DEPARTMENT OF THE INTERIOR

Roy O. West, Secretary

U. S. GEOLOGICAL SURVEY 

George Otis Smith, Director

Bulletin 807

GEOLOGY OF HYDER AND VICINITY 

SOUTHEASTERN ALASKA

WITH A RECONNAISSANCE OF 

CHICKAMIN RIVER

BY

A. F. RUDDINGTON

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1&29
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CONTENTS

Page

Foreword, by Philip S. Smith._________________________ vn

Introduction...____________________________________________________ 1

Field work_.._.___._.______..____...____. -_-__-. .. 1

Acknowledgments. _-_-________-_-___-___-__--_____-__-- -____-_ 2

History._________________________________________________________ 2

Bibliography ________-______ _____________._-__.-___-__--__--_--_-_ 3

Alaska.__-___-__---______-_-____-_-___--____-___-_-___-__-___ &

British Columbia____-_____-___-___________-_-___--___.._____- 4

Geography_______________________________________-____--___-__--_ 4

Location and transportation facilities.___________________________ 4

Climate. __--______-______.____--__---____-_______--._--.--__- 5

Vegetation ___________________________________________________ 6

Water power._--___._____.________.______-_.._____-___.-_____ 7

Topography-___________--____-_-___--____.___-___-----__--_-- 7

General features of the relief----______-_---___-__------_-_-_ 7

Streams.._ _______________________________________________ 9

Glaciation.. _ __-_____-__--__--_____-__---_____-__--_----__ 10

Geology.... __----_-._ -._---_--__-.- _-_____-_____-___-_ 13

General features___-_-____-__-__-___-..____--___-_-____--__-._ 13

Hazelton group._....._.._>___-_-.__-______----_-----'_-__-..-- 17

General character.-----.-------.-------------------------- 17

Greenstone and associated rocks.._______.__.-.--__--_--_--_ 18

Graywacke-slate division.._________-_-__--_-_-----_--_----_ 19

Coast.Range intrusives__________-__-__--___-----------_-----_- 22

Texas Creek batholith and associated dikes..__--__.__-__-__-. 22

Character and extent._________.__-__-__-____--.----_-. 22

Granodiorite core.._____-___-_-_-__---_-___--_-_--__-. 25

Quartz diorite border facies.__.__-___-__--_----___-__-_ 27

Diorite contact facies..._______._-.____.-__-----_---_-- ^27

Granodiorite and quartz porphyry dikes_________________ 28

Aplite and pegmatite.__-----__-----_--_---------_----- 28

Hyder and Boundary batholithic intrusions and associated dikes. 29

Character and extent--_______-__-__------------.__-_-_ 291

Hyder quartz monzonite..--_-___--------_------_----_- 29"

Boundary granodiorite--_-----___-_-------------------- 32

Granodiorite porphyry dikes.________-___-_-.__--____-_ 33>

Aplite and pegmatite--.----------.----..-------------- 35-

Malchite dikes-___--__-____-_--__-_--____---_------------- 35>

Lamprophyre dikes ______________________ l"^j.L - - -__-_--____ 36-

Basaltic dikes--_--__--__---_--_----_---------l^-^-^---.-- 37

Contact metamorphism----------.----------------------..-- 37

Texas Creek intrusives.___.__._____-__--_-------_--__- 37

Hyder and Boundary intrusives._-____-__-___-_--_-_____ 38

Superficial deposits_._.___._____.-_-___-___-------_-----_._.-__ 39

Pleistocene and Recent deposits.___________________________ 3.9

HI
[V CONTENTS

Geology Continued. Page

Structure.. ______________________________________________ 40

Bedded rocks _--_----________________________________ 40

Texas Creek batholith_____________________________________ 41

Faults._______ __________________________ 42

Joints ___________________________________________________ 42

Mineral deposits _--------__----____--____________________________ 42

Classification---_--__--_----__________________________________ 42

Relation to country rock.______________________________________ 44

Type of vein___i___-____________________________________. 44

Strike and dip________-__________________________________ i 44

Character of the veins.________________________________________o 46

Fissure veins at an angle to the structure ____________________ 46

Veins parallel to the structure._____________________________ 47

Mineralogy of the deposits.____________________________________ 48

Classification of the minerals.______________________________ 48

Metal content.___________________________________________ 48

Native elements._________________________________________ 48

Sulphides-__----________________________________________. 49

Sulphosalts.-- ___ _______-__----_-___--__---_-__._- 50

Sulphates __-_-_______-____________-__________----_______.. 51

Oxides.__________________________________________________ . 51

Carbonates. __--___-_-_________.-___-_-_____-______-___-_- 52

Tungstate__________________________________ 52

Undetermined minerals.___________________________________ 52

Interrelation of ore minerals.________________-_--___-__--__- 52

Genesis ______________________________________________________ 53

Relation of the mineral deposits to the intrusive masses.--.---. 53

Texas Creek batholith and associated porphyry dikes. _____ 53

Relation of the porphyry dikes of the Texas Creek batholith

to the Premier ore bodies of British Columbia.______._. 54

Younger Coast Range intrusive rocks.___________________ 55

Temperature and pressure________________________________ 55

Comparison of deposits of the Texas Creek batholith with silver-lead

deposits of the Boulder batholith, Montana____________________ 57

Notes on prospecting__________________________________________ 58

Mines and prospects___-!__--_____---_-___-________------------_ 63

Mountain View.__________________________________________ 63

Lucky Boy Extension.--_____-_-___________.._----__---__--_ 67

Bishop.._ ___________----___-_-_-__--_--_^_----_----_---_- 67

Victoria... ____----__--_____-_-____---__;--_-----__-------- 67

Fish Creek.____._----____.__________._____-___-_.- 68

Hyder Jumbo_--___----_------_______-__----__----__-- 72

Hyder Skookum..________________ f _____..___. 72

Titan.--.--.-------------.-----_______________________ 72

Monarch.-..---.-__-______--_.__ _-_____________-.-__ 74

Last Shot_____--____--_____-__----------------_---------- 75

Howard..._________________________ ._- 76

Sixmile. ______ _-_-___.__ _________ _________ 76

Riverside ____-___-__----_----__-_---_----_--------'------- 77

Butte-___________________________ -_- 81

 Crest.________-_____--_____--__--_-_---_-_-----------_--- 81

Cripple Creek.________________-__---_-_-__------_--------. 82

Portland.-...-____- ___ __-___- _ - 84
CONTENTS

Mineral deposits Continued.

Mines and prospects Continued.

Hobo_______._._..._.__.._..__._.____..._._...-.... 84

Alaska-Premier.__________________________________________ 85

Daly-Alaska____________________._._______ 86

Stoner-Clegg-O'Rourke.-_-------------- -----------_----- 88

Virginia.._ _______________________________________________ 88

Stoner. __________________________________________ 89

Border... ____________________-_---_-_____--_.___-__-- 90

Gold Cliff Premier________________________________________ 90

Cantu_______._________________________________ 91

Bartholf._____________________.-___-___-.__________-___ 92

Ninety-six______________________________________________ 93

Silver Bar.___________._______________ ____ 93

Liberty._______________________________________ 93

Nothiger ________________________________________________ 94

Evening and Morning Star_________________________________ 94

Homestake__________________-___________________________ 94

Silver Coin_________________.____._______________________ 95

Ibex_.________________________________ 96

Silver Star.__________________.____._._.__________ 97

Silver Bell.______________________________ 97

Texas Discovery_____________________-___________.________ 98

Iron Cap._________-_________________________ 98

Hummel__-._____________________________________ 98

Double Anchor.__________________________________________ 98

Dugas___________________-_---________-__-__- 99

Silver King__________________________________ 99

Chickamin. ____________________________________ 100

Blasher______________-_.____________________ 100

Lake. _____________._..__________________________ 101

Morning ________________________________________________ 101

Edelweiss and Jumbo-____-__-----______________________.__ 101

Heckla._._______.__________.___...______ 101

Texas Creek Comstock (Hyder Lead)_____________________ 102

Keno___________._____________._______ 108

Juneau___________________________-__-_«>_________.____-- 108

Sunset. ____________________._____________ 109

Engineer_______________________________________________« 109

North Star______________.________________________________ 110

Jumbo Mining.___________________________________________ 111

Commonwealth. __________________________________________ 111

Geologic reconnaissance along Chickamin River._--__--_---_-_____-___ 112

Geography ______--__.___________ _________________ 112

Geology.____ _____ ___ ___ ________________ 114

General features ______--___-_-___-__-_________-__-____---- 114

Metamorphic complex.____________________^_v __ ___________ 115

Coast Range intrusives____________________________^_______ 116

Structure ________________________________________ 1__. __"_ _ 118

Metamorphism ___________________________________________ 119

Mineralization. ______________________________________________ 120

Prospects. ________________________________________ 120

Gnat_ ________ . ____________________________________ 120

Glacier. ______________..._______________ 120

Index ________________________________________ 123
ILLUSTRATIONS

Page 

PLATE 1. Topographic map of the Hyder district_-_____-_-___-__ In pocket.

2. Geologic map of the Hyder district ____________________ In pocket.

3. Generalized sketch map of the upper Portland Canal and

Chickamin River regions____--_-_-------___-__--_-___- 8

4. A, Town of Hyder, at the head of Portland Canal and the 

mouth of Salmon River; B, Dense forest growth on slopes 

below an altitude of 3,000 feet, Salmon River Valley------ 8

5. A, Mountains of Coast Range on west side of Salmon River,

northwest of Hyder; B, View of valley of Salmon River____ 8

6. A, Valley of West Fork of Texas Creek below Casey Glacier;

B, Head of Hidden Glacier.____________._____ 8

7. A, Foot of Salmon Glacier and tunnel from which Salmon 

River emerges; B, View up Boundary Glacier from moraine 

on Salmon Glacier___________.________________________ 24

8. A, Ferguson Glacier from top of ridge on the north side of 

West Fork of Texas Creek; B, Glacier occupying cirque on 

the west side of Through Glacier._____________________ 24

9. A, Chickamin Glacier, Through Glacier, and Chickamin Valley;

B, Mountains of the Coast Range__-_________________ 24

10. A, Glaciers on south side of West Fork of Texas Creek west of 

Ferguson Glacier; B, Valley of Indian Creek, looking toward 

Chickamin River Valley_____-_-_-__-__--__-_____-_--__ 24

11. Sketch map of Mountain View group of claims.____________ 72

12. Sketch map of claims near Fish Creek.____________________ 72

13. Sketch map of Stoner, Daly-Alaska, Virginia, and other claims. 72

14. A, View at head of Chickamin River, showing the foot of 

Chickamin Glacier and old terminal moraine; B, Snow field 

and tributary glaciers on the pass at the head of Through 

Glacier.______________________-----____--_--_____ 72

FIGURE 1. Sketch map of Crest group of claims__---_--___--__-_.--__ 82

VI
FOREWORD 

By PHILIP S. SMITH

Among the important duties of the United States Geological Survey in Alaska have been the exploration for mineral deposits and the 

critical examination of those that have been found. Southeastern 

Alaska has long been known to contain valuable mineral deposits, 

many of which have been developed by producing mines, and most 

of them have been studied more or less thoroughly by the geologists 

of the Alaskan branch of the Geological Survey. The region near 

the head of Portland Canal was early known to be one of the places 

where there were indications of valuable ores. However, not until 

the discovery in 1918 of the phenomenally rich silver and gold ores 

of the Premier mine, on the Canadian side of the international 

boundary, was much public interest in the district aroused. To meet 

the call for information as to the possibility of similar ores occurring 

on the American side, L. G. Westgate, geologist, in 1920 spent a 

month in field work in the district and prepared a report of his observations, which was published in Geological Survey Bulletin T22. 

The amount of prospecting that had been done on the American side 

at that time was so slight that no definite prediction as to the future 

of the district could be made. Enough information was obtained, 

however, to show that further prospecting and development were 

fully justified.

In 1924 the Geological Survey prepared a topographic map of 

Hyder and vicinity to serve as a base on which the geology could be 

mapped in some detail, and in 1925 A. F. Buddington, who had spent 

several years examining the geology and mineral deposits in many 

parts of southeastern Alaska, was assigned to study the district. The 

results of Mr. Buddington's studies, as well as the observations and 

interpretations by other geologists who have authoritative information on the problems involved, are set forth in the accompanying 

report. ^

Without attempting to summarize or brief the contents of the 

report it may be pointed out that the region is of great scenic and 

geologic interest, as it lies within the eastern portion of the Coast

VII
VIII FOREWORD

Range and includes part of the eastern contact of the Coast Range 

batholith. In the main the rocks are of igneous origin, and probably 

the most significant determination by Mr. Buddington is that the 

igneous rocks belong to three rather distinct divisions (1) a granodiorite which forms the Texas Creek batholith and was intruded into 

a series of greenstone, tuff, graywacke, and slate called the Hazelton 

group, (2) a pink quartz monzonite that forms the Hyder batholith, 

(3) a pink granodiorite that forms the Boundary stock. The ore 

deposits are intimately and probably genetically associated with the 

Texas Creek batholith, which is the oldest of these igneous members. 

Five types.of veins are discriminated quartz fissure veins of leadsilver-gold type, veins and veiiilike replacement deposits of silvergold type (not.yet recognized in the American part of the district), 

veins 'of the gold type, disseminated and lenticular replacement 

deposits, and mineralized fissure zones approximately parallel to the 

structure.

As a whole the region is still in a prospecting stage, though a small 

amount of ore has been shipped from some of the claims. Much 

further prospecting and study will be required before the real value 

of its mineral deposits can be determined. In the search and development, however, the numerous suggestions made by Mr. Buddington in 

the section of the report entitled " Notes on prospecting " should 

focus attention on the areas where efforts are most likely to be successful and prevent waste of time and money on those areas where 

geologic conditions are not regarded as favorable.
GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

WITH A RECONNAISSANCE OF CHICKAMIN RIVER

By A. F. BTJDDINGTON

INTRODUCTION

The drainage basin of Salmon Eiver lies in part within southeastern Alaska in the Hyder mining district and in part within British 

Columbia. It has been known for 25 years that mineral deposits 

occur within the Alaskan part, but until the development of the 

Premier mine in adjoining British Columbia the country, which was 

relatively inaccessible, attracted but little capital for prospecting. 

Within the last few years, however, the outstanding success of the 

Premier mine and the active prospecting and development work being 

prosecuted in the Canadian part of the Salmon Eiver and adjoining 

Bear River drainage basins have stimulated interest in prospecting 

and in the development of prospects within the American part of 

the Salmon River Basin. A number of new mineral deposits that 

warrant the expenditure of capital in prospecting have been discovered, several properties have undergone active development, and 

the Riverside mine has been brought to a stage of production within 

this period.

In 1925 geologic mapping of the Hyder district was undertaken 

by the writer to obtain a more complete picture of'the geologic setting 

and mode of occurrence of the mineral deposits as an aid to intelligent 

prospecting of the area and development of the discovered deposits 

and to present for public information a systematic account of the 

known mineral deposits and the work done on them. A reconnaissance of the Chickamin River Valley was made in order to evaluate 

the possibilities of that region as an area for prospecting.

FIELD WORK * " *V

In 1920 L. G. Westgate was engaged from July 19 to August IT in 

making a geologic investigation of the country between Salmon 

Kiver and the international boundary. In 1924 a topographic base 

map of the Hyder district was prepared by R. M. Wilson. (See pi. 1.) 

In 1925 the writer was engaged from July 8 to September 19 in mak-
2 GEOLOGY OF HYDEE AND VICINITY, SOUTHEASTERN ALASKA

ing a geologic map of this district and in an investigation of the 

mineral deposits. (See pi. 2.) The time was too short to penetrate 

the country south of Thumb Creek and to map accurately the northern 

border of the Hyder quartz monzonite west of Salmon River; this 

contact is therefore inferred and is indicated by a dotted line. In 

1925, between August 25 and September 16, Willard B. Jewell made 

a geologic reconnaissance of the country lying along Chickamin River 

from Behm Canal to the head of the West Fork of Texas Creek. 

(See pi. 3.) The detailed description of the mines and prospects 

covers only the development up to 1925. Since that date considerable additional work has been done at many of the properties, and a 

number of them have passed into the hands of other owners.

The writer is deeply indebted to Willard B. Jewell for able assistance in the field and in the laboratory. Mr. Jewell made a reconnaissance and prepared a report on the geology along the Chickamin River Valley and subsequently in the laboratory made an intensive study, followed by a report upon the nature and relations of 

the metalliferous minerals of the Salmon River area as studied with 

the microscope. The parts of the present report that deal with the 

geology of the Chickamin River Valley and the microscopy of the ore 

minerals are based on his work.

The writer is also under obligations to E. M. Jones and Malcolm 

Smith, of Hyder, for their satisfactory services as packers, and to 

George King and Wesley Myers, of Ketchikan, for their efficient aid 

as boatmen on Chickamin River. The prospectors and men in 

charge of the development of prospects were uniformly obliging in 

giving information and assistance whenever requested.

The report on the Salmon River district by Westgate* has been 

o>f the greatest assistance to the writer, and much of Westgate's material has been incorporated in this report.

The photographs reproduced in Plates 5, 6, and 9 were taken by 

R. M. Wilson in connection with his phototopographic survey of the 

district.

HISTORY

A brief summary of the history of the district has been given by 

Westgate,2 who writes:

Metal-bearing lodes, chiefly of gold and silver, were found in the Canadian 

portion of this region about 1898 [the year of the great Klondike gold rush], 

and similar discoveries had been made on the Alaska side of the boundary by 

1901. These deposits received relatively little attention until 1909, when a small

1 Westgate, L. G., Ore deposits of the Salmon River district, Portland Canal region: 

U. S. Geol. Survey Bull. 722, pp. 117-140, 1921. 

'Idem, p. 117.
HISTORY 3

boom was started in the Canadian district. This boom, subsided in a few years, 

but meanwhile the town of Stewart and some 12 miles of railroad were built. 

Interest was revived in 1917 by the discovery of some rich silver ores on the 

Canadian side of the line, and in 1918 a commercial ore body was found at the 

Premier mine, which, though in the Salmon River Basin, is also in Canada. As 

a result, many claims were staked on both sides of the boundary, and the town 

of Hyder sprang up.

In their search for placer gold the early prospectors proceeded into 

the Chickamin Kiver Valley in part by way of Salmon and Chickamin Glaciers. Old stakes indicate that incidentally they took their 

way along the branches of Chickamin and Texas Glaciers and along 

the West Fork of Texas Creek, but without any intensive search for 

vein deposits.

In 1923 employees of the United States Forest Service, who were 

engaged in building a prospector's trail up the West Fork of Texas 

Creek, recognized quartz fissure veins with shoots of auriferous and 

argentiferous lead ore. About 30 prospectors rushed to the district, 

and over 100 claims were recorded by the middle of September. In 

1925 a 60-ton mill for the concentration of gold-silver-lead ore was 

completed at the Riverside property and put into operation for a 

couple of months in the early part of the year. The property was 

then idle for several months pending arrangements for its operation 

by. .a new company, after which a small additional production was 

made in the later part of the year. The newspapers reported that 

218.5 tons of concentrate was produced in 1926 from the Riverside

mine.

BIBLIOGRAPHY

The following references may prove useful to those wishing further information on the geologic features and ore deposits of the 

Hyder district and adjoining areas:

ALASKA

Brooks, A. H., Preliminary report on the Ketchikan mining district, Alaska,

with an introductory sketch of the geology of southeastern Alaska: U. S.

Geol. Survey Prof. Paper 1, 1902. 

Buddington, A. F., Mineral investigations in southeastern Alaska: U. S. Geol.

Survey Bull. 773, pp. 73-95, 1925. 

 and Chapin, Theodore, Geology and mineral deposits of southeastern

Alaska: U. S. Geol. Survey Bull. 800, 1929. 

Chapin, Theodore, Mining developments in southeastern Alaska: U. S. Geol.

Survey Bull. 642, pp. 94-98, 1916. 

Jewell, W. B., Mineral deposits of the Hyder district, southeastern Alaska:

Econ. Geology, vol. 22, pp. 494-517, 1927. °£., ; - Mertie, J. B., jr., Notes on the Salmon-Unuk River region: U. S. Geol. Survey

Bull. 714, pp. 129-142, 1921. 

Westgate, L. G., Ore deposits of the Salmon River district: U. S. Geol. Survey

Bull. 722, pp. 117-140, 1921. 

Wright, F. E. and C. W., The Ketchikan and Wrangell mining districts, Alaska:

U. S. Geol. Survey Bull. 347, pp. 1-210, 1908.
BEITISH COLUMBIA

Bunting, Charles, The Premier gold mine, Portland Canal, B. C.: Min. and

Sci. Press, vol. 119, pp. 670-672, 1919. 

Burton, W. D., Ore deposition at Premier mine, B. C.: Econ. Geology, vol. 21,

pp. 586-604, 1926. 

Campbell, E. E., Mineral occurrences in the Stewart district: Canadian Min.

Inst. Trans., vol. 23, pp. 391-401, 1920. 

Clothier, G. A., Northwestern district (No. 1) : British Columbia Bur. Mines

Ann. Kept, for 1917, pp. 68-73, 1918; idem for 1918, pp. 76-83, '1919; idem

for 1919, pp. 61-80, 1920; idem for 1920, pp. 52-68, 1921; idem for 1921,

pp. 57-72, 1922; idem for 1922, pp. 63-87, 1923; idem for 1923, pp. 64-89,

1924; idem for 1924, pp. 56-75, 1925. 

Dolmage, Victor, The high-grade silver ores of the Stewart district, B. O.:

Canadian Min. Jour., vol. 41, pp. 454-458, 1920.

 Coast and islands of British Columbia between Douglas Channel and

the Alaskan boundary: Canada Geol. Survey Summary Kept, for 1922.

pt. A, pp. 9-34, 1923. 

McConnell, E. G., Portions of Portland Canal and Skeena mining divisions,

Skeena district, B. C.: Canada Geol. Survey Mem. 32, 191?. 

O'Neill, J. J., Salmon River district, Portland Canal mining division, B. C.:

Canada Geol. Survey Summary Kept, for 1919, pt. B, pp. 7-12, 1920. 

Schofield, S. J., and Hanson, George, The Salmon River district, B. C.: Canada

Geol. Survey Summary Rept. for 1920, pt. A, pp. 6-12, 1921.

 Geology and ore deposits of Salmon River district, B. C.: Canada Geol.

Survey Mem. 132, 1922. 

Wilhelm, V. H., The geology of the Portland Canal district: Min. and Sci. Press,

vol. 122, pp. 95-96, 1921. 

Wright, F. E., Report on the Unuk River mining region of British Columbia:

Canada Geol. Survey Summary Rept. for 1905, pp. 46-53, 1906.

GEOGRAPHY

The Salmon River area of southeastern Alaska lies at the head of 

Portland Canal, a steep-walled fiord which cuts obliquely across the 

Coast Range for some 90 miles from Dixoii Entrance, at the southern 

border of Alaska. Its limits are defined on the east and north by the 

international boundary, and on the west by the drainage divide 

between the headwaters of the streams tributary to Salmon River and 

those tributary to Chickamin River. (See pi. 1.) The area lies 

in the northeastern -part of the Hyder mining district, and the mine 

recording office is at Hyder.

The portion of the Salmon River area that lies in British Columbia has been well described by Schofield and Hanson.3

The town of Hyder is situated at the head of Portland Canal, at 

the mouth of Salmon River and on the international boundary, at

3 Schofield, S. J., and Hanson, George, Geology and ore deposits of Salmon River 

district, B. C.: Canada Geol. Survey Mem. 132, 1922.
GEOGEAPHY 5

approximately latitude 55° 55', longitude 130° V. (See pi. 4, A.) 

A spur of the Reverdy Mountains extends south to the coast, where 

the delta and tidal fla.ts built out into the canal by Salmon River 

extend around the base of the steep mountain slope. Part of the 

town is built on piling over the tidal flats, but the newer part is on 

the gravel-floored valley of Salmon River, to the northwest. The 

original settlement was called Portland City, but it was renamed in 

honor of George Hyder, engineer for the Alaska-Gastineau MiningCo., which had an option on the Big Missouri property on the Canadian side in 1915. A wharf about two-thirds of a mile long has 

been built over the tidal flats to deep water, and Hyder is accessible 

to ocean vessels throughout the year. It may be reached by means 

of the regular steamship service to Stewart from Vancouver and 

Prince Rupert, B. C, (135 miles), by regular weekly mail boats from

Ketchikan (155 miles), and by occasional steamships direct from 

Seattle.

The town of Stewart lies about 2 miles to the northeast, on the 

British Columbia side of the boundary, and although older than 

Hyder it is of about the same size. It is connected with Hyder by a 

road suitable for automobiles.

The district0 has been opened up by a road suitable for automobiles 

from Hyder to the Premier mine, on the Canadian side. This road 

runs along the east side of Salmon River most of the way, and about 

11 miles of its course is in American territory. It affords the only 

practical mode of access to the mineral deposits in the upper part 

of the drainage basin of Salmon River, a factor that has contributed 

to the growth of Hyder.

A pack trail has been built by the United States Forest Service up 

the West Fork of Texas Creek, one of the major tributaries of. 

Salmon River, from the bridge across Salmon River above Ninemile, 

at an. altitude of 335 feet, to Chickamin Glacier, at the head of the 

West Fork Valley, at an altitude of 2,350 feet, a distance of about 

11 miles. A branch trail goes over a low saddle, at an altitude of 

870 feet, to the foot of Salmon Glacier, at an altitude of 535 feetl 

Another pack trail has been built by the Forest Service up Fish Creek 

from the Salmon River Road, and a branch from it to the Titan 

property.

CLIMATE

The Salmon River district lies within the Pacific coast climatic 

province, where there is abundant rainfall and relatively moderate 

temperature. From November to March the precipitation at sea 

level is chiefly in the form of snow. The rainfall is least in late 

spring and early summer; it is greatest in July, August, September,.
6 GEOLOGY OF HYDBE AND VICINITY, SOUTHEASTERN ALASKA

and October, when rain falls on about half the total number of days. 

A summary of the climatic conditions at Stewart, B. C.,4 is equally 

applicable to Hyder.

Summary of meteoroloaic observations at Stewart, British Columbia, 1911-1921

Month

April.................... _ . __ ............. .................

July.............................-... ... .. .

Vaor

Temperature (°F.)

19.3

25.9

30.5

39..2

48.2

54.4

57.4

55.8

50.0

41.9

31.7

26.0

40.0

Rainfall 

(inches)

7.23

5.87

4.59

3.69

2.07

1.99

3.24

7.88

7.72

11.35

8.42

9.68

73.73

Snowfall 

(inches)

58.20

37.17

17.05

5.10

25.90

60.68

219. 56

Days of 

precipitation

13

9

10

10

9

8

10

13

15

19

17

16

149

The snowfall is much heavier at most places inland than at Stewart.' 

At the Premier mine it is reported to have amounted to 40 feet in 

1923 and 60 feet in 1924. On the other hand, it is much less at the 

foot of Chickamin Glacier, where it is reported to have been only 

6 feet in 1923.

VEGETATION

All the valley bottoms, except those occupied by glaciers or the 

immediate flood plains of the rivers, are well wooded. In general, 

the slopes, up to an altitude of 3,000 feet and in favorable places 

3,500 feet, are clothed with a dense growth of forest, except where 

it has been swept away by snowslides. (See pi. 4, B.) Above the

timber line to a height of about 4,000 or 4,500 feet there is a belt 

which, is covered by heather, with here and there straggling patches 

of stunted and scrawny trees. Above the heather is a zone of alternating bare rock, rock flakes, and angular glacial debris, with patches 

of snow, which extends to the lower limit of the glaciers and the snow 

or ice caps. On comb ridges too narrow to support a snow field this 

zone may extend as high as 6,400 feet.

The forests consist chiefly of hemlock and spruce, commonly with 

hemlock predominating. Yellow cedar is found locally. There is 

sufficient timber along Salmon River, Texas Creek, West Fork, and 

the mouth and head of Thumb Creek to supply all mining needs.

The slopes at the ends of the ridges between Through and Green - 

point Glaciers,' between Greenpoint and Ferguson Glaciers, and

4 Schofleld, S. J., and Hanson, George, Geology and ore deposits of Salmon River district, B. C.: Canada Geol. Survey Mem. 132, pp. 6-7, 1922.
TOPOGEAPHY 7

between Texas and Chickamin Glaciers are covered with timber as 

high as 3,000 to 3,500 feet; but near the head of Skookum Creek, east 

of Salmon Kiver, the forest extends only to a height of 2,800 feet.

WATER POWER

There are water-power sites on Thumb Creek, the West Fork of 

Texas Creek, Salmon River, and many of the smaller mountain 

streams. Development of water power on the three major streams, 

however, would necessitate consideration of the fact that in the 

spring and summer they carry considerable glacial flour, which would 

tend to silt up the reservoirs. Adequate power for prospecting can 

usually be developed from the mountain streams on most of the 

properties.

TOPOGRAPHY 

GENERAJ, FEATURES OF THE RELIEF

The Salmon River district lies within the eastern part of the 

Coast Range. The topography of the district is one of great relief, 

with the highest peaks 4,000 to 5,000 feet above the valley bottoms. 

(See pi. 5, A and B.) The scenery is bold and striking and is 

particularly grand in the vicinity of the international boundary 

just west of Mount Bayard, where the highest sharp-pointed peaks 

reach altitudes of over 7,000 feet above sea level, and though they 

rise above great uniform fields of snow and ice that cover many of 

the lower mountain tops and partly fill all the valleys, yet they 

themselves bear, carved in their sides, large amphitheaters occupied 

by glaciers.

The mountains in general have been glacially rounded to a height 

of about 6,000 feet or more, and sharp-pointed, serrate peaks are 

found only above this altitude. Snow or ice caps cover all large 

areas above 5,000 feet that are not too steep, and on protected divides 

they occur locally as low as 4,600 feet. Glaciers are found in protected basins at still lower levels. The valley walls have been 

glaciated and usually have very steep slopes or, in some parts of the 

region, sheer cliffs. Except where broken by these cliffs or by the 

narrow gorges and gulches cut in postglacial time, the slopes, though 

steep, are generally smooth. At the base of the steeper slopes in the 

valleys that are now free of glaciers there are large accumulations of 

talus which, with the alluvial fans built up at the mouths of gulches, 

have flattened the lower slopes and have tended to give a V-shape 

to what were previously glaciated U-shaped valleys.

Most of the area shown on Plates 1 and 2 lies within the drainage 

basin of Salmon River, but the extreme western parts lie within
8 GEOLOGY OF HYDEIl AND VICINITY, SOUTHEASTERN ALASKA

the drainage basin of Chickamin Kiver. The major tributaries of 

Salmon Kiver are Cascade Creek, Texas Creek, Thumb Creek, Fish 

Creek, and the creek that enters from the southwest on the west 

side of the river about 3l/2 miles northwest of Hyder. The divide 

between the drainage basins of Chickamin and Salmon Eivers 

trends, in general, almost true south parallel to Salmon Kiver and 

Salmon Glacier. The West Fork of Texas Creek has, however, 

pushed its headwaters far back into this divide and has produced in 

it a big bend to the west. Indeed, the West Fork would not have 

to cut its bed much lower and advance headward much farther to 

capture the drainage of the upper part of Chickamin Valley, now 

occupied by Chickamin Glacier.

The dominant elements of the relief are the Bear River Ridge, 

between Salmon and Bear Rivers, the unexplored group of mountains south of Thumb Creek, the ridge between Thumb Creek and 

the West Fork of Texas Creek, the ridge between the West Fork 

of Texas Creek and Texas Glacier, and tlie ridge between Texas 

Glacier and Boundary Glacier. The Bear River Ridge trends north; 

the other ridges trend west.

The part of the Bear River Ridge that is within this district 

is rounded and flat-topped. It has a general altitude of about 5,000 

feet and culminates on the south in the snow-capped peak of Mount 

Dolly, at an altitude of 5,475 feet. This ridge rises with steep 

slopes from the valley floor of Salmon River.

The divide between the drainage to Thumb Creek and Greenpoint 

Glacier and the drainage to the West Fork is iy2 times as far from 

the West Fork as from Thumb Creek. It has a length'of about 

5 miles, and for a third of this distance it is 6,000 feet or more in 

altitude. The lowest pass accross it is Ferguson Glacier, at an 

altitude of about 4,600 feet. Several peaks rise to heights of 6,300 

feet. Snow fields and ice caps cover most of the divide, and from 

it flow five major glaciers Hidden, Casey, and Ferguson to the West 

Fork, and Gray and Thumb to Thumb Creek.

The divide between the West Fork and Texas Glacier is three 

times as far from the West Fork as from Texas Glacier. It is 

about 4=y2 miles long, and nearly half of it is above 5,000 feet in altitude. There are two ice caps with their crests at about 5,800 feet, 

separated by a pass at the head of Ibex Gulch at an altitude of about 

4,800: feet.

