the most recent publications on the 

tin deposits of the world, and a brief bibliography of these is presented 

on pages 55-56.

The greater part of the world's supply of tin is obtained from alluvial deposits. Over three-fourths of it comes from alluvial deposits 

in the Malay Peninsula, otherwise known as the Straits Settlements, 

and the islands of Banca arid Billiton, off the north coast of Sumatra, 

the former region producing about half of the tin of the world. A 

large amount is produced from alluvial deposits in Australia, while in 

Cornwall, Saxony, and Bolivia most of the tin ore is obtained from 

vein deposits in the bed rock. ,

MALAY PENINSULA/*

The Malay Peninsula, in which the Straits Settlements tin deposits 

are located, consists of a central axis of rugged hills running north 

and south, with occasional subordinate or diverging axes and isolated 

peaks. The whole region is covered by a jungle of tropical vegetation so dense that the roads and trails have to be hewn through. In 

the tin regions the main range is composed of granitic rocks, occasionally cut by feldspathic and other dikes, while in some places are found 

gneissic and schistose rocks, with occasional areas of a white, highly 

crystalline limestone.

Tin ore occurs in nearly every part of the western side of the Malay

a Weed, W. H., The El Paso tin deposits: Bull. U. S. Geol. Survey No. 178, 1901.

&Rolker, C. M., Production of tin in various parts of the Mrorld: Sixteenth Ann. Kept. U. S. Geol. 

Survey, pt. 3, 1895, pp. 523-525.

cRolker, C. M., cit., p. 530.

rfThe following notes regarding the Malay tin deposits are taken almost verbatim from R. A. F. 

Penrose, Tin deposits of Malay Peninsula: Jour, of Geol., vol. 1.1, 1903, pp. 135-154.
COLLIEE.] TIN OEES OF MALAY PENINSULA. 47

Peninsula for a distance of 900 miles, but the principal mining district 

is located about 300 miles northeast of Singapore, and is known as the 

Kinta district. The district comprises a more or less inclosed valley 

about 40 miles in length, extending in a north-south direction, about 

30 miles in width at its south end and about 5 miles wide at its north 

end. The valley includes some lower mountains and areas of limestone, surrounded and partly covered with great tracts of alluvium. 

Much of this alluvium contains oxide of tin, or cassiterite, in particles 

and fragments of varying size, forming what might be termed "tin 

placers," in which the tin occurs in different ways. Sometimes it is 

scattered through it from top, to bottom in comparatively uniform 

quantities; sometimes it is in layers or pay streaks separated by barren 

ground; sometimes it -is richest on the bed rock. As a general rule, 

however, there is a covering or "overburden" of barren alluvium from 

10 to 40 feet or 'more in thickness above the tin ground. The best 

ground occurs immediately at the foot of the mountains. Higher 

up it is often richer, but of small extent, while farther away it is 

thicker,.but of lower grade. The ordinary tin-bearing beds vary from 

1 to 30 feet in thickness, though sometimes they reach over 100 feet. 

In one instance the tin-bearing.formations extend from the surface 

down to.a depth of from 5 to 30 feet, without any barren overburden. 

In another instance large open pits in the alluvium of the river valley 

show tin-bearing strata, varying from 2 to 10 feet in thickness, with a 

barren overburden about 40 feet in thickness. In another instance 

the overburden is from 30 to almost 40 feet in thickness, and the tinbearing ground below has been penetrated 140 feet vertically without 

reaching the bottom. In the mountains near its source the ore is 

angular and in comparatively large fragments, sometimes from an inch 

to a foot or more in diameter. Farther down the hill it becomes more 

and more rounded and finer in grain.

Most of the mines are operated by. Chinamen, and the labor is performed by coolies from southern China. The tin-bearing alluvium is 

worked mostly in open cuts or large pits, except where the covering 

or overburden is very thick, when shafts are sunk to the tin stratum. 

The average depth of the working is about 40 feet, and the greater 

depth can not ordinarily be reached on account of water in the pits. 

It is a common thing to see water raised from these pits by a rude 

treadmill pump worked by the feet of Chinese laborers. 

. The pay gravel dug from the bottom of the pit is carried up an 

incline to the surface in baskets hung on either end of a stick carried 

on the back of a Chinaman. It is then dumped into wooden troughs, 

supplied with running water, and, if necessary, stirred with a shovel 

until washed into the sluice boxes. These boxes are from a few feet 

to several hundred feet in length, and are built of wood or cut in the 

sandy clay of the region. In the description of them no mention is
48 TIN DEPOSITS OF THE YORK EEGION, ALASKA. '[NO. 229.

made of riffles being used. After running for some time, the water 

is shut off and the material in the boxes is cleaned up. . This material is 

further concentrated by hand panning in fiat wooden bowls, which 

resemble the American gold pan. The final process is cleaning by 

hand picking, by which the magnetic iron and other impurities are 

removed. Ore treated in this way will average from 60 to 70 per cent 

tin. In one instance hydraulic monitors are used, but the greater 

part of the tin ore from this region is produced by the more primitive 

methods.

BANCA.

In the island of Banca/( which is under the Dutch Government, the 

geological conditions resemble those of the Malay Peninsula. The bed 

rock consists of granite masses flanked b}^ Silurian slates. Tin ore 

has been found occurring as impregnations in the granite and also as 

veins in the slate, but these deposits are not worked. The tin wash 

consists mainly of fragments of granite, "schorl," 6 and sandstone. 

The bed rock near!}''always consists of granite more or less decomposed. A section of an average stream-tin deposit shows above the 

bed rock 3 feet of tin-bearing gravel, overlain by red sand, folloAved 

by red cla}7 , then coarse sand with pockets of clay, layers of fine sand 

with a little fine tin ore. The average overburden is from 25 to 35 

feet; shallow diggings are prospected by pits, deeper ones by sj^stematic borings. In 1891 and 1892, according to the United States Bureau 

of Statistics, 7,982 men were employed in the mines of Banca and produced 5,753 tons of tin, a yearly product per man of seventy-two onehundredths of a ton. There is water for working in the lower valley 

diggings but eight months each year, and for only five months in the 

upper diggings.

BILLITON.