The ridge between Texas and Boundary Glaciers in general slopes 

from a maximum of 6,100 feet at the head of Boundary Glacier to 

4,700 feet just west of the international boundary. Practically the 

whole ridge is capped with snow throughout the year.
U. 8. GEOLOGICAL SURVEY

131'

BULLETIN 807 PLATE 3

10' 130"

EXPLANATION

River sand and gravel and

Granodiorite, including 

Boundary granodiorite

and Hyder quartz monzortite; grades into quartz 

diorite on southwest 

border

v

i

or

Texas Creek granodiorite

Tuffaceous graywacke,

slate, and argil I ite

Greenstone, volcanic brec

Metamorphic complex

(Crystalfine schist and

injection gneiss with

in tercalated limestone

and cjudrtzite)

Glacier

130"

GENERALIZED SKETCH MAP OF THE UPPER PORTLAND CANAL AND CHICKAMIN RIVER REGIONS
U. S. GEOLOGICAL SURVEY BULLETIN 807 PLATE 4

A. TOWN OF HYDER, AT THE HEAD OF PORTLAND CANAL AND THE MOUTH

OF SALMON RIVER

B. DENSE FOREST GROWTH ON SLOPES BELOW AN ALTITUDE OF 3,000 FEET, 

SALMON RIVER VALLEY
U. S. GEOLOGICAL SURVEY BULLETIN 807 PLATE 5

.1. MOLVl'AI.NS OK COAST RA!N(JE ON \\KST SIDK OK SM.MON HI\KR. NOHTIHVKST OK IIYDI'iK

B. VIEW OF VALLEY OF SALMON RIVER
U. S. GEOLOGICAL SURVEY BULLETIN 807 PLATE 6

- 1. VALLKY OF WEST FlIHK OF TKXAS CHEICK BliLOW CASKY GLACIIOR

B. HEAD OF HIDDEN GLACIER
TOPOGRAPHY 9 

STREAMS

Salmon River is the master stream of the district. It heads in 

Salmon Glacier (see pi. 7, A), which heads against the Nass River 

divide. Salmon River from the foot of the glacier to Portland 

Canal is approximately 13 miles long. For about 1% miles from 

its head the river flows in a flat gravel-floored valley, below which it 

flows through a rock gorge to the point where Cascade Creek comes 

in. There is another gorge 100 feet deep where Boundary Creek 

cascades into the river. From the Daly-Alaska property, at Elevenmile, the river flows again in a flat-floored, gently sloping valley to 

the junction with Texas Creek, at an altitude of 300 feet. From, this 

point the valley is about three-fifths of a mile wide and has an average slope of about 31 feet to the mile. In this stretch the river is a 

winding stream, flowing rapidly in a network of channels cut 

through gravel bars and low islands that are constantly being built 

up and destroyed. The river is subject to considerable floods and 

at high water occupies the greater part of the valley floor.

Texas Creek heads in Texas Glacier. The valley of the creek is 

wide, flat floored, covered with gravel, and gently sloping. It may be 

readily forded with horses above the junction of the West Fork.

The West Fork is larger than Texas Creek where the two come 

together. The valley of the West Fork is about 8 miles long and 

consists of several broad gravel-floored flats with intervening long, 

narrow, deep postglacial rock gorges that have steep gradients. One 

flat extends from the upper end of Texas Lake, at the head of the 

valley, to the Government cabin. Here the creek has been forced 

over against the cliffs on the north side of the valley by the old 

rough moraines of Ferguson Glacier that extend for half a mile or 

so beyond the present front of the ice. Another flat extends for 

three-quarters of a mile opposite and west of Casey Glacier. Most 

of the drainage carried by the West Fork comes from the south side 

and mainly from the three glaciers, Hidden, Casey, and Ferguson. 

The steeply sloping sides of the valley have been scarred over half 

their area or more by slides, which are mostly covered with well-nigh 

impassable thickets of fern, alder, salmonberry, and blueberry. (See 

pi. 6, A.) Below Hidden Creek the West Fork flows for a short 

distance in a rock chasm 100 feet deep.

Thumb Creek is relatively inaccessible, as Salmon River normally 

can not be forded during the summer and the lower 1% miles of 

the Thumb Creek Valley is an impassable gorge, the floor of which 

slopes w.ithin this distance from an altitude of about 1,000 feet to 

the level of Salmon River at 250 feet. Several prospectors have 

entered the upper valley of the creek by way of the West Fork of

6190 29 2
10 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

Texas Creek, Ferguson Glacier, and the pass at the head of the 

glacier at an altitude of 4,600 feet. A few have gone in from the 

east by back-packing over the tops of the mountain shoulders north 

or south of the gorge. If supplies could be transported in the spring 

over the snow to a point above the gorge the upper valley would be 

easily prospected, as the rock exposure is favorable. The morairial 

hillocks at the head of the creek are well timbered and would afford 

good camp sites. About one-third of the water of Thumb Creek 

comes from Gray Glacier, near the head, and the larger part of the 

remainder comes from Thumb Glacier. An old terminal moraine, 

breached by the creek, extends in a semicircle across the valley about 

in a line with Gray and Ked Glaciers. The hillocks in the head of the 

valley are all morainal material. With the exception of these hillocks 

a great boulder flat extends from the foot of Thumb Glacier for about 

2 miles to the alluvial fan of the stream that enters from the south 

at an altitude of about 1,450 feet. The total fall in this 2 miles is 

about 500 feet. Between the altitudes of 1,450 and 1,000 feet the 

slope is much steeper. At 1,000 feet there are benches of bouldery 

gravel in which the creek has cut a deep valley, and below is the 

rock gorge through which it flows to Salmon R.iver. At some places 

snow arches persist across the creek until early summer. The north 

side of the valley is very steep, with many sheer cliffs, and is completely lined along its base by a coalescing body of talus, slide debris, 

and gulch deposits. Some of the slides have brought down giant 

fragments. Nowhere else ,in southeastern Alaska has the writer seen 

slides and talus developed on so extensive a scale.

GLACIATION

Above an altitude of 5,000 feet most of the broader ridges are 

covered with snow and ice caps from which glaciers creep down the 

mountain sides.

The major glacier of the Salmon River drainage basin is Salmon 

Glacier, which lies almost wholly in Canada, with its tip just crossing 

the international boundary at an altitude of somewhat over 500 feet. 

(See pi. 7, A.) Pack trains are taken up over Salmon Glacier to 

its head, and the trail is indicated by tripod markers.

Boundary Glacier is about 4 miles long and may be reached by 

way of Salmon Glacier. About a mile of the lower part of the glacier 

is in Canadian territory. The glacier is readily traversed from its 

foot to an altitude of about 4,200 feet, at the base of the ice cascades 

at its head. (See pi. 7, B.)

Texas Glacier, which fills the valley north of the West Fork, is 

a through glacier. It flows from the divide at an altitude of 5,300 

feet eastward 5% miles down to an altitude of a little over 1,000 feet.
TOPOGRAPHY 11

It also flows westward from the divide 2^ miles and joins Chickamin Glacier at an altitude of about 2,800 feet. Texas Glacier can b<i 

traversed from its eastern foot to the divide, except for a deeply 

crevassed portion about 2 miles from the foot, where there is a drop 

of several hundred feet within a short distance. Here it is necessary 

to climb over the rock shoulder on the north side and regain the 

glacier at an altitude of about 3,300 feet. The part of the glacier 

that flows westward into Chickamin Glacier is so crevassed as to be 

practically impassable above an altitude of 4,000 feet. The south wall 

of the valley of Texas Glacier, on both the Chickamin and Texas 

Creek sides, is uniformly precipitous, with many high, sheer cliffs. 

Hidden Glacier occupies a hanging valley whose edge is TOO feet 

above the bottom of the valley of the West Fork. The glacier is fed 

by two great ice cascades, which descend at a gradient of about 2,000

feet to the mile. (See pi. 6, B.) The glacier is readily traversed to 

an altitude of about 4,200 feet, at the foot of the ice cascades. Hidden 

Creek has cut a gorge 20 to 50 feet deep in the old morainal material 

and the bedrock at the foot of the glacier.

Casey Glacier, like Hidden Glacier, occupies a hanging valley 

which, at the foot of the glacier, is about 500 feet above the bottom of 

 the valley of the West Fork. Casey Glacier is easily traversed up to 

.the foot of the ice cascades at its head, at about 4,000 feet. The peaks 

.above may be reached with difficulty by way of the southeast arm, 

which affords access also to Thumb Creek by way of Gray Glacier.

Ferguson Glacier (pi. 8, A) is about 4 miles long. The head of 

'Thumb Creek may be reached by going up Ferguson Glacier to the 

divide at about 4,600 feet and over the snow field and down a steep 

snow-filled gulch which opens on the lower slope of Thumb Glacier. 

From this point it is possible to travel up Thumb Glacier and over 

the divide at its head to Greenpoint Glacier, a tributary of Chickamin Glacier.

The northern tributaries of Chickamin Glacier head against those 

of Salmon Glacier. Chickamin Glacier is about 17 miles long, and 

about 10 miles of it lies in Alaska. The upper part flows south 

and the lower part in a general westerly direction. (See pis. 3; 9, 

A;U,A.)

Several other glaciers are shown on Plates 1 and 2, and a .view of 

two small glaciers west of Ferguson Glacier is given in Plate 10, A.

At the heads of the valley glaciers and in the high mountain ridges 

and peaks there are great basins and amphitheaters, which have 

been excavated by processes connected with the presence or activities 

of the glaciers that have occupied them in the past or are now occupying them and with the snow fields that partly cover their steep 

^back walls and side slopes. These basins, known as cirques, are found
12 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

as low as 4,100 feet and are still locally in process of formation at 

altitudes of 4,500 feet or higher. (See pi. 8, B.) The area south of 

the West Fork and west of Salmon River is a " fretted upland " 

whose riblike ridges have been produced by the headward and sideward erosion of the cirques. (See pi. 9, B.) The lateral ridges between adjoining glacier basins have been worn away near their heads 

until many of them are not more than 100 feet wide. Locally they 

are covered with snow and are in the process of being reduced to 

cols or low divides. A few isolated mountain peaks have been left 

with one or more radiating short, narrow ridges. Narrow as are 

the ridges between the glaciers, some of them afford good traveling. 

Unusually fine examples are the ridges at the head of Hummel 

Glacier, the ridge between the glacier above the Keno group of claims 

and the first small glacier west of Ferguson Glacier, and the higher 

part of the ridge on the east ^ide of Ferguson Glacier on which the 

Sunset claims are located. These ridges are, to a considerable extent, 

coated with rock spalls. There is relatively little evidence of the 

formation of cirques either in the past or in the present in the Bear 

River or in the ridges north of the West Fork.

Most of the valley glaciers can be easily traveled up to altitudes of 

3,900 to 4,200 feet, where crevasses usually make further progress 

difficult or impossible.

The well-rounded form of the mountain ridges up to and locally 

above 6,000 feet and the glacially grooved and striated walls of the 

valleys indicate that the whole district has in the past been flooded 

with ice as high as 6,(|00 feet. The ice must have flooded the valleys 

to a height of about 4,100 feet until a relatively recent time and then 

melted away very rapidly to a condition approximately like that of 

the present time. This conclusion is based upon the fact that below 

4,100 feet there is little or no evidence of the cirques that must certainly have been.formed to some extent had the valleys not been filled 

with ice, which later withdrew too quickly to permit the excavation 

of cirques at the lower altitudes. It is probable that in the Salmon 

River district cirques were formed at low levels during the first part 

of the last glacial epoch, while the snow line was descending and 

before the valleys were completely filled, but such cirques must have 

been obliterated by the valley glaciers during the time of maximum 

ice flooding.

In the West Fork Valley opposite Ferguson Glacier steep bluff 

faces below and a marked smoothing of slope and rounding of 

shoulders above indicate that the ice here filled the valley to an 

altitude of 4,400 feet for a considerable time. On the north side of 

the West Fork glacial striae parallel to the valley were noted up to 

altitudes of 4,000 feet, and this altitude corresponds to a line above 

which there is a marked decrease in the steepness of the slope.
GENERAL FEATURES 13

Every glacier in the district, whether large or small, shows marked 

evidences of retreat within recent years, and the universal testimony 

of prospectors is to the effect that the glaciers are melting back at 

the present time.

Boundary Glacier is shown on the maps of the International 

Boundary Survey as joining Salmon Glacier, and this relation is 

reported to have continued up to 1922. In 1925 there was no connection between the two glaciers; Boundary Glacier had melted back, 

and a deep depression lay between its terminal moraine and the 

lateral moraine of Salmon Glacier. Some branches of Chickamin 

Glacier are similarly in the process of dismemberment from the main 

glacier. Hummel Glacier no longer joins Chickamin Glacier, and 

the west branch of Texas Glacier is melting away so that a lake has 

now formed on each side of its junction with Chickamin Glacier.

All the glaciers show bare rock surfaces along their sides for a 

hundred feet or more above their present surface. The surface of 

the glaciers has melted down so recently that vegetation has not yet 

had a chance to get a foothold. Old lateral moraines are conspicuous along the sides of Ferguson and Greenpoint Glaciers 100 

feet or locally as much as 250 feet above the level of the present 

lateral moraines. Remnants of lateral moraines extend down both 

sides of Texas Creek for three-quarters of a mile below the present 

foot of the ice. Old terminal moraines are conspicuous in front of 

Ferguson, Chickamin, and Thumb Glaciers. R. M. Andrews reports that in 1902 the foot of Chickamin Glacier was only a few 

feet from an old terminal moraine 20 to 30 feet high, which in 1925 

was 4,600 feet from the ice front. Malcolm Smith reports that the 

ice front of the Chickamin Glacier retreated 600 feet between July, 

1923, and July, 1925. (See pi. 14, A.)

GEOLOGY

GENERAL FEATURES

The Salmon River area in Alaska lies adjacent to and includes a 

portion of the northeastern border of the Coast Range batholith. 

This batholith extends for some 1,100 miles from the southern 

boundary of British Columbia northwestward into Yukon Territory and ranges from 20 to 110 miles in width. Within the latitude, 

of southeastern Alaska it is in most places 35 to 60 miles in width. 

In the adjacent country rock near its northeastern border there 

are local outlying stocks and dikes of igneous rock that belong to 

the same general period of intrusion as the main batholith. Mineral 

deposits have been found in this border belt wherever it is more 

readily accessible to prospecting, as at the head of Alice Arm and 

Portland Canal and on Unuk, Stikine, and Taku Rivers. This 

belt is often referred to as the eastern or interior belt of mineraliza-
14 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

tion, as distinguished from a western belt, of mineralization which 

occurs along the southwestern border of the Coast Range batholith.

The predominant rocks of the area are summarized in the geologic 

table below. They consist of (1) a great central mass of gray 

granodiorite composing the Texas Creek batholith intrusive into 

(2) the Hazelton group, of probable Jurassic age, comprising greenstone, tuff, volcanic breccia, graywacke, slate, argillite, quartzite, 

and rare limestone, which borders the Texas Creek batholith on the 

east and the west; into both the Texas Creek granodiorite and the 

Hazelton group are intruded (3) a pirikish quartz monzonite. the 

Hyder quartz monzonite, composing the Hyder batholith, which 

forms the northeastern border portion of the main Coast Range 

batholith and which here lies along the southern border of the Texas 

Creek batholith, and (4) a pink granodiorite, the Boundary granodiorite, composing the Boundary stock or apophysis, which occurs 

along the northern border of the Texas Creek granodiorite and the 

Hazelton group and is a facies of the main Coast Range batholith. 

Small stocks and dikes of gray sheared porphyry, genetically allied 

with the Texas Creek granodiorite, occur in the beds of the Hazelton group. At many places dikes of pink to white granpdiorite or 

dark diorite porphyry intrude both the Texas Creek batholith and 

the sedimentary and volcanic rocks of the Hazelton group. These 

are genetically associated with the Hyder quartz monzonite and 

the Boundary granodiorite. The Texas Creek batholith and associated stocks and dikes, the Hyder batholith and associated dikes, 

the Boundary stock and associated dikes, and the rocks of the 

Hazelton group are all cut by narrow dikes of dark to black lamprophyre and malchite. The major river valleys are floored with

recent gravel and sand and locally with morainal deposits. Here 

and there benches along the river valleys at a considerable height 

above their floors are covered with morainal gravel, clay, and sand 

of Recent age. A thin veneer of glacial drift occurs locally in 

some of the valleys and on the gentler mountain slopes.

Formations m the Hyder district

Quaternary (Pleistocene 

and Recent).

Jurassic or Cretaceous.

Jurassic (?)

Base not exposed.

Coast Range intrusives.

Hazelton group.

Glacial moraines and drift. 

River gravel, sand, and clay. 

Local terrace deposits.

Lamprophyre and malchite dikes.

Hyder quartz monzonite, Boundary granodiorite, and 

associated granodiorite and diorite porphyry dikes.

Texas Creek granodiorite and associated porphyry dikes. ^

Tuffaceous graywacke, slate, argillite, quartzito, and rare 

limestone. 

Greenstone, tuff, volcanic breccia, and sparse slate.
GENERAL FEATURES 15

The economically important mineral deposits of this area, so far 

as found, are connected exclusively with the Texas Creek batholith 

and its associated outlying stocks and dikes. They occur largely 

within the Texas Creek granodiorite or within the bedded rocks 

near the contact. They are cut by granodiorite and diorite porphyry dikes that are genetically associated with the Hyder quartz 

monzonite and with the Boundary granodiorite and also by the 

still younger malchite and lamprophyre dikes.

In southeastern Alaska the dominant structural features of the 

formations older than the Coast Range intrusive rocks consist of 

northwestward-striking folds, in part overturned or isoclinal. The 

gneissic structure of the Coast Range batholith similarly has a 

northwest strike. The folds immediately adjacent to the batholith 

on the southwest border are closely folded and in part overturned

toward the southwest, and the foliation of the batholith dips uniformly steeply to the northeast. Similarly, in the Salmon River 

area in British Columbia, just to the north of the area considered in 

this report, the formations are folded into a series of anticlines and 

synclines with a north-northwest strike.6

In the Salmon River area of the Hyder district there are beds 

along the international boundary east of Salmon River that .strike 

north-northwest and dip steeply southwest; but in general within 

the area covered by this report the trend of the folds of the bedded 

rocks, of the gneissic structure of the Texas Creek batholith, and of 

the schistose structure of the greenstones is within 20° of true east 

and is therefore completely out of harmony with the prevailing 

structure of the surrounding country.

The granodiorite that forms the core of the Texas Creek batholith 

has a marked fine banding or gneissic structure. There are many 

slickensided planes of movement within the rock; but thin sections 

examined with the microscope usually show no evidences of crushing 

or metamorphism such as might have produced the foliation. The 

gneissic or banded structure is due in large part to the parallel orientation of the conspicuous crystals of black hornblende and of the 

large phenocrysts of potash feldspar and therefore had its origin in 

flowage currents within the magma during its crystallization and 

consolidation. As this foliation is of primary origin and strikes 

N. 60°-90° E., it follows that the peculiar structural trend of this 

area had its inception prior to the intrusion of the younger Coast 

Range magmas which formed the Hyder quartz monzonite and the 

Boundary granodiorite. It is thought, nevertheless, that the prevalent approximate!}' east-west structure of the bedded rocks of this 

area is in considerable part due to the thrusts exerted by the intru-

" Schofleld, S. J and Hanson, George, op. cit., p. 34.
16 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTEBN ALASKA

sion of these younger Coast Kange magmas. The northeastern contact of the Coast Eange batholith as a whole usually trends northwest, 

but in this area it swings around to more nearly east-west, probably 

as a result of the control exerted by the older structure of the Texas 

Creek batholith and the surrounding rocks, which had a similar 

strike.

There is abundant evidence of the great pressure exerted by the 

younger magmas at the time of their intrusion. The Texas Creek 

granodiorite along its southern boundary adjacent to the Hyder 

quartz monozonite is partly or completely pulverized as a result of 

the pressure exerted by the intrusion of the magma that consolidated 

as the Hyder quartz monzonite and grades away from the contact 

through an augen gneiss into the normal granodiorite. To the west 

of the Texas Creek granodiorite the Hyder quartz monzonite magma 

came into contact with the graywacke-slate division of the Hazelton 

group and produced in those rocks close folds overthrust toward the 

north. On the north side of the area the magma of the Boundary 

granodiorite similarly exerted a thrust upon the graywacke-slate 

division of the Hazelton group and produced close folds overturned 

toward the south. The bedded rocks were thus pinched between the 

Hyder quartz monzonite magma on the south and the Boundary 

granodiorite magma on the north, and folds overturned in opposite 

directions were the result. Microscopic examination shows that locally, near the contacts with the intrusive masses, grains that compose the bedded rocks and the intrusive aplite dikes belonging to the 

Texas Creek batholith have been severely mashed and pulverized. 

It is probable that part of the schistose structure in the porphyry 

dikes associated with the Texas Creek granodiorite, the gneissic 

structure in some of the sulphide masses, and the crushing of some 

of the mineralized quartz veins also resulted from the pressure attendant upon the intrusion of the younger Coast Range magmas.

On the east side of Salmon River the contact between the Texas 

Creek batholith and the greenstones of the Hazelton group strikes 

about north. The gneissic structure of the granodiorite, however, 

and the foliation of the greenstone both strike approximately east. 

The mineralized quartz fissure veins cross the structure of both rocks 

at an angle. There must have been, therefore, an epoch of marked 

deformation and folding slightly preceding and accompanying the 

intrusion of the Texas Creek batholith. Subsequently both the Texas 

'Creek granodiorite and the Hazelton group were affected by a second 

epoch of deformation accompanying the intrusion of the Hyder

 quartz monzonite magma.

The mapping is not sufficiently detailed to indicate the general

 direction of strike of the porphyry dikes in the rocks of the Hazelton
HAZELTON GROUP 17

group. The granodiorite porphyry dikes connected with the younger 

Coast Kange intrusive rocks that cut both the Texas Creek granodiorite and the Hazelton group, however, have in general a northwest strike ranging usually from N. 20° W. to N. 70° W., but at 

some places their strike is northeast. Along the international boundary the dip is usually 45°-60° SW. In the district to the north these 

dikes have a northwest strike.

HAZELTON GROUP 

GENERAL CHARACTER

No fossils have been found in the sedimentary and volcanic beds 

of this area. The beds are assigned to the Hazeltor* group because of 

their lithologic similarity to the formations of that group to the 

southeast and north in British Columbia and because of similar 

structural relations to the Coast Range intrusive rocks. The Hazelton group has been described by Hanson 6 as consisting of a lower 

formation comprising volcanic tuff, breccia, and flows of green or 

gray to purplish andesitic rock and an upper formation comprising 

argillite, quartzite, and tuffaceous sandstone. The argillite of the 

upper division carries fossils which are referred to the Jurassic.

The sedimentary and volcanic rocks found north of this area, on 

the British Columbia side of the international boundary, are assigned 

by Schofield and Hanson 7 to three conformable formations of probable Jurassic age, as indicated below:

Formations m the Salmon River district, British Columbia

Feet 

Nass formation: Slate, fossiliferons_____________ 1,000+

Salmon River formation: Conglomerate__________ 300+ 

Bear River formation: Agglomerate and tuff________ 2,000+

The greenstone, tuff, and volcanic breccia of the Alaskan side along 

the international boundary east of Salmon River are continuous 

with the similar rocks of the so-called Bear River formation on the 

Canadian side and correspond to the lower division of the Hazelton 

group as shown on Plate 2.

A bed resembling the Salmon River conglomerate of the Canada 

Geological Survey was seen at one locality. This is a thin bed of 

fine conglomerate included in a porphyry dike at an altitude of 

about 4,500 feet on the slope of Bear River Ridge east of the mouth 

of Thumb Creek. Cobbles and boulders of similar conglomerate are 

found here and there along the lower slopes of the ridge, indicating 

that perhaps other lenses may be or may have been present here.

6 Hanson, George, Reconnaissance between Skeena River and Stewart, B. C.: Canada 

Geol. Survey Summary Rept. for 1923, pt. A, pp. 32-36, 1924.

7 Schofield, S. J., and Hanson, George, op. cit, pp. 10-13.
18 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

A tuffaceous graywacke formation, which very locally is conglomeratic, appears to overlie the greenstone on the American side and 

to occupy a position stratigraphically similar to that of the Salmon 

River conglomerate of British Columbia.

Schofield and Hanson describe their Nass formation as consisting 

"mainly of argillites which in many places, especially near the Coast 

Range batholith, show a slaty cleavage. Beds of sandstone and fine 

conglomerate occur here and there through the formation." Fossils 

of probable Jurassic age are found near the base of the formation. 

It seems probable that the slate and fine quartzitic beds of Mineral 

Hill and the slate and argillite of the region near the head of the 

West Fork and Chickamin Glacier are the equivalent of the Nass 

formation of British Columbia.

The slate in the American part of the Salmon River Basin is so 

completely infolded and interbedded with graywacke that the writer 

was unable to map the beds separately without further and more 

detailed work. The graywacke and slate are therefore mapped and 

treated together in this report. In the absence of fossils and the 

lack of exact knowledge as to the structural relations it is not known 

whether the graywacke should be grouped as a separate formation, 

or whether it is the equivalent of one or more of the formations found 

on the Canadian side. The evidence at hand seems to indicate that 

the graywacke formation is not the equivalent of the Bear River 

formation but overlies it and that the graywacke is in turn overlain 

by a formation characterized by slaty argillite.

GREENSTONE AND ASSOCIATED ROCKS

East of Salmon River, along the international boundary, north 

of the Mountain View property, there is a belt of rock consisting 

predominantly of more or less schistose greenstone. The dominant 

type is a soft green and gray fine-grained chloritic rock of indeterminate origin. With it are associated locally bands of thinbedded dark slate with layers of quartzite or graywacke. On the 

slope of Bear River Ridge, just west of the international boundary 

and east of the Titan property, between altitudes of 4,500 and 4,750 

feet, there is a bed of coarse purplish to green-gray andesitic volcanic breccia several hundred feet thick, striking a little west of 

north and dipping steeply west. Tuff, clearly recognizable as such, 

both in the field and with the microscope, is also found in this 

vicinity. Large boulders of the breccia are abundant along the lower 

slopes of the mountain. Rarely a bed is found that consists of 

angular fragments of greenstone in a matrix of slate. This forma-
HAZELTON GROUP 19

lion continues north across the international boundary into British 

Columbia. Schofield and Hanson 8 describe it as follows:

This group of rocks is almost entirely of volcanic origin, and the name 

"greenstone" commonly applied to it is suitable in a general way. The lower 

members are largely fragmental rocks of agglomerate character. Their constituent fragments are angular purple and green masses of andesite in an 

undesitic matrix. They vary in size from minute particles to pieces a foot 

or more across. In thin section they show phenocrysts of a plagioclase,

 * * probably an andesine, scattered through a highly altered matrix in 

which hornblende and plagioclase are the main constituents. The rock is highly 

altered, and many secondary minerals, such as calcite, epidote, and chlorite, are 

present. * * * The agglomerates are overlain by fine-grained tuffs that 

form the upper part of the Bear River formation. The tuffs are massive in appearance and, as a rule, green, but purple bands occur at irregular intervals 

in the green. * * * Under the microscope the rock is seen to be highly 

sheared and altered. The minerals are chiefly secondary and consist of seri-

 cite, calcite, chlorite, quartz, altered plagioclase, rutile, pyrite, and leucoxene.

 coxene.

Westgate 9 thus describes the greenstone on the American side:

Throughout most of the area * * * the greenstone is a gray or green 

fine-grained soft calcareous rock, indistinctly banded and specked with minute 

grains of pyrite. Thin sections show aggregates of quartz, calcite, sericite,

 chlorite, and feldspar, and usually pyrite and leucoxene or granular titanite. 

The micas are not abundant enough to give a foliation. The rock is rather 

uniform over considerable areas and ordinarily does not show any structure 

in the outcrop. Neither in the outcrop nor in the thin section is the original

 character of the rock to be seen. A real variability in some thin sections suggests a tuff. There is nothing to suggest sedimentary origin. The uniformity 

of the rock and its mineral character indicate that it is probably either an 

altered tuff or lava. * * * As it is difficult to destroy the structure of a 

porphyry completely, the general absence of any recognizable porphyritic structure in the greenstone is taken to mean that most of them are tuffs.

GRATWACKE-SLATE DIVISION

The graywacke-slaty argillite division of the Hazelton group occupies most of the country along the upper part of the West Fork and 

around Chickamin Glacier and its branches. It forms the roof over 

the Texas Creek batholith, which here plunges to the west. The 

mountain ridges are usually composed of the graywacke-slate series, 

but the valleys at many places have been cut below the roof of 

the batholith and into the underlying quartz diorite, so that the 

lower part of the slopes and the valleys usually expose the Texas 

Creek batholithic igneous rock. Near the contact with the batholith 

there are dikes of granodiorite porphyry in the sediments, and within 

500 feet of the contact aplite dikes are common. Dikes of pink to

8 Schofleld, S. J., and Hanson, George, op. cit., pp. 11-12.

B Westgate, L. G., Ore deposits of the Salmon River district: U. S. Geol. Survey Bull. 

722, pp. 122-124. 1921.
20 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

white granodiorite porphyry that are offshoots from the Hyder 

quartz monzonite and the Boundary granodiorite are common at 

most places throughout the bedded rocks and the Texas Creek 

batholith.

The beds forming the mountain ridges between Casey and Ferguson Glaciers are predominantly of the graywacke type. Thickbedded massive graywacke and local beds of conglomerate preponderate at the north on the slope to the West Fork. They are adjoined on the south by beds which in general are somewhat finer 

grained and have considerable associated argillite, but coarse graywacke is common throughout. The ridge on which the Sunset claims 

are located is composed of argillite and graywacke.

The bedded rocks of the south slope of the valley of the West Fork 

west of Ferguson Glacier consist almost wholly of graywacke with 

very-little slate. The first big beds of slate occur at an altitude of 

5,100 feet on the northeast slope of the ridge north of Hummel 

Glacier, where they are interbedded in thick zones with graywacke. 

Slate forms the crest of this ridge. Beds consisting of fragments 

so long and coarse that the structure seems breccia-like are common 

in the graywacke. The ridge just west of Ferguson Glacier is composed of graywacke-like beds, predominantly medium grained, with 

intercalated sparse slaty and thin argillaceous layers and one band 

of greenstone. In this ridge between altitudes of 4,800 and 5,100 feet 

there is a belt of greenstone schist with intercalated beds of graywacke, which locally has a breccia structure. These beds dip steeply 

to the north, though the prevailing dip is uniformly steep to the 

south. Graywacke beds with only a little slate form the slope northeast of Hummel Glacier and the north spur of the mountain between 

Hummel Glacier and Through Glacier. The top and south slope of 

the ridge between Greenpoint and Hummel Glaciers, however, are 

composed of banded slate and very fine grained graywacke and 

quartzitic beds, with intercalated thick beds of graywacke and dark 

blue-gray fissile limestone. The slates are crinkled and show a 

tendency toward pencil structure.

Banded Mountain, which rises between Chickamin Glacier and 

Through Glacier, and the shoulder between Greenpoint and Through 

Glaciers are composed of graywacke with a very few thin beds of 

argillite. They strike about N. 60° W. and dip 30°-50° S.

The ridge between the West Fork and Texas Glaciers west of 

Ibex Creek is composed predominantly of argillite, in part of a 

slaty character, thinly banded with fine to coarse graywacke or 

quartzitic layers and with sparse interbeds of graywacke. Locally 

there are beds of coarse graywacke with a structure similar to that 

of volcanic breccia, arid rarely a bed of dark fine-grained limestone.
HAZELTON GROUP 21

Beds of argillitic character are dominant. At the west end of the 

ridge, below 4,500 feet, graywacke beds are dominant.

The mountains in the angle north and west of Chickamin Glacier 

are composed of graywacke with a little interbedded argillite.

The mountain spur that extends southwest from the international 

boundary between Texas and Chickamin Glaciers is composed of 

graywacke and argillite, intruded on the northwest by a stock of 

Boundary granodiorite and on the southeast tip by an extension 

of the Texas Creek quartz diorite. The mountain at the head of the 

spur appears to consist of a syncline of thin-bedded slate and graywacke overturned toward the south and riven by great dikes of 

granodiorite. A belt of graywacke with an east-west strike and a 

northerly dip forms the mountain spur to the foot of the glacier that

 covers much of it. The narrow neck of the spur and the steep slope 

up to the foot of the glacier at the north are composed of slaty 

argillite. On the west side of the spur the contact between the slaty 

argillite and the predominant graywacke formation lies on the north 

side of the shoulder that projects to the west. The south westernmost 

part of the spur, for a length of three-quarters of a mile, is composed 

of metamorphosed graywacke.

The rocks here called graywacke are compact, massive, green-gray 

to gray, and fine to coarse. At many places they are so uniform 

that bedding is indistinguishable even within thick masses. Some 

of the, beds are coarse and show a somewhat modified agglomeratic 

structure. The materials of which the rocks are composed aix_> 

almost wholly volcanic, and it is probable that they are waterworn 

andesitic tuff and breccia. They are so wholly volcanic in nature 

that it may be possible that some portion of the beds are of direct 

Tolcanic origin; but their bedded character, the intercalation of 

argillite, the complete absence of anything that might be considered 

a flow, and the somewhat waterworn character of the materials in the

 coarser beds suggest that they are predominantly only indirectly of 

volcanic origin. The term tuffaceous graywacke might be appropriate for them. They probably correspond in part to what Hanson

 calls tuffaceous sandstone. The finer-grained beds, interlayered with 

the argillite, are much more quartzitic in nature.

The typical graywacke is distinctly tuffaceous. It consists almost 

wholly of green hornblende and plagioclase with associated secondary alteration products. Hornblende is approximately equal i?i 

quantity to the plagioclase. Locally a little orthoclase is present, aini

 occasionally accessory apatite. In the freshest specimens both the 

hornblende and the plagioclase show many crystal faces. The feldspars are partly altered to sericite and epidote. The ferromagnesian 

minerals are chloritic. A little calcite is not uncommon, and rarely
22 GEOLOGY ;OF HYDEE AND VICINITY, SOUTHEASTERN ALASKA

there is a trace of secondary quartz. A little residuum of augite is 

left at the core of many of the hornblende crystals, suggesting that 

the original ferromagnesian mineral was in part, if not wholly, a 

pyroxene.

There are three main belts in which beds of slaty argillite or argillite that is in part thin banded with light green-gray to dark quartzitic layers and with intercalated graywacke predominate. Mineral 

Hill is composed of such beds. A second belt forms the crest and 

southern slope of the ridge between Greenpoint and Hummel 

Glaciers and the southern part of the area of sediments between 

Casey and Ferguson Glaciers. A third belt forms the whole ridge 

north of the West Fork and west of Ibex Creek except for its west end. 

This belt may also include the band of slaty argillite that forms the 

narrow part of the spur between Texas and Chickamin Glaciers. 

Earely a dark blue-gray limestone is thin bedded with the argillite 

and quartzitic layers or occurs intercalated as a bed. The two belts 

of slaty argillite in the vicinity of the upper part of the West Fork 

and of Texas and Greenpoint Glaciers appear to represent the same 

formation isoclinally infolded within the predominant graywacke 

formation which stratigraphically underlies them. The southern 

belt dips prevalently to the south, whereas the northern belt dips, 

prevalently to the north or is vertical, though minor folds locally 

give dips in the opposite direction in both belts. In the absence of 

detailed structural study it is impossible to estimate the thickness of 

either the graywacke or the slaty argillite.

TEXAS CREEK BATHOLITH AND ASSOCIATED DIKES 

CHARACTER AND EXTENT

A batholith of igneous rock with a few outlying cupolas and dikes 

occupies most of the area shown on Plate 2. This is known as the 

Texas Creek batholith. The rock is chiefly a granodiorite and is 

intimately and probably genetically connected with most of the ore 

deposits of this district. The mass is therefore very important 

because of its relation to the mineral deposits, and its contacts will 

be described in detail.

The core of the Texas Creek batholith is a porphyritic granodiorite, here named Texas Creek granodiorite, but the border facies 

and the outlying stocks are in general nonporphyritic quartz diorite. 

Locally, immediately adjacent to the contact, diorite or monzodiorite 

is found. These less alkalic and more basic facies are probably 

due to quicker cooling, which resulted in a less advanced stage of 

differentiation.
COAST RANGE INTEUSIVES 23

The Texas Creek batholith is cut by dikes of granodiorite and 

granodiorite porphyry genetically associated with the Hyder quartz 

monzonite and the Boundary granodiorite, by a few light-colored 

dikes of quartz porphyry, and by dark-colored dikes of malchite and 

lamprophyre. Within 500 feet of the borders or roof of the batholith 

aplite and pegmatite veins are common in both the batholith and the 

country rock. Where small dikes of the Texas Creek batholith occur 

in the country rock the dike rock has a fine to dense grain and a 

porphyritic aspect, so that it is difficult or impossible to discriminate 

between such dikes and the quartz porphyry dikes that cut the Texas 

Creek batholith. The quartz porphyry dikes, must be genetically 

associated with the Texas Creek batholith, as they have suffered the 

same metamorphism, are cut by the metalliferous veins, and are 

older than the Hyder quartz monzonite and Boundary granodiorite. 

It is probable that the porphyries with which the Premier ore bodies 

in British Columbia are associated are outlying stocks genetically 

associated with the Texas Creek batholith.

The southern boundary of the Texas Creek batholith is against the 

Hyder quartz monzonite and runs almost due west for 4y2 miles. 

From an altitude of about 3,500 feet on the southwest slope of Mount 

Dolly it crosses the Salmon Eiver road just north of Fish Creek and 

probably follows the ridge on the south side of Thumb Creek, though 

the contact here was not traced. All of the valley of Thumb Creek 

to a point within three-quarters of a mile of the foot of Thumb 

Glacier is in Texas Creek granodiorite. The head of Thumb Creek 

Valley is in the Hyder quartz monzonite. The. boundary of the 

Texas Creek granodiorite strikes northwest along the east side of the 

valley of Ked Glacier and crosses Thumb Creek, then just below the 

foot of Gray Glacier it swings more toward the west, crosses Thumb 

Creek at the head of Ferguson Glacier, and continues nearly along 

the crest of the ridge to a point about 2 miles to the west, where it 

turns north and then a little east of north to a point on the west side 

of Ferguson Glacier about three-quarters of a mile from its foot, at 

an altitude of about 3,000 feet.

West of an approximately north-south line passing through the 

head of Ferguson Glacier, Casey Glacier, and Ibex Gulch the Texas 

Creek granodiorite plunges beneath a roof of tuffaceous graywacke 

arid slate and is exposed only on the slopes and int the bottom of the 

valleys of Ferguson Glacier and the West Fork, which have been 

eroded below the level of the roof of the batholith, and locally farther west where upward bulges or cupolas of the batholith have been 

partly unroofed or trenched in the valleys of Texas and Chickamin 

Glaciers.

From the west side of Ferguson Glacier the contact between the 

Texas Creek granodiorite and the tuffaceous graywacke strikes west
24 GEOLOGY OF HYDEB AND VICINITY, SOUTHEASTERN ALASKA

and rises to 3,300 feet on the slope facing the West Fork and to 3,600 

feet on the east side of the first small glacier west of Ferguson 

Glacier. It drops to about 3,500 feet where it crosses very near the 

foot of this glacier, and then rises to about 3,800 feet or a little more 

on the spur between the two small glaciers, again dropping where it 

crosses the second glacier. On the ridge west of the second glacier 

the, contact is at about 3,900 feet. In the second gulch farther west 

the contact descends abruptly to an altitude of about 3,340 feet and 

then.swings northwest around the west spur, descending to about 

2,600 feet in the gulch southwest of Blasher's cabin. It then strikes 

west to the bend of Chickamin Glacier, at an altitude of about 

2,350 feet.

North of the West Fork the boundary of the granodiorite is at an 

altitude of about 2,400 feet near the east end of Disappearing Lake. 

From this point it strikes a little north of east along the slope and 

reaches an altitude of about 3,650 feet on the shoulder between Ibex 

Creek and the West Fork, just south of the Ibex tunnel. It swings 

north up the west slope of Ibex Creek, passing about 125 feet below 

the Ibex tunnel. Above the head of Ibex Gulch it passes beneath 

Texas Glacier at ,an altitude of about 4,500 feet.

Cupolas of the Texas Creek batholith are exposed on the west side 

of Texas Glacier near its junction with the Chickamin; on the east 

side of Chickamin Glacier about half a mile north of Disappearing 

Lake; on the west side of Chickamin Glacier 11/4 to 2 miles north of 

the turn; and on the north side of Chickamin Glacier in the vicinity 

of the creek about V/2 miles west of the turn. None of these cupolas 

reach an altitude much above 3,500 feet, and at the level of exposure 

they are small in diameter.

The Texas Creek granodiorite forms the south slope of the ridge 

north of Texas Glacier for about 3 miles west of the international 

boundary. It is bordered oji the west and north by the Boundary 

granodiorite, which is intrusive into it, except where a narrow baml 

of argillite about a mile long intervenes, capping the ridge just above 

the shoulder that produces the impassable crevasses in Texas Glacier 

about 2 miles above its foot. Just west of the international boundary 

the Boundary granodiorite comes down as low as 3,300 feet. The 

Texas Creek granodiorite forms the low pass between Texas and 

Salmon Glaciers and the north slope of the pass up to the contact 

with the Boundary granodiorite at an altitude of 3,300 to 4,000 feet. 

The contact between the Boundary and Texas Creek granodiorites 

turns at about the international boundary and approximately parallels it, passing a little to the west of the peak of Mount Bayard. 

The lower part of the south side of the valley of Boundary Glacier 

is in Texas Creek granodiorite.
U. S. GEOLOGICAL SURVEY BULLETIN 807 PLATE 7

A. FOOT OF SALMON GLACIER AND TUNNEL FROM WHICH SALMON RIVER

EMERGES

S. VIEW UP BOUNDARY GLACIER FROM MORAINE ON SALMON GLACIER
U. S. GEOLOGICAL SURVEY BULLETIN 807 PLATE 8

A. FERGUSON GLACIER FROM TOP OF RIDGE ON THE NORTH SIDE OF WEST 

FORK OF TEXAS CREEK

B. GLACIER OCCUPYING CIRQUE ON THE WEST SIDE OF THROUGH GLACIER
TJ. S. GEOLOGICAL SURVEY BULLETIN 807 PLATE 9

A. CHICKAMIN GLACIER, IN LEFT FOREGROUND; THROUGH GLACIER, IN CENTRAL BACKGROUND; AND CHICKAMIN VALLEY, AT EXTREME RIGHT

It. MOUNTAIN'S OF TITK COAST RANGE 

A "fretted upland "; view looking west from the upper end of Ferguson Glacier
U. S. GEOLOGICAL SURVEY BULLETIN 807 PLATE 10

A. GLACIERS ON SOUTH SIDE OF WEST FORK OF TEXAS CREEK WEST OF 

FERGUSON GLACIER

Black line marks contact between Texas Creek granodiorite below and rocks of Hazelton group

above

S VALLEY OF INDIAN CREEK, LOOKING TOWARD CHICKAMIN RIVER VALLEY
COAST RANGE INTRUSIVES 25

The eastern contact of the Texas Creek granodiorite with the rocks 

of the Hazelton group probably lies beneath Salmon Glacier. For a 

mile below the foot of Salmon Glacier the contact follows the valley 

of Salmon River; then it makes a jog to the west across the pass between Salmon River and Texas Creek and extends along the west 

side of Mineral Hill to a point about half a mile north of the south 

end of the hill; here it turns southeast and strikes across Salmon 

River to a point about half a mile above the Salmon River bridge, 

whence it strikes southwest for a quarter of ,a mile to an altitude of 

about 850 feet, then turns and strikes southeast for a mile to an altitude of about 3,100 feet on the west slope of Bear River Ridge. It 

then turns a little west of south and with several small jogs through 

the Fish Creek and Mountain View mining properties strikes approximately along the valley of Skookum Creek and the lower part 

of Fish Creek to a point about 1% miles above the Salmon River 

road. It then turns at right angles and strikes up the mountain side 

until it is cut off by the Hyder quartz monzonite at an altitude of 

about 3,500 feet.

GRANODIORITE CORE

The core of the Texas Creek batholith occupies the area from Texas 

Glacier on the north to the contact with the Hyder quartz monzonite, 

south of Thumb Creek. Its approximate western border is a line 

through the shoulder east of the intersection of the Homestake and 

West Fork trails, Casey Glacier, and the head of Ferguson Glacier; 

from this line it extends east to Texas Creek and Salmon River and 

up the lower part of the slope of Bear River Ridge. The rock forming this "core is in general a medium-grained porphyritic rock with 

large phenocrysts and is dull greenish gray to light gray, mottled 

with black. The phenocrysts, which usually form several per cent 

of the rock, are crystals of dull-pink orthoclase 1 to 3 centimeters in 

length. The rock nearly everywhere shows abundant black prisms 

of hornblende as much as 1 centimeter in length, many of them oriented in common planes so as to give a gneissic structure or grain to 

the rock. The large crystals of orthoclase are also usually oriented 

with their longer diameter parallel to the gneissic structure. Rarely 

the rock is almost free of dark minerals. Some of the granodiorite 

has a distinctly greenish hue due to mashing and chloritization, or a 

pale yellowish green hue due to epidotic alteration.

The average composition of 20 specimens from the core of the Texas 

Creek batholith, as determined by the Rosiwal method, is given as 

No. 1 in the following table. The relative percentages of hornblende 

and biotite are difficult of determination, owing to the extensive alterations which the ferromagnesian minerals have suffered. It is prob6196 29 3
26 GEOLOGY OP HYDER AND VICINITY, SOUTHEASTERN ALASKA

able, however, that the biotite ranges from 2 to 5 per cent and that 

the ferromagnesian minerals are predominantly hornblende.

Mineral composition of Coast Range wtrusvve rooks in the Hyder Mstrict

1

2

3

4

5

6

7

8

9

10

TEXAS CHEEK GBANODIORITE

Average of 20 specimens from core of

batholith. .............................

Average of 5 specimens from quartz dioContact facies of batholith, south side

HYDER QUARTZ MONZONITE

Average of 4 specimens from Salmon

River Valley north of Hyder _____

Average of 4 specimens taken along

Average of 8 specimens taken along

Chickamin River north of Indian

Creek... __ . ........................

Average of 2 specimens of contact facies

Average of 3 specimens of aplite associated with Hyder quartz monzonite...

BOUNDARY GRANODIORITE

Average of 5 specimens of Boundary

Aplite from dike at east end of ridge north

of Texas Creek... .....................

Andesine

48

fift

66

48

Ollgoclase

39

36

37

45

22

14.5

Potassic feldspar

20

5

11

30.5

34

33

30

43

17

50

Hornblende

 if

14

17.4

.15

4

7

Biotite

.5

.5

1.6

5

2.5

4.3

6

6

Quartz

1Q

20

4

91 7

24.5

24

14

35

19.5

34

Magnetite

0.

.75

.64

2

Accessory minerals

5

6

1.1

.3

.65

1

.5

.5

The plagioclase is a typical andesine. Andesine and hornblende 

(and biotite) appear to have been the first of the major minerals 

to crystallize. The andesine occurs in stout lath-shaped crystals 

of euhedral to subhedral form. The hornblende is in well-formed 

columnar crystals many of which show perfect euhedral cross sections.

The potassic feldspars include orthoclase, microcline, and microperthite. The microcline occurs predominantly in the groundmass, 

and the phenocrysts are usually orthoclase. The orthoclase phenocrysts inclose disseminated small euhedral crystals of hornblende and 

plagioclase, and the potassic feldspars in general occur interstitial 

to hornblende and andesine. The microperthite usually shows only 

a very slight amount of the plagioclase phase.

The quartz is in part contemporaneous with the other minerals 

and in part was the last mineral to crystallize and occurs interstitially.

The accessory minerals are usually sparse, and only here and 

there do they form as much as iy2 per cent of the rock. Titanite, 

magnetite, and apatite are the common ones. Pyrite is rarely present. Titanite and magnetite may each form as much as 1 per cent
COAST RANGE INTRUSIVES 27

of the rock. The titanite is in good euhedral crystals, some of 

which inclose small crystals of magnetite and apatite; it tends to 

occur predominantly within the quartz and potassic feldspars, suggesting that it belongs to the last half of the period of crystallization. The magnetite and apatite occur in groups of crystals and 

also as disseminated crystals in the hornblende.

The rock is usually more or less extensively altered. The hornblende and biotite are partly or completely altered to chlorite and 

epidote, with chlorite predominant. Near the contact with the 

Hyder quartz monzonite or the Boundary granodiorite the hornblende is commonly, replaced by an interlocking fine-grained aggregate of biotite. The plagioclase is usually altered to a sericitic 

aggregate or to an aggregate of sericite and epidote, with locally a 

little chlorite. The potassic feldspars are commonly fresh and unaltered. Veinlets of chlorite and calcite or of epidote and calcite 

traverse the minerals. Along such cracks local replacement of the 

potassic feldspars has occurred,

QUARTZ DIORITE BORDER FACIES °

The border facies of the Texas Creek batholith and the outlying 

stocks are usually medium-grained and nonporphyritic and contain 

less potassic feldspar than the core. West of the line through the 

shoulder east of the intersection of the Homestake and West Fork 

trails, Casey Glacier, and the head of Ferguson Glacier the rock is 

in general a medium-grained nonporphyritic quartz diorite. The 

outlying stocks to the west along Chickamin Glacier are believed 

to be quartz dior.ite also, though they have not been carefully studied, 

except locally.

The average composition of several specimens of quartz diorite 

from the head of West Fork is given in the table as No. 2. The 

rock differs from the granodiorites of the core in being nonporphyritic and in the marked relative .increase of plagioclase over 

potassic feldspar. The minerals have suffered extensive alteration 

similar to that in the granodiorite.

DIORITE CONTACT FACIES

Locally, immediately adjacent to the contact, the quartz diorite 

border facies passes into diorite or monzodiorite. An example 

of this transition is found on the mountain slope on the south side 

of the West Fork, just west of Casey Glacier, at an altitude of about 

4,550 feet. The composition of a specimen taken 20 feet from the 

contact is given in the table as No. 3. The marked features are a 

decrease in quartz and an increase in plagioclase and hornblende, 

as compared with the average rock farther away.
28 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA 

GRANODIORITE AND QUARTZ PORPHYRY DIKES

Adjacent to the borders of the main Texas Creek batholith there 

are outlying dikes and small masses of granodiorite porphyry that 

are genetically connected with this batholith. These dikes are gray 

and are characterized by large crystals of pink to white orthoclase 

in a fine-grained groundmass. There are a number of such masses 

in the sedimentary and volcanic rocks on the west slope of Bear 

Kiver Kidge. Quartz veins, locally metallized with shoots of ore, 

occur at many places along the contacts of these dikes or within or 

across them. There are, on the other hand, younger granodiorite 

porphyry dikes which are connected with the Hyder quartz monzonite 

and which cut the metalliferous quartz veins. These younger dikes 

are pink, are of much fresher and more massive appearance, and are 

in places finer grained and only inconspicuously porphyritic. The 

tunnel at the Titan prospect starts in a dike of the porphyry of the 

Texas Creek batholith.

A typical specimen of the porphyry from the dikes associated with 

the Texas batholith, as seen with the microscope, is found to consist 

of phenocrysts of plagioclase, orthoclase, hornblende, and rounded 

quartz in a dense groundmass of quartz and feldspar that consists in 

part of a micrographic intergrowth of the quartz and potassic feldspar crystals. The rock is usually highly altered; the plagioclase is 

mostly altered to sericitic aggregates with some epidote, and the hornblende and biotite to chlorite and epidote. Titanite, apatite, and 

magnetite are present as accessory minerals.

At a few localities dikes of quartz porphyry cut the rocks of the 

Texas Creek batholith and also the near-by sedimentary and volcanic 

rocks. These dikes are so much altered that their original nature 

can not be determined. They evidently consisted of phenocrysts of 

quartz and feldspar in a dense groundmass. The quartz is in euhedral crystals and unaltered, but the groundmass is partly altered to 

sericite, and the feldspar phenocrysts are almost wholly altered to 

aggregates of sericite and quartz. Sparse ferromagnesian minerals 

have been altered to chlorite and muscovite. In some of the freshest 

specimens of these dikes both orthoclase and plagioclase phenocrysts 

are present in addition to quartz; in others only remnants of 

plagioclase can be identified, and quartz phenocrysts are sparse. At 

the Cantu prospect on Salmon Glacier and at the upper workings of 

the Daly-Alaska mine such porphyry dikes are cut by metalliferous 

veins.

APLITE AND PEGMATITE

Aplite dikes are usually common within 500 or 600 feet of the roof 

or borders of the batholith. They tend to occur more abundantly 

and to extend farther from the contact in the country rock than in
COAST -RANGE INTRUSIVES 29

the batholith. As a rule, they are practically restricted to the immediate vicinity of the contacts of the batholith or its outlying stocks. 

The aplite is generally white and fine grained. A few of the dikes 

are shattered and veined and impregnated with sulphides. On the 

Mountain View property an aplite dike is impregnated with molybdenite, and on the Dugas claims, north of the West Fork, an aplite 

dike is veined and impregnated with pyrite, galena, and sphalerite. 

Pink aplite dikes are found in the Texas Creek batholith and the 

sediments and volcanic rocks of the Hazelton group, but these belong 

to the younger Hyder and Boundary batholiths.

The aplite dikes consist almost wholly of quartz, microperthite 

or microcline, and albite; but the proportions of these minerals are 

highly variable. Quartz ranges from a trace to 40 per cent, albite 

from 25 to 75 per cent, and potassic feldspar from 12 to 60 per 

cent. The more sodic varieties may be associated with the more sodic 

(quartz diorite) facies of the batholith, but further study would be 

necessary to verify this suggestion. The microperthite has only a 

very slight intergrowth of the plagioclase phase, and microcline is 

often present. Calcite is a very common secondary mineral facing 

fractures in the rock. Otherwise the rocks are fresh and chemically 

unaltered. Physically, however, they are severely mashed and locally 

pulverized.

The pegmatite dikes are relatively few and small and were not 

studied.

HYDER AND BOUNDARY BATHOLITHIC INTRUSIONS AND ASSOCIATED DIKES 

CHARACTER AND EXTENT

The rock about the town of Hyder is a quartz monzonite that forms 

a part of the eastern border of the main Coast Range batholith. 

The rock around the head of Boundary Glacier is a granodiorite that 

is either an apophysis or an outlying stock of the eastern border of 

the main Coast Range batholith. Both these intrusive masses send 

off dikes of granodiorite porphyry far into the surrounding country. Dikes of aplite and pegmatite, malchite, and lamprophyre cut 

the intrusive rocks as well as the sedimentary and volcanic rocks and 

are believed to have originated as late facies of the Hyder and Boundary batholithic magmas. The aplite and pegmatite dikes in general 

are not found in the country rock far from the contact of the main 

intrusive masses, but the malchite and lamprophyre dikes may occur 

a score of miles or more away.

HYDER aTIARTZ MONZONITE

The southern portion of the Salmon River area is formed entirely 

of quartz monzonite that is a part of the northeastern border section
30 GEOLOGY OP HYDEE AND VICINITY, SOUTHEASTERN- ALASKA

of the Coast Eange batholith. Between Portland Canal and Chickamin River it forms a belt 10 to 14 miles wide and about 25 miles 

long. On the south it is bordered by the granodiorite of the core of 

the main Coast Eange batholith.

This rock is here named the Hyder quartz monzonite, as it is well, 

exposed at Hyder and along the Salmon Eiver road as far north as 

Fish Creek. On the east side of Portland Canal, in British 

Columbia, the Hyder quartz monzonite appears to form the coast 

line, though the Texas Creek (?) granodiorite and the sedimentary 

and volcanic rocks of the Hazelton group form the mountains farther 

back. On the Marmot River trail to the Porter-Idaho property the 

Hyder quartz monzonite occurs up to the first bench, and a rock 

resembling the Texas Creek granodiorite thence up to an altitude 

of 2,000 feet. The contact of the Hyder batholith appears to strike 

a little east of north for about 2% miles, and to lie just back from 

the coast line. At the international boundary on Mount Dolly the 

contact strikes a little north of west at an altitude of about 4,700 

feet. It lies at about 4,800 feet on the south slope of Mount Dolly 

and runs almost due west, crossing the Salmon River road just 

north of Fish Creek. It probably keeps to the ridge on the south 

side of Thumb Creek Valley as far west as Red Glacier. The head 

of the valley of Thumb Creek is in the Hyder quartz monzonite, and 

the contact with the Texas Creek granodiorite strikes northwest 

across the valley about three-quarters of a mile from the foot of 

Thumb Glacier, then north-northwest to the head of Ferguson 

Glacier, follows the crest of the ridge between Ferguson and Greenpoint Glaciers for about 3 miles, and then strikes west across the 

glacier to the northern part of the ridge between Through and 

Greenpoint Glaciers. The contact on this ridge is at an altitude of 

about 4,000 feet. It has not been traced farther, but in general it 

strikes west to Chickamin River at a point about 4 miles below the 

present foot of Chickamin Glacier. The heads of Greenpoint and 

Through Glaciers are both in quartz monzonite. To the south the 

Hyder quartz monzonite passes into the granodiorite or interbanded 

granodiorite and quartz monzonite that forms most of the core of 

the Coast Range batholith.

The Hyder quartz monzonite is essentially a massive mediumgrained rock with a very inconspicuous gneissic structure due to the 

aUnement of bio.tite crystals. The rock on fresh surfaces is light pink 

to white and is sprinkled with small black biotite crystals. A few 

minute honey-colored titanite crystals can usually be distinguished. 

Quartz and feldspar form practically all of the rock. The average 

composition of four specimens from the vicinity of Hyder and 

the Salmon River road to the north, four taken along Greenpoint
COAST RANGE IBTTRUSIVES 31

Glacier, and eight taken along Chickamin River north of Indian 

Creek is given in the table on page 26 as Nos. 4, 5, and 6, 

respectively.

The plagioclase is conspicuously zoned and is often found in 

euhedral crystals. Many of the smaller crystals are inclosed in the 

potassic feldspar. Locally, the plagioclase is replaced to a trifling 

extent by sericite. The tendency of the plagioclase to occur in euhedral forms is in part due to its early crystallization but is probably 

due also to a very considerable extent to its strong crystallization 

forces.

The feri'omagnesian minerals are represented almost exclusively 

by biotite. Rarely a little hornblende is present. The biotite tends 

to occur irregularly segregated in streaks, often with several crystals 

grouped together. The individual crystals are chunky and are 

locally corroded on the edges by potassic and plagioclase feldspars 

or quartz. They appear to have started crystallization later than 

some of the plagioclase but to be contemporaneous with much of it. 

Here and there a crystal of biotite is inclosed in the plagioclase and 

is corroded by it. A few crystals of biotite have thin leaves of 

chlorite .hxtergrown parallel to the cleavage as a result of alteration. 

In a few places the biotite is completely altered to chlorite with a 

trace of epidote.

The potassic feldspars include microcline with a well-developed 

gridiron structure, microperthite with only a slight amount of the 

plagioclase phase, and a clear feldspar that may be orthoclase but is 

probably microcline. The potassic feldspar occurs in grains of about 

the same size as the plagioclase, but it does not show good crystal 

faces as often, and it includes small crystals of_ plagioclase. It 

therefore must have begun crystallization somewhat later than the 

plagioclase, but it is in major part contemporaneous. The accessory 

and f erromagnesian minerals occur commonly inclosed in the potash 

feldspar.

The accessory minerals are in small euhedral crystals. In part 

they tend to be segregated together and to be associated with the 

ferromagnesian minerals, within which they may occur, and in part 

they tend to occur at the borders between the quartz and feldspar. 

Such relations suggest that their period of crystallization was long, 

starting early and finishing late. Locally apatite crystals are 

inclosed in magnetite and both in titanite. The magnetite crystals 

commonly occur in groups of as many as a score, some separate, some 

impinging, and some interfering with one another.

The quartz is for the most part in grains of size similar to the 

feldspars and of the same period of crystallization; but in part it 

was the last mineral to finish crystallization. Much of it shows 

strain shadows and incipient crushing.
32 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

Locally the minerals are considerably crushed and reduced to a 

granular aggregate. Practically no hydrothermal alteration accompanied this mashing.

BOUNDARY GRANODIORITE

A mass of granodiorite forms the northeast corner of the Salmon 

Biver area between the top of the ridge north of the eastern part of 

Texas Glacier and the international boundary. The eastern border 

of this mass appears to coincide almost exactly with the international 

boundary and to pass just west of the peak of Mount Bayard. 

The rock is well exposed along both sides of Boundary Glacier at 

its head and to a point about a mile above its foot, also on the top 

of the ridge north of the eastern part of Texas Glacier. It is therefore here named the Boundary granodiorite.

This granodiorite is medium grained, and on the fresh surface it 

is seen to be composed predominantly of white plagioclase with 

scattered grains of pink orthoclase, glassy quartz, crystals of black 

biotite and hornblende, and sparse minute crystals of yellowishbrown titanite. Epidote faces some fractures in the rock. In contrast to the older Texas Creek granodiorite, into which it is intrusive 

and with which it may be confused, the Boundary granodiorite is 

much more massive, is lighter colored, with a pinkish hue, and 

contains conspicuous biotite plates. The rock exposed on the Canadian side along the lower part of Boundary Glacier is the Texas 

Creek granodiorite. The average composition of five specimens of 

granodiorite, as determined in this section, is given in the table as 

No. 9.

Narrow greenrgray and dark-gray dikes of sparsely porphyritic 

malchite and of pink aplite are common in the Boundary granodiorite and are locally very abundant near the southern and eastern 

boundaries on the ridge north of Texas Glacier. The malchite dikes 

strike in general northwest.

Biotite and hornblende both occur as euhedral crystals, locally 

slightly replaced and corroded on the borders by the feldspars or 

split by the feldspars and quartz. The plagioclase is zoned, but its 

average composition is about that of a typical andesine. It is in 

part contemporaneous with the ferromagnesian minerals, and in part 

its period of crystallization overlapped, beginning slightly earlier 

and finishing later. The potassic feldspar contains included crystals 

of plagioclase, hornblende, and biotite and occurs in part interstitial 

to the plagioclase. It contains a small amount of plagioclase in 

microperthitic intergrowth. The quartz overlaps the microperthite 

in its period of crystallization. The apatite tends to be associated 

in considerable degree with the magnetite and in part occurs as
COAST RANGE INTBUSIVES 33

crystals included in the magnetite. Titanite crystals are sparsely 

disseminated through the rock, and a few of them include crystals 

of apatite and magnetite. They are present both as euhedral crystals 

and as rounded grains. Rarely a trace of zircon is present. Chlorite 

and magnetite secondary after the ferromagnesian minerals are 

locally common. Sparse grains of secondary epidote are usually present. The chlorite in part has the appearance of being intergrown 

with the biotite.

The geology of the area north of the international boundary has 

not been studied, so that it is not known whether the Boundary granodiorite forms an apophysis from the main Coast Range batholith 

or is a separate stock. In either case it represents a less advanced 

stage of differentiation than the Hyder quartz monzonite.

GRANODIORITE PORPHYRY DIKES

Light-colored dikes, genetically associated with the Hyder quartz 

monzonite here collectively grouped as granodiorite porphyry dikes, 

are common and locally abundant everywhere throughout the Texas 

Creek granodiorite and the sedimentary and volcanic rocks of the 

Hazelton group of this district, except in a belt between Casey Glacier 

and the ridge top between Ferguson and Greenpoint Glaciers and 

west of the Salmon River between the ridge at the heads of Ferguson, 

Casey, and Hidden Glaciers and a line within a mile of the southern 

boundary of the Texas Creek granodiorite in the western half and 

within 2 miles of the boundary in the eastern half. They are abundant within a belt 1% miles wide along the southern border of the 

Boundary granodiorite. Many of these dikes are exposed along the 

Salmon River road north of the mouth of Fish Creek and along the 

international boundary on the bare ridge extending north from Mount 

Dolly. The cream-colored bands which from a distance are seen 

to cut across Mount Dolly in such conspicuous fashion are the granodiorite porphyry dikes. They cut across the zones of rusty-weathering rock impregnated with iron sulphide but are not themselves 

affected by the metallization. More than a dozen large dikes are 

exposed along the Salmon River road between the bridge at Ninemile 

and the international boundary.

The granodiorite porphyry dikes range in width from 10 to 1,200 

feet and have in general a northwest strike, usually between N. 20° 

W. and N. 70° W., though here and there they strike northeast. 

Along the international boundary they dip in general 45°-60° SW.

At some places there are dikes 10 feet or less in width of a finegrained, inconspicuously porphyritic dark-gray rock. The narrower 

granodiorite porphyry dikes usually show borders of similar rock. 

These dark-gray dikes and borders are less siliceous and alkalic than
34 GEOLOGY OF HYDEB AND VICINITY, SOUTHEASTERN ALASKA

the granodiorite porphyry and have the composition of a typical 

diorite or a quartzose diorite. A number of such dikes are shown on 

the map by Schofield and Hanson 10 of the adjoining Salmon River 

area in British Columbia, where they are termed granite dikes; they 

are described more specifically as quartz diorite dikes. These dikes 

also show the persistent northwest strike.

The granodiorite porphyry is much more resistant to weathering 

than the country rock, so that the percentage of boulders of rock of 

this type found in glacial moraines or stream gravel may give a misleading impression of the relative extent of these dikes in the drainage area from which the fragments have come. The boulders are, for 

instance, very abundant in the material brought down by Texas 

Glacier, though they are not unusually abundant in the country along 

the course of the glacier. Furthermore, they tend to weather out in 

relief, so that below timber line in that part of the country covered 

by vegetation they may form the predominant outcrops. This is conspicuously the case on Mineral Hill, where most of the exposed bluffs 

and outcrops are of the granodiorite porphyry dikes, which are not 

representative of the country rock.

The granodiorite porphyries are pink to white or light gray and, 

owing to the abundance of plagioclase phenocrysts, they resemble 

granodiorite in appearance. In hand specimens the rock is characterized by the presence of biotite or hornblende crystals, or both, and 

occasionally orthoclase or quartz may be distinguished. The interstitial groundmass is dense to fine grained. The plagioclase phenocrysts are 1 to 2y2 millimeters in diameter. Under the microscope 

the plagioclase shows a zonal character, but its average composition 

is about that of andesine. In the dikes that have been somewhat 

quickly chilled plagioclase forms the predominant phenocrysts, with 

associated biotite, hornblende, and a little magnetite and apatite. In 

a more coarsely crystalline type orthoclase and quartz and locally 

titanite occur as phenocrysts in addition to the other minerals mentioned. The biotite and hornblende are partly or completely altered 

to chlorite, with a few associated grains of epidote and secondary 

magnetite.

The groundmass consists usually of a micrographic intergrowth 

of quartz and potassic feldspar or a microgranitic aggregate of 

quartz, potassic feldspar, and plagioclase. The composition of the 

rocks may vary toward a diorite or quartz diorite porphyry, on the 

one hand, or toward a granite porphyry, on the other hand. Calcite veinlets commonly traverse the rock and locally replace it. The 

plagioclase crystals are in local portions partly altered to sericite.