In Billiton, also under the^ Dutch Government, the geologic conditions resemble those in Banca. There are granite masses surrounded 

by quartzites, schists, and slates of Silurian age. Some tin is obtained 

from ledges that occur both in the granite and in the quartzite, but 

the greater part of the tin comes from alluvial deposits. In 1891-92 

8,690 men were employed here, the output averaging per man a little 

over seven-tenths of a ton of tin. The prospecting is done very 

systematically, and is in charge of a corps of European engineers 

who test the fields in advance of the mining operations by boring first 

at intervals of, say, 100 yards, and supplementary holes are made from 

20 to 25 }^ards apart to ascertain the course, average thickness, and

aKolker, C. M., Production of tin in various parts of the world: Sixteenth Ann. Kept. U. S. Geol. 

Survey, pt. 3,1895, p. 484. 

b "Schorl" is an old name for rocks composed mainly of tourmaline and quartz.
COLUEH.] TIN ORES OF TASMANIA. 49

character of the pay gravel. The contents of each hole is carefully 

washed and the tin ore weighed, and from these results calculations as 

to the probable yield of the ground are made. On the basis of this 

estimate the fields are let to Chinamen.

AUSTRALIA.

In Australia tin ore has been found very widely distributed, and is 

mined in New South Wales, Queensland, South Australia, Tasmania, 

Victoria, and West Australia. The occurences present considerable 

variety, and both alluvial and vein deposits have been worked, though 

the greater part of the tin is produced from alluvial deposits. The 

two best-known localities of stream tin are Vegetable Creek in New 

South Wales, and Bischoff Mountain in Tasmania/' All the tin gravels 

of Vegetable Creek are derived from masses of granite that are permeated by numerous tin veins. The width of the channel deposits of

this creek varies from 5 to 15 chains, or from 330 to 990 feet, but 

the richest portions are reported to be from 1 to 5 chains wide. The 

average thickness of the deposit is reported to be 7 feet, while the 

thickness of the pay gravel averages 2£ feet. The average yield per 

cubic yard of pay gravel is said to be about 20 pounds of tin ore, equal 

to about 0.8 per cent. In this district the mining is done by hydraulic 

monitors and other modern mining appliances.

The tin deposits of the Mount Bischoff region in Tasmania are largely 

residual gravels derived from decomposition in situ of the bed rock. 

The bed rock of this mountain consists of Paleozoic clay slates and 

quartz, and to a less extent of sandstones and dolomites. The slates 

are traversed by numerous veins of quartz-porphyry. The porphyry 

and also the slates have undergone great transformations, so that all 

of the original feldspar and mica, as well as the primary quartz, have 

been replaced by topaz, tourmaline, secondary quartz, tinstone, and to a 

less extent by fluorspar, arsenious pyrites, and magnetite. The gravels 

are sometimes astonishingly rich in tin. In one instance 240 tons of 

concentrated ore were tajven from an area of 66 square feet. Masses 

containing 6 hundredweight, almost free from the matrix, have been 

found. The accumulation of tin ore in the gravel is exceedingly patchy, 

as might be expected in deposits of this nature. Frequently within 

60 feet of the richest deposits the wash dirt is found to contain only 

traces of tin. The ore is first concentrated by sluicing, then crushed 

and further concentrated; 5,500,000 tons of material handled previous 

to 1899 is reported to have yielded 44,560 tons of black tin, or 0.81 

per cent of the total material treated. The value of a ton of gravel 

probably averaged about 6s. 10d., or $1.70. The total cost of mining, 

crushing, dressing, and bagging the concentrates amounted to 4s.

aRolker, C. M., Production of tin in various parts of the world: Sixteenth Ann. Kept. U. S. Gcol. 

Survey, pt. 3, 1895, p. 497.

Bull. 229 04 4
50 TIN DEPOSITS OF'THE YORK REGION, ALASKA. [NO. 229.

or about $1.05 per ton, and the dressing and smelting was covered by a 

yield of 0.5 per cent tin oxide, equal to about 10 pounds of black tin 

per ton."

Nearly all the ore obtained in Tasmania is smelted at the Mount 

Bischoff Company's smelting works in Launcester, Tasmania.

CORNWALL.

The tin-bearing district of Cornwall 6 is at the extreme southern end 

of England and has a length of about 100 miles and a width of from 

10 to 30 miles. The bed rock consists of metamorphosed clay slates, 

called "killas," of Devonian age, intruded by large masses of granite. 

Both the granite and the slates are cut by dikes of quartz-porphyry, 

called "elvan courses," whose outcrops form a fringe around the 

granite areas. Five granite areas of this kind are shown on geological 

maps of the region, while the Scilly Islands, about 20 miles to the 

southwest, form a sixth.

The tin gravels of Cornwall were exploited as early as Koman and 

Grecian times, when the British Islands were called Cassiterides. At 

present the original tin-bearing gravels have long been exhausted and 

abandoned. What is called "stream Avorking" at the present day is 

merely the extraction of tinstone from the tailings of the stamp mills 

collected in the valley depression. In 1894 about 6 per cent of the total 

tin production of Cornwall came from the washing of these poor slimes.

The tin-bearing lodes of Cornwall have been worked for many years 

and afford the best examples of lode mining for comparison. These 

lodes occur in the granites, slates, or elvans, or in the contacts between 

them. Nearly all of the mineral wealth occurs within 2 or 3 miles on 

either side of the boundaries between the slates and the granite.

The granites, especially in their outer portions, are usually more or

less altered, and the name greisen is often applied to them. Typical 

greisen consists principally of quartz and lithia mica, with tourmaline, 

zircon, topaz, fluorite, and cassiterite in small amounts. In some 

cases the rock consists very largely of tourmaline and quartz, with 

fluorite in varying quantities.

The common minerals associated in the veins with the cassiterite are 

quartz, feldspar, chlorite, and tourmaline, with fluorite, lepidolite, 

topaz, copper pyrites, and copper glance in varying proportions. Several of the mines have produced both copper and tin ores, and in some 

cases mines which were opened as copper mines have become tin 

mines in depth by a gradual increase in the amount of tin ore and 

corresponding decrease in copper ore.

aRolker, C. M., Production of tin in various parts of the world: Sixteenth Ann. Kept. U. S. Geol. 

Survey, pt. 3,1895, p. 505, quoted from Min. Res. of Tasmania, Nov., 1894.

& Do la Bcche, H. T., Report on the geology of Cornwall, Devon, and West Somerset, with map: 

Gt. Britain Geol. purvey, London. 1839,
COLLIER.] TIN ORES OF CORNWALL, ENGLAND. 51

The metalliferous contents of the tin-bearing lodes appear to be 

affected not only by the mineral composition of the contiguous rocks, 

but also, in some degree, by their position and mechanical structure. 