10 Schofleld, S. J., and Hanson, George, op. cit., p. 26 and map.
COAST RANGE INTRUSIVES 35 

APLITE AND PEGMATITE

Aplite dikes are present but not abundant in the Hyder quartz 

monzonite and in the adjacent country rock. The aplite is fine 

grained and has a characteristic pink hue. It consists of the same 

minerals as the quartz monzonite but in different proportions. The 

percentage of quartz and potassic feldspar is much higher in the 

aplite than in the quartz monzonite. The dikes are fresh and unaltered and thus are in marked contrast to the aplite dikes associated 

with the Texas Creek batholith, which are shattered and crushed. 

In thin section the aplite shows a hypidiomorphic granular aggregate 

of microcline, in part with a trace of microperthitic intergrowth, 

rounded quartz grains, and subhedral plagioclase. A trace of biotite 

is locally present. Accessory minerals are sparse; the most common 

is magnetite. The average composition of three specimens is given 

in the table on page 26 as No. 8.

Small dikes of pink fine-grained aplite are abundant in the Boundary granodiorite near the south contact. Only one was examined. 

Its composition, as shown by No. 10, is very similar to that of the 

aplite associated with the Hyder quartz monzonite (No. 8).

MALCHITE DIKES

Dikes of a green-gray or medium to dark gray rock of felsitic to 

sparsely porphyritic felsitic texture cut the sedimentary and volcanic 

rocks, the Texas Creek granodiorite, the ore veins, the Boundary 

granodiorite, the Hyder quartz monzonite, and the granodiorite porphyry dikes that are genetically connected with the Boundary granodiorite and the Hyder quartz monzonite. Rock of similar appearance is found here and there as a chilled border zone along each 

side of the granodiorite porphyry dikes. The dikes must therefore 

be of two ages. Barely the rock has a greenish-gray hue, and there 

is scarcely any ferromagnesian mineral present. A dike of this 

kind cuts both granodiorite porphyry of the Boundary type and the 

ore vein at the Ibex prospect. The rocks are the same as those 

which have been described by Westgate 11 as diorite porphyry, and 

by Buddington 12 as andesite porphyry and are in part the same as 

those described by Schofield and Htanson 18 as lamprophyre.

The writer is here adopting the name malchite for these dark to 

medium gray dike rocks because (1) they are not sufficiently coarse 

grained to satisfy the requirements for a typical diorite porphyry; 

(2) the term andesite porphyry is undesirable, as it commonly sug11 Westgate, L. G., op. cit, pp. 126-127.

12 Buddington, A. F., Mineral investigations in southeastern Alaska: U. S. Geol. Survey 

Bull. 773, p. 86, 1925.

13 Schofleld, S. J., and Hanson, George, op. cit., p. 27.
36 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

gests an association with volcanic extrusives, whereas these dikes 

are definitely associated with batholithic intrusives; (3) more typical lamprophyre dikes are also present, and it appears preferable 

to restrict the use of that term to such dikes; (4) the rocks correspond in part to typical malchite, which is defined as a microdiorite in which phenocrysts are not conspicuous. In some of the 

dikes, however, the hornblende has a brownish-green hue and the 

rocks grade toward a lamprophyre.

When examined microscopically the malchite is seen to consist 

typically of small phenocrysts of plagioclase, or rarely of plagioclase 

and hornblende, in a felsitic groundmass composed of a mat of 

plagioclase laths with subordinate hornblende rods and a little interstitial quartz and potassic feldspar. Abundant minute crystals of 

magnetite are distributed throughout the groundmass. Apatite is 

occasionally seen. The hornblende is, as a rule, partly or completely 

altered to chlorite, commonly with a little associated epidote and 

calcite, and the plagioclase is in places slightly sericitized. Pyrite 

in well-formed crystals occurs locally along fractures in some of 

the dikes.

The variety of plagioclase is difficult to determine but appears to 

range from an albite-oligoclase to andesine. Rarely a little biotite is 

present. The hornblende in some of the freshest dikes has a brownish-green hue. Hornblende or its alteration products form usually 

less than 25 per cent of the rock.

LAMPROPHYRE DIKES

The lamprophyre dikes are dark-green to gray-black rocks of fine 

grain, which cut both the batholithic intrusive masses and the country 

rock. With the possible exception of certain basaltic dikes they are 

the youngest intrusive rocks in the district. The most common type 

of lamprophyre in this district belongs to the spessartite group. 

Spessartite is typically composed of brown or basaltic hornblende 

and plagioclase feldspar with some pyroxene. In this district the 

feldspar is almost wholly the oligoclase or andesine variety of plagioclase, locally with some labradorite. Plagioclase appears to be more 

abundant in most of the spessartite of this area than is typical elsewhere, and to this extent the rock varies toward malchite. Hornblende may form only 10 to 30 per cent of the rock, but types in 

which the hornblende forms 30 to 50 per cent are also common. Here 

and there the hornblende occurs as long black rods in a fine-grained 

groundmass and gives to the rock a prorphyritic aspect.

The predominant type of lamprophyre consists of long prismatic 

rodlike crystals of brown hornblende with or without a few crystals 

of augite in a groundmass formed by a felt of oligoclase or andesine
COAST BANGE IFTEUSIVES 37

laths with or without associated rods of brown hornblende. In 

places a little biotite is present. Magnetite is usually present as 

abundant disseminated small crystals, and apatite in long, slender 

rods. Titanite is found in a few specimens. There is commonly a 

trace of interstitial quartz. Secondary minerals due to alteration 

are invariably present and may be very prominent; they comprise 

calcite, chlorite, and epidote. Calcite is usually abundant in the 

groundmass, and much of it shows replacement relations to the other 

minerals, but in part it is interstitial to the plagioclase crystals and 

is molded against them. It probably belongs to a late magmatic 

stage and an early phase of alteration.

BASALTIC DIKES

Near the head of Casey Glacier, on the west side, at an altitude of 

about 4,300 feet, there are dark basaltic dikes in the Texas Creek 

granodiorite. One of these consists of labradorite and augite with 

some interstitial altered greenish glass and small phenocrysts of labradorite. This rock is not a typical lamprophyre and is probably of 

Tertiary or Quaternary age.

CONTACT METAMORPHISM 

TEXAS CREEK INTRUSIVES

One of the most amazing features of the geology of this district 

is the almost complete failure of the Texas Creek intrusives to produce 

any observable contact metamorphism in the country rock. This is 

the more striking when contrasted with the contact-metamorphic 

effects which the Boundary granodior,ite, the Hyder quartz monzonite, and their associated porphyry dikes have produced in .the 

same kind of country rock and in the Texas Creek granodiorite 

itself. The writer could see little or no difference between the slate 

and graywacke immediately in contact with the roof of the batholith and that several thousand feet above. In the vicinity of the 

Kiverside mine, however, there are slabs and fragments of schist 

included in the Texas Creek batholi.th. These appear to consist of 

thin intrusive sheets of a porphyritic facies of the Texas Creek 

granodiorite alternating with thin layers of recrystallized sedimentary or tuffaceous material. Subsequent movement has been localized along some of these layers so .that the porphyritic schist has 

been puckered and plicated and the minerals crushed. The Lindeborg vein on the Riverside propertj'- is in such a schist band. In 

thin section the schist is found to consist of phenocrysts of oligoclase 

and quartz and rare hornblende in a microcrystalline groundmass 

of quartz and feldspar. There is considerable secondary epidote, 

chlorite, calcite, and sericite.
38 GEOLOGY OP HYDER AND VICINITY, SOUTHEASTERN ALASKA 

HYDER AND BOUNDARY INTRTTSIVES

The Hyder quartz monzonite, the Boundary granodiorite, and 

their associated dikes in the older country rock have locally produced contact metamorphism. Mechanical, thermal, and hydrothermal alterations and replacements have been effected. The chemical me.tamorphism, though noteworthy, is nevertheless not comparable with what might be expected along the contact of so large 

a body as the Coast Kange batholith or even the Hyder quartz 

monzonite portion of it.

The pressure and thrust attendant upon the intrusion of the Hyder 

quartz monzonite magma, with the resultant mashing, have produced schist, gneiss, and augen gneiss from the Texas Creek intrusive 

rocks where they border the younger igneous mass. This mechanical 

mashing of the Texas Creek rocks may or may not be accompanied 

by hydrothermal alterations of the minerals. Some of the rock 

shows merely the effects of mechanical crushing, pulverization of 

the minerals, v and production of mortar structure, without noteworthy alteration. At most places the plagioclase feldspars are 

partly or completely altered to epidotic aggregates or to sericitic or 

muscovitic aggregates with a little associated chlorite and epidote, 

and the hornblende is altered to aggregates of fine flaky biotite with 

some associated epidote, chlorite, magnetite, and sericite. Usually a 

little calcite is present. Generally there are numerous schistosity 

planes, parallel to which streaks or bands of chlorite or epidote or 

both replace or vein the rock. Rarely a little garnet is associated 

with the epidote, and a few grains of green spinel (hercynite) and 

chloritoid have been found with the chlorite. Usually a little magnetite is associated with the chlorite. The potash feldspars are 

uniformly fresh and unaltered.

On the west slope of Mount Dolly solutions from the Hyder quartz 

monzonite magma have locally produced high-temperatur^ alterations for a distance of V/2 miles north of the present contact. The 

greenstone and graywacke are locally banded with epidote, and 

there are quartz lenses and veinings, both parallel and across the 

bedding, which carry associated garnet and epidote and in places a 

little chalcopyrite. To the north, on Bear River Ridge, there are a 

number of granodiorite porphyry dikes, which are offshoots from 

the Hyder quartz monzonite. Locally, in the greenstone adjoining 

the dikes, there are fractures along which the rock has been altered 

to epidote, with which are commonly associated pockets of crystalline 

hematite (specularite).

On the north side of Greenpoint Glacier the contact between the 

graywacke and Hyder quartz monzonite is exposed in a gulch. Here 

graywacke is much disturbed and metamorphosed. Epidote, horn-
SUPERFICIAL DEPOSITS 39

blende, and garnet are common. The quartz monzonite adjacent to 

the contact is white and contains gash veins a few inches long with 

disseminated chalcopyrite, also small fracture surfaces faced with 

molybdenite. On the mountain slope northeast of Greenpoint 

Glacier the slate has a pencil structure in the vicinity of the contact 

with the Hyder quartz monzonite.

On Chickamin River the slate is changed to crinkled phyllite near 

the contact, and both graywacke and slate are predominantly hornblendic, chloritic, and locally biotitic. Quartz veins, in part with 

garnet and chlorite parallel to the schistosity, are common. The 

Boundary granodiorite and its associated dikes have caused the 

argillite in the band on the top of the ridge north of Texas Creek to 

be metamorphosed to tactite. There are great irregular masses and 

veinlets of epidote, garnet, and pyroxene, and abundant small veinlets of quartz, calcite, and unidentified minerals.

SUPERFICIAL DEPOSITS 

PLEISTOCENE AND RECENT DEPOSITS

A considerable part of the area, particularly along the lower 

slopes, is covered with glacial drift, and glacial erratic boulders arot 

common.

Along the Salmon River road between the Daly-Alaska camp and 

the international boundary there is a series of beds of interlaminated 

clay and fine sand up to an altitude of about 450 feet, which pass into 

and are overlain by gravel and sand toward the boundary. Pebbles 

and boulders are scattered here and there through the sand and 

clay. On the west side of Salmon River, about opposite the DalyAlaska camp, there is a bench crossed by the Premier tramway at an 

altitude of about 600 feet. This bench is underlain by bedded gravel 

corresponding to that on the east side of the river a little to the north. 

McConnell 14 found stratified clay and sand at an altitude of 500 feet 

at Bear Lake on Bear River. Fossiliferous beds with a marine fauna 

were found by him at an altitude of 345 feet. These beds indicate 

post glacial uplift of as much as 500 feet.

In the valley of Thumb Creek above the rock gorge there are 

benches of boulder gravel at an altitude of about 1,000 feet, in which 

the creek has cut a deep valley. These gravel benches appear to be 

older river deposits which have been trenched by the creek during 

its canyon-cutting activities consequent upon the uplift of the area.

Remnants of bench gravel are also found locally along the West 

Fork of Texas Creek and a few of its tributaries. On the trail west 

of the cable crossing coarse waterworn bedded gravel occurs at an

14 McConnell, R. G., Portions of Portland Canal and Skeena mining divisions, Skeena 

district, B. C.: Canada Geol. Survey Mein. 32, p. 22, 1913.
40 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

altitude of 700 feet, and along the valley of Ibex Creek there v are 

deposits of bench gravel that have been deeply dissected by recent 

erosion.

Salmon River and Texas Creek are depositing great quantities of 

gravel upon the floors of their valleys, except in the gorge of Salmon 

River just above Cascade Creek, and Salmon River is building forward a delta into the head of Portland Canal. The upper valleys of 

Thumb Creek and the West Fork and of their main tributaries below 

the points where these streams emerge from the glaciers are likewise 

being aggraded with gravel deposits. Terminal and lateral moraines are being formed at the borders and sides of the many glaciers. Talus accumulations and landslide aggregates are common at 

the foot of the steeper mountain slopes.

STRUCTURE 

BEDDED ROCKS

Most of the bedded rocks within this area have an approximate 

east-west strike, but two narrow belts of bedded rock with an approximate north-south strike were noted. One of these is high on Bear 

River Ridge opposite the mouth of Thumb Creek, and the other, which 

comprises slate interlayered with graywacke and greenstone, extends 

north, with some interruptions, from a point southwest of the upper 

workings of the Daly-Alaska claim to the Doggat claims on the Salmon River road. Superimposed on the greenstones east of Salmon 

River, however, there is a schistose structure which trends N. 70°-90° 

W. The beds of tuffaceous graywacke and slate in the southern part 

of this belt of bedded and volcanic rocks east of Salmon River also 

have a strike that ranges from N. 80° E. to N. 75° W. The foliation 

of some of the porphyry dikes associated with the Texas Creek granodiorite in this belt likewise has an approximately east-west trend. 

O'Neill 15 describes the shearing near the Premier mine as striking 

nearly due east.

In the vicinity of Chickamin Glacier and its tributaries and of the 

upper part of the West Fork the beds are closely folded, with uniform dips to the south on the south and west and to the north on 

the north. The major structure appears to consist of an anticlinal 

axis on which the graywacke of the south slope of the West Fork is 

exposed; a syncline overturned toward the north, in which the slate 

of the northeast slope of the valley of Greenpoirit Glacier is infolded 

in the graywacke; and a syncline overturned toward the south, in 

which the slaty argillite of the ridge north of the West Fork and 

along Texas Glacier is infolded in the graywacke. Along the west

15 O'Neill, J. J., Salmon River district: Canada Geol. Survey Summary Rept. for 1919, 

pt. B, p. 9, 1920.
STRUCTURE 41

side of Chickamin Glacier and along Through Glacier the beds dip 

almost uniformly to the south, except for minor local drag folds. 

These beds form the roof of the Texas Creek batholith, which here 

plunges to the west, and they are cut off down the dip by the batholithic rock. The strike of the beds ranges prevalently from N. 60° 

W. to N. TO 0 E., with a general trend of about N. 80° E.

In the north half of the area between Casey and Ferguson Glaciers 

the strike of the beds ranges from N. 25° E. on the east to N. 60° E. 

on the west, and the dip is almost vertical. In the southern half of 

this area the beds on the west strike N. 65°-90° E. and dip 60° N. to 

vertical. In the vicinity of the small glaciers just west of Ferguson 

Glacier, as far west as the west side of the second glacier, the beds 

strike N. 75°-85° E. and dip 55°-90° S. From this point to Through 

Glacier the beds strike N. 55°-75° W. and dip 40°-60° S. On the 

west side of Through Glacier the strikers N. 50°-70° W. and the 

dip 40°-70° S. On the west side of Chickamin Glacier, south of the 

conspicuous gulch just below the ice cascades, the beds strike N. 70°- 

90° E. and dip 25°-75° S.; north of the gulch tne beds strike N. 

60°-70° W. and dip 30°-65° S. On the west end of the ridge between the West Fork and Texas Glacier the beds strike N. 70°-95° E. 

and dip 45°-90° both north and south; at the east end of this ridge 

the strike is N. 75°-90° W. and the dip usually vertical. Only a 

few observations were made in the mountains north of Texas Glacier, 

but the prevalent dip appears to be north.

TEXAS CREEK BATHOLITH

In the part of the Texas Creek batholith east of Salmon River the 

strike of the gneissic banding varies between N. 80° E. and N. 80° W. 

with an average about east-west. Between Salmon Eiver and Chickamin Glacier the strike of the banding is N. 50°-90° E., with N. 60°- 

70° E. very common, and an average of N. 67° E. for 17 observations. 

In the outlying mass of Texas Creek quartz diorite bordering Chickamin Glacier the strike of the foliation is N. 50°-55° E.

The Texas Creek grano diorite is mashed to a schist along its 

southern contact with the Hyder quartz monzonite. To the north 

this schistose facies grades through an augen gneiss into the normal 

porphyritic granodiorite, which has gneissoid structure resulting 

largely from orientation of the minerals during a stage when the 

rock was not yet completely consolidated. Microscopic examination 

of the schist and augen gneiss, on the other hand, shows that they 

have resulted from the mechanical crushing and pulverization of 

the minerals by pressure exerted presumably by the thrust of the 

Hyder quartz monzonite magma at the time of its intrusion. Shearing planes and slickensiding are common in this highly foliated 

6196 29 4
42 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

border of the Texas Creek batholith. The width of the belt of the 

Texas Creek granodiorite in which the rock shows marked effects of 

mechanical crushing and shearing ranges from a quarter of a mile 

to 1^ miles. A band of augen gneiss and schist iy2 miles wide 

resulting from such mashing is well exposed along the Salmon River 

road north of Fish Creek.

FAULTS

Within the rocks of the Hazelton group there is a great deal of 

offsetting of the beds on a small scale, but no fault of any considerable magnitude was identified. Within the Texas Creek batholith 

some of the veins are offset 5 to 100 feet by small faults. On the 

Fish Creek property a group of veins is offset by a series of faults 

that run N. 30° E. and dip steeply northwest. The valleys of 

Skookum and Fish Creeks appear to have been eroded along a fault 

zone.

JOINTS

The observations on the joints in the Texas Creek granodiorite 

show no well-defined groups. The strike varies markedly in different 

localities, and there appears to be no constancy in the direction of the 

dip except for local areas. If any groupings in direction are more 

common than others they are N. 20°-50° W. and N. 30°-60° E., 

though strikes of N. 10° W. to N. 20° E. are about equally common. 

Joints that strike N. 50°-60° W. are found, and joints that strike 

N. 60°-90° W. or N. 60°-90° E. that is, within 30° of east-west are 

present though not numerous.

In the Hyder quartz monzonite the joints commonly strike N. 30°- 

35° E. and have predominantly a vertical dip. Other joints, which 

may belong to the same genetic group, strike N. 10° E. to N. 30° E., 

' with a dip 70° to vertical. Some others noted strike N. 60°-65° E., 

with dip usually 60°-90° N., N. 10°-30° W., N. 50° W., and rarely 

east-west.

MINERAL DEPOSITS

CLASSIFICATION

The mineral deposits of economic importance in the Salmon River 

district in Canada have been classified by Schofield and Hanson,16 

and those in the Alaskan part of the district by Westgate.17 The 

following classification is a combination of both of these, somewhat 

modified by the writer:

18 Schofleld, S. J., and Hanson, George, The Salmon River district, B. C. : Canada Geol. 

Survey Summary Kept, for 1920, pt. A, pp. 9-12, 1921.

17 Westgate, L. G., Ore deposits of the Salmon River district, Portland Canal region: 

U. S. Geol. Survey Bull. 722, pp. 127-129, 1922.
MINERAL DEPOSITS 43

1. Quartz fissure veins of lead-silver-gold type: The principal value is in lead, 

the silver ranges from moderate to high, and gold is in moderate amounts but 

high for this type of vein. The veins occur principally within the Texas Creek 

granodiorite but are found also in the rocks of the Hazelton group and with 

outlying stocks and dikes of porphyry associated with the Texas Creek grauodiorite. Nearly all of them cut across the structure of the rocks in which they 

occur. The sulphides occur in shoots within the quartz veins. The predominant 

metalliferous minerals so far as quantity is concerned are galena and pyrite. 

Sphalerite and chalcopyrite are present as accessory minerals in practically all 

the veins, and tetrahedrite, pyrrhotite, and native gold occur in small amounts 

in many of them. Scheelite is locally present in a few of the veins. Barite is 

a common gangue mineral in about half of them. Examples of this type are 

found on the Fish Creek, Mountain View, Riverside, Homestake, Cantu, and 

Texas Comstock properties, and they constitute one of the major types of veins 

in the district.

2. Veins and veinlike replacement deposits of silver-gold type in porphyry and 

in tuff near the contacts or included within the porphyry: The Premier ore body 

in Canada is described by Schofleld and Hanson as of this type. This ore body 

occurs within a stock of granodiorite porphyry that contains numerous inclusions 

of greenstone. Burton M describes its relations as follows: " Fracturing has 

been concentrated along the contact between the porphyry stock and the greenstone, and the main ore zone, striking N. 40° E., follows this contact, with a 

dip of 50°-75° N. W. The northwest ore zone is ill defined, but where it joins 

the southwest end of the main ore zone, mineralization has been particularly 

intense, and the sulphide body is unusually wide, due to the porphyry being 

rendered highly permeable in that locality." The large ore shoots are lenticular. 

The minerals present are pyrite, chalcopyrite, sphalerite, galena, tetrahedrite, 

freibergite, polybasite, pyrargyrite, argentite, stephanite, native silver, and gold. 

The predominant mineral is sphalerite. The gangue is rather abundant and is 

almost entirely quartz. Deposits of this type, characterized by the rich silver 

minerals, have not been found in the Alaskan part of the district.

3. Veins of the gold type: Schofield and Hanson refer a body of ore in the 

Premier mine in Canada to this type. It is a siliceous heavy-sulphide deposit. 

Quartz and pyrite are the predominant minerals. Small quantities of chalcopyrite, sphalerite, and galena are present. Assays show moderate to high 

value in gold and practically no silver. A similar mineral aggregate appears to 

occur in the Texas Creek batholith on the Cantu property on the Alaskan side.

4. Disseminated and lenticular replacement deposits: These occur mainly 

in the greenstones parallel to the schistose structure and are principally of 

base-metal types. The predominant metalliferous minerals are pyrite, galena, 

sphalerite, and pyrrhotite, or pyrrhotite with minor amounts of chalcopyrite and 

arsenopyrite and a very little sphalerite. Chalcopyrite is present in practically 

all the veins and is the predominant ore mineral in some. Tetrahedrite and 

arsenopyrite are found in a considerable number of them. The sphalerite carries gold, but the quantity ranges from very low to very high. Some secondary 

rich silver minerals are found in these deposits on the Canadian side, and a 

trace of native silver has been found in deposits of this type on the Alaskan 

side. The gangue commonly consists of the altered country rock, quartz, rather 

abundant calcite, and at some places barite. Examples of this type are found 

on the Daly-Alaska, Virginia, Hobo, and Stoner properties. Analogous deposits

18 Burton, W. D., Ore deposition at Premier mine, B. C.: Econ. Geology, vol. 21, p. 588, 

1926.
44 GEOLOGY OF HYDEE AND VICINITY, SOUTHEASTERN ALASKA

on the Canadian side are found on the Big Missouri and Forty-nine properties. 

Deposits of this character form one of the major types of occurrence throughout 

both the Alaskan and Canadian portions of the district.

5. Mineralized fissure zones, approximately parallel to the structure, in slate 

and tuffaceous graywacke of the Hazelton group: These zones consist in part 

of fissure fillings and in part of partly replaced country rock. The amount of 

gangue is extremely variable. The mineralization consists predominantly of 

galena or sphalerite, or both, with variable amounts of pyrite, chalcopyrite, 

pyrrhotite, tetrahedrite, and arsenopyrite. Examples are found on the Silver 

Bell and Iron Cap claims.

RELATION TO COUNTBY BOCK 

TYPE OF VEIN

The deposits made up of veins and veinlike replacement lodes 

and the disseminated deposits are practically limited to the greenstone. The veins that are approximately parallel to the structure 

and consist for the most part of fissure fillings and in slight part of 

replacement deposits are predominantly restricted to the graywacke, 

argillite, and slate. The mineralized quartz fissure veins that lie 

at an angle to the structure (that is, the gneissic structure of the 

Texas Creek batholith, the bedding of the sediments, or the foliation 

of the greenstone) occur predominantly in the Texas Creek batholith. Westgate 19 has described the relations of the type of deposit 

to the nature of the inclosing rock. He writes:

The softer greenstones, at the prospects mainly altered tuffs, are thought 

incapable of retaining open fissures, so that in them the deposit was formed 

by replacement along shear zones. The granite [Texas Creek batholith] seems 

to have been firmer and able to retain open fissures; hence it holds typical 

veins. At the depth of the deposits at the time of their formation the granite 

was in the zone of fracture, and the greenstone in the zone of flowage.

The graywacke appears to have been more favorable for the formation of fissure veins than the greenstone or argillite, and a number 

of veins occur within it. The outlying dikes of porphyry in the rocks 

of the Hazelton group also appear to have been brittle, and many 

veins of quartz occur in them or along their contact with the country 

rock.

STRIKE AND DIP

Observations on the strike and dip of 125 veins in the district were 

obtained. Almost half of the veins strike N. 30°-60° W. and dip 

45°-TO° E. One-fifth of the veins strike between north and N. 30° W. 

and dip 45°-70° E., and another fifth strike within about 15° of eastwest. A few veins have different strikes. Ve.ins with strikes between 

N. 30° E. and N. 75° E. are rare. In the Texa,s Creek granodiorite

18 Westgate, L. G., op. cit, p. 129.
RELATION TO COUNTRY ROOK 45

about two-thirds of the veins strike N. 30°-60° W.; in the graywacke, 

tuff, slate, and greenstone about half the veins strike N. 75° E. to 

N. 70° W. that is, parallel to the cleavage or schistose structure or 

to the bedding planes.

The northwestward-striking veins in the Texas Creek granodiorite 

are oriented at angles of about 45°-70° to the gneissic structure. 

Within the West Fork area the strike of the gneissic structure averages about N. 70° E. and that of the northwest veins about N. 40° 

W.; east of Salmon River the gneissic structure averages about N. 

85° E. and the northwest veins about N. 50° W. These northwestward-striking veins and the veins that strike between N. 35° E. and 

N. 30° W. not only cut across the grain or structure of the Texas 

Creek batholith but also across the bedding or structure of the sedimentary and volcanic rocks. They are all fissure veins. The eastwest group of veins in the sedimentary and volcanic rocks, on the 

contrary, are approximately parallel to the bedding or cleavage and 

were formed both by fissure filling and by partial or complete 

replacement of the country rock.

Several belts or areas may be defined in which the strike of the 

veins shows a certain uniformity or systematic grouping. One such 

area lies between Salmon River and the international boundary, 

south of the junction between Texas Creek and Salmon River and 

north of the Hyder quartz monzonite. In the Texas Creek granodiorite of this area two groups of veins predominate and are about 

equal in number: One group strikes N". 50°-60° W. and dips 45°- 

70° E.; the other strikes N. 10°-30° W. and dips similarly 

45°-70° E. The small percentage of veins that differ strike north, 

N. 80° W., or N. 60°-80° E. East of Salmon River in the sheared 

sedimentary and volcanic rocks there are two groups and types of 

veins. One group consists of metalliferous veins similar in type 

to those found in the Texas Creek granodiorite, and occurring as 

fissure fillings in the rocks. Some of these vein? lie along the contacts of the dikes of granodiorite porphyry with the country rock 

or within the dikes. Almost all these veins strike N. 40°-60° W. 

and dip 45°-60° NE., though a few dip southwest. The veins oif 

the other group lie more or less parallel to the foliation or slaty 

structure of the rocks and consist of replacement and disseminated 

deposits and fissure fillings. They strike almost uniformly between 

N. 80° E. and N. 70° W.; about half of them strike east-west. They 

may dip either south or north, though a southward dip is more 

common.

Between Salmon River and Texas Creek, north of their junction, 

is an area in which the strike of the veins within the Texas Creek 

granodiorite, so far as observed, shows no uniformity or system. 

The strike is N. 10°-20° W., N. 50° W., N. 70°-80° W., or N. 70° E.
46 GEOLOGY OF HYDEE AND VICINITY, SOUTHEASTERN AT.ASTTA

A belt in which the veins in general strike between N. 5° W. and 

N". 35° E. was noted in the vicinity of Casey Glacier and Ibex Gulch. 

Here the veins dip east, most commonly at angles of 40°-70°.

West of the Casey Glacier-Ibex Gulch belt, at the head of the 

West Fork and including in particular the Texas Comstock ridge 

and the valley of Ferguson Glacier, is an area in which the veins 

in the granodiorite and quartz diorite have a very uniform strike, 

trending almost exclusively N. 30°-50° W. and dipping 45°-80° E.; 

the dip is about equally divided between 45°-50° and 60°-80°. In 

the graywacke and slate of the same area there are three groups of 

veins; about half the veins have the same general strike as the veins 

in the granodiorite, N. 30°-50° W., and most of the other half fall 

into two groups, one north to N. 20° W., the other N. 75° E. to N. 

70° W. The veins that strike north to northwest in general dip 

45°-70° E., cut across the bedding of the sediments, and carry 

mineralization of about the same type as the northwest veins in the 

granodiorite. The veins within 15° or 20° of east-west are approximately parallel to the bedding, though they may cross it at a slight 

angle, and they carry a somewhat different mineralization. The 

dip of these veins is variable, both in amount and in direction.

CHARACTER OF THE VEINS 

FISSURE VEINS AT AN ANGLE TO THE STRUCTURE

Quartz veins occur at altitudes ranging from sea level on the 

Riverside property to 5,100 feet on the east side of Ferguson Glacier. 

The mineralization is similar at the different altitudes.

The total length of only a few of the mineralized quartz fissure 

veins has been determined. The Cross vein on the Riverside property 

is 750 feet long; a vein on the Sunset claims has been traced for 900 

feet; the Lindeborg vein is reported to have been traced for 1,800 

feet; and a considerable number of veins have been traced for 450 to 

600 feet without ascertaining their total length. Like most quartz 

veins, they show local contractions and expansions. They range from 

mere stringers to veins 15 feet in width but predominantly are between 

1 and 5 feet. Locally they consist of a breccia of the country rock 

intersected by a network of veinlets. The sulphides occur mostly 

in shoots within the quartz but in part are disseminated through 

the quartz in sufficient quantity to constitute a milling ore. The 

heavy sulphide ore shoots range from several feet to 150 feet in length 

and from 6 inches to 5 feet in width. Considerable quartz, barren 

or with only sparse sulphides, may intervene between the concentrated shoots of ore; and the major portions of some of the veins are
CHARACTER OF THE VEINS 47

relatively barren. None of the veins have been prospected to any 

great depth. A shaft has followed the Cross vein on the Riverside 

property down the dip for 350 feet; the Olympia Extension vein on 

the Fish Creek group of claims has been developed for a difference 

in altitude of 250 feet; the Lindeborg vein on the Riverside property 

is reported to be exposed for a difference in altitude of TOO feet; and 

veins on the Texas Creek Comstock property are exposed for a difference in altitude of 500 feet.

VEINS PARALLEL TO THE STRUCTURE

The veins and veinlike replacement deposits in the greenstone and 

in the porphyry dikes of the Texas Creek batholith have been but 

little prospected. The greatest amount of development work on 

deposits of this type has been done on the Daly-Alaska property. 

Small shoots of ore have been found here, but not in sufficient number 

or continuity to warrant the installation of a mill or attempts at 

mining.

Practically no development work has been done on veins approximately parallel to the structure in the graywacke, argillite, and 

slate beds, as contrasted with the fisssure veins at an angle to. the 

structure in the same beds. One vein aproximately parallel to the 

bedding has apparently been traced for about 600 feet and found 

to consist of mineralized quartz stringers in a narrow fissured zone 

in the argillite, but most of them have not been definitely traced for 

more than 150 feet because of the overburden and lack of prospecting. 

The veins consist of stringers of mineralized quartz and calcite or of 

solid sulphide in fissured zones ranging in width from a few inches 

to 15 feet. The stringers may be at considerable distance apart, or 

they may be close together and interlock to form a more definite vein.

Pyrrhotite is sparse or absent in the veins in the Texas Creek 

batholith and in the slate and argillite of the Hazelton group, but it is 

common in the veins in the graywacke and is one of the chief minerals in the veins in the greenstone. As the veins in the greenstone 

were probably formed at a lower temperature than those in the 

Texas Creek batholith, it is improbable that the relative abundance 

of pyrrhotite in these veins in the greenstone, as contrasted with 

the predominance of pyrite in the fissure veins, can be due to differences in temperature during their formation. It is probably due to 

some influence of the country rock, though just how this influence has 

operated is not clear.
48 GEOLOGY OP HYDEB AND VICINITY, SOUTHEASTERN ALASKA

MINERALOGY OF THE DEPOSITS

CLASSIFICATION OF THE MINERALS

The ore and gangue minerals of the Hyder district are listed below.

Native elements________ Gold, silver.

Sulphides____________ Galena, pyrite, pyrrhotite, sphalerite, ehalcopyrite, molybdenite, chalmersite, covellite, marcasite.

Sulphosalts__________ Tetrahedrite, freibergite, arsenopyrite, proustite. 

Sulphates____________ Barite, anglesite.

Oxides_____________. Quartz, magnetite, specularite, limonite. 

Cfarbonates__________. Calcite, ankerite, malachite, azurite. 

Tungstate___________. Scheelite. 

Undetermined minerals.

METAL CONTENT

The content of the principal valuable metals in these mineral deposits is indicated by assays of representative samples given in the 

table below.

Content of gold and silver in different minerals in the Hyder district

Sample

Pyrite, nearly pure, Fish Creek No. 2 vein, Mountain View _ .

Pyrite from disseminated deposits in quartz, Fortuna claims, 

Texas Creek ____________________ ..... .....

Pyrite, nearly solid, Cantu No. 8 claim _ . ...................

Galena ore, Homestake vein ___ _ . ___ . _______ ..

Galena, Joe-Joe vein, Texas Creek Comstock group.. ..........

Galena concentrate, test sample, Riverside mine.. .............

Tetrahedrite, nearly pure, lower adit, Olympia claim, Fish 

Creek group ____ ... ________________ . ......

Tetrahedrite, Homestake claim... _______ . ___ .__ _ ...

Ore about one-half tetrahedrite, average of assays on 2 samples, 

Fisb Creek No. 2 vein, Mountain View, ___________

Sphalerite, nearly pure, Hummel group, West Fork of Texas 

Creek........................................................

Chalcopyrite, nearly pure, Fish Creek No. 2 vein, Mountain 

View _ . ____ . _____________ .. _ . ____ ...

Gold 

(ounces 

per ton)

0.20

1.50

.02

1.40

.18

.18

.40

1.4

.84

1.30

.92

.03

.44

Silver 

(ounces 

per ton)

0.80

1.2

6.8

13.1

16.9

58.0

21.36

266.0

598.0

40.2

232.5

22. 78

13.16

Lead 

(per cent)

62.0

72.8

74.0

60.9

.6

Copper 

(per cent)

0.9

.5

11.6

1.13

NATIVE ELEMENTS

Gold (Au). Practically all the mineral deposits in the district 

carry at least a little gold. Gold is known to occur in part as the 

native metal, at some places in coarse flakes, but its mode of occurrence at other places has not been ascertained. Native gold has 

been observed in abundance locally in certain quartz veins on the 

Kiverside property. On the Sixmile group of claims it occurs in 

narrow quartz stringers and in the granodiorite wall rock adjacent 

to the contact of the veins. It has also been observed in quartz
MINEKALOGY OF THE DEPOSITS 49

veins on the Monarch, Crest, and Cantu properties and in a boulder 

of float on the Texas Creek Comstock. All the quartz veins that carry 

free gold have local shoots heavily mineralized with sulphides.

Silver (Ag). Native silver is very rare on the Alaskan side of 

the international boundary, though it is very plentiful in the Premier ore and is found on the Spider, Silver Tip, Porter-Idaho, and 

other properties on the Canadian side. Native silver has been found 

in small amounts near a fault plane on the Daly-Alaska property 

and in a vein on the Mountain View group of claims.

SULPHIDES

Galena (PbS). Galena is the predominant ore mineral of the 

district and has been found in every vein. The galena is usually of 

medium grain, but locally it has been mashed and crushed by movement to a fine-grained aggregate called steel galena. Such dense 

galena may show a flowage relation toward other minerals. The 

galena generally occurs concentrated in local shoots in the quartz 

fissure veins, but in the mineralized bands that constitute the replacement veins in the lower part of the Hazelton group it is more 

uniformly distributed. It carries moderate quantities of silver and 

usually $2 to $4 in gold to the ton. Several representative assays are 

given in the table on page 48.

Pyrite (FeS2 ). Pyrite is probably the most abundant metallic 

mineral in the district, and it, too, has been found in every vein. 

Where the mineralization is sparse, pyrite may be of the only metallic 

mineral present. In such places it occurs usually in good crystals. 

commonly in the form of pyritohedrons or cubes in the quartz fissure veins and in the form of cubes in the disseminated deposits 

in the Hazelton group. At many places it is associated in considerable amounts with the galena in localized ore shoots in the quartz 

fissure veins. The amount of gold and silver in the pyrite is variable. Several representative assays are given in the table. Some 

pyritic quartz veins in the Texas Creek granodiorite and some pyritic 

impregnation and replacement deposits in the beds of the Hazelton 

group carry considerable gold; others do not. At some places the 

silver content of the pyrite is high.

Pyrrhotite (FenSn+1 ). Pyrrhotite has been found as a minor accessory mineral in about one-third of the quartz fissure veins in the 

Texas Creek granodiorite, is common in the veins in the graywacke 

and slate, and is one of the chief minerals in every vein in the greenstone. The amount of gold and silver contained is usually very low.

Sphalerite (ZnS). Sphalerite is present in practically every vein 

in the district, but in the quartz fissure veins within the Texas Creek 

granodiorite that are more than 1,000 feet from the contact of the
50 GEOLOGY OF HYDER ANT) VICINITY, SOUTHEASTERN ALASKA

diorite with the rocks of the Hazelton group sphalerite is sparse or 

is present only in very local shoots associated with other sulphides. 

It is more abundant in veins within the Texas Creek granodiorite 

that are not more than 1,000 feet from its contact with the 

Hazelton group. In veins in the Hazelton group sphalerite is 

one of the principal minerals. Usually it is associated with 

other sulphides, but locally it may form narrow almost solid 

stringers. At many places the sphalerite is dark brown and presumably has considerable iron in solid solution. At other places 

it is of a light resin color. The resinous sphalerite is usually associated with tetrahedrite. The gold and silver content of the sphalerite is exceedingly erratic. In the greenstones of the Hazelton group 

and the associated porphyry dikes the gold content ranges from very 

little to 35 ounces to the ton. At the Premier mine sphalerite shoots 

have been found with a gold content of 60 ounces to the ton. Assaying appears to be the only means known of gaining an idea as to the 

amount present. An assay of a sample from the Hummel group is 

given in the table.

Chalcopyrite (CuFeS2 ). Chalcopyrite is present in practically 

every vein examined but usually in small amounts only. An assay 

showing the gold and silver content of a sample from the Fish Creek 

No. 2 vein is given in the table.

Molybdenite (MoS2 ). Molybdenite has not been found in the normal vein deposits. It is abundant in an aplite dike associated with 

the Texas Creek granodiorite on the banks of Fish Creek on Fish 

Creek No. 2 claim of the Mountain View property. In the vicinity 

of the head of the West Fork many of the thin quartz veinlets facing 

fractures in the Texas Creek quartz diorite carry pyrite and molybdenite. In the vicinity of Greenpoint Glacier fractures in the 

Hyder quartz monzonite adjacent to the contact with the graywacke 

and slate are coated at some places with molybdenite.

Chalmersite (CuFe2S3 ). Chalmersite was observed in but one of 

the veins in the Hyder district, where it occurs as laths in chalcopyrite associated with pyrrhotite.

Covellite (CuS). Covellite occurs as a secondary mineral only, in 

sparse veinlets in tetrahedrite, chalcopyrite, and rarely other minerals, 

as a result of weathering and the action of surface water.

Matrcasite (FeS2 ). Marcasite in this area is entirely secondary 

and is found locally where it has replaced pyrrhotite in or near 

surface outcrops.

SULPHOSALTS

Tetrahedrite (CugSbaSj) and freibergite ((CuAg) 8Sb2S7 ). Tetrahedrite has been found in about half the veins examined. Although 

present in minor amounts, it is an important ore mineral because it
MINERALOGY OP THE DEPOSITS 51

usually carries much gold and silver. Representative assays are 

given in the table. Native gold in flakes of microscopic size was 

found in one specimen. With an increase in silver content tetrahedrite grades into freibergite. Most of the sulphantimonide of 

copper in this district is tetrahedrite, but freibergite was identified 

in the veins on Fish Creek Nos. 2 and 3 claims of the Mountain View 

group, the Olympia claim of the Fish Creek group, and the Last Shot 

group. At all these places the freibergite is associated with tetrahedrite.

Arsenopyrite (FeAsS2 ). Arsenopyrite is very rare in the quartz 

fissure veins in either the Texas Creek granodiorite or the Hazelton 

group, but it is ,a common mineral in replacement deposits in the 

greenstone and in vein deposits parallel to the structure in the 

graywacke and slate. It is usually well crystallized.

Proustite (Ag3AsS3 ). Proustite, one of the ruby silvers, was 

identified only at a prospect pit on Fish Creek No. 2 vein on the 

Mountain View property. It is rare here and occurs as a secondary 

mineral in minute veinlets along fractures in the ore.

SULPHATES

Barite (BaS04 ). Barite, though only locally abundant, occurs 

in a large percentage of the mineral deposits and must be considered 

a common gangue mineral. Where barite occurs in considerable 

quantities tetrahedrite is usually also more abundant.

Anglesite (PbS04 ). Anglesite is a common alteration product 

along the cleavage surfaces of galena in or near the surface outcrop.

OXIDES

Quartz (SiO2 ). Quartz is the predominant gangue mineral of 

the fissure veins and is one of the chief gangue minerals in the 

replacement deposits. The quartz is usually massive, white and 

milky.

Magnetite (Fe3 04 ). Magnetite has not been found within the 

fissure veins associated with the Texas Creek granodiorite. It is, 

however, one of the principal minerals, associated with pyrite, in 

quartz fissure veins in the Hyder quartz monzonite. In this association it also occurs in a bladed form pseudomorphic after 

specularite.

Specularite (Fe2O3 ). The crystalline variety of hematite specularite is found in zones of contact metamorphism on Bear River 

Ridge adjacent to the granodiorite porphyry dikes genetically associated with the Hyder quartz monzonite. It also occurs in quartz 

fissure veins within the Hyder quartz monzonite, where it is associated with magnetite and pyrite.
Limonite (2Fe2O8 .3H2O). The iron hydrate limonite is present 

as a surface alteration product in the outcrops of the mineral deposits 

and also occurs to considerable depths along weathered fracture 

surfaces.

CARBONATES

Calcite (CaCO8 ). Calcite is a very common and rather abundant 

gangue mineral in the mineral deposits and veins within the Hazelton group, but it is rare in the quartz fissure veins.

Ankerite (Ca(MgFe) (C03 ) 2 ). Ankerite is present locally in 

small amounts in a few of the veins, but on the whole it is sparse.

Malachite ((CuOH) 2C03 ). Malachite is common in the surface 

croppings of veins that carry chalcopyrite.

Azurite, (Cu(OH) 2 .(CuCO3 ) 2 ). Azurite is rare but occurs in sparse 

amounts associated locally with malachite in the surface outcrops.

TUNGSTATE

Scheelite (CaWOJ. Scheelite was identified in four different 

fissure veins in the Hyder district and probably occurs in others. 

It has been found in abundance locally in one of the veins at the 

Riverside mine and in Fish Creek No. 2 vein on the Mountain View 

property. It occurs disseminated in quartz and in association with 

barite as a result of veining and replacement of the quartz by the 

barite.

UNDETERMINED MINERALS

Five minerals that were distinguishable only by microscopic examination and chemical tests and that could not be positively identified 

with any known mineral were found in the ores. They occur in 

small amounts and in but few of the veins, associated with tetrahedrite and galena. In some places they seem to bear a definite relation 

to the tetrahedrite-galena contacts.

INTERRELATION OF ORE MINERALS

Study of samples of ore with the reflecting microscope shows that 

the ore minerals in considerable part were not formed simultaneously 

but successively, and that earlier minerals of deposition are partly 

replaced, corroded, or veined by later minerals. A study by W. B. 

Jewell 20 shows that the succession or paragenesis and interrelations 

of the ore minerals are the same in all the veins studied, irrespective 

of their position relative to the contact between the Texas Creek 

granodiorite and Hazelton group, the altitude, or the type of country

20 Jewell, W. B., Mineral deposits of the Hyder district, southeastern Alaska: Econ. 

Geology, vol. 22, pp. 494-517, 1927.
GENESIS 53

rock. In a few places reversals occur, but all these are where the 

minerals concerned were deposited very nearly together and some 

overlapping might therefore be expected. The order given below 

is that noted in a great preponderance of the veins, with the oldest 

mineral listed at the top:

1. Scheelite.

2. Pyrite and arsenopyrite.

3. Arsenopyrite.

4. Pyrrhotite.

5. Sphalerite, chalcopyrite, and chalinersile.

6. Chalcopyrite.

7. Galena, chalcopyrite, tetrahedrite, freibergite, gold (?), and the undetermined minerals.

8. Tetrahedrite, freibergite, and the undetermined minerals.

The earlier minerals (1, 2, 3, and 4) are such as form typically at 

relatively high temperatures, and the later minerals (7 and 8) 

such as form characteristically at intermediate temperatures. In 

this district, however, it seems at least possible that arsenopyrite and 

pyrrhotite were formed under conditions of intermediate temperature.

In practically all the fissure veins that contain only one metallic 

mineral in sparse amounts the mineral is pyrite. Where the mineralization is slightly greater, chalcopyrite may accompany the pyrite. 

In the heavily mineralized sulphide shoots galena or galena and 

pyrite are usually predominant. Tetrahedrite and sphalerite are 

generally associated with the veins in which galena forms most oi: 

the sulphides and pyrite is minor in amount. All combinations, 

however, may occur along the same vein. Chalcopyrite does not 

necessarily increase in amount correspondingly with total increase 

in sulphides, and whereas sphalerite may rise to noteworthy amounts, 

chalcopyrite may still remain minor. Where antimony was present 

in the solutions the copper tends to form tetrahedrite, and where 

tetrahedrite is common chalcopyrite is usually sparse.

GENESIS

RELATION OF THE MINERAL DEPOSITS TO THE INTRUSIVE MASSES 

TEXAS CREEK BATHOLITH AND ASSOCIATED PORPHYRY PIKES

Most of the mineral deposits so far discovered in the Alaskan 

part of the Salmon Kiver Basin occur near the contact between the 

Texas Creek batholith and the rocks of the Hazelton group or in 

association with outlying stocks and dikes of porphyry. The deposits occur both within the igneous rock itself and also in the bedded 

rocks and the greenstone. At a few places they are cut by dikes 

believed to be offshoots connected with the Hyder quartz monzonite
54 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

and the Boundary granodiorite. They must therefore belong to a 

period of mineralization that followed the intrusion of the Texas 

Creek batholith and its outlying dikes and stocks of porphyry and 

preceded the intrusion of the younger Coast Kange intrusives. It 

is thought that the mineral deposits were formed from residual 

solutions released by the crystallization and consolidation of the 

magma that formed the Texas Creek batholith.

Along the east side of Salmon River mineralized veins are found 

within the Texas Creek batholith at depths of 3,000 to 3,500 feet beneath its roof. Mineralized veins are also found in the bedded rocks 

1,000 feet above the roof, both along the West Fork and east of 

Salmon Eiver. Most of the known mineralized veins, however, 

occur within 1,500 to 2,000 feet of the contact.

At many places the solutions probably rose from large igneous 

masses which are not exposed at the surface but whose presence at 

considerable depth is indicated by stocks or dikes that crop out in 

the rocks of the Hazelton group at the present erosion levels. Those 

associated with the main Texas Creek batholith may in part have 

come from the core of the mass now exposed.

RELATION OF THE PORPHYRY DIKES OF THE TEXAS CREEK BATHOLITH TO 

THE PREMIER ORE BODIES OF BRITISH COLUMBIA

The mineralization in the Canadian part of the Salmon River 

Basin has been ascribed by Schofield and Hanson 21 to a genetic connection with the closing stages of the Coast Range igneous activity. 

They write as follows concerning the relation of the ore deposits 

and the porphyry dikes:

In studying the age relationships of the primary ore deposits and the various 

dike series, it was found that primary mineralization affected some of the 

quartz porphyry dikes belonging to the " belt of dikes," but that the ore bodies 

were cut by dikes of quartz diorite, lamprophyre, and some of the dikes belonging to the " belt of dikes."

The conditions described by Schofield and Hanson are duplicated 

on the Alaskan side; but the interpretation placed upon these relations by the present writer is somewhat different. The porphyry 

dikes older than the ore bodies and the Premier granodiorite porphyries on . the Canadian side are believed by the writer to be the 

equivalent of the porphyry masses on the Alaskan side and to be 

genetically connected with the same general magma that gave rise to 

the Texas Creek batholith. The quartz diorite dikes that cut the ore 

bodies on the Canadian side are, on the other hand, believed to be 

the younger Coast Range intrusive rocks and to be connected genetically with the same general magma that formed the Hyder quartz 

monzonite. The writer believes that the porphyry dikes on the

a Schofleld, S. J., and Hanson, George, op. dt., p. 42.
GENESIS 55

Canadian side, as on the Alaskan side, belong in general to two 

different epochs of magmatic intrusion and that most of the mineral 

deposits are genetically associated with the magma that gave rise to 

the older dikes the Premier and those associated with the Texas 

Creek batholith. The mineral deposits are therefore not strictly 

associated with the closing stages of the Coast Range igneous activity but with an epoch preceding the closing stages.

YOUNGER COAST RANGE INTRUSIVE ROCKS

No mineral deposits of economic importance have yet been located 

within the younger Coast Kange intrusive rocks (Hyder quartz 

monzonite and Boundary granodiorite) in this district, though they 

have been found in association with them elsewhere, as at Anyox, 

B. C. A few mineral deposits of no present value have been noted 

in connection with them in this district, but they are vastly different 

from those related to the Texas Creek intrusive rocks. Narrow 

glassy quartz veins carrying magnetite, pyrite, and specularite are 

common locally, in the Hyder quartz monzonite, and small amounts 

of specularite are found locally in the country rock adjacent to offshooting granodiorite porphyry dikes on Bear River Ridge. Quartz 

veins with molybdenite and in places a little chalcopyrite or pyrite 

also occur within the Hyder quartz monzonite. About 3 miles south 

of Hyder on Portland Canal, on the Ebb Tide group, a 60-foot adit is 

reported to have been driven on a fissured zone in the quartz monzonite. This zone is said to carry disseminated pyrite, a trace of chalcopyrite, and rare galena and to yield a little gold. On the Glacier 

group, at the foot of Chickamin Glacier, quartz veins with pyrite and 

small amounts of pyrrhotite and chalcopyrite and rare galena occur 

in graywacke in genetic association with the Hyder quartz monzonite. 

In the slates of the ridge on the north side of Greenpoint Glacier 

there is a large quartz vein with pockets of galena and pyrite and 

locally disseminated garnet and a little epidote. This vein may also 

be genetically connected with the Hyder quartz monzonite. In the 

schist inclusions within the younger Coast Range intrusive rocks 

there are bands with disseminated pyrite, pyrrhotite, and a little 

chalcopyrite and locally sphalerite.

TEMPERATURE AND PRESSURE

The fissure veins were formed under conditions of temperature and 

pressure that varied within wide but definite limits. Many of the 

quartz veins that are barren or sparsely mineralized with pyrite or 

scheelite belong to the high-temperature type, whereas those that 

carry shoots consisting predominantly of pyrite (or more rarely
56 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN" ALASKA

pyrrhotite) and galena,, with some sphalerite and tetrahedrite and 

considerable barite, are typically of intermediate-temperature type. 

The prevalent type of vein, mineralized dominantly with pyrite 

and galena and locally with native gold, probably belongs within 

the higher limits of the intermediate-temperature veins. Many of 

the veins are of composite character, as is well illustrated by the 

Fish Creek No. 2 vein, on the Mountain View property. This vein 

began as a large quartz vein of early stage high-temperature type 

mineralized with pyrite, pyrrhotite, scheelite, and a little chalcopyrite. Later galena and sphalerite were introduced locally, and 

finally the vein matter was partly replaced by barite and tetrahedrite, 

which are minerals typical of intermediate-temperature conditions. 

The older scheelite and quartz show marked evidences of corrosion 

and replacement by the later barite and tetrahedrite, which form a 

distinct shoot. There must have been repeated movements of mineralizing solutions along the fissure, which caused the character of 

the vein matter to change with progressive decrease in temperature. 

The veins "parallel to the structure of the bedded rocks of the 

Hazelton group and the veinlike replacement deposits in the greenstone were formed under conditions of temperature that are difficult 

of estimation. Pyrrhotite is a common mineral in the veins in the 

graywacke and is one of the chief minerals in the veins in the greenstone. Arsenopyrite is very rare in the fissure veins in the Texas 

Creek batholith but is common in the veins in the Hazelton group. 

These two minerals suggest that the veins are of high-temperature 

type. On the other hand, calcite is a very abundant gangue mineral 

in the veins in the greenstone and is common to abundant in the 

veins in the slate and graywacke. Sericite and chlorite are also 

abundant gangue minerals in the altered country rock and, together 

with calcite, suggest that the deposits are typically of intermediatetemperature type. The spatial relations of the veins with respect 

to the Texas Creek batholith also indicate that they are of intermediate type. They lie outside of and above the batholith, where it 

might reasonably be expected that cooler temperatures would prevail 

than within the batholith. The veins are therefore assigned to the 

intermediate type. The occurrence of so much pyrrhotite is ascribed 

to the influence of the country rock. The arsenopyrite is believed to 

have been formed at intermediate temperature, though slightly earlier 

than the other minerals. The tendency for mineralizing solutions in 

the same area to form pyrrhotite in andesitic rocks and pyrite in 

siliceous rocks has been noted also in the Kouyn district, in Quebec, 

by Cooke,22 who suggests that it may be due to the influence of the 

larger percentage of iron already present in the more basic rocks.

" Cooke, H. C., Ore deposits of the Rouyn area, Quebec: Canadian Min. Jour., vol. 47, 

pp. 572-575, 1926.
SILVER-LEAD DEPOSITS OF BOULDER BATHOLITH, MONT. 57

All the mineralization noted in connection with the younger Coast 

Range intrusive rocks is of the high-temperature type, in contrast 

to the prevalent intermediate-temperature types associated with the 

older or Texas Creek intrusives.

Veins are found now at altitudes ranging from sea level to 5,000 

feet. After making a reasonable allowance for the erosion of overlying material that must have taken place during the Tertiary and 

Quaternary periods, it seems probable that the veins were formed at 

depths below the surface ranging, at a minimum estimate, from 

4,000 to 10,000 feet. They therefore originated under a considerable 

load, such as is characteristic of intermediate to deep-seated types.

A number of veins have been affected by pressure subsequent to 

their formation, and there have been local adjustments through movement and slickensiding of the walls. A few of the veins have 

yielded slightly through crushing. On the Homestake property the 

so-called steel galena is what was originally coarsely crystalline 

galena now reduced to a pulverized mass by crushing. It has flowed 

like a plastic mass under the deforming pressure, and the other 

minerals have been broken up and occur as knots or eyes in the 

groundmass of galena. In superficial appearance the ore resembles 

an augen gneiss. The quartz of this vein, when examined with the 

microscope, shows that it also has been crushed. The gneissic structure of the galena appears to be due to the varying orientation of the 

cleavage along adjacent bands. Steel galena and a banding or gneissic structure in the galena have been observed in a number of other 

veins.

COMPARISON OF DEPOSITS OF THE TEXAS CREEK BATHOLITH 

WITH SILVER-LEAD DEPOSITS OF THE BOULDER BATHOLITH, 

MONTANA

The mineral deposits of the fissure veins associated with the Texas 

Creek batholith seem to have many points in common with the fissure veins carrying silver, lead, and zinc (as distinguished from the 

copper ores) of the Boulder batholith" in Montana. A short description of these veins, summarized from a paper by Billingsley and 

Grimes,23 is given below.

The veins occur both within ,the quartz monzonite of the Boulder 

batholith and in the country rock immediately adjacent to the contact. Most of the veins, however, are within 1,000 feet of the contact 

or original roof of .the batholith and occur within the quartz monzonite. The few veins more deeply placed within the batholith

28 Billingsley, Paul, and Grimes, J. A., Ore deposits of the Boulder batholith of Montana: 

Am. Inst. Min. Bug. Trans., vol. 58, pp. 284-361, 1918.

6196 29 5
58 GEOLOGY OF HYDEB AND VICINITY, SOUTHEASTERN ALASKA

contain little but quartz and suggest the eroded roots of veins that 

were of the normal mineralized type above. The typical vein aggregate is pyrite, galena, and sphalerite in a gangue of quartz. Pyrite 

and galena exceed any other combination. Chalcopyrite, tetrahedrite, bornite, stibnite, and argentite also occur. High-grade ores 

carry as much as $11 a .ton in gold. The universal trend in the composition of these veins has been an increase in the proportion of 

quartz to ore minerals with increasing depth. There is also a 

change of sulphide mineralization with depth. The galena is usually found, in the higher parts of the ore shoots, most of the zinc 

occurs below the lead zone, and this in turn gives way within a short 

distance to lean pyrite accompanied by small amounts of copper 

sulphides. Veins in which lead is predominant are found above 

the contact or within 1,000 feet below the former or present roof 

of the batholith. Whatever zinc is present is just below the lead 

zone, which places it between 1,000 and 1,200 feet from the roof. 

Pyrite is present throughout but persists to greater depths than the 

zinc. The best-known veins are several thousand feet or more in 

length, strike usually about east, and dip steeply. Their strike is 

about at right angles to the elongation of the batholith. A very 

large amount of aplite (about 10 per cent) is associated with the 

quartz monzonite of the Boulder batiholi'th, whereas very little 

aplite is associated with the' Texas 'Creek batholith. Again, about 

one-sixth of the veins associated with the Boulder batholith carry 

tourmaline or rhodochrosite, or both, whereas neither of these minerals has been noted in the Hyder district. The Boulder veine 

consist of many reticulated and parallel fissures, rather than of the 

filling in a single large opening. Similar mineralization appears to 

have occurred throughout a greater range in the veins of the Texas 

Creek batholith than in those of the Boulder batholith.

NOTES ON PROSPECTING

It is important that one engaged in searching for mineral deposits 

in this region, or in developing them, should be familiar with the 

distinguishing characteristics of the Boundary granodiorite, the 

Hyder quartz monzonite, the younger granodiorite porphyry dikes, 

the malchite and lamprophyre dikes, and the Texas Creek granodiorite and its variations and associated dikes.

The areas occupied by the Hyder quartz monzonite and Boundary 

granodiorite are shown on the map. The quartz monzonite and 

granodiorite are pink to white and are much more massive than the 

dull-gray fractured and locally sheared Texas Creek intrusive rocks. 

The Hyder quartz monzonite characteristically shows a small amount 

of biotite, whereas the Texas Creek granodiorite usually shows
NOTES ON PROSPECTING 59

abundant black hornblende rods in parallel orientation, giving rise 

to a gneissic or banded structure, and is usually marked by many 

slickensided fracture surfaces with green chlorite and yellowishgreen epidote.

The distinction between the older porphyry dikes and the younger 

Coast Kange intrusive rocks should be borne in mind. The older 

dikes are green to gray, are sheared and altered, and are associated 

at many places with ore deposits. The younger dikes are pink to 

white, massive, and little altered; they are not known to be associated 

with ore deposits and at several localities cut the ore bodies. A 

younger dike of granodiorite porphyry in the Texas Creek granodiorite is well shown in a road cut just opposite the Salmon Biver 

bridge above Ninemile. There is a fissured zone in the younger 

dike, but practically no alteration other than weathering is 

observable.

The distribution of the discovered mineral deposits indicates that 

the zone within 1,500 to 2,000 feet of the contact of the Texas Creek 

batholith with the rocks of the Hazelton group is a favorable belt for 

prospecting. Mineralization is also common in the immediate 

vicinity of the porphyry dikes and stocks of the Texas Creek batholith, especially along their contact. The map shows, however, that 

along considerable portions of the contact no mineral deposits have 

yet been located. This may be due in part to the fact that those 

areas are mostly covered with vegetation, which has hindered prospecting. Mineral deposits probably occur there.

An area that from its geologic relations should be favorable for 

prospecting lies above and in the vicinity of the practically buried 

ridge of Texas Creek quartz diorite that extends a little north of west 

from the head of the West Fork of Texas Creek. This area is about 

2 miles wide and 3 l/2 to 4 miles long and includes the lower part of 

the valley of Texas Glacier and the mountain slopes west and north 

of the abrupt westward bend of Chickamin Glacier.

The rocks of the Hazelton group in the block that forms Bandedl 

Mountain and the mountains on the west side of Through Glacier 

and that extends to a point 3y2 miles below the foot of the Chicka*- 

min Glacier are also geologically suitable for prospecting. Thought 

no economically valuable deposits have yet been found here, minerallized float is common. The area of graywacke west of Through 

Glacier and south of the lower part of Chickamin Glacier, however,, 

has the disadvantage of being separated from the West Fork trail1 

by the glaciers. It would be necessary to find here either evidenceof high-grade ore or large bodies of low-grade ore to warrant extenisive development work.

A part of the mountain ridge on the north side of Texas Glacier is> 

capped by a narrow band of argillite, which is intruded on. the- south
60 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

by the Texas Creek granodiorite and on the north by the Boundary 

granodiorite. Part of this band of argillite lies directly above the 

first ice cascades met in going up Texas Glacier from Texas Creek. 

The mountain slope in this vicinity deserves careful surface prospecting.

The core or central area of the Texas Creek batholith between 

Casey and Gray Glaciers on the west and Salmon River on the east 

and between the West Fork on the north and the Hyder quartz, monzonite on the south is relatively inaccessible and has been only slightly 

prospected. No mineral deposits of importance have been located 

within it, but whether the reason is that little or no mineralization 

has occurred within the core of the batholith or that the area has 

been so little prospected is not known. In making a quick trip up 

Thumb Creek the writer picked up several pieces of good float consisting of quartz heavily mineralized with galena and a little pyrite. 

Theoretically, however, it is to be expected that the borders of the 

batholith near the older rocks would be more favorable zones for the 

occurrence of ore bodies than the interior core. In prospecting 

the core of the batholith the portions at the higher altitudes should 

be prospected most carefully.

On the south the Texas Creek batholith is in contact with and is 

intruded by the Hyder quartz monzonite, which is believed to be 

younger than the ore deposits. This contact is therefore wholly dissimilar to the contacts of the Texas Creek batholith with the older 

rocks of the Hazelton group and, so far as our knowledge goes, is as 

unfavorable for prospecting as any other part of the core of the 

Texas Creek batholith.

Where large milky-white quartz veins with little or practically no 

sulphides are found their foot and hanging walls should be carefully 

 examined for shoots of ore, for there may have been later movements 

between the vein and its inclosing rocks that afforded places favor- 

.able for the introduction of subsequent sulphide solutions. Quartz 

veins carrying green chlorite or calcite, or both, have been found 

locally in the Hazelton group and in the Texas Creek granodiorite, 

but none of them were mineralized.

The continuity of the veins and the quality of their mineralization 

are, of course, most important considerations. The veins are of intermediate to deep-seated type, and the chances are therefore good 

that the stronger veins in the granodiorite and graywacke, which 

have been traced on the surface for several hundred feet and more, 

will persist in depth for at least several hundred feet, the depth 

being probably in similar proportion to the length. A few veins 

are exposed in natural section for depths bf 500 to TOO feet, but 

mining developments have not yet followed veins down for1 more
NOTES ON PROSPECTING 61

than a few hundred feet. The slate alone is unfavorable for the 

- formation of strong continuous veins, but along the contact between 

a thick massive graywacke bed, or series of graywacke beds, and a 

slate formation conditions are more favorable. The data are insufficient to warrant a generalization as to the usual conditions where 

the veins pass down from overlying graywacke and slate.into the 

Texas Creek granodiorite. On the Texas Comstock property several 

veins were observed to cross the contact and go deep into the quartz 

diorite without diminution in size. The known length and depth of 

a number of the veins and their arrangement in a definite system 

indicate that they occupy fissures which are not of a gash type.

The mineralized veins are known to occur throughout a vertical 

range of over 5,000 feet. The ore. minerals are almost exclusively 

primary, and only traces of enrichment have been found, From

these facts it is highly probable that the same general quality and 

quantity of mineralization which is shown at the surface in the 

vein as a whole will be found to persist in depth unless the character 

and kind of country rock changes in depth, and that any change in 

mineralization occurring in depth must be due to peculiarities of 

original deposition. On the Texas Comstock property there are 

several veins which, as exposed, are practically barren in the Texas 

Creek quartz diorite but contain good ore shoots in the overlying 

graywacke. In many other veins within the Texas Creek batholith, 

however, there are good ore shoots, so that the exact significance of 

the facts cited is not apparent, though the facts are worth bearing 

in mind.

There is also the question as to just what the chances are for the 

occurrence on the Alaskan side of rich silver ores such as some of 

those found in the adjoining areas in British Columbia. Unfortunately this question can not be answered from the information now 

available. The controlling conditions in the origin of the Canadian 

high-grade silver deposits are not known with sufficient definiteness. 

Some of them, such as the upper part of the veins now being worked 

at the Porter-Idaho, are certainly due predominantly to weathering 

and enrichment; others, such as those at the Premier mine, appear 

to have resulted from original primary deposition of rich silver 

minerals combined with some enrichment; and still others may be 

wholly primary.