Whether the rock be granite, slate, or el van the hardest portions are 

always quartzose, and in these the lodes are seldom rich.

If, on the contrary, the grain of the rock be neither Arery fine on 

the one hand, nor particularly coarse on the other, while the inclosed 

crystals of feldspar have a greenish, brownish, or pinkish tint and 

indistinct outlines, quartz, mica, and sometimes schorl being present, 

the appearance of the rock is considered to be favorable, and lodes 

inclosed in it may be expected to be fairly productive, especially of 

tin ore/'

The lodes which afford lead ores occur in the slates, usually at 

some distance, from the granite, while the lodes which cut both slate 

and granite, though they carry both tin and copper, are usually richer

in copper where the walls are slate, and richer in tin where the walls 

are granite.

The walls of the tin-bearing veins are seldom well defined, and generally the ore is disseminated through the wall rock on one side or the 

other, so that at some distance away from the veins it is rich enough 

to Avork. This is especially common when the vein is inclosed in 

granite, but also happens in the slates and elvans.

All Cornish tin ores can not, however, be distinctly connected with 

veins. In some instances the deposits are stockworks which consist 

of a mass of granitic or other rock traversed by a network of small 

veins interlacing with one another and running through the rock in 

various directions. Other large deposits in Cornwall, known as 

"floors" or "carbonas," 6 are usually connected with well-defined 

lodes, though in some cases they are surrounded by hard granite and 

apparently unconnected with any lode or vein. Enormous deposits 

of this kind have been found in the Avorkings of the St. Ives Consols 

mine. The Standard lode at this place has been Avorked to a depth of 

nearly 200 fathoms and has in the aggregate been very productive, 

though it does not average more than 4£ feet in Avidth. Several large 

carbonas have been found branching off from this lode at various 

levels, and many of the Avorkings are in the form of enormous caverns 

from 60 to 75 feet high and equally wide.

The Dolcoath c mine is one of the best known of the Cornish tin 

mines, and in 1902 the lodes had been traced for over 2 miles, Avhile the 

workings had reached a vertical depth of about 2,100 feet and were 

still producing large amounts of ore. The main lode of Dolcoath

aPnillips, J. A., and Louis, Henry, A treatise on ore deposits, Macmillan & Co., London, 189G, p. 108. 

'>Phillips, J. A., and Louis, Henry, Idem, p. 169.

cFrecheville, R. J., Great main lode of Dolcoath: Trans. Royal Geol. Soc. Cornwall, vol. 10,1887, 

pp. 146-156.
52 TIN DEPOSITS OF THE YORK KEG-ION", ALASKA. [NO. 229.

varies in width from 12 inches to 27 feet and is richest in tin in the 

deepest levels, where the ores sometimes average 10 per cent cassiterite. 

The richest ore occurs where a number of veins intersect and is said 

to be of a compact, bluish rock, consisting of a mixture of chlorite, 

quartz, and tourmaline, with stringers of cassiterite running through 

it. On the north side it passes gradually into a barren granite. From 

its upper workings., which are in the slate, this mine yielded only copper ores, but from the deeper levels mined at the present time, which 

are in the granite, only tin ores are obtained. 08

The average richness of the ore from a number of Cornish mines 

for ten years, from 1871 to 1881, is given in pounds of black tin per 

ton, as follows: Dolcoath, 59 pounds; Cook's Kitchen, 43 pounds; Tincroft, 53 pounds, and Carn Brea, 35 pounds. 6 This is approximately 

equivalent to 1.8 per cent, 1.3 per cent, 1.6 per cent, and 1 per cent, 

respectively, in metallic tin. During the half year ending. December 

31, 1902, the average product of the Dolcoath mine was 38.28 pounds 

black- tin per ton, approximately equivalent to 1 per cent, while during the year ending April 24,1903, the product of the Wheal Grenville 

Mining Company at Camborne averaged 43.6 pounds black tin per 

ton, c approximately equivalent to 1.1 per cent in metallic tin.

Many examples showing the nature of occurrence and extent of the 

tin ledges of Cornwall might be cited for comparison, but those given 

above will probably be sufficient for present purposes, and will show 

the general resemblance of the occurrence of tin ore in the York region 

and in Cornwall.

BOLIVIA.

The tin mines of Bolivia occur in veins that are regarded as exceptional in that the tin ore is intimately associated with silver ores, bismuth ores, and various sulphides, while the gangue includes barite and 

certain carbonates. The deposites often occur in trachytes and andesites erupted during Cretaceous or Eocene time.

REDUCTION OF TIN ORES.tf

Tin ore is prepared for smelting by roasting, if necessary, then 

crushing and concentrating to at least 60 per cent cassiterite. This 

may be done with ordinary stamp mills and concentrating machinery. 

In Cornwall both gravity and steam stamps are used.

The earliest and simplest method of smelting was as follows: A hole, 

about 2 feet in diameter, was dug in the earth, preferably in a bank, 

in which sticks of wood and well-cleaned ore were piled in alternate

a Phillips, J. A., and Louis, Henry, A treatise on ore deposits, Macmillan.Co., 1896, p. 211. 

&Frecheville, R. J., Great main lode of Dolcoath: Trans. Royal Geol. Soc. Cornwall, vol. 10,1887, 

p. 154.

cNewland, D. H., Tin, the mineral industry, vol. 11, 1903, p. 595. 

d Louis, Henry, The metallurgy of tin: Mineral Industry, vol. 5,1896, pp. 533 to 588.
COLLIER.] REDUCTION OF TIN ORES. 53

layers and burned; the tin was thus reduced, dropping or flowing to 

the bottom of the hole. Remains of many such rude furnaces have 

been found in Cornwall. Afterwards, bellows were introduced to 

force the fire, and still later charcoal was added. In some parts of 

the Malay Peninsula small amounts of tin are produced b}r reducing 

in this manner, charcoal being used without artificial draft.

For a long while the shaft furnace was used, but it is now almost 

entirely superseded by the reverberatory furnace. An average furnace of this kind has about the following dimensions: Bed, 10 by 17 

feet; fire bridge, 2 by 6 feet; space below fire arch, 3 feet, and below 

fire bridge, 15 inches. The bed of the furnace is built over a hollow 

vault and with the hollow fire bridge is cooled by allowing the air to 

circulate freely beneath it.

In Singapore water has been used below the bed to catch the tin 

that leaks through, since the metal is very fluid at the high temperature of the smelter. 