Stocks, dikes, and sills of premineral porphyry are reported to 

occur in the Salmon Kiver drainage basin in British Columbia at 

least as far north as the Big Missouri mine, and the writer believes 

that they are genetically connected with the Texas Creek intrusive 

rocks. There is a possibility that some of the mineralized veins that 

occur farther away from the main Texas Creek batholith in associa-
62 GEOLOGY OF HYDER A1STD VICINITY, SOUTHEASTERN ALASKA

tion with these far outlying porphyries may carry minerals richer 

in silver; this, however, is only a hypothesis.

The Coast Range batholith in the Hyder district consists of quartz 

diorite, granodiorite, and quartz monzonite, with included belts and 

fragments of schist and injection gneiss and small quantities of associated diorite and more basic rocks. Very few mineral deposits have 

been discovered within the core. In the past this has commonly been 

ascribed to an actual scarcity of metallization there, but it is now 

being recognized as possibly due in part to the exceeding ruggedness 

of the country and its inaccessibility, with consequent slight prospecting. Mineral deposits of economic importance occur in the belts 

of metamorphic complex inclosed within the batholith, and there is 

no doubt that others will be found. In the writer's opinion, however, 

the chances are slim for any individual prospector to find an ore deposit of economic importance under present conditions within the 

Coast Range batholith along a valley as inaccessible as that of Chickamin River. If prospecting is carried on within the batholith, the 

bands of schist and the extreme borders of the batholith would in general appear to be the more favorable localities.

The predominant types of metalliferous deposits within the belta 

of crystalline schist and injection gneiss included within the core 

of the Coast Range batholith include replacement and impregnation deposits carrying copper (chalcopyrite) and zinc (sphalerite). 

Quartz fissure veins with copper or rarely molybdenite and mineralized schist bands with galena, sphalerite, and tetrahedrite, are also 

present. Within the belts of schist and gneiss bands of oxidized, 

rusty-weathering, sulphide-impregnated rock are also common. 

Predominantly these bands carry only pyrite or pyrrhotite or both, 

with a little chalcopyrite and a very low content in gold, and under 

present conditions they are of no value. But some carry combinations of pyrrhotite, chalcopyrite, sphalerite, and galena and deserve 

consideration. Both types of deposit the iron sulphide impregnated bands and the base-metal bands have a similar weathered appearance, and the pyrite-pyrrhotite bands are so predominant that 

the base-metal bands carrying chalcopyrite, sphalerite, or galena, or 

a combination of these minerals, are liable to be passed over through 

lack of careful examination of the fresh rock.

Sphalerite and pyrrhotite are the predominant minerals in several metallized zones in the schist and gneiss belts at or near the western border of the batholith. It seems highly probable that other 

similar deposits will be found as these belts of metamorphic rocks 

are more thoroughly prospected.

The low-grade copper deposit of the Hidden Creek mine, at Anyox, 

British Columbia, occurs in a belt of greenstone and argUlite in-
MINES AND PROSPECTS 63

closed within the central part of the batholith. Dolmage 24 reports 

that 13,215,000 tons of copper ore averaging 2.14 per cent copper has 

been developed. About 7 miles west of the Hidden Creek mine, at 

Maple Bay, on the east side of Portland Canal, another copper mine 

is being developed in the same belt of schist. This schist is reported 

to occur also on the west side of Portland Canal. The common metallic minerals are pyrite, pyrrhotite, chalcopyrite, zinc blende, magnetite, and arsenopyrite. They are believed to be the result of the 

replacement of greenstone and argillite.

Wright 25 reports a 2-foot copper vein in a belt of schist included 

within the Coast Range batholith on Unuk River about a mite below 

the international boundary. The vein consists of pyrite, pyrrhotite, 

and chalcopyrite.

A vein carrying considerable quantities of sphalerite is reported 

to occur on Taku River about a mile from the international boundary. 

The predominant minerals are pyrrhotite and sphalerite with a little 

pyrite, galena, and locally chalcopyrite. The ore gives low assays for 

gold and silver.

On Quartz Creek, a tributary of Iskoot River, about 30 miles from 

its mouth, there are bands of schist metallized with sphalerite and 

galena and locally with stringers of tetrahedrite carrying considerable silver.

At the Whiting River prospect, in the Juneau district, there is a 

quartz fissure vein in a belt of marble inclosed in quartz diorite. 

The metallic minerals comprise arsenopyrite, pyrite, galena, sphalerite, and chalcopyrite, with arsenopyrite predominant. The silver 

content is moderate, but there is considerable gold. Quartz porphyry 

dikes cut the marble near the vein.

MINES AND PROSPECTS

As stated on page 2, the following descriptions cover only the 

developments to 1925.

MOUNTAIN VIEW

The Mountain View group (see pi. 11) comprises eight claims and 

a fraction and lies mainly between Skookum and Fish Creeks just 

above their junction but in part below it. Five of the claims are 

patented by John Hovland. The property has been undergoing 

active development since June, 1925, in charge of Arthur Moa. In 

1926 the purchase of the property by a group of Ketchikan business 

men was reported.

M Dolmage, Victor, Coast and Islands of British Columbia between Douglas Channel 

and the Alaskan boundary: Canada Geol. Survey Summary Kept, for 1922, pt. A, p. 20, 

192:1,.

 « Wright, F. E., The Unuk River mining region of British Columbia : Canada Geol. 

Survey Summary Kept, for 1905, p. 50, 1906.
64 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

The eastern contact between the Texas Creek granodiorite and the 

rocks of the Hazelton group runs through the middle of the property. 

The veins occur both in the granodiorite and in the sedimentary beds. 

Most of the work has been done on three veins, but several other 

quartz veins and stringers are found on the property. ^

On Fish Creek No. 3 claim a quartz fissure vein with mineralized 

shoots has been prospected by several open cuts and stripping, and 

an adit 325 feet in length driven on the vein had been completed 

by December 8, 1925. The vein is in granodiorite and has been 

traced for 400 feet with a strike of about N. 7° E. and a dip of 45°- 

50° E. The southern 250 feet of the vein ranges between 3 and 4 

feet in width. The northern part splits into two branches about 10 

feet apart. The upper branch is several inches thick and carries 

shoots of ore. The lower branch is the main one; for 75 feet it ranges 

from 6 inches to 2 feet in width, averaging about a foot, and for 

the next 75 feet it is between 5 and 9 inches wide. About 120 feet 

north of the adit portal the vein is cut by a malchite dike. Along 

the northern part of the vein a large barren vein of milky-white 

quartz strikes in toward it and from the point of contact runs 

parallel to it. The barren vein is the older, as it is intersected by 

a narrow offshooting stringer from the mineralized vein. An open 

cut has been made where the two veins touch. The mineralized vein 

pinches to narrow stringers beyond the open cut, and its possible 

extension is covered; the large barren quartz vein continues beyond. 

In the adit the first 110 feet of the vein averages about 4^ feet 

in width and carries seams and pockets of sulphide throughout. As 

exposed at the surface the vein shows many moderately to heavily 

mineralized shoots. The adit will give a maximum depth of about 

100 feet. About 200 feet north of the adit portal a 60-foot mineralized 

shoot with an average width of 2 feet is exposed at the surface. 

It is reported to average about $14 to the ton. The sulphides include pyrite (which in one local shoot several inches thick assayed 

$30 to the ton in gold), pyrrhotite, galena, chalcopyrite, sphalerite, 

a little tetrahedrite and freibergite, and a trace of arsenopyrite.

On Fish Creek No. 2 claim a vein has been traced by a series of 

open cuts for a length of 475 feet. It is in the Texas Creek granodiorite, strikes N. 50° W., and dips 40° NE. Mr. Moa reports that 

the vein has an average width of about 4 feet and that it is 43/4 feet 

wide at the northwest end and 5 feet wide at the southeast end; its 

extensions in each direction are buried under overburden. The 

southeastern part of the vein consists of pyritic quartz with some 

chalcopyrite, galena, and tetrahedrite. In the northwestern part 

the sulphides comprise mainly pyrrhotite and pyrite, with sonvi 

galena and chalcopyrite and a little sphalerite, tetrahedrite, f reiberg-
,i MINES AND PKOSPECTS 65

ite, and scheelite. The. vein material breaks free from the country

* rock and is separated by a surface of gouge. A 40-foot crosscut adit

has been driven to the vein about 20 feet below the outcrop. At the

V end of the adit there is a iy2 -foot vein of quartz, heavily mineralized,

,; with pyrite and small quartz stringers in the hanging wall. A short

i drift on the vein 3 feet to the west is reported to have shown 3 »feet

of solid quartz with mineralization similar to that at the surface.

( In the open cut above the tunnel the vein zone is 6 to 8 feet thick,

with 5 to 6 feet of mineralized quartz and the remainder included

<:' bands and fragments of country rock. The quartz is heavily miner-

'' alized with layers and disseminated deposits of coarsely crystalline

I pyrite, which may form as much as half the vein by volume. A

k noteworthy feature of this vein is a mineralized shoot about 15 feet

;' long and as much as 18 inches wide, composed of interbanded fine-

 > grained barite and quartz with seams of tetrahedrite and freibergite,

\ considerable disseminated scheelite and pyrite, and a little chalcopyrite. This shoot is well exposed in the open cut about 15 feet

\ northwest of the cut above the adit. In the southeast wall of this

'; cut the vein consists of two parts. One is a quartz vein 2 feet thick,

very heavily mineralized with pyrite, which pinches to a narrow

stringer on the northwest, in the face of the open cut. The other is

'. the baritic shoot, which is here 12 to 18 inches thick but which to the

; northwest passes into a quartz vein 10 inches thick, with only a few

thin interbands of barite in the hanging wall, and about 8 feet to the

f southeast thins to a few inches. In the face of the open cut the

vein is offset several feet by a thrust fault. Mr. Moa reports that

recent work has shown that a little barite occurs in the vein for a

length of 100 feet, and that tetrahedrite in varying amounts occurs

throughout a length of 400 feet. Moil samples across this vein for

widths of 9 to 32 inches are reported by Mr. Moa to show assay

values ranging from $5 to $12 in gold to the ton and from 1 to 70

ounces in silver, with an average of about 15 ounces to the ton. The

pyritic quartz vein shows the smaller assay returns in silver, and

the baritic shoot the higher. A few general assays are given below

to show the character of the ore.

Assays of general samples from Fish Creek No. 2 vein, Mountwhi View

property, Hyder district

Source of sample

East end of vein..

Old ore pile from vicinity of baritic shoot.................. _ ...... __ ..

Open cuts made in 1925 .. ____ ...--..... ..........................

(per

C)

0

2.6

Silver

(ounces 

to the

ton)

21.24

39.84

10.20

Oold

(ounce 

to the

ton)

0.28

.38 .60'

'Not determined.
66 GEOLOGY OP HYDER AND VICINITY, SOUTHEASTERN ALASKA

On Fish Creek No. 1 claim a mineralized quartz vein that strikes 

N. 60° W. and dips 55°-70° NE., has been prospected by a series of 

small pits and a stripping and has been traced for a length of 450 

feet. In the Texas Creek granodiorite at the northwest end there is 

a fissured zone iy2 fee^ wide with 8 inches of quartz. A malchite 

dike cuts across the vein here. In the first open cut east of the trail 

the vein is along the contact between granodiorite and contact-metamorphosed brown quartzitic slate. The vein is 12 to 20 inches thick 

and contains a few small pockets heavily mineralized with galena, 

pyrite, and sphalerite. To the southeast the vein is in the quartzitic 

beds, where it occupies a fissured zone apparently at an angle to 

the bedding. The vein is cut by a 75-foot dike of pink granodiorite 

porphyry, which is connected in origin with the Hyder quartz monzonite. Southeast of the dike a 25-foot cut has been made along the 

vein, which occurs here ,in a light-colored granitic facies of the Texas 

Creek granodiorite that is probably a dike with small inclusions of 

quartzite. Still farther southeast the vein cuts white aplite dikes. 

Here the fissured zone is 15 feet or so thick, and within this zone 

there is a 2-foot quartz vein with bands of galena, pyrite, or sphalerite and narrow stringers of quartz, some of which are moderately 

mineralized. In the face of the slope to Fish Creek two adits have 

been driven on a vein that belongs to this fissured zone. The upper 

adit is 50 feet long and follows a sparsely mineralized quartz 

stringer. The country rock is mostly a light-colored facies of the 

Texas Creek granodiorite with practically no ferromagnesian minerals. About 70 feet vertically below this adit another 50-foot adit 

follows the vein, which ranges from 3 inches to 2,y2 feet in width 

and is locally heavily mineralized with sphalerite, pyrite, and galena.

Molybdenite flakes are present here and there in the aplite and 

pegmatite dikes. About 60 feet vertically below this adit another 

has been driven for 90 feet along a stringer that lies slightly to the 

southwest and below the vein zone in which the upper two adits 

were run. This lowest adit starts in a granitic rock and ends in 

quartzitic beds. The rock at the mouth of the adit appears to be 

an altered aplite. The vein is 6 inches to 2 feet in width. An 

8-foot crosscut at the end of the adit exposes a stringer of quartz 

4 to 6 inches thick carrying free gold.

Slightly to the northeast and above the main Fish Creek No. 1 

vein on the bank of Fish Creek there- is a small mineralized quartz 

vein in an aplite dike. This vein strikes N. 80° W. and is exposed for 

a vertical distance of 35 feet. It is moderately to heavily mineralized with pyrite, galena, sphalerite, and tetrahedrite.

The veins along the bank of Fish Creek that have been described 

may be considered as all belonging to the same fissured zone, over
MINES AND PEOSPEOTS 67

100 feet thick, in a complex of Texas Creek granodiorite and aplite 

dikes and baked quartzitic slate.

The Mountain View property is equipped with a bunk house and 

kitchen, cabin, assay office, a 50-horsepOAver water wheel operating 

under a 100-foot head and fed through 750 feet of 14-inch wooden 

pipe, a compressor, and a 4,000-foot aerial tramway running from 

the cabin to the Salmon River road.

LUCKY BOY EXTENSION

The Lucky Boy Extension claim is held by John Coghlan, of Vancouver, and is just east of the junction of Skookum and Fish Creeks, 

adjoining Fish Creek No. 5 claim of the Mountain View group. On 

the bank of a small creek southeast of Fish Creek, at an altitude of 

about 650 feet, a 50-foot crosscut adit has been driven to cut a vein 

about 30 feet below its outcrop. From the end of the adit a 50-foot 

drift has been run on the vein. The country rock is brown thinbedded slaty quartzite. The vein consists of a fissured zone 2 to 3 

feet thick with quartz stringers aggregating 6 to 12 inches in thickness, locally mineralized with pyrite, galena, and sphalerite. At the 

surface an open cut exposes a 2-foot fissured zone with as much as 

16 inches of quartz moderately mineralized with pyrite, a little galena 

and sphalerite, and a trace of pyrrhotite and chalcopyrite. The vein 

strikes N. 60° W. and dips 40°-55° N.

BISHOP

The Bishop claim is north of the Mountain View property, on the 

west side of Skookum Creek. It is patented by Pete Low. A strong 

quartz vein, which is as a rule 15 to 27 inches wide but is 6 to 7 feet 

wide on the slope to Skookum Creek, has been prospected by several 

open cuts and on surface exposures. It has been traced for 600 feet 

with a strike of N. 45° W. and a dip of 50° NE. and is exposed for 

a difference in altitude of 100 feet. The country rock i& the Texas 

Creek granodiorite. The mineralization is relatively low, and the 

sulphides comprise pyrrhotite and pyrite with a little chalcopyrite. 

Galena is rare, and the content of gold and silver is reported, to be 

low.

VICTORIA

The Victoria group comprises 25 claims held by the Adanac1 Syndicate, with offices in Victoria, British Columbia. Of these claims 15 

were staked in 1921 as the Adanac group and 10 are claims belonging1 

to what was formerly known as1 the Mammoth group, relocated in 

1924. These claims are four deep along the international boundary
68

west of Mount Dolly. Several short adits have been driven to fulfill 

assessment requirements, but only local sparse mineralization has 

been found.

FISH CREEK

The Fish Creek group (see pi. 12) comprises 18 claims, of which 3 

the Olympia, Nevada, and Starboard are patented. They lie mainly 

on the /ridge between Fish and Skookum Creeks but extend to both 

sides of these creeks, particularly west of Skookum Creek. On the 

south they are joined by the Mountain View group and on the west 

by the Monarch group. The property is under the control of the 

British American Holding & Development Co.

The contact between the Texas Creek granodiorite and the Hazelton group of greenstone, graywacke, and slate crosses the property in 

a direction a little west of north. The veins are predominantly in 

the granodiorite, but in part they cross the contact and occur to a 

minor extent within the Hazelton group. Mineral deposits of two 

types occur in this group of claims (1) quartz veins with shoots of 

galena, sphalerite, pyrite, tetrahedrite, and chalcopyrite; (2) lenticular bodies of pyrrhotite with small amounts of chalcopyrite, pyrite, 

and arsenopyrite. The quartz veins are predominant and so far as 

known are the only ones of value.

Most of the work has been done on the Starboard, Olympia, and 

Olympia Extension claims. Several tunnels and drifts on the 

Olympia Extension claim are not shown on the claim map, owing to 

lack of a survey. On these three claims there are four approximately 

parallel quartz veins lying just at the contact of the granodiorite and 

the Hazelton group but almost wholly within the granodiorite. 

These veins occur within a distance of 2,000 feet, measured on a horizontal plane at right angles to the strike.

The vein nearest the cabin on Starboard No. 1 claim has been 

prospected by two adits, Nos. 1 and 2, which are 50 and 40 feet in 

length on the vein at altitudes of 1,510 and 1,410 feet, respectively. 

The vein strikes N. 35°-40° W. and dips 65°-70° NE. It has been 

traced for a length of 400 feet from the upper adit to Skookum Creek. 

On the slope to Skookum Creek and at the portal of the lower adit 

the vein is 3 feet wide. At the portal of the upper adit it is 2 to 3 

feet wide, but along the adit to the southeast it breaks up into a number of quartz stringers. The vein carries local shoots mineralized 

with sulphides but is lean for considerable portions.

About 450 feet northeast of this vein is another on the Starboard 

No. 2 claim, which strikes N. 60° W. and dips 65° NE. At an altitude of about 1,600 feet a TO-foot adit (No. 3) has been driven on 

this vein. At the portal the vein is 3 feet 9 inches thick, but at about
MINES AND PROSPECTS 69

50 feet from the portal it breaks up into a zone o'f fractured country 

rock and narrow quartz stringers. At this point large quartz stringers 

shoot off into the footwall. About 30 feet vertically below this adit 

an open cut has been made on the vein. The vein here consists of a 

fissured zone in granodiorite with stringers of quartz, some of which 

carry shoots a few inches to 8 inches thick and heavily mineralized. 

In general shoots of good ore occur in this vein, but much of it is 

lean. To the northwest it can be traced across Skookum Creek. The 

visible minerals it carries are galena, tetrahedrite, pyrite, and some 

chalcopyrite and sphalerite.

On the Olympia claim, about 350 feet northeast of this vein, at 

right angles to the strike, is another vein, which has been prospected 

by three adits (Nos. 4, 5, and 6) at altitudes of about 1,930,1,900, and 

1,800 feet, with lengths of 60, 109, and 185 feet, respectively. The 

vein strikes N. 50° W. and dips 45°-50° NE. Its width at the portals 

of the three adits is 19, 24, and 15 inches. A raise connects the middle 

and upper adits, and the vein has been partly stoped for 30 feet 

above the upper adit. In these upper workings it averages less than 

a foot in thickness but contains shoots of ore up to the full width. 

Locally, many quartz stringers occur in the footwall at a wide angle 

to the main vein. Most of the upper two adits are in Texas Creek 

granodiorite. but the ends of the adits are in intensely fractured 

tlickensided brown honistone, which is a metamorphosed facies of 

the Hazelton group. Westgate reports that the vein in the middle 

and lower adits is cut off by a fault that strikes N. 30° E. and has, 

an approximately vertical dip. The lower adit was filled with water 

at the time of the writer's visit. "Westgate 28 gives the following 

description:

On the Olympia claim the longest tunnel on the property goes in on the 

vein 240 feet, to a point where the vein is cut off by a fault that strikes N. 30° 

E. and dips 60° NW. Drifts have been driven parallel to the fault in both 

directions, but the vein has not been recovered, unless a composite vein, offset 

about 50 feet to the southwest, is its continuation. The work had not been 

carried far enough to demonstrate this. From the mouth of the tunnel the 

vein can be followed on the surface northward perhaps 30 feet, to a point 

where it is cut out by a fault and broken zone that seems to have much the 

same direction as that at the face of the tunnel. The vein system in this part 

of the property is thus cut by a series of faults which run N. 30° E. and dip 

steeply northwest.

The visible sulphides comprise galena and pyrite with tetrahedrite, 

sphalerite, and a little chalcopyrite. Microscopic examination shows 

a little freibergite also present locally.

North of the Olympia vein, on the Olympia Extension claim, a mineralized quartz vein in the Texas Creek quartz diorite has been traced 

for 600 feet by prospect pits and trenches. The vein strikes N. 60°

20 Westgate, L. G., op. cit. p. 136.
70 GEOLOGY OF HYDER VICINITY, SOUTHEASTERN" ALASKA

W. and dips 40°-5t)° NE. It ranges from an inch or so to 10 feet in 

width and averages about 3 feet. The vein matter breaks freely from 

the wall rock, and the walls show marked slickensiding. A narrow 

dike of dense black lamprophyre cuts the vein. At the longest surface trench the vein is 4 to 6 feet wide and consists of quartz with 

5 per cent or more of disseminated sulphides and with stringers of 

solid sulphides so localized as to constitute rich ore shoots. The 

gangue is mostly quartz, with some ankerite and here and there a 

little barite. The visible sulphides include galena, tetrahedrite, chalcopyrite, pyrite, and sphalerite. The tetrahedrite occurs in solid 

stringers as much as 2 inches wide. At an altitude of 2,800 feet on 

the west side of the ridge west of Skookum Creek a crosscut adit 125 

feet long is driven to intersection with the vein. Near the end of 

the adit is a winze on the vein 42 feet deep and a drift that extends 

87 feet to the southeast and 12 feet to the northwest. Near the southeast end of the drift there is another winze on the vein and a raise. 

Along the drift the vein ranges from 2 to § feet in width. In the 

winze the vein is reported to narrow and the tenor to decrease. In 

the face of the northwest end of the drift there is 6 feet of quartz 

with inclusions of the country rock; 2 feet of the quartz is heavily 

mineralized. It is reported that a sample across the face of the drift 

here averaged $20 to the, ton. At the southeast end of the drift the 

vein is <% feet thick, and a sample across it is reported to have averaged $64 to the ton. A shipment of 64 tons' of sorted ore from this 

drift sent to the Tacoma smelter is reported to have averaged $90 to 

the ton.

The following figures are taken from assay reports furnished by 

the mining company representing lots of sorted ore taken from veins

on the Starboard and Olympia claims and shipped to the Tacoma 

Smelting Co. in 1916 and 1917, also samples across the Olympia 

Extension vein.

.Assays of ore from Starboard, Olympia, and) Olympia Extension claims, Hyder

district

Starboard No. 2 ___ ..........

Do... ... ... ... -

T)Q. .........................

T)n

DO.-- ......... . ...... .

DO.- ........... -- _ .

Do... 

Do.. - "Hn

Do.. .

Material represented by 

sample

15 (?) tons.. ................

5 tons. ........ _ .... 

.....do.. .................

Yt ton... . ........... ........

5 tons _ . ____ . ..........

.....do... ................

8 tons ____ ______ ..

Gold 

(ounces 

to the 

ton)

0.40

.21 

.18

.90

.18

.37

.15

.30

.27

Trace. SR

1.42

.92

.32

Silver 

(ounces 

to the 

ton)

376

161.1 

103. 4

706.7

216.0

316.0

110.4

205.4

299. 96

3.0

04 a

79 1

,4.4

Lead 

(Per 

cent)

32.4

18.3

01 <1

32.2

IQ n

38 Q

32.5

17.0

26.

6.5

C)

C)

H

e '

9 *

Copper 

(per 

cent)

3.30

1.96 

1.51

7.68

2.79

i ns

Trace.

3.90

3.36

Trace. ( )

(«)

2.0

TVnr»A

 Not determined.
MINES AND PROSPECTS 71

On the west slope of Skookum Creek the Olympia Extension vein 

has been prospected by two tunnels, giving a maximum depth on the 

vein of 250 feet. On the east side of Skookum Creek, at an altitude 

of about 2,400 feet, an adit (No. 8) has been driven 175 feet in the 

greenstone with the intention of cutting the projected extension of 

the Olympia Extension vein.

On the Nevada claim a quartz fissure vein in the greenstone has 

been prospected by several pits and a 44-foot crosscut .adit (No. 7) 

with a 25-foot drift. The vein strikes N. 70° W. and dips 45° N. 

The surface rock looks like greenstone, but the rock in the tunnel 

is a brown fractured, slickensided hornstone. A dike of Texas Creek 

quartz diorite cuts the beds at the portal of the adit. At the east 

end of the drift the vein is 15 inches wide, and at the west end it is 

several inches wide. There are many quartz stringers in the footwall

zone, some of which are as much as 2 feet in width. Pits expose the 

outcrop of the vein 50 feet vertically above the adit. The sulphides comprise galena and a little chalcopyrite, sphalerite, and 

tetrahedrite.

On the Summit claim at its north end, at an altitude of about 

2,850 feet, a body of pyrrhotite has been prospected by a shaft and 

pits. A dike of Texas Creek quartz diorite cuts the Hazelton group 

north of the shaft. Westgate 27 gives the following description:

Here the country rock is a greenish-gray fine-grained greenstone marked by 

veins of calcite and abundant small crystals of pyrite. The microscope shows 

it to be composed almost wholly of secondary minerals, chiefly quartz and sericite. Abundant chlorite and calcite occur along seams, with leucoxene, pyrite 

crystals, and a little fine-grained orthoclase. A few large rounded quartz 

.grains resemble the phenocrysts in rhyolite and suggest that the original rock 

may have "been a quartz porphyry. An indistinct bedding bears N. 70° E. 

and is nearly vertical. In this greenstone are masses of almost pure pyrrhotite. The largest measures about 5 by 12 feet at the surface and stands 

 6 feet above the water level in a shaft that was sunk in all 10 feet without 

reaching the bottom of the pyrrhotite. With the pyrrhotite there is a little 

chalcopyrite and quartz. A polished section of the ore shows mainly pyrrhotite, with small amounts of pyrite, arsenopyrite, chalcopyrite, and a little 

gangue, mainly quartz. The order of mineral formation seems to be pyrite, 

arsenopyrite, quartz, pyrrhotite, and chalcopyrite, the last two essentially contemporaneous. A polished section of the immediately adjoining country rock, 

which contains abundant sulphides, shows mainly quartz and some arsenopyrite, irregularly cut by pyrrhotite, finely veined by later pyrite, and chalcopyrite. The arsenopyrite appears to have been fractured before the introduction of the quartz and other sulphides. An assay of samples from thirf 

l>ody was reported by the owner to give gold, 0.36 ounce to the ton; silver, 

4 ounces to the ton; copper, 2 per cent.

The property is equipped with a bunk house, cookhouse, office, 

blacksmith shop, and compressor, favorably located for the development of the Olympia Extension vein.

" Westgate, L. G., op. cit, pp. 137-138.
72 GEOLOGY OP HYDER AND VICINITY, SOUTHEASTERN ALASKA

HYDEfl JUMBO

The Hyder Jumbo group of claims includes 18 surveyed claims 

lying adjacent to the international boundary north of the Titan 

group. This group was restaked in 1924. Practically no work has 

been done on the property, and no mineralization of importance 

has been found. Gash veins of quartz with some chlorite occur but 

are not known to be of value.

HYDEK SKOOKUM

The Hyder Skookum group comprises 12 claims tnat lie on the flattopped ridge and slope west of Fish Creek and adjoin the Fish Creek, 

Titan, and Hyder Jumbo groups. At an altitude of about 3,200 

feet there are two very strongly defined approximately parallel 

quartz veins striking northwest and dipping steeply to the south. 

Both veins locally form a breccia with the country rock. The southern vein is in part in a dike of porphyry belonging to the Texas 

Creek batholith and in part in greenstone of the Hazelton group. 

A small stringer in the greenstone carries a little disseminated 

sulphide. The northern vein is wholly in the greenstone. Locally 

fragments of country rock, forming a breccia with the quartz, are impregnated with pyrite. The veins have a width of as much as 7 feet. 

As exposed at the surface they carry a little calcite but are mostly 

barren oi sulphides.

At an altitude of 3,200 feet, just northeast of the cabin, an open 

cut has been made on a sulphide replacement deposit in a schistose 

zone in greenstone near the contact with a dike of porphyry of the 

Texas Creek batholith. The sulphides occur as solid Aasses and 

seams in the greenstone and as disseminated deposits in quartz 

within the zone. Pyrrhotite predominates, and with it are associated a little chalcopyrite and arsenopyrite. The vein is 2% feet 

wide, strikes N. 50° W., and dips 60° S.

TITAN

The Titan group comprises 10 claims between the upper part of 

Fish Creek and the international boundary. They were staked 

in 1917.

The country rock here consists of -greenstone and intercalated 

beds of slate, belonging to the Hazelton group, with dikes of gray 

sheared porphyry of the Texas Creek batholith and dikes of pink 

to white fresh, relatively massive granodiorite porphyry of the Hyder 

batholith. Just west of the international boundary, at altitudes of 

4,500 to 4,700 feet, there is a bed of coarse purplish to green-gray 

volcanic breccia several hundred feet thick, which extends in a 

direction a little west of north.
J. 8. GEOLOGICAL 8TJBVEY BULLETIN 807 PLATE 31

 RIVERSIDE 

M//V//VG Co.

B/SHOP QUARTZ CLAIM 

Peter Low (owner)

TUNNEL No. 3 

TUNNEL No 2 

TUNNEL No I

Quartz 1, 

showing

 INTAKE DAM 

ABOVE POWER PLANT

PROPOSED

PLANT

LUCKY BOY EXT.

SKETCH MAP OF MOUNTAIN VIEW GROUP OF CLAIMS 

Adapted from map by A. O. Moa
U. S. GEOLOGlfiAL SURVEY BITLLETIN 807 PLATE 12

(,000 Feet

SKETCH MAP OF CLAIMS NEAR FISH CREEK 

Adapted from map by F. J. Wettrick, United States mineral sat veyor
U. 8. GEOLOGICAL SURVEY BULLETIN 807 PLATE 13

B. C.

SILVER MINES 

LTD.

2,000 Feet

SKETCH MAP OF STONER, DALY-ALASKA, VIRGINIA. AND OTHER CLAIMS
U. S. GEOLOGICAL SURVEY BULLETIN 807 PLATE 14

A. VIEW AT HEAD OF CHICKAMIN RIVER

Showing the foot of Chickamiu Glacier in the foreground and old terminal moraine in center

i»

B. SNOW FIELD AND TRIBUTARY GLACIERS ON THE PASS AT THE HEAD OF

THROUGH GLACIER
MINES AND PROSPECTS

Most of the development work has been done to prospect a vein 

in a big northwestward-trending dike of sheared and altered 

porphyry, which includes many thick layers of slaty rock and greenstone. It is impossible to delimit the southwestern boundary of the 

dike owing to the interlamination of the rock and to its covering 

of moss. The porphyry is an offshoot from the Texas Creek batholith, which probably underlies the country at a depth of not more 

than a few thousand feet. The porphyry contains some large crystals 

of feldspar, but for the most part it shows small quartz and feldspar 

phenocrysts in a dense pale-green sericiti/ed and silicified groundmass. Hornblende crystals are seen where the rock is not too fine 

grained.

The vein is being prospected by an adit and several crosscuts with 

a total length of 540 feet and by a couple of open cuts at the surface.

It has been traced by intermittent outcrops for 250 yards and for a 

difference in altitude of 275 feet. The vein strikes N. 50°-60° W. 

and dips 45° SW. At the southeast end there is a 10-foot fissured 

zone containing 1 to 2 feet of quartz in stringers and a narrow band 

of slate. At an altitude about 180 feet above the adit level there is a 

wide zone in which narrow quartz stringers and a band of slaty 

rock 12 feet thick are exposed. A band of the porphyry several feet 

to 5 feet wide contains quartz stringers, some of which are 8 inches 

thick. The porphyry is impregnated with pyrite, and the quartz 

contains disseminated sphalerite, galena, pyrite, and chalcopyrite. 

Sphalerite is by far the most abundant. Quartz stringers occur also 

in the foot and hanging walls of the slate. The vein has no definite 

walls. To the northwest and ,at an altitude about 30 feet lower 

another open cut exposes a band of porphyry about 20 feet wide 

impregnated with pyrite and containing reticulating narrow quartz 

stringers. The slate band found in the upper open cut is absent 

here. From its portal, at an altitude of about 3,350 feet, the adit 

starts about N. 70° E., turns southeast, and in 1925 was being driven 

about S. 30° W. Two crosscuts from the adit run in a general northeasterly direction. The vein had not yet been cut, but if it continues to 

that depth with the same dip as that at the surface it should be intersected by the adit within a short distance. The irregular course of 

the adit resulted from difficulties in correctly tracing the course of 

the vein down the hillside above the tunnel. It now appears that 

what may be the continuation of the vein zone was cut near the 

portal of the adit and that the adit has been driven wholly in the 

footwall country rock. In the adit, 100 feet from the portal, there 

is a 5-foot pyritized zone with quartz stringers, and at 60 feet in 

there is a 1^-foot quartz vein with included stringers of rock. If 

this is the vein zone in depth, then the maximum difference in alti6196 29 6
tude exposed on the vein is 450 feet. The slate band exposed at the 

surface evidently is cut off in depth. Assays of average samples of 

the vein .are not available. Picked samples from the mineralized 

surface outcrops are reported to run high in gold and silver. Low 

assays in gold and silver are reported from mineralized bands intersected in the adits and crosscuts.