The bed has a depth of about 6 inches and slopes from all three sides 

to the tap hole at one end. Opposite the tap hole is a charging 

door, and there are openings for working the charge at both ends of 

the furnace. The average charge is about 2 tons of concentrated ore, 

mixed Avith from 15 per cent to 20 per cent of powdered anthracite, a 

small amount of slaked lime, according to the quality of the ore, and 

sometimes a little fluorspar. » A good heat is raised and the charge kept in a reducing atmosphere 

at about the temperature of melting cast iron, and after several rabblings is drawn off at the end of from five to seven hours. At Fenzance, Cornwall, 16 men working twelve-hour shifts run four such 

furnaces.

The tin from the reverberatory furnace must be refined, and after it 

is run into molds it is placed in a liquating furnace, an inclined table 

under which a fire is built, which raises the temperature, just above 

the melting point of tin. The.tin trickles slowly through the tap hole 

into the "float" or tank for the molten metal, leaving unmelted the 

more infusible substance in the form of "hardheads," which are alloys 

of tin with baser metals, such as copper and iron, and these are refined 

by other methods. The molten tin in the float is allowed to settle a 

few hours, after which wood is forced down beneath the molten mass, 

and the steam and gases formed create a strong ebullition. Bismuth, 

lead, arsenic, and other impurities, and some tin are oxidized and float 

as a scum on top and are skimmed off to be smelted again with the 

slags. The same result is accomplished by dipping up the tin in ladles 

and pouring it back from a height of 2 or 3 feet, but this involves 

more labor and seems to possess no advantage over boiling.

After boiling, the tin is allowed to settle for two or three hours, and 

then the uppermost part is ladled into molds and sold as refined tin,
54- TIN DEPOSITS OF THE YORK EEGION, ALASKA. [NO. 229.

the middle portion is sold as block tin, and the lowest portion must be 

further refined. Average English refined tin is from 98.64 to 99.76 

per cent pure. The cost of refining tin in the Straits Settlements is 

said to be about $12 per ton of 2,000 pounds. There is always some 

loss in smelting tin; slags from the furnace seldom contain less than 

5 per cent, and the average loss in smelting is said to be about 9 per 

cent.

PRODUCTION AND VALUE OF TIN IN 1902-3.

During the years 1902 and 1903 the total world's production of tin 

is estimated at 90,233 and 92,536 long tons, respectively, as shown by 

the following table.« 

Production of tin, estimated on trade statistics.

Straits (Malay Peninsula) .............

Australia. ............................

Banca ...............................

Billiton ..............................

Bolivia ..............................

Cornwall, England. ...................

Total ..........................

Net increase, 2,303 long tons.

Long tons.

1902.

54, 062 

3,500 

14, 978 

3,951 

9,000 

4,392 

350

90, 233

1903.

54, 797 

4,991 

15, 070 

3,653 

9,500 

4,150 

375

92, 536

Changes.

Increase.

735 

1, 491 

92

500

25

2,843

Decrease.

298

242

540

Of this total, production only about 30 tons were mined in the

United States.

The total consumption of tin in the United States approximated 

39,000 tons, or 43 per cent of the world's output. The production of 

tin last year, as in fact for several years past, has hardly exceeded the 

consumption, and from some of the older districts, especially Banca 

and Billiton, there are signs of a diminution in the output. The 

average price of tin in New York for 1903 was 28.09 cents per pound, 

or about li cents per pound higher than for 1902. The price varied 

during the }7 ear from 25.42 cents to 30.15 cents per pound. The total 

amount of tin. consumed in the United States was worth at market 

prices over $24,500,000.

VALUE OF TUNGSTEN AS A BY-PRODUCT.

Tungsten ores in the form of wolframite occur in association with 

the tin ores in several places in the York region. At present prices 

these ores in the York region evidently have no commercial value, but

a Tin in 1903, Eng. and Min. Jour., vol, 77, Jan. 7, 1904, pp. 18-20.
COLLIER.] LITERATURE OF TIN DEPOSITS. 55

considering the difficulty which may arise in separating wolframite 

from cassiterite the following information will be of interest:"

Since the latter part of 1903 there has been a very large increase in 

the demand for tungsten, and it is probable that from October 1,1903, 

to October 1,1904, will see the marketing of about 1,000 tons of tungsten minerals. Where the tungsten mineral is an associate of some 

other economic mineral that is being mined it should be a valuable 

by-product. Its value varies with the percentage of tungsten oxide 

and has been about $100 per ton for a 55 to 60 per cent ore. As an 

associate of tin ore it should be of value as a by-product, and could be 

separated from the tin mineral by an electro-magnetic separator.

As the demand for tungsten is limited there could readily be an 

overproduction, with a corresponding reduction in price.

BIBLIOGRAPHY.

The following are a few of the more important papers relating to the 

tin deposits in various; parts of the world which may be useful for 

comparative purposes in estimating the value of the tin deposits of 

Alaska:

BECK (RICHARD). Lehre von den Erzlagerstiltten, Berlin, 1901. Second edition,

1903.

Contains descriptions of the occurrence and method of mining tin ore, both in alluvial and in lode deposits, in various parts of the world, and discusses the origin 

of tin ore. 

BLAKE (W. P.). Tin ore veins in the'Black Hills, and columbite and tantalite in the

Black Hills: Traiis. Am. Inst. Min. Eng., vol. 13, 1885, pp. 691-697. 

Structure of the Etta vein; percentage of black tin in the ore; minerals associated

with the ore; extent of the tin region. 

CLAYPOLE (E. W.). The tin islands of the Northwest: Am. Geol., vol. 9, 1892, pp.

228-236.

Describes the structural characteristics of the igneous and sedimentary rocks that

form the Black Hills and the movements of elevation and subsidence that have

occurred in the region. The cassiterite is confined to the granite veins, and is

very finely and irregularly disseminated.

DAVID (T. W. E.). Geology of the Vegetable Creek tin-mining fields of New England

district, New South Wales: Geol. Surv. New South Wales, 1887, pp. 4-169. 

Minerals associated with tin ore; methods of mining stream tin; tin occurs both in 

recent gravels and in old channels covered by basalt flows; lodes from which the 

Vegetable Creek tin has been derived; average thickness, extent, and richness of 

the alluvial deposits. 

EMMONS (S. F.).' Geological distribution of the useful metals in the United States:

Trans. Am. Inst. Min. Eng., vol. 22, 1893, pp. 71-72.

Describes the geologic occurrence of tin in various parts of the United States. 

FAIRBANKS (H. W.). The tin deposits at Temescal, southern California: Am. Jour. 

Sci., 4th ser., vol. 4, pp. 39-42, 1897; Min. and Sci. Press, vol. 75, 1897, p. 362. 

Describes the.geologic features of the region and the occurrence of the vein system 

and the tin deposits.

«Communicated to the author by Mr. Joseph Hyde Pratt.
56 TIN DEPOSITS OF THE YORK REGION, ALASKA. [NO. 229.

FRGCHEVILLE (R. J.). Great main lode of Dolcoath: Trans. Eoyal Geol. Soc. Cornwall, vol. 10, 1887, pp. 146-156.

Relation of tin lodes to older dikes; vein minerals tourmaline,'quartz, and mica; 

depth of workings; physical character of the rich tin ore; passing of tin ore into 

the granite wall; average richness of tin ore from a number of Cornish mines. 

HALSE (EDWARD). The occurrence of tin ore at Sain Alto, Zacatecas, with reference 

to similar deposits in San Luis Potosi and Durango, Mexico: Trans. Am. Inst. 

Min. Eng., vol. 29, 1900, pp. 502-511,. figs. 1-6. 

Describes the occurrence of the various ore bodies.

HANKS (H. G.). Cassiterite: Fourth Annual Report of the State Mineralogist of California, 1884, pp. 115-123. 

Notes on tin ores from Temescal, Cal. 

HOPMAN (H. 0.). Dry assay of tin ore: Trans. Inst. Min. Eng., vol. 18, 1890, pp.

3-54. 

Describes an exhaustive series of experiments with the ores of the Black Hills to

ascertain the best method of assaying tin ores. 

INGALLS (W. R.). The tin deposits of Durango, Mexico: Trans. Am. Inst. Min.

Eng., vol. 25, 1896, pp. 146-163.

Presents a map of a portion of Mexico, showing the location of the tin-ore deposits, 

describes the general geologic features and the character and distribution of 

the ore bodies, and discusses their origin. 

KEMPTON (C. W.). The tin deposits of Durango, Mexico: Trans. Am. Ins. Min.

Eng., vol.'25, 1896, pp. 997-998.

In discussion of paper on the same subject by W. R. Ingalls, mentions an occurrence of tin placers at Sain Alto, Zacatecas, Mexico.

Louis (HENRY). Metallurgy <5f tin: The Mineral Industry, vol. 5, 1896, pp. 533-588. 

Methods of smelting tin; character of furnace lining, etc. Three stages in tin

smelting: (1) reduction; (2) refining impure tin; (3) cleaning the slags. 

Louis (HENRY). Production of tin. Reprint of series of articles in the Min. Jour.,

Railway and Commercial Gazette, 12 mo., 39 p. and map 3s., London, 1900. 

MINCHIN (J. B.). Tin in Bolivia: The Mineral Industry, vol. 11, 1902, pp. 588-590. 

Description of tin-producing district and tin-bearing lodes; methods of mining,

transporting, and concentrating tin ores. 

OWENS (F\). A review of the tin industries of the Malay Peninsula up to the end 

of 1899: The Mineral Industry, vol. 9, 1901, pp. 646-656.- 

PENROSE (R. A. F.). Till deposits of the Malay Peninsula: Jour. Geol., vol. 11,

1903, pp. 135-154. 

Geology of the Kinta district; description of tin placers; methods of mining and

treating tin ores. 

PHILLIPS (J. A.) and Louis (HENRY). Treatise on ore deposits: MacMillan & Co.,

London, 1896. 

Description of both alluvial and lode deposits of tin in various parts of the world,

and discussion of the genesis of tin ore. 

PHILLIPS (WILLIAM). "On the veins of Cornwall," and "Oxide of tin:" Trans.

Geol. Soc. London, vol. 2, 1814, pp. 336-376. 

Standard authorities on the tin deposits of Cornwall. 

ROLKER (C. M.). The alluvial tin deposits of Siak, Sumatra: Trans. Am. Inst. Min.

Eng., vol. 20, 1892, pp. 50-84. 

Notes on the geology and the occurrence and methods of working tin-bearing

gravels. 

ROLKER (C. M.). The production of tin in various parts of the world: Sixteenth

Ann. Rept. U. S. Geol. Survey, pt. 3, 1895, pp. 458-538.

Includes statistics of production in various countries, and notes on the occurrence 

of tin in Maine, Virginia, North Carolina, Alabama, Texas, South Dakota, and 

California.
LITERATURE OF TIN DEPOSITS. 57

Uucfi (TiTus). A contribution to tlie geology of tlie Dakota tin mines: Eng. and

Min. Jour., vol. 53, 1892, p. 547. 

Includes a brief description of the Archean rocks in which tin occurs, the mineral

species found, and a discussion as to the origin of the tin-bearing granites. 

UbKE (TITUS). The occurrence of tin ore at Kings Mountain, North Carolina, and 

near Vesuvius, Virginia: Mineral Resources XI. S. for 1893, U. S. Geol. Survey, 

1894, pp. 178-182. 

Describes the character of the country rock of the two localities, and the manner

of occurrence of the tin ore.

WEED (W. H.). The El Paso tin deposits: Bull. U. S. Geol. Survey, No. 178, 1891. 

Description of occurrence of cassiterite in Texas.

INDEX.

Paga 

Alabama, tin ore in, occurrence of......... 44

Anikovik River, gravel deposits of, tin

in........................... 10,35,36

Anikovik River Basin, gold placers in, discovery of ....................... 10

Arctic coast, gravel deposits along......... 14

Asses Ears, origin of name ................. 28

tin ore reported from................... 29

Australia, tin deposits in, character, occurrence, and thickness of......... 49

tin production of....................... 54

Baituk Creek, tin on, report of occurrence

of............................... 30

Balling, Carl A. M., quoted on assay of tin

ores............................. 42

Banca, geological conditions in............ 48

tin deposits in, character, occurrence,

and thickness of ............... 48

tin production of ........................ 54

Banner Creek, tin on, reported occurrence

of............................... 36

Bartels, W. C. J., tin ore discovered by, on

Cape Mountain................. 25

Bibliography of literature relating to tin

deposits ........................ 55-57

Billiton, geological conditions in .......... 48

tin deposits in, character and occurrence of ........................ 48

prospecting of...................... 4M9

tin production of....................... 64

Black flux, composition of................. 42

Black flux substitute, composition of...... 42

Bolivia, tin deposits in, occurrence of...... 52

tin production of....................... 54

Brooks, A. H., cited on Kuzitrin slates...... 14

cited on tin in the York region......... 10

letter of transmittal by................. 7

quoted on stream tin on Buhner Creek. 35-36 

Brooks, A. H., Schrader, F. C., and, investigations by, in Nome region .... 10

Brooks Mountain, dikes in ................. 15

elevation and location of............... 10

tin ore on, possible occurrence of ...... 26

Buck Creek, features of .................... 30

gravel deposits of, width of ............ 31

tin in ............................ 11,29-35

source of........................ 31

value of ore in...................... 32

location of.............................. 29

rock formations near................... 30-31

Buhner Creek,gravel depositsof, tin in. 10,35-36 

California, tin ore in, occurrences of....... 44

California State Mining Bureau, cited on

tin deposits in California....... 44

Page.