About three-eighths of a mile east of the camp, at an altitude of 

about 4,000 feet, in the bed of a gulch, a quartz vein 7 to 10 feet 

thick is exposed. This vein appears to strike northeast and dip 30° 

SW.; but it is crossed by a dike of granodiorite porphyry belonging 

to the Hyder batholith, which has caused considerable disturbance, 

as indicated by the pronounced slickensiding within the quartz vein. 

Local shoots in the hanging wall and footwall of the quartz carry a 

little disseminated galena, sphalerite, pyrite, and chalcopyrite. The 

vein occurs within slate and tuff and is cut off on the northeast, on 

the downstream side, by a dike of the same granodiorite porphyry, 

which strikes northwest. Another dike of the porphyry lies about 

125 feet to the south and strikes north-northwest. Above the outcrop 

of the vein, between these two granodiorite porphyry dikes, there 

are two dikes of the older porphyry in the slate and greenstone tuff 

of the Hazelton group. One of the younger dikes on the northeast 

side appears to terminate at an altitude about 300 feet higher than 

the quartz outcrop, and it forms the northeast bank of the gulch 

above the outcrop. The vein is exposed for a vertical difference in 

altitude of 75 feet. The strike and dip of this, vein are uncertain; 

it is exposed for only a short distance, and more surface prospecting 

is necessary before any extensive underground development should 

be undertaken.

In the south bank of the gulch, north of the Titan adit and at 

about the same altitude, there is exposed a shear zone in schistose 

greenstone heavily mineralized with arsenopyrite and a little galena. 

This has not been prospected.

Between altitudes of 4,450 and 4,800 feet there is an immense 

quartz vein in the slate, tuff, and greenstone, which lies near the 

contact of a porphyry dike. The vein is about 4 feet thick at the 

lower altitude and 10 to 15 feet thick at the higher. At the higher 

altitude the vein consists of interbanded very coarse calcite and 

 quartz. The calcite forms more of the vein than the quartz. A 

branch vein runs off to the northwest at this locality. The vein 

strikes N. 35°-40° W. and dips 65°-75° NE.

MONARCH

The Monarch group comprises 10 claims held by Moa, Ickis & 

Hovland. They lie between the group of the Fish Creek Mining 

Co. and the Kiverside group. A series of northwestward-striking
MINES AND PROSFECTS 75

quartz veins in the Texas Creek granodiorite, with local narrow 

shoots mineralized with sulphides, are being prospected, but practically no development work has been undertaken.

At an altitude of 2,400 feet on the North Star and Alaska claims, 

below the old upper Fish Creek camp, there is an open cut on a 

quartz vein several inches to 10 inches thick, with local shoots heavily 

mineralized with galena, pyrite, tetrahedrite, sphalerite, and chalcopyrite. Locally there is considerable barite and sparse grains of scheelite. The mineralized shoots are reported to give assays of $20 to $30 

to the ton in gold. A specimen of the clear tetrahedrite is reported 

to have assayed 266 ounces in silver and $28 in gold to the ton. The 

vein strikes N. 55° W. and dips 75° NE.

At an altitude of 2,000 feet, in the bed of a small gulch, an open 

cut has been made along the strike of a fissured zone in granodiorite. 

This zone is about 6 feet wide, with about 2 feet of quartz as stringers 

or as masses with many layers of the country rock. There are sparse 

local shoots of galena in the quartz, and disseminated crystals and 

thin bands of pyrite are common. The vein strikes N. 55° W. and 

dips 70° NE.

About 1,000 feet southwest of the camp, at an altitude of 2,100 

feet, a big vein of milky-white quartz has been traced for 500 to 

600 yards on the Wano claim. Grains of pyrite are present here and 

there, and rarely grains of galena, but no ore shoot has yet been 

found.

On the Extenuate claim, about a quarter of a mile a little south of 

west of the camp, in the bed of a small gulch, at an altitude of 1,550 

feet, a quartz vein has been exposed by stripping for 25 yards and

 can be traced for a length of 200 feet. It ranges from 5 to 16 inches 

in width and carries local shoots of galena and pyrite with a little 

chalcopyrite. The vein strikes N. 50° W. and dips 45° N.

LAST SHOT

The Last Shot group comprises two claims patented by Charles 

Fehring. They adjoin the Monarch and Riverside groups and lie 

about three-quarters of a mile southeast of the Riverside. There are 

two veins exposed on the group, only one of which has been prospected. Both veins are in the Texas Creek granodiorite and strike 

northwest. ^ A quartz vein has been traced by surface exposures, pits, and open

 cuts for a length of about 150 feet and is exposed for a vertical difference of 75 feet. This vein strikes N. 60° W. and dips 45° NE. 

At the southeast end, where stripped, it is only a couple of inches 

thick and contains disseminated sulphides. About 35 feet northwest 

it is l!/2 feet thick and has inclusions of country rock; 12 feet farther
76 GEOLOGY OP HYDER AND VICINITY, SOUTHEASTEKN ALASKA

northwest it is exposed in the face of a bluff, where it is 12 feet 

thick, with the hanging wall not exposed. This thick cap of quartz, 

is exposed for a length of 50 feet. A shoot of almost solid sulphide8 to 18 inches thick is exposed for a length of 30 feet in the footwall 

of the thick quartz cap. At an altitude of about 1,300 feet, a 25-foot 

crosscut adit has been driven just below the surface outcrop. In; 

the breast of this tunnel it is seen that the thick quartz cap passes 

downward into a series of stringers in the country rock. The mineralized shoot persists. The granodiorite for 4 or 5 feet beneath thevein at the portal of the tunnel contains man}7 narrow reticulating 

quartz veins inclosing pyritized fragments of the granodiorite, Avhich 

are locally so altered as to resemble schist. To the northwest of theadit each of two small pits shows about 3 feet of quartz Avith sparsedisseminated sulphides. The sulphides of the mineralized shoot comprise galena, pyrite, sphalerite, pyrrhotite, and chalcopyrite. Microscopic examination shows that tetrahedrite and freibergite are alsopresent.

At an altitude about 100 feet lower than the tunnel there is a largequartz vein 10 to 15 feet thick, with a strike of N. 10° W. and a steepdip to the west. At one point a small pocket of mineralized quartz. 

is exposed in the footwall.

HOWARD

The Howard claim lies to the north of the Sixmile group and 

adjoins the Riverside claims. The vein, at an altitude of. about 

630 feet, is in gr'anodiorite, strikes N. 30° W. and dips 40° NE., and 

consists of a fissured zone of indefinite thickness with many quartz, 

stringers. The vein is exposed for about 150 feet by several open, 

cuts and stripping. A few of, the quartz stringers are locally mineralized with sulphides or barite, or both. One such shoot consists 

of a body of quartz 10 feet long and 12 to 15 inches wide, moderately 

mineralized with galena, pyrite, and sphalerite.

SIXMILE

The Sixmile group comprises three claims at Sixmile, staked by 

Davis & Elvigion in October, 1924. They are at the foot of themountain on the east side of the Salmon River road.

The ore at this place was discovered when the rock was blasted 

out along the line of the new Salmon River road. Narrow stringersof quartz, phenomenally rich in visible free gold, were first found in 

loose fragments of fcne broken rock. One small picked sample 

assayed 1,080 ounces of gold and 200 ounces of silver to the ton. 

The gold occurs within the borders of the quartz stringers and in
MINES AND PROSPECTS 77

the adjacent granodiorite. Some of the stringers carry galena, and 

flakes of gold occur also within the galena. The country rock on 

the property is the Texas Creek granodiorite.

An average of five samples taken from the granodiorite, without 

visible quartz, in the wide zone where the narrow quartz stringers 

with free gold occur, gave 0.05 ounce of gold and 2.5 ounces of 

silver to the ton. A little pyrite is disseminated through the granodiorite. The quartz stringers are only one-sixth of an inch to an 

inch wide; the adjoining country rock is impregnated with pyrite, 

and some of its fractures are faced with pyrite and galena.

Two adits were being driven in 1925 on narrow quartz stringers. 

The southern vein strikes N. 50° W. and clips 70° NE. An adit 

35 feet long shows the vein at the portal a fraction of an inch wide; 

this thickens to 6 inches in the adit, and at the breast there is a

shattered zone several feet thick, with quartz stringers and shoots of 

sulphides consisting of galena with a little pyrite and chalcopyrite. 

Free gold has been found in a pocket at the portal of the adit.

Another adit 15 feet to the north is 35 feet long and follows a 

fissured zone, which in the breast of the adit is 5 feet wide and contains narrow stringers of quartz. The main quartz vein, 1 to 8 

inches wide, has shoots of galena and .pyrite with a little chalcopyrite and sparse sphalerite. Free gold is obtained by panning a narrow band of gouge exposed at the breast of the adit.

At an altitude of about 260 feet, in the bed of a gulch, an open 

cut exposes a fissured zone, 15 to 20 inches wide, with quartz stringers, some of which carry shoots of galena and pyrite. The vein 

strikes N. 42° W. and dips steeply to the northeast. A heavy pyritic 

quartz stringer is reported to have assayed 0.06 ounce in gold and 

0.6 ounce in silver to the ton; where galena was associated an assay 

gave 0.68 ounce of gold and 8.4 ounces of silver to the ton and 8.7 

per cent of lead.

RIVERSIDE

The Riverside group comprises ten claims on the east side of the 

Salmon River road, a little north of Sevenmile. The property has 

been developed to a stage more advanced than any other on the 

Alaskan side of the boundary in the Salmon River district. In 1924 

a 50-ton mill Avas installed for the concentration of the ores, using 

both tables and flotation, and in 1925 there were over 5,000 feet of 

underground workings. This mill was put into operation in the 

early part of 1925, and in a two months' run 109 tons of galena concentrate, carrying gold and silver, was produced. The property was 

idle for several months, pending arrangements for its operation by 

a new company. A small additional production was made in the
78 GEOLOGY OF HYDEE AND VICINITY, SOUTHEASTERN ALASKA

later part of the year. The altitude of the main adit is about 

260 feet.

The country rock is the Texas Creek granodiorite, with sparse 

included bands of rocks of the Hazelton group, which have been 

metamorphosed and recrystallized to injection gneiss. Pink to white 

granodiorite porphyry dikes associated with the Hyder quartz monzonite cut the country rock but have not been found in contact with 

the mineral veins on this property. Dark malchite dikes cut the 

country rock and also the veins.

Three mineralized quartz veins are 'being prospected, known as 

the Ickis vein, Cross vein, and Lindeborg vein or main lead. The 

Ickis and Cross veins are in the granodiorite; the Lindeborg is in a 

band of crumpled schist or injection gneiss included in the 

granodiorite.

The Ickis vein has been prospected by three adits; the lowest one 

is about 15 feet long; the middle one (now covered by the dump from 

the upper adit) is 35 feet higher and about 20 feet long; and the upper 

one, about TO feet above the lowest adit, is 500 feet long. In the 

upper adit the vein is about 20 inches wide at the face and is reported 

to be 4 to 5 feet wide in front of the entrance, where it is now covered 

by the dump. The adit was driven on the vein, which narrows to a 

stringer a fraction of an inch wide at about 200 feet from the entrance 

and does not thicken again within the length of the adit. The vein 

within the adit averages about 8 to 10 inches in width, with local 

pinches. The country rock is a shattered, slickensided gneissoid 

granodioritic rock. The vein occupies a fissure and consists of quart/ 

with local bunches strongly mineralized with pyrite arid galena and 

rarely with sphalerite. The vein has a general northwest strike, 

though varying considerably, and a steep northeast dip. Assays as 

high as $20 to the ton in gold, silver, and lead are reported. The 

vein matter breaks free from the walls. Stringers (droppers) of 

quartz several feet long shoot off into the wall rock.

The Cross vein has an approximate north-south strike and lies 

between the Ickis and Lindeborg veins. It was cut in the underground workings when a crosscut Avas driven from the drift on tho 

Ickis vein with the intention of reaching the Lindeborg vein. It has 

been explored by drifts on the level of the adit and t\yo lower levels, 

and one ore shoot has been partly stoped and run through the mill. 

The vein, as known, has a total length of about 750 feet in the drift 

on the level of the adit, but it splits into small stringers at each end: 

the main body of the vein is G50 to 670 feet long. It varies in thickness, both along the strike and along the dip, ranging from 6 or 8 

inches up to 4% feet. At the north end on all three levels the vein 

pinches out abruptly as it nears the schist band in which the Lindeborg vein occurs. Much of the vein averages 2 feet or more in thick-
MINES AND PROSPECTS 79'

ness. The vein has been explored along the dip for 100 feet above 

the main level and 250 feet below, a total of 350 feet. The vein dips 

30° E. below the main level but steepens to 45° in the raise. It is 

possible that the vein may widen again south of the present end of 

the drift. The vein is in considerable part frozen to the walls. The 

ore occurs in shoots with intervening barren or lean portions.

On the level of the adit of the Cross vein three shoots of ore have 

been found a small one north of the crosscut tunnel, a larger one 

south of the crosscut tunnel, and another, TO feet in length, still 

farther south. About 150 feet of sparsely mineralized quartz intervenes between the two main shoots. The southern part of the vein 

is sparsely mineralized and of low tenor. A raise has been driven 

in the southern ore shoot for 100 feet above the main level. This 

shoot is about a foot thick at the main level, thickens to 2 feet up

the raise, and pinches to the merest stringers at the top. The central 

shoot, for about 50 feet south of the crosscut tunnel, ranges from 

1^ to 3 feet in width, is well mineralized with sulphides, and is 

reported to average locally $40 to the ton in lead, gold, and silver. 

A raise has been driven 40 feet on this shoot from the main level, 

but the shoot pinches out at the top. A winze has been sunk on the 

vein from the adit level 140 feet to the first level, and 110 feet from 

the first level to the second. On the first level drifts have been 

run 200 feet to the south of the winze and 90 feet to the north. North 

of the winze, where the vein consists mainly of stringers, the mineralization is lean, except for a shoot 15 feet in length. A shoot that 

starts 25 feet south of the winze has a length of 70 feet. On this 

level its width averages more than 3 feet, ranging from 2 to 5 feet. 

Its value is reported to average $46 a ton, with variations from $36 

to $100 a ton. This ore shoot has been partly stoped toward the 

main level, and the upper part averaged 10 to 18 inches in thickness. 

A sample from a muck pile accumulated while driving the drifts 

yielded about 25 per cent of concentrates. The ore of this muck 

pile is reported to have averaged about $7 or $8 to the ton in gold 

and an ounce of silver to the ton for each per cent of lead. On the 

second level an ore shoot north of the winze is 15 feet long and 10 

inches thick and averaged $60 to the ton. The last 20 feet of the 

vein to the south on this level averages about 5 inches in thickness 

and shows a little galena and pjaite. It comes against a dike at 

the south end. A 14-foot raise has been driven tq get into the ore 

shoot exposed above on the first level. The ore shoots are believed 

to pitch to the southeast on the dip of the vein. All the ore that 

has been treated in the mill and all the concentrates shipped came 

from stopes on this vein. The galena concentrates are reported tohave assayed as high as $240 to $300 to the ton in lead, gold, and
.'80 GEOLOGY OP HYDER AND VICINITY, SOUTHEASTERN ALASKA

silver. The sulphides are predominantly galena and pyrite. Chal-

 eopyrite, sphalerite, tetrahedrite, and pyrrhotite are also found. 

Locally there are pockets and crystals of barite in the gangue.

The Lindeborg vein is a locally mineralized quartz vein in a 

narrow band of crumpled injection schist included in the Texas 

Creek granodiorite. The schist band, which is 50 feet wide at the 

portal of the Lindeborg adit, constitutes a weak zone along which 

movements have taken place, and the vein is in a shear zone. The 

vein in part of its length crosses the foliation of the schist a't a slight

 angle and strikes about N. 60° W. Through underground workings 

and open cuts it has been explored for a length of 800 feet and a

 depth of 250 feet. It is reported to have been traced at the surface 

for 1,800 feet, and in that distance it has a difference in altitude of 

700 feet. At the outcrop and in its west end exposed on the mountain slope the vein is a well-defined mineralized quar.tz vein, but 

the underground workings, as far as they have gone, indicate that 

as it goes down and in to the southeast from the mountain side the 

vein splits up into stringers and bunches of quartz in schis.t. There 

is, however, a probability that mineralized quartz may come in again,

 either in depth or along the vein to the southeast, though no prediction can be made as to the depth or the distance to the southeast. 

The vein has been prospected by two adits driven on the vein, a 

400-foot drift along the vein southeast from the main crosscut tunnel, a 180-foot drift northwest from this tunnel, and a 70-foot raise 

between the upper adit and the intersection of the main crosscut 

tunnel and the drifts. The lower adit is about 90 feet below the 

Lindeborg adit, is 150 feet long, and is driven on the vein. At the 

portal the vein is 2 feet wide, but within 50 feet it pinches markedly.

Stringers of quartz occur in the adjacent country rock, and stringers 

and veins of quartz are found along the remainder of the adit. 

There is here no well-defined persistent mineralized vein, but sulphides, mainly pyrite and galena, are present locally in considerable 

quantity. On the main adit level the vein in the drifts for 400 feet 

to the southeast and 175 feet to the northwest of the intersection of 

the crosscut tunnel .consists of scattered narrow stringers and 

bunches of quartz and sparse lenses and seams of sulphide in the 

schist. Pyrite is common, and one small pocket of arsenopyrite was 

found. At the face of the drift, about 180 fee.t northwest from the

 crosscut tunnel, the vein is about 40 inches wide, is of milling grade, 

and consists of mineralized quartz with included fragments of schist 

and angular fragments of Texas Creek granodiorite. The sulphides 

are mainly pyrite and galena with a little chalcopjTite and sparse 

sphalerite. It was reported in the Hyder Herald early in 1926 

that this drift had been extended to the northwest and had shown
MINES AND PROSPECTS 81

that the vein continued with ore of milling grade and locally with 

shoots of high grade. Two ounces of free-milling gold to the ton 

of concentrates is reported to have been recovered from a shipment 

of 65 tons from a shoot on this portion of the vein. The two malchite dikes .that.were cut in the Lindeborg adit higher up were also 

crossed here. The Lindeborg adit is about 70 feet above the main 

tunnel and is driven on the vein for about 350 feet. The first 250 

feet of the vein is mineralized quartz that contains inclusions of 

schist, and its average width is about 3 feet. It is reported to average about $14 a ton in lead, gold, and silver. The sulphides are 

pyrite and galena, usually localized in bands, with here and there a 

little sphalerite and chalcopyrite. The vein is cut by two malchite 

dikes. At about 250 feet in from the portal the*" quartz vein splits

into a number of narrow stringers and lenses in schist. Seams of 

sulphide also occur in the schist, but taken as a whole this part of 

the vein is leanly mineralized. In one of the surface exposures the 

vein is 5 feet wide and consists of quartz wi.th 18 inches of finegrained galena that assayed 27 ounces of silver to the ton.

BTJTTE

The Butte group comprises six claims restaked by W. C. Peterson* 

and Nils Olson. They lie just to the south of the Crest group and 

extend southeastward up the mountain side from the Salmon River 

road. The property was not seen by the writer, and the followingdata were reported by the OAvners.

The lowest open cut is 450 feet from the road. The vein has been 

traced for about 500 feet with a west-northwest strike and is 1 to 2* 

feet thick. High assays in gold are reported. At an altitude of 

350 feet, on the south bank o»f the gulch, a shaft 25 feet deep has 

been sunk on a quartz vein. The vein strikes N. 32° W. and dips 

65° NE. At the top of the shaft the vein is 2 feet wide, and at the 

bottom 10 inches wide. It has been traced for about 400 feet to* 

the southeast and is 3 feet wide on the side of the gulch. Mineralized 

shoots and inclusions of wall rock occur in the quartz. The sulphidesare predominantly pyrite with galena subordinate. An assay of a 

sample that contained 11.4 per cent of lead yielded 0.24 ounce in 

gold and 10.2 ounces in silver to the ton; another sample that contained 14.1 per cent of lead yielded 0.6 ounce in gold and 20.6 ouncesin silver to the ton.

CREST

The Crest group (see fig. 1) consists o>f six claims held by Moar 

Ickis & Hill, of Hyder. They lie on the mountain slope on the east, 

side of Salmon River, about three-quarters of a mile below the Salmon River bridge.
$2 GE'OI/OGY OF HYDER A1STD VICINITY, SOUTHEASTERN ALASKA

A narrow but persistent vein, at an altitude of about 1,400 feet, 

is being prospected. It strikes N. 50° W., dips 55°-70° NE., and 

has been traced for 350 feet by a series of open cuts and strippings. 

It consists of a fissured zone several feet thick in Texas Creek granodiorite, with stringers or a solid vein of quartz aggregating several 

inches to 2 feet thick, which carry local shoots heavily mineralized 

with galena and some associated pyrite and a little chalcopyrite. The 

-quartz exposed would indicate an average width oif less than 9 inches.

[3TiGUBE 1. Sketch map of Crest group of claims. (Adapted from map by A. 0. Moa)

Along much of the vein the country rock is impregnated with dis-

 seminated pyrite, and fracture surfaces are coated with pyrite and 

rgalena.

At one open cut, in the bed of a small gulch, the vein consists of 

a number of small quartz stringers, some of which carry free gold. 

Assays of the quartz have yielded as high as $105 in gold to the ton. 

At another open cut a moil sample of the country rock and quartz

 stringers, 2 feet in width, averaged $4.80 in gold to the ton. The 

.mineralized shoots run from $7 to $12 in gold to the ton.
MINES AND PROSPECTS 83 

CRIPPLE CREEK

The Cripple Creek group comprises eight claims and a fraction. 

They are on the east side of the Salmon River road, just below the 

.bridge across Salmon River at Tenmile. The property has been 

taken over by the Brigadier Mining Co.

Two types of deposit are being prospected, both in the Texas 

Creek granodiorite a quartz fissue vein containing local shoots of 

sulphide and a fissured zone in which narrow-stringers of quartz 

.and the intervening rock contain pyrite in seams and disseminated.

Just beside the road an adit has been driven 45 feet along a vein, 

with an 8-foot crosscut at the end. The vein consists of a sheeted 

.zone. 10 to 15 feet wide, with quartz stringers and a large quartz 

vein in the footwall portion. Some of the granodiorite is so

.sheared as to resemble greenstone. In the bed of the gulch, on the 

.south side of the portal to the adit, there is 8 feet of quartz in which 

local sparse pockets are mineralized with galena. The adit parallels the main quartz vein and is run in the hanging-wall portion of 

the fissured zone. A cross section of the vein is exposed only in the 

crosscut at the end of the adit. At the breast of the adit the quartz 

vein is 3 feet wide at the bottom and pinches toward the top. About 

15 feet in altitude above the adit stripping exposed 4 feet of fissured 

granodiorite with a quartz vein 1 to 2 feet wide, and small quartz 

.stringers, one of which is several inches thick and is heavily mineralized with galena and a little pyrite and sparse chalcopyrite. The 

vein is exposed for about 65 feet; it strikes N. 73° W. and dips 

.steeply to the north. In the adit a stringer has along its footwall 

seams of sulphides consisting of galena and a little pyrite and 

.sphalerite. A little tetrahedrite is also found locally in the vein. 

About 175 feet uphill from the adit portal is a 20-foot open cut 

on a vein that strikes N. 70° E. and dips 40° S. The vein consists 

of a fissured zone 4 to 5 feet thick with quartz stringers 1 inch to

 3 feet thick. There are abundant slivers of altered country rock in 

the thicker portion of the vein.

On the Salmon River road just above the bridge there are several 

fissured zones with many narrow quartz stringers in the Texas 

Creek granodiorite. A few of the stringers carry shoots with disseminated galena and pyrite several inches to a foot thick. The 

country rock carries considerable disseminated pyrite.

At an altitude of 450 feet just beneath the tram line a stripping 

and two open cuts expose a breccia vein several feet wide, consisting

 of narrow reticulating quartz veins and fragments of Texas Creek 

granodiorite impregnated with pyrite. Locally there is a little dis-
84 GEOLOGY OF HYDEB AND VICINITY, SOUTHEASTERN ALASKA.

seminated galena and sphalerite. Narrow quartz stringers occur 

within a zone wider than the main breccia vein. The vein strikes 

N. 50° W. and dips 45° S. At an altitude of 480 feet a stripping 

shows similar pyritized granodiorite with narrow quartz stringers..

PORTLAND

The Portland group comprises three claims adjoining the Hobogroup. They were staked in 1919 by Ickis & Moa. On the Hobo and 

Portland groups, at an altitude of 2,200 to 2,250 feet, between the 

cabins on the two groups, there is a dike of granodiorite porphyry 

belonging to the Texas Creek batholith, which cuts across the greenstone and slate with a strike of N. 60° W. On the Portland group,, 

at an altitude of 2,200 feet, an open cut has been made on a quartz, 

vein along the contact between the dike and the black slate. The 

quartz contains inclusions of both slate and dike. On the Hobogroup there is a quartz vein 2 to 3 feet wide in the dike itself. At 

an altitude of 1.750 feet a 15-foot adit has been driven along a 2-foot 

quartz vein in slate. The vein strikes N. 60° W. and dips 52° S. It 

has been traced for 500 yards by pits and surface exposures. It 

contains sparse disseminated fine grains of pyrite, galena, and blebs 

of sphalerite and a little chalcopyrite. Other quartz veins and 

stringers are found in the slate.

HOBO

The Hobo group comprises two claims staked in 1919' by Morris 

Pederson and Albert Johnson. They lie to the south of the AlaskaPremier group.

At an altitude of 2,400 to 2,450 feet a mineralized zone of greenstone is being prospected in which three open cuts have exposed! 

shoots of sulphides forming veins or veinlike replacement deposits. 

The shoots have an almost east-west strike. At an altitude of about 

2,400 feet, in the bed of a gulch, a 10-foot open cut exposes greenstone with seams and stringers of sulphide consisting of 1 foot of 

rock with pyritic seams and disseminations, 2 feet with quartz lenses 

and stringers of solid sulphide, mostly sphalerite, 5 feet of relatively 

barren greenstone, and 2 feet with seams and fracture facings of 

sphalerite and a solid pyrrhotite vein several inches thick with a 

little chalcopyrite. Two other open cuts show similar mineralization'. 

Quartz and some calcite are the predominant gangue minerals. 

Pyrite and pyrrhotite are the predominant sulphides. Sphalerite is 

next in abundance; some samples are reported to carry 9 ounces in 

gold, but the gold content is extremely variable. Galena is sparse. 

Chalcopyrite is usually present but minor in amount. A little arsen-
MINES AND PROSPECTS 85

opyrite is also present. The gold content is low in the pyritic and 

pyrrhotitic ore, and the silver content is in general low.

Another mineralized shoot in greenstone is exposed at an altitude 

of about 1,315 feet and consists of pyrite and pyrrhotite with a little 

arsenopyrite, in a quartz gangue, in a vein that is as much as 1 foot 

wide. The vein strikes east-west and dips south. It is exposed in 

the bed of a gulch for 100 feet. The sulphides are reported to 

average $4 to $12 to the ton in gold.

On the Red Rose claim, at an altitude of 1,050 feet, an open cut has 

been made on slate that contains disseminated pyrite and abundant 

reticulating veinlets of pyritic quartz. A band 6 feet wide is heavily 

mineralized with pyrite. The strike is about N. 75° W. The pyritic 

slate at this locality is just above the contact with the Texas Creek 

quartz diorite.

South of the cabin, in the bed of a small gulch at an altitude of 

about 2,900 feet, there is a fissured zone in greenstone with reticulating quartz veins. This zone is several feet thick, strikes N. 25° W., 

and dips 60° S. Several inches of quartz in the hanging wall is 

heavily mineralized with pyrite, galena, and sphalerite. The writer 

is not certain that this vein is on the Hobo claims.

ALASKA-PREMIER

The Alaska-Premier group (not to be confused with the Premier 

mine, which is on the Canadian side of the boundary) comprises 25 

claims lying to the southeast of the Daly-Alaska and southwest of 

the Stoner-Clegg-O'Rourke groups.

The general country rock is greenstone with intercalated beds of 

slate and graywacke. Three sheets of felsite occur within the greenstone and the sedimentary rocks. It is not certain whether these are 

intrusive quartz porphyry sills or facies of the greenstone. Development work is being done within two of these sheets in hope of 

finding an ore body. The northern sheet, on the Alaska claim, is 

about 40 feet thick, strikes about N. 60° W., and dips 50° E. A 

short prospect tunnel 15 feet long, at an altitude of 1,400 feet, has 

been driven on a mineralized zone in the sheared felsite. Veinlets of 

quartz several inches thick containing pyrite, sphalerite, galena, and 

a little pyrrhotite and carrying considerable gold have been found. 

On the Ready Money claim the second sheet of felsite is being prospected. Open cuts have been made, and a tunnel is being driven. 

At about 40 feet above the tunnel an open cut was made on a very 

rich pocket of altered felsite. The rock is shattered, veined with 

quartz, and much silicified. Veinlets and, blebs of sulphides occur 

throughout the pocket and comprise pyrite, sphalerite, galena, and a 

little pyrrhotite and chalcopyrite. As much as 35 ounces of gold
86 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

to the ton is reported to, have been obtained on assays of selected, 

specimens. A crosscut tunnel at an altitude of about 1,300 feet driven, 

to cut the felsite sheet goes in about 200 feet and has cut about 30' 

feet of the felsite. The country rock at the entrance to the tunnel 

is a dark-gray to brown hornlike stone of uncertain origin. The 

tunnel passed through about 50 feet of a light-colored granodiorite 

porphyry dike, belonging to the" Hyder batholith, which does not 

show at the surface. The whole zone of felsite is fractured, and the 

fractures are faced with small pyrite cubes. These small cubes are 

also disseminated throughout the felsite. Rarely a bleb of pyrrhotite 

occurs. Such rock is reported to average $2 to $3 in gold and about 1 

ounce of silver to the ton.

In the bed of the gulch just below the cabins there is a mineralized 

shear zone striking east-west at an altitude of about 1,215 feet. The 

sulphide-bearing sheet is about 3 feet wide and comprises pyrite,. 

galena, sphalerite, chalcopyrite, tetrahedrite, pyrrhotite, and arsenopyrite.

At an altitude of 900 feet, in the bed of the gulch, there is a bigdike of porphyry belonging to the Texas Creek batholith, with associated quartz stringers.

DALY-ALASKA

The Daly-Alaska group (see pi. 13) comprises 10 claims and a. 

fraction. The first claims were located in 1912 and 1913. They liesouthwest of the Stoner groups and south of the Virginia group 

and extend from the flat of Salmon River at Elevenmile up themountain slope to an altitude of 1,800 feet. This group has also» 

been known as the New Alaska and Elevenmile property. Thecountry rock consists of greenstone, which is cut by dikes of quartz, 

and feldspar porphyry belonging to the Texas Creek batholith; 

and both the greenstone and the older porphyry are cut by dikes of 

granodiorite porphyry of the Hyder batholith and by malchite and 

lamprophyre dikes. Westgate 28 summarizes the occurrence of 

mineralization as follows:

Two kinds of mineral deposits occur on this property; one carries sphalerite,, 

galena, and pyrite, and the other chiefly pyrrhotite. Only those of the first 

type are being developed. They lie in a system of fracturing, in which certains 

zones are richer in sphalerite, galena, pyrite, with a very little chalcopyrite,. 

than the others. These richer zones carry gold and silver. The greenstone [also 

the older porphyry] lying within the zone of fracture is lighter colored than-, 

the normal country rock and carries a large amount of introduced silica and 

calcite. The difference between ore and country rock is a difference in thedegree and kind of mineralization. There are no well-defined walls to the 

deposits, and the richer portions grade into the country rock. The introduction of the sulphides and silica seems to have been contemporaneous..

28 Westgate, L. G., op. cit, p. 132.
MINES AND PROSPECTS 8T

At the upper workings on this property two adits have been 

driven. At the upper adit the country rock is a schistose mass of 

quartz porphyry with feldspar crystals oriented in flowage lines*. 

This is probably an intrusive offshoot from the Texas Creek batholith. An open cut has been made at an altitude of about 1,500 feet.. 

The porphyry here is highly silicified, with associated seams and 

disseminations of pyrite, a few gash veins of milky quartz or of 

calcite, and locally a little sphalerite. About 50 feet below the open 

cut is an adit 150 feet in length with 15 feet of drift about 75 feet 

in from the portal. The drift appears to be on a shoot mineralized 

predominantly with pyrite but with some sphalerite and galena. A 

careful examination also reveals the presence of tetrahedrite, chalcopyrite, pyrrhotite, and arsenopyrite.

At an altitude about 60 feet lower than this adit is another one

about 220 .feet in length. Westgate 29 describes the first 114 feet of 

the adit, driven before 1921, as follows:

For the first 50 feet from the portal the rock is M light greenish-gray finegrained rock, here more siliceous, there more calcareous, and everywhere 

somewhat pyritized. Then follows 27 feet of a similar rock containing bands 

and patches of sulphides (sphalerite, galena, and pyrite). This is followed 

in turn by 15 feet of less mineralized rock and 10 feet of mineralized rock. 