Cape. Sec Distinctive name. 

Cape Mountain, granite of................. 14,15

settlements near ....................... 23

tin deposits of, examination of......... 11

character of........................ 24-25

discovery of........................ 25

topographic features of................. 23

view of, plate showing................. 22

Cape York bench, character and origin of. 17

Cassiterite, gold associated with ........... 20

occurrence and character of. 20,24,31,35,39-40 

Cassiterite Creek, dike on, minerals of..... '20

features of.............................. 19

tin ore in gravels of ..................... 21

Cassiterite ledge, width and extent of ..... 23

Coal; source of supply of, for York region.. 39 

Collier, A. J., cited on geology of the York

region .............. 10-11,24,26,27,28

field work by........................... 11

Colorado, tin ore in, occurrence of......... 44

Cone Hill. Sec Potato Mountain.

Connecticut, tin ore in, occurrence of...... 45

Cornwall, tin ores of, character of......... 50-52

tin ores of, minerals associated with ... 50 

value of ............................ 62

reduction of........................ 52-53

tin production of....................... 54

De la Beche, H. T., cited on tin-bearing

district of Cornwall ............ 50

Diomede Islands, tin ore reported from.... 25

Dolcoath mine, Cornwall, ore of, character

of............................... 51-62

Don River, tin ore on,possible occurrence of. 26 

Bumble, E. T., cited on occurrence of tin

in Texas........................ 45-46

Ear Mountain, luxulianite from, thin section of.......................... 28

porphyritic dike on, thin sections of... 26 

rocks of, character of................... 27

tin ore of, character of................. 27

tin ore reported on ..................... 26

topographic features of ................ 26-27

Emmons, S. F., cited on occurrence of tin

in South Dakota................

Epidote, character and occurrence of......

Fairbanks, H. W., cited on tin deposits in 

California ...............'.........

45

41

44

Fluorito,- character and occurrence of...... 41

Freeheville, R.' J., cited on the tin' ore of

the Dolcoath mine ............. 51

Fuel, sources of............................. 39

Galena, occurrence of.................. '...... 21

Garnet, character and occurrence of....... 40

59
60 INDEX.

Georgia, tin ore in, occurrence of .

Gold Bottom Creek, bed rock of...

tin on, reported occurrence of.

Granite, alteration of.

.Page. 

45 

36 

36 

15

occurrences of.................... 15,27,28-29

Granitic ore, assays of...................... 20

Gravel deposits, character and distribution

of............................ 14,29-30

Greisen, definition of....................... 16

Grouse Creek, tin ore on ................... 32

Harbors, character of....................... 38

Harker, Alfred,cited on luxulianite........ 27

Herendeen Bay, coal at, occurrence of..... 39

Hess, F.L., acknowledgment to.....:.....- 12

field work by........................... 11

work of, in Buck Creek region......... 29,32

Hoffman, H. 0., quoted on assay of tin ores." 42 

Hot Springs, tin ore reported from......... 28

Hunt, T. S., cited on occurrence of tin in

Maine.......................... 45

Hutchinson, J. H., acknowledgment to ... 21 

Idaho, ti n ore in, occurrence of............ 45

Igneous rocks, character and distribution

of............................... 15

Jackson, C.T., cited on tin deposits in Maine 45 

Kerl, Bruno, quoted on assay of tin ores... 42 

Kemp, J.F.,cited on luxulianite........... 27

Kigezruk Creek, tin on, reportof occurrence

of............................... 30

King River mining district, organization of- 22 

Lisburne, Cape, coal in vicinity of, occurrence of ........................ 39

Literature relating to tin deposits.......... 55-57

Lode tin, occurrences of................... 17-29

Lopp Lagoon, features of ................ 10,29-30

Lost Elver, course and features of ......... 17-18

dikes along and near .................. 15,19

Port.Clarence limestone along......... 19

sketch map of.......................... 18

tin ore of, analysis (partial) of......... 21-22

assay of............................. 21

character of........................ 19

examination of .................... 11

polished surface of plate showing.; 28 

valley of, from the coast, view of, plate

showing........................ 20

Louis, Henry, cited on reduction of tin ores. 52 

Louis, Henry, Phillips, J. A., and, cited on

tin deposits of Cornwall........ 51,52

Luxulianite from Ear Mountain, thin section of.......................... 27-28

Magnetite, character and occurrence of ... 41 

Maine, tin ore in, occurrence of............ 45

Malay Peninsula, geological conditions in. 4C 

tin mines in, manner of working of.. 47-48 

tin ore in, occurrence, character and

distribution of.................. 46-47

tin ores of, reduction of................ 53

tin production of....................... 54

Massachusetts, tin ore iii, occurrence of... 45 

Missouri, tin ore in, occurrence of ......... 45

Moffit, Fred H., note on Asses Ears furnished

by .............................. 28

Montana, tin ore in, occurrence of......... 45

Mount Bischoff region, Tasmania, tin deposits of, character of .......... 49

Page. 

Mount Bischoff region, tin deposits of, cost

of mining of.................... 49^50

.tin deposits of, richness of.............. 49

New South Wales, tin deposits in .......... 49

Newland, D. H., cited on production of

Cornwall tin mines............. 52

North Carolina, tin ore in, occurrence of.. 44 

Old Glory Creek, cassiterite reported from. 29 

Penrose, R. A. F., quoted on Malay tin

deposits......................... 46-48

Phillips, J. A., and Louis, Henry, cited on

tin deposits in Cornwall........ 51,52

Phillips, William B., cited on cassiterite in

Alabama ....................... 44

Porphyritic dike near Tin Creek, thin sections of......................... 24

Porphyritic dike on Ear Mountain, thin

sections of...................... 26

Port Clarence, character of harbor at...... 38

Port Clarence limestone, age of............ 13

dip and thickness of.................... 19

distribution and extent of.............. 12-13

slate areas in........................... 13-14

Port Moller, coal at, occurrence of......... 39

Potato Mountain, rocks of.................. 30

Pratt, J. H., cited on tin deposits in North

Carolina........................ 44

cited 011 value of tungsten as a byproduct ........................ 55

Prince of Wales, Cape, coast between Cape

York and, sketch of............ 9

mission at.......... ................... 10

Quartz, character and occurrence of....... 41

Raymond, R.W., cited on occurrences of tin

in Montana and Missouri ...... 45

Reduction of tin ores, methods of.......... 52-54

Rhyolite, dikes of, along Lost River ....... 19

Rickard, Edgar, cited on tin deposits in

the York region ................ 11

quoted on source of cassiterite in Buck

. Creek region ................... 31

Rolker, C. M., cited on occurrence of tin in

Virginia........................ 46

cited on occurrence of tin in Wyoming. 46 

cited on tin deposits in California...... 44

cited on tin deposits of Banca........... 48

cited on tin deposits of Tasmania...... 49,50

Rosenbusch, H., cited on luxulianite....... 27

Rutile, character and occurrence of....... 40

Saddleback Mountain, elevation of........ 19

Schaller, W. T., cited on analyses of lithic

mica............................ 20

Schorl, name for rocks composed of tourmaline and quartz................. 48

Schrader, F. C., cited en coal at Cape Lisburne. .......................... 39

Schrader, F. C., and Brooks, A. H., investigations by, in Nome region .... 10

Seward Peninsula, coast line of, character

of............................... 9-10

outline map of, showing .position of

York region .................... 8

Singapore, reduction of tin ores at, method

of............................... 53

Slates, occurrence of, in York region ...... 13-14

South Dakota, tin ore in, occurrence of.... 45
INDEX. 61

Page. 

Stannitc, occurrence of..................... 22

composition of.......................... 40

Sullivan, Eugene, acknowledgment to..... 12

assays of ore by, report of........ 22,24,25,28

quoted on wet assay of tin ores ........ 43

Tasmania, tin deposits'in................... 49

Texas, tin ore in, occurrence of............ 45-46

Tin, production and value of, table showing ............................. 54

lode, occurrences of.................... 17-29

placer, box used in washing concentrates, figure showing.......... 34

on Buck Creek ..................... 29-35

on Buhner Creek ................... 35-36

separation of ....................... 33-34

sluice boxes used in washing, figure

showing........................ 33

Tin Creek, granite outcrop on.............. 19

porphyritic dike near, thin sections of.. ?4 

rock exposures on...................... 19

tin lode on, character of............... 19-20

tin ore in gravels of.................... 21

Tin deposits, literature relating to......... 55-57

Tin ore, assay of............................ 21

character of............................ 16

distribution of.......................... 1C

genesis of, reference to................. 1C

methods of assaying ................... 41-43

physical characteristics of.............. 39-40

polished surface of, plate showing..... 28

reduction of, methods of............... 52-54

Tin pyrites. See Stannite.

Tourmaline, character and occurrence of.. 40

Transportation, facilities for ............... 37-38

Tundras, definition of...................... 29

Tungsten, association of, with tin ores..... 54-55

value of, as a by-product............... 54-55

United States, tin in, consumption of...... 54

tin in, occurrences of................... 44-46

production of ...................... 64

Page.

Vegetable Creek, New South Wales, tin deposits of ........................ 49

Virginia, tin ore in, occurrence of ......... 46

Weed, W. H., cited on occurrence of tin in

Texas........................... 46

Whitehead, Cabcll, occurrence of cassitecite '

reported by..................... 29

Wolframite, association of, with tin ores... 64-55

Wolframite, character and occurrence of... 41

value of, as a by-product............... 55

Wyoming, tin ore in,occurrence of......... 46

York, settlement at, location of............ 10

York, Cape, coast between Cape Prince of

Wales and, sketch of........... 9

York Creek, tin on, reported occurrence of. 36 

York Mountains, elevation and character

of............................... 10

Port Clarence limestone near ........... 12-13

rocks of, character of.................... 19

topographic features of ................ 17-18

York Plateau, elevation of................. 24

rock formations of...................... 24

topographic features of................. 10,24

York region, drainage of................... 10

exploration and development of....... 10-11

geographic position of.................. 9-10

geologic sketch map of................. 13

gravel deposits of...................... 14

igneous rocks in, description of........ 15

location of, outline map of Scward

Peninsula, showing lode tin in. 8 

placer tin in, sluice boxes used in washing, figure showing ............ 33

sedimentary rocks in, description of... 12-14 

tin in, discovery of..................... 10-11

distribution of...................... 16

summary of occurrences of......... 36-37

topographic map of.................... 12

transportation and fuel supply in...... 37-39

watershed in........................... 10

o

PUBLICATIONS OF UNITED STATES GEOLOGICAL SURVEY.

[Bulletin No. 229.]

The serial publications of the United States Geological Survey consist of (1) Annual 

Reports, (2) Monographs, (3) Professional Papers, (4) Bulletins, (5) Mineral 

Resources, (6) Water-Supply and Irrigation Papers, (7) Topographic Atlas of 

United States folios and separate sheets thereof, (8) Geologic Atlas of United 

States folios thereof. The classes numbered 2, 7, and 8 are sold at cost of publication; the others are distributed free. A circular giving complete lists may be had on 

application.

The Bulletins, Professional Papers, and Water-Supply Papers treat of a variety of 

subjects, and the total number issued is large. They have therefore been classified 

into the following series: A, Economic geology; B, Descriptive geology; C, Systematic geology and paleontology; D, Petrography and mineralogy; E, Chemistry and 

physics; F, Geography; G, Miscellaneous; H, Forestry; I, Irrigation; J, Water storage; K, Pumping water; L, Quality of water; M, General hydrographic investigations; N, Water power; 0, Underground waters; P,. Hydrographic progress reports. 

This bulletin is the thirty-sixth in Series A,'the complete list of which follows 

(B = Bulletin, PP = Professional Paper):

SERIES A, ECONOMIC GEOLOGY.

B 21. Lignites of Great Sioux Reservation: Report on region between Grand and Moreau rivers,

Dakota, by Bailey Will is. 1885. 1C pp., 5 pis. (Out of stock.) 

B 40. Nature and origin of deposits of phosphate of lime, by R. A. F. Penrose, jr., with introduction

by N. S. Snaler. 1888. 143pp. (Out of stpck.) 

B 05. Stratigraphy of the bituminous coal field of Pennsylvania, Ohio, and West Virginia, by J. C.

White. 1891. 212 pp., 11 pis. (Out of stock.) 

B 111. Geology of Big Stone Gap coal field of Virginia and Kentucky, by M. -R. Campbell. 1893. 106

pp., C pis.

B 132. The disseminated lead ores of southeastern Missouri, by Arthur Winslow. 1896. 31pp. 

B 138. Artesian-well prospects in Atlantic Coastal Plain region, by N. II. Darton. 189G. 228 pp., 19

pis. (Out of stock.) 

B 139. Geology of Castle Mountain mining district, Montana, by W. H. Weed and L. V. Pirsson. 1896.

164 pp., 17 pis. ' - . 

B 143. Bibliography of clays and the ceramic arts, by J. C. Brainier. 1896. 114 pp. 

B 164. Reconnaissance on the Rio Grandecoal fields of Texas, by T. W. Vaughan, including a report

on igneous rocks from the San Carlos coal field, by E. C. E. Lord. 1900. 100 pp., 11 pis. 

B 178. El Paso tin deposits, by W. H. Weed. 1901. 15 pp., 1 pi.

B 180. Occurrence and distribution of corundum in United States, by J. H. Pratt. 1901. 98 pp., 14 pis. 

B 182. A report on the economic geology of the Silverton quadrangle, Colorado, by F. L. Ransome.

1901. 200 pp., 16 pis. 

B 184. Oil and gas fields of the western interior and northern Texas Coal Measures and of the Upper

Cretaceous and Tertiary of the western Gulf coast, by G. I. Adams. 1901. 04 pp., 10 pis.

(Out of stock.) 

B 193. The geological relations and distribution of platinum and associated metals, by J. F. Kemp.

1902. 95 pp., 6 pis. (Out of stock.) . *

B 198. The Berea grit oil sand in the Cadiz quadrangle, Ohio, by W. T. Griswold. 1902. 43 pp., 1 pi. 

PP 1. Preliminary report on the Ketchikan mining district, Alaska, with an introductory sketch of

the geology of southeastern Alaska, by Alfred Hulse Brooks. 3902. 120 pp., 2 pis. 

B 200. Reconnaissance of the borax deposits of Death Valley and Mohave Desert, by M. R. Campbell.

1902. 23 pp., 1 pi. ' . B 202. Tests for gold and silver in shales from western Kansas, by Waldemar Lindgren. 1902. 21 pp. 

PP 2. Reconnaissance of the northwestern portion of Seward Peninsula, Alaska, by A. J. Collier.

1902. 70pp., 11 pis,
II ADVEETISEMENT.

PP 10. Reconnaissance from Fort Hamlin to Kotzebue Sound, Alaska, by way of D'all, Kanuti, Alien,

and Kowak rivers, by W. C. Mendenhall. 1902. 68 pp., 10 pis.

PP 11. Clays of the United States east of the Mississippi River, by Heinrich Ries. 1903. 298 pp., 9 pis. 

PP 12. Geology of the Globe copper district, Arizona, by F. L. Ransome. 1903. 168 pp., 27 pis. 

B 212. Oil fields of the Texas-Louisiana Gulf Coastal Plain, by C. W. Hayes and William Kennedy.

1903. 174 pp., 11 pis. 

B 213. Contributions to economic geology, 1902; S. F. Emmons, C. W. Hayes, geologists in charge.

1903. 449pp. 

PP 15. The mineral resources of the Mount Wrangell district, Alaska, by W. C. Mendenhall and

F. C. Schrader. 1903. 71pp., 10 pis.

B 218. Coal resources of the Yukon, Alaska, by A. J. Collier. 1903. 71 pp., C pis. 

B 219. The ore deposits of Tonopah, Nevada (preliminary report), by J. E. Spurr. 1903. 31 pp., 1 pi. 

PP 20. A reconnaissance in northern Alaska, in 1901, by F. C. Schrader. 1904. 139 pp., 16 pis. 

PP 21. Geology and ore deposits of the Bisbee quadrangle, Arizona, by F. L. Ransome. 1904. 168 pp.,

29 pis.

B.223. Gypsum deposits of the United States, by G. I. Adams and others. 1904. 129 pp., 21 pis. 

PP 24. Zinc and lead deposits of northern Arkansas, by G. I. Adams. 1904. 118 pp., 27 pis. 

PP25. Copper deposits of the Encampment district, Wyoming-Colorado, .by A. C. Spencer. 1904.

107 pp., 2 pis. 

B 225. Contributions to economic geology, 1903; S. F. Emmons, C. W. Hayes, geologists in charge.

1904. 527 pp., 1 pi. 

PP 26. Economic resources of the northern Black Hills, by J. D. Irving, with contributions by S. F.

Emmons and T. A. Jaggar, jr. 1904. pp., 20 pis. 

PP 27! A geological reconnaissance across the Bitterroot Range and Clearwater Mountains in Montana

and Idaho, by Waldemar Lindgren. 1904. pp., 15 pis.

Correspondence should be addressed to

THE DIRECTOR,

UNITED STATES GEOLOGICAL SURVEY,

WASHINGTON, D. G. 

JUNE, 1904.
LIBRARY CATALOGUE SLIPS.

[Mount each slip upon a separate card, placing the subject at the top of the 

second slip. The name of the series should not be repeated on the series 

card, but the additional numbers should be added, as received, to the first

entry.]

Collier, Arthur J [ames]

. . . The tin deposits of the York region, Alaska, by 

Arthur J. Collier. Washington, Gov't print..off., 1904.

61, III p. illus., 7 pi. (incl. maps). 23$°'". (U. S. Geological survey. 

Bulletin no. 229.)

Subject series A, Economic geology, 36. 

"Bibliography:" p. 55-57.

Collier, Arthur J [ames]

. . . The tin deposits of the York region, Alaska, by 

. Arthur J. Collier.. Washington, Gov't print, off., 1904.

u

f 61, HI p. illus., 7 pi. (incl. maps). 23£om. (U. S. Geological Survey. 

88 Bulletin no. 229.)

Subject series A, Economic geology, 36.

"Bibliography:" p. 55-57.

U. S. Geological survey.

J Bulletins.

& no. 229. Collier, A. J. The tin deposits of the York 

region, Alaska. 1904.

iU. S. Dept. of the Interior.

a

| see also

* U. S. Geological survey.

Bull. 229 04 5