The remainder of the tunnel is in barren rock like that at the entrance. The 

rock structure at the entrance strikes N. 80° B. and has a nearly vertical dip, 

and the indistinct banding farther in agrees with this attitude.

Near the bend of the gulch, at an altitude of about 600 feet, two 

open cuts have been made on a mineralized shoot in the greenstone. 

There is a vein 3 feet wide here, consisting of greenstone streaked 

with stringers of fine granular galena, pyrrhotite, and sphalerite,, 

with some chalcopyrite and pyrite and a little arsenopyrite, together with calcite and quartz veinlets carrying some sulphides. 

The sulphides may form about 20 per cent of the shoot. The vein, 

strikes about N. 80° W. and dips 60° S., and it is reported to average 

30 to 40 ounces of silver to the ton. In another open cut on the 

same zone, about 10 feet above, the sulphides consist mainly of pyrite 

with local sphalerite stringers that assay high in gold.

Just above the camp at Elevenmile a great deal of underground 

prospecting has been done within the last few years. At the 

time of the writer's visit work had been suspended and accurate information as to what had been found could not be obtained. .The 

mineral deposits here are in altered greenstone and consist of shoots 

similar to those in the higher prospects already described. No large 

ore body has been found. Material on the dump would indicate 

that a dike of older porphyry of the Texas Creek batholith. was 

cut in the tunnel. The sulphides comprise pyrrhotite, sphalerite,

20 Westgate, L. G., op. cit., p. 133.
88 GEOLOGY OP HYDER AND VICINITY, SOUTHEASTERN" ALASKA

pyrite, galena, tetrahedrite, and chalcopyrite. Some of the tetrahedrite is the silver-rich variety freibergite. Assays of selected 

samples are reported to have yielded as high as 500 ounces of silver 

to the ton. A fault was cut in one of the tunnels, and it is reported 

that a little native silver was found near the fault.

STONER-CLEGG-O'ROURKE

The Stoner-Clegg-O'Kourke group comprises nine claims southwest of the Stoner group and adjoining the Daly-Alaska group.

Above the cabin on the Liberty claim, on the bank of a gulch, 

at an altitude of about 1,350 feet, a tunnel 75 feet long has been 

driven N. 65° E. in greenstone. The material on the dump shows 

veinlets of calcite with sphalerite, pyrite, and galena. Small amounts 

of pyrrhotite, chalcopyrite, and tetrahedrite are also present. Open 

cuts have been made at other localities on bands in the greenstone 

carrying disseminated pyrite and pyrrhotite and seams of calcite, 

sphalerite, pyrite, and galena.

VIRGINIA

The Virginia group (pi. 13) comprises four claims and a fraction 

staked in 1919. The claims are mainly east of the Salmon River 

road along Boundary Creek and are bordered on the south by the 

Daly-Alaska group.

Mineralized shoots in greenstone are being prospected. On the 

banks of Cascade Creek a crosscut adit has been driven 50 feet to a 

mineralized body and a drift extended 225 feet to the southeast and 

30 feet to the northwest. The mineralized shoot strikes N. 50° W., 

dips south, and is' in a highly altered basic porphyry or porphyritic 

greenstone, and is in a sheared zone several feet thick exposed along 

the northwest end of the drift for about 50 feet. At the northwest 

face of the drift there is a shoot of almost solid sulphide, consisting 

of pyrrhotite, sphalerite, pyrite, and a little galena in a quartz 

gangue. A little tetrahedrite is also present. To the southeast, mineralized bands are exposed in the roof of the drift, and quartz veins 

and calcite seams are common. Southeast of the mineralized shoot 

the drift follows a dike. A malchite dike was crossed near the portal 

of the adit. Selected samples of ore are reported to have run as 

high as 4J/2 ounces of gold to the ton.

About 125 feet east of the road, southeast of the adit, an open cut 

at an altitude of about 670 feet has been made on altered porphyritic 

greenstone. This exposure shows numerous stringers of barren to 

sparsely mineralized glassy quartz, fractures faced with sphalerite, 

and stringers, threads, and blebs of galena and pyrite. About 150 

feet upstream from the portal of the adit another adit has been
MINES AND PROSPECTS 89

started in mineralized greenstone, which contains many seams and 

stringers consisting mostly of pyrrhotite, with some pyrite and a little chalcopyrite and sparse sphalerite and galena, and which also 

shows a notable quantity of epidote in bands and veins. Two other 

open cuts have been made on the property on schistose bands of 

greenstone mineralized with disseminated deposits and veinlets of 

pyrite and a little pyrrhotite and locally a little sphalerite and 

galena. Several granodiorite porphyry dikes on the property have 

produced local contact-metamorphic minerals, especially epidote and 

rarely garnet, in their immediate vicinity.

STONER

The Stoner group (see pi. 13) comprises 14 claims, originally 

staked by H. B. Stoner and sold by him to Matthew Lodge, of Moncton, New Brunswick, who has incorporated them under the name 

Stoner Gold & Silver Mining Corporation. The claims lie along the 

international boundary southeast of Cascade Creek. The StonerClegg-O'Rourke group of nine claims borders them in part on the 

southwest. The development work consists of a number of open 

cuts and a 15-foot shaft.

The country rock on this property belongs to the Hazelton group, 

with greenstone predominating. In this there are dikes of quartz 

porphyry, quartz diorite porphyry of the Texas Creek batholith, and 

granodiorite porphyry of the Hyder batholith. There are three 

types of deposits (1) veins and disseminated deposits in greenstone, 

(2) sparsely mineralized quartz fissure veins within or along the 

contact of a dike of quartz diorite porphyry with slate, and (3) seams, 

disseminated deposits, and fracture facing of fine crystalline pyrite 

in quartz porphyry at an altitude of about 850 feet on Cabin Creek. 

Practically all the work has been done on the mineralized greenstone.

At an altitude of about 1,450 feet on American No. 2- claim a 

mineralized band in the greenstone has been prospected by a shaft 

and two open cuts. The western open cut measures 30 feet across 

the greenstone, and most of it shows seams and disseminated crystals 

of pyrite. There is a shoot several inches thick of pyrite and sphalerite, with a little galena, tetrahedrite, and pyrrhotite. Calcite is 

an associated gangue mineral. About 50 feet up the hillside and 20 

feet vertically above the open cut, a 15-foot shaft has been sunk on 

a shoot of sulphide. This shoot is 7 feet wide at the top of the shaft 

and consists of greenstone with many seams parallel to the schistose 

structure mineralized with pyrite, sphalerite, and galena. The vein 

strikes about east and dips north, so that only the north wall of the 

6196 29 7
90 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

shaft is mineralized with sulphides other than pyrite. There is considerable quartz with the sulphides, and the greenstone is somewhat 

silicified. At 25 feet to the east a 40-foot open cut exposes 3 feet of 

similar mineralized greenstone.

Specimens obtained from mineralized shoots on other claims are 

reported to have yielded $6 to $8 to the ton in gold and silver, in addition to the lead in the galena.

BORDER

The Border group consists of two claims adjacent to the international boundary on the Salmon Kiver road. They are held by 

Lon Doggat.

The country rock is interlayered dark-gray slate and fine graywacke. Scattered seams and narrow stringers of mineralized quartz 

are distributed through a wide zone in the form of gash veinlets at 

an angle to the bedding. The sulphides comprise galena, sphalerite, 

pyrite, and a little chalcopyrite and occur in heavily mineralized 

shoots as much as 6 inches wide. The ore minerals are not in uniform association but tend to occur with one or another predominant. 

Considerable carbonate occurs with the ore minerals. An adit has 

been driven TO feet for the purpose of cutting the mineralized 

fissured zone, which lies between two dikes of granodiorite porphyry.

GOLD GLUT PREMIER

The Gold Cliff Premier group comprises 24 claims lying along 

both sides of Salmon River above the junction of Cascade Creek and 

includes the east side of Mineral Hill. The claims were staked in 

1920 and regrouped in 1925. The bedrock consists of quartzite, 

tuff, and intercalated slate, with a few dikes of older porphyry of the 

Texas Creek batholith and younger dikes of granodiorite porphyry of the Hyder batholith. Locally the quartzite is intensely 

fractured, the fractures are lined with pyrite, and the rock is impregnated with pyrite. Usually such pyritic rock yields only very low 

assays in gold and silver, but on the east side of the river a 20-foot 

open cut made on a shear zone several feet thick in greenish finegrained tuffaceous rock has shown a pyritized band carrying considerable gold. Some calcite and quartz is associated with the pyrite. 

This heavily pyritic band is 2^ feet wide, and samples are reported 

to assay as much as 1 ounce in gold and 3 to 4 ounces in silver to 

the ton. On the west side of the river, at an altitude of about 800 

feet, there is a narrow stringer of galena and also a 1-inch stringer 

of sphalerite, chalcopyrite, tetrahedrite, and pyrrhotite.
MINES AND PEOSPECTS 91 

CANTU

The Cantu group consists of 17 claims adjacent to the international 

boundary, on the west side of Salmon Glacier, extending from a 

point just west of its terminus to the north side of the low pass 

north of Cantu Mountains and occupying the east side and the crest 

of Cantu Mountain. These claims are held by Cronholm & McDonald and were located July 2, 1925. No work had been done on 

them when they were seen by the writer.

The country rock of the whole of Cantu Mountain except its 

southernmost tip and the base of the cliffs below Salmon Glacier is 

the Texas Creek granodiorite. On the west side of the mountain 

the rock is usually porphyritic, with large crystals of potassic feldspar, but on the crest and east side it is generally even grained and

only locally porphyritic. The gray Texas Creek granodiorite is cut 

by many dikes of pink to white granodiorite porphyry and dark 

dikes of malchite that are genetically connected with or are offshoots from the Boundary granodiorite intrusive mass which lies 

to the north along Boundary Glacier. The contact between the 

Texas Creek granodiorite and the Hazelton group of greenstone and 

sedimentary rocks probably lies in the valley of Salmon Glacier, and 

the Cantu group of claims therefore lies close to the eastern border 

of the Texas Creek batholith. Greenstone containing some pyrrhotite 

and cut by dikes of the granodiorite porphyry of the Boundary 

batholith, crops out at the base of the mountain below the foot of 

the glacier. Quartzitic beds are exposed in the pass between Salmon 

River and Texas Creek.

On Cantu No. 4 claim, at an altitude of about 1,200 feet, a vein 

is exposed for about 20 feet in length. It ranges from 4 inches to 

2,y2 feet in width. The country rock is the Texas Creek granodiorite. About 10 feet below the vein is a dike of quartz porphyry. This 

is locally shattered and reticulated by stringers of highly mineralized 

quartz, and the rock is much altered to sericite. The chief metallic 

mineral produced by the mineralization of the veins here is granular 

galena. With the galena are associated in subordinate amounts resincolored sphalerite and veinlets of tetrahedrite. Pyrite and chalcopyrite are sparse. Quartz is the predominant gangue mineral, but barite 

is common and locally is equal in amount to the quartz. A little 

calcite is present. The vein strikes north to N". 20° E. and dips 

30°-50° E.

About 300 yards to the south, on No. 6 claim, at an altitude of 

about 1,350 feet, there is a vein of heavily metallized quartz exposed 

in the bed of a small gulch for a difference in altitude of 30 feet. 

The vein is 6 inches to 3 feet thick, with local stringers and shoots 

of galena as much as 6 inches thick. Coarse to medium crystalline
92 GEOLOGY OF HYDEE AND VICINITY, SOUTHEASTERN" ALASKA

galena predominates. Tetrahedrite, resin-colored sphalerite, and 

pyrite are associated with the galena. There is more pyrite and 

less barite here than in the other veins. Stringers of quartz, slightly 

metallized and containing plates of barite, occur in the footwall. 

The vein strikes north-northeast and dips 40° SE. This vein may be 

an extension of the vein on Cantu No. 4 claim, though no prospecting 

has been done to prove it.

On Cantu No. 8 claim, according to B. W. W. McDougall, another vein is exposed at altitudes between 1,960 and 2,180 feet and 

can be traced for more than 500 feet. The part examined by Mr. 

McDougall was 30 to 35 feet wide and consisted of grayish quartz 

with pyrite disseminated and in solid streaks. A grab sample of 

chunks knocked off at random is reported to assay 0.8 ounce in 

gold and 1.2 ounces in silver to the ton. The vein is thought to 

strike about N. 20° W., the dip is not known.

A test shipment of 20 tons of carefully sorted ore from the Cantu 

group was sent to the Selby smelter. The returns on this shipment 

are given below, together with assay by Mr. McDougall on grab 

samples.

Assays of ore from Cantu group of claims, Hyder district 

[Blanks indicate percentages not determined]

Silver.... ........ ............ ......... .do. _

Zinc...... .do... .

i

0.30

13.80

37.20

38.80

3.30

5.60

10.70

2

0.175

31.05

44.1

22.8

.9

12.2

13.5

3

0.42

61.2

29.3

16.4

4.5

4

0.10

27.1

43.4

12.2

2.75

5

0.40

17.0

38.8

5.2

1.20

6

0.01

5.20

19.8

7

0.80

1.20

1. Smelter assay on about 6^ tons of sorted ore from Cantu No. 6 claim.

2. Smelter assay on about 12 tons of sorted ore from Cantu No. 4 claim.

3. Grab sample from 30 sacks of sorted ore with considerable tetrahedrite, Cantu No. 4 claim:

4. Grab sample from 180 sacks of sorted galena ore with less tetrahedrite, Cantu No. 4 claim.

5. Grab sample from 150 sacks of sorted ore, Cantu No. 6 claim.

6. Sample across vein, width 12 inches, Cantu No. 6 claim.

7. Grab sample from vein on Cantu No. 8 claim.

The gross value of the sorted ore from Cantu No. 6 claim, with 

silver at 69% cents an ounce and lead at 9% cents a pound was $88.10 

a ton, and the net value, after deduction for smelter charges, was 

$59.83 a ton. The gross value of the sorted ore -from Cantu No. 4 

claim was $108.79 a ton, and the net value, after deduction for 

smelter charges, was $76.76 a ton.

BARTHOLF

The Bartholf claims lie mainly on the Canadian side of the international boundary on the west side of Salmon Glacier, in the valley 

north .of Cantu Mountain, at an altitude of about 1,430 feet. The
MINES AND PROSPECTS 93

vein strikes N. 18° W. and dips 55° W. It consists of quartz with 

disseminated chalcopyrite and local shoots of pyrite and galena. 

Chalcopyrite predominates. The quartz contains many vugs, and 

barite plates are common. The vein ranges from several inches to a 

foot in width and averages 6 inches.

NINETY-SIX

The Ninety-six group comprises six claims located just above the 

Texas Creek trail on the west side of Mineral Hill about 1*4 miles 

north of the Salmon River bridge. They are held by Ray Snyder and 

Pete Wilson. At an altitude of about 500 feet a 63-foot adit has 

been driven to crosscut the vein at about 30 feet below the outcrop. 

The vein occurs in a dike of Texas Creek granodiorite which cuts 

interbedded slate and quartzite. The vein consists of interlacing 

mineralized quartz stringers in a brecciated or shattered zone of 

the granodiorite. There are no well-defined walls to'the vein. At 

the outcrop above the tunnel the vein is about 5 feet thick with 

stringers of sparsely to heavily mineralized quartz aggregating about 

a foot in thickness. In the breast of the adit there is 12 to 15 inches 

of quartz heavily mineralized with galena, sphalerite, tetrahedrite, 

pyrite, and chalcopyrite. Galena predominates. The vein strikes 

about N. 10° W. and dips 40° E.; it has been traced at the surface 

for a length of 200 feet.

SILVER BAR

The Silver Bar claim is north of the West Fork trail and about 

li/4 miles east of the Homestake trail, iiy a gulch, at an altitude of 

1,930 feet. It was staked by David McVey in 1923. The vein is 

in the Texas Creek granodiorite; it strikes N. 30° W., dips 45° E., 

and is exposed for a length of 250 to 300 feet and a difference in 

altitude of 175 feet. It consists of quartz, with local shoots and 

small pockets and bands sparsely to moderately mineralized with 

sulphides and barite. Much of the vein is barren. The sulphides 

consist predominantly of chalcopyrite with a little associated galena 

and pyrite. The vein ranges from several inches to 3 feet in width. 

At the discovery stake there is a 5i/2 -foot fissured zone in the granodiorite with a 15-inch vein on the f ootwall that consists of quartz and 

barite sparsely to moderately mineralized with small pockets and 

stringers of sulphides.

LIBERTY

The Liberty claim is on the1 east side of Casey Glacier, just below 

its foot. It was staked by Joe Jackson. The vein is exposed in the 

bed of a small stream at an altitude of about 1.800 feet. It ranges
94 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

from several inches to 2 feet in width and is exposed for about 200 

feet in length, with a strike of N. 50° E. and a dip of 70° E. The 

vein occurs in the Texas Creek granodiorite and is probably cut by a 

25-foot dike of granodiorite porphyry with dark chilled borders. 

The vein consists of quartz, with local shoots of galena. The claim 

was staked in September, 1925; no work has been done on it.

NOTHIGER

On the west side of Casey Glacier1 , just above its foot, an adit 

has been driven to cut an intensely sheared zone in the Texas 

granodiorite. The shear zone is 20 to 40 feet thick and contains 

one main quartz vein and abundant small stringers of quartz. The 

main vein strikes about N. 40° E. and dips 38° E.; it is 2y2 feet 

thick at the adit and 6 feet thick at the discovery stake. The adit 

is at an altitude of about 2,240 feet, and it has been driven 12 feet 

through the main vein into the footwall. There is only a trace of 

galena and pyrite in the quartz. Surface prospecting for a possible" 

shoot of ore within or along the walls of the quartz vein would be 

advisable before further underground crosscutting or drifting is 

done.

EVENING AND MORNING STAR

The Evening and Morning Star claims are on the east side of the 

gulch, just above the cabin of Carlson & Hewitt; they were staked 

by McVey & Connors in 1923. A short 10-foot adit has been driven 

along a narrow stringer of steel galena in the Texas Creek granodiorite, which strikes N. 15° W. About 100 feet up the mountain 

slope this stringer is paralleled by a quartz vein.

HOMESTAKE

The Homestake group comprises eight claims staked in 1923 and 

held by J. H. Hewitt and C. Carlson. The claims lie about 1% miles 

north of the West Fork on the creek that flows into Ibex Creek. 

A pack trail for horses has been cut almost to the site of the vein.

At an altitude of about 3,550 feet an adit 25 feet in length has 

been driven to cut the vein about 25 feet below the outcrop. The 

vein, which is in the Texas Creek granodiorite, strikes about N. 15° 

E. and dips 45° E. It has been traced for a length of about 250 feet. 

The northern 150 feet is strongly mineralized, but the southern 100 

feet is milky-white quartz very sparsely mineralized. The vein is 

5y2 feet thick in the tunnel and ranges in general from 4 to 5% feet. 

At the north end it pinches abruptly; its projected line of extension 

is covered by snow. At the south end the vein strikes toward a bluff
MINES AND PROSPECTS 95

face but does not show in the bluff and is covered for a narrow width 

at its base by debris. Inclusions of granodiorite occur in the vein. 

In the adit the walls of the vein are slickensided and the upper foot 

of the vein consists of shattered country rock with stringers of 

quartz and ore. Stringers of tetrahedrite are found in the hanging 

wall. In the mineralized portion of the vein bands of solid sulphide 

occur in widths of as much as a foot. The sulphides consist predominantly of dense steel galena with some pyrite and chalcopyrite and 

locally a trace of sphalerite.

A test shipment of 9y2 tons of sorted ore from this vein sent to 

the American Smelting & Refining Co. at Selby, Calif., in 1925, had 

an average total gross value of $116.80 and a net value of $83.72 a 

ton after deduction of the smelting company's charges and the cost 

of freight from Hyder to Selby. Representative assays from this

vein are given below.

Assays of samples from the item on the Homestake group, Hyder district 

[Blanks indicate percentages not determined]

Lead ______________ ...

Silver.... _._._____.__.__ ..........

Qold..............................

Zinc.. ............................

______________ percent..

_ . __ . __ ...ounces to the ton,.

.-. .-. .. ... ......do....

......................... ......do....

........................... ....do....

........... ................ ....do....

...... .. . ... . .........do....

1

50.0

22.87

.29

.7

6.3

24.0

12.5

 

2

43.8

5.8

.26

1.0

3

5.5

1.3

.22

.84

1.20

4

0.5

24.3

.14

.4

1. Smelter assay on 9)4 tons of sorted ore.

2. Sample across 20 inches, 12 feet south of discovery post.

3. Sample across 5 feet, 25 feet south of discovery post.

4. Grab sample from slightly mineralized part.

o SILVER COIN

The Silver Coin claim is on the east side of the western gulch 

tributary to that on which the Homestake is located about TOO feet 

above it. It was staked by Paul Meagher and Ray Snyder. The vein 

is in granodiorite and is about 50 feet in length. It strikes N. 5° W. 

and dips 45° E. The northern 25 feet of the vein consists of a shoot 

of ore that widens abruptly southward from a few inches to 5 feet. 

At its south end the vein passes into practically barren milky-white 

quartz; the quartz splits into stringers, and an extension to the south 

can not be traced. The quartz vein zone at the south end is 10 feet or 

more thick and has no well-defined hanging wall or footwall. The 

quartz stringers appear to pinch and stop abruptly down the dip. 

The granodiorite shows many slipping planes, and along the footwall 

of the ore shoot these are coated with malachite. The mineralized 

shoot of the vein consists of quartz containing a high percentage of 

galena with a little pyrite and chalcopyrite.
96 GEOLOGY OF HYDEE AND VICINITY, SOUTHEASTERN ALASKA

IBEX

r

The Ibex group is on the west side of Ibex Gulch. It comprises 

six claims staked by Carlson & Hewitt in 1923 and now held by Day 

Bros., of Wallace, Idaho, and their associates; also one claim, Ibex 

No. 7, staked in 1924 by Carlson & Hewitt. Three veins are exposed 

on this group, all within 200 feet of the contact of the Texas Creek 

granodiorite and the overlying sediments. The veins occur in both 

the argillite and quartzite, as well as in the granodiorite.

On Ibex No. 1 the vein is exposed where it is crossed by a small 

deep gulch. The country rock consists of thin-bedded gray to black 

argillite and quartzite cut by dikes of granodiorite porphyry. The 

vein is of the fissure type. It strikes N. 5° E., dips steeply eastward, 

and cuts across the strike of the bedding. The vein is exposed for 

a length of about 100 feet, with a difference in altitude of 75 feet. 

It pinches and swells but is 15 inches to 2 feet in width for considerable portions. As exposed at the bottom of the gulch the vein contains about 18 inches of sulphides with only a little quartz gangue. 

The sulphides .consist almost wholly of interbanded pale-colored 

sphalerite and coarse-grained galena. The vein is cut by a dike of 

pink granodiorite porphyry, along which it is offset a few feet, and 

by a dike of fine-grained green-gray malchite, which cuts both the 

granodiorite porphyry and the vein. The vein is also offset by a 

fault striking N. 30° W. At an altitude of 3,700 feet, about 100 feet 

lower than the outcrop, an adit 131 feet in length was driven to cut 

the vein, but the vein was not found, and work was abandoned. It 

is not known whether the failure to find the vein was due to faulting, 

to pinching out downward, or to local cutting out by a dike of 

granodiorite porphyry younger than the vein. The top of the Texas 

Creek batholith, which is older than the vein, lies about 125 feet 

below.

On Ibex No. 3 claim, southwest of the tunnel on Ibex No. 1 and 

at an altitude of about 3,650 feet on the West Fork slope, an 8-inch 

vein of quartz, heavily mineralized with galena and a little associated pyrite and chalcopyrite, occurs in the Texas Creek granodiorite. 

The vein is barely exposed, and no work has been done on it. It 

probably lies below the top of the Texas Creek batholith, just beneath its contact with the overlying argillite.

In the bed of Ibex Gulch on Ibex No. 7, upstream from the position of the crosscut adit on No. 1 claim, a vein is exposed in the 

Texas Creek granodiorite. It has been traced for several hundred 

feet and ranges from 5 inches to 2 feet in width. The vein strikes 

about N. 5°-10° W. and dips east. At the north end, where it passes 

under the snow, it forms a fissured zone 3 feet wide with stringers
MINES AND PROSPECTS . 97

of quartz. Heavily mineralized shoots consisting of galena with 

a little pyrite occur along the vein. One such shoot is 20 feet long 

and 8 inches to 2 feet wide. The vein is offset by faults of small 

displacement.

SILVER STAR

The Silver Star group comprises two full Claims and two fractions, lying between the Iron Cap on the west and the Ibex group 

on the east, on the mountain slope north of the West Fork trail, about 

1,600 yards west of the trail to the Homestake group. They were 

staked by McVey & Connors in 1923. The contact of the Texas 

Creek granodiorite with the argillite crosses the claims, and mineralized veins are found both below and above the contact.

At an altitude of 2,900 feet a 30-foot adit has been driven along 

a vein in the footwall portion of a fissured zone in the Texas Creek 

granodiorite. The vein strikes about north and dips 55° E. It can 

be traced up a gulch for about 100 feet, to a point where it is offset 

about 30 feet to the west. Its extension is covered. About 100 feet 

above the adit entrance the fissured zone is about 7 feet wide, with 

mineralized quartz as much as 9 inches wide in the footwall portion 

and over a foot of quartz with sparse mineralization in the hangingwall portion. The heavily mineralized shoots in the quartz consist 

predominantly of galena and pyrite.

At an altitude of about 3,760 feet stringers of quartz occur along 

a narrow fissured zone in the argillite, which is traceable by exposures in gulches for a length of 600 feet. The quartz stringers 

are locally mineralized with galena or sphalerite or pyrite. Small 

quantities of pyrrhotite, arsenopyrite, and freibergite are also 

present. The vein zone strikes about N. 70° W., approximately 

parallel to the bedding.

SILVER BELL

The Silver Bell group comprises two claims north of the West Fork 

trail and northwest of the Silver Star group, at an altitude of 4,600 

feet. They were staked by Joe Connors on August 4,1925. The vein 

is in a brecciated fissured zone in argillite and graywacke. It strikes 

N. 80° W., in general at a slight angle to the bedding, and dips north. 

It is exposed for a length of 50 feet and consists in part of quartz 

2 feet thick, with inclusions of country rock and sparsely disseminated sulphides, and in part of a solid shoot of sulphide, predominantly galena, that is 13 inches thick at its widest parts. The 

sulphides disseminated in the quartz are pyrite and chalcopyrite, 

with a little galena and sphalerite at some places. The galena0 shoot 

has some tetrahedrite associated with it. The vein was seen by the 

writer at the time of staking, and no work was done on the property.
98 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

The Texas Discovery claim is on the West Fork trail at an altitude 

of about 2,000 feet. It was staked in 1923. The vein is in the Texas 

Creek granodiorite; it strikes N. 15°-30° W. and dips 45°-60° NE. 

It ranges from 1 to 14 inches in width, has been traced for 100 feet, 

and pinches out at the northwest end. The sulphides comprise 

galena, pyrite, pyrrhotite, and sparse chalcopyrite, with galena predominant. A 4-inch stringer of quartz a short distance away strikes 

N. 50° W., dips 45° NE., and is mineralized with galena and chalcopyrite. An assay of a picked sample from the main vein is reported 

to have given 30 per cent of lead, with $22 in gold and $6 in silver 

to the ton.

I IRON CAP

The Iron Cap group comprises three claims at an altitude of about 

3,800 feet, north-northwest of Malcolm Smith's cabin on the West 

Fork trail. The claims were staked in 1923 by David McVey. An 

open cut 12 feet wide has been made across an 11-foot zone of finegrained graywacke and slate that contains stringers and veins of 

sulphides. The vein zone strikes N. 75° E., approximately parallel 

to the bedding, and dips about vertically. On the northeast wall 

there is a 2-foot vein of quartz and coarse calcite with shoots of solid 

pyrrhotite and chalcopyrite, pockets of solid sphalerite, and a little 

arsenopyrite. Stringers several inches to a foot wide occur here and 

there in the remainder of the fissured zone. The vein is exposed for 

a length of about 50 feet. The contact of the sedimentary beds with 

the Texas Creek granodiorite lies at an altitude of a little more 

than 100 feet below the open cut.

The Hummel group comprises six claims at an altitude of about 

4.250 feet, on the north side of the West Fork, opposite the foot of 

Ferguson Glacier. They were staked by Harry Hummel in July, 

1925. The vein consists of a shear zone in argillite and slate that 

strikes N. 50° E., at a small angle to the bedding, and dips 35° W. 

The fissured zone contains stringers of sulphides and some quartz 

and is at least 2 feet wide. The vein has been uncovered for 12 yards 

by stripping. On the hanging wall there is a maximum of 6 inches 

of solid sulphides consisting predominantly of dark sphalerite 

with some associated galena, pyrite, and chalcopyrite and a little

tetrahedrite.

DOUBLE ANCHOR

The claims that make up the Double Anchor group lie at an altitude of 4,000 feet, near and at the head of a steep gulch, due north
MINES AND PROSPECTS 99

of Texas Lake, near the head of the West Fork. They were staked 

in 1923. The deposit is a shear zone in banded argillite and finegrained graywacke, with seams and stringers of quartz and sulphides. The strike is about east, and the dip is flat. The sulphides 

comprise brown sphalerite, galena, pyrite, and chalcopyrite. Pyritebearing quartz is common; pyrrhotite is sparse. One mineralized 

shoot, consisting of country rock with quartz and stringers of galena 

and pyrite is 30 feet in length and as much as 21^ feet in width, but 

pinches out into thin seams at each end. On the whole, there are 

only a few seams of sulphides in the vein zone, and these are usually 

less than an inch thick. Thick quartz veins are exposed in the gulch 

to the west, but they are only sparsely mineralized.

DTJGAS

Jerome Dugas holds five claims on the west end of the ridge north 

of the West Fork, in general at altitudes between 3,700 and 4,200 

feet. The country rock is graywacke with an intercalated zone of 

black slate. The prevalent strike of the bedding is N. T0°-80° E. and 

the dip is north.

The mineral deposits consist in part of fissure veins in shattered 

zones at an angle to the bedding, in part of mineralized quartz in 

stringers in shear zones parallel to the bedding, and in part of 

stringers of solid sulphide (usually brown sphalerite) parallel to the 

bedding. At one place there is a fractured aplite dike in wh,ich the 

fractures are faced with galena, pyrite, and chalcopyrite. The sulphides on these claims, so far as now exposed at the surface, are 

sparse or occur in scattered narrow stringers. No ore shoot of any 

size is exposed.

On the Copper Claim there is a fissured zone in graywacke 10 to 

15 feet wide, which strikes N. 30° W. and dips 45° W. Stringers 

of sulphides with a little quartz gangue several inches wide are 

scattered through this zone, but they are not close together. The 

sulphides comprise galena, sphalerite, pyrite, and chalcopyrite. Two 

open cuts have been made on the fissured zone, and it has been traced 

for about 50 yards.

SILVER KING

The Silver King group comprises six claims at the west end and 

on the north slope of the ridge north of the West Fork. It was 

staked by Angus Kennedy, August 28, 1925. Mineralized quartz 

is exposed in graywacke and argillite at two places about 200 yards 

apart; these exposures may be on the same vein. The vein crosses 

a dike of quartz diorite of the Texas Creek batholith that cuts the
100 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

sedimentary rocks. At an altitude of 3,800 feet the vein has been 

stripped for 50 feet.. There it ranges in width from 6 to 30 inches 

and has on the footwall 2 inches of solid sulphides comprising brown 

sphalerite, galena, pyrite, chalcopyrite, and a little arsenopyrite. At 

the upper exposure a stripping 8 feet in length has exposed a quartz 

vein with 8 inches of solid sulphides consisting of galena with some 

associated pyrite, chalcopyrite, sphalerite, tetrahedrite, and a little 

barite. At both exposures the quartz vein strikes N. 35° W. and 

dips 35° NE. and is a typical fissure vein at an angle to the bedding 

of the graywacke. A specimen sample of the galena ore from the 

upper outcrop is reported to have assayed 1.28 ounces of gold and 

5.96 ounces of silver to the ton, 55.2 per cent of lead, and 2.2 per 

cent of copper.

CHICKAMIN

The Chickamin group consists of two claims at an altitude of 

3,000 feet on the slope southeast of Texas Glacier near its junction 

with Chickamin Glacier. They were staked in 1925. A fissured 

zone in graywacke, striking N. 25° W. and dipping 50° NE., contains quartz stringers mineralized with galena, chalcopyrite, sphalerite, pyrite, and a little pyrrhotite and tetrahedrite. A quartz vein 

3 feet wide, striking N. 30° W., is also present on the claims. Practically no work has been done, and the veins are exposed only for 

very short lengths.

SLASHER

Frank Blasher holds four claims on- the north side of the West 

Fork near its head. The vein is below timber line and therefore

mostly covered with forest litter and vegetation. An open cut shows 

a 10-foot shattered and fissured zone in fine-grained brownish quartzite. About 4 feet of the hanging wall is almost solid quartz, and 

stringers of quartz are common in the rest of the fissured zoneMany of the stringers are heavily mineralized with galena, pyrite, 

sphalerite, and a little chalcopyrite. Mineralization is reported to 

have been traced for a length of 500 yards. The strike is N. 20° W., 

and the dip 45° E. This strike is at an angle to the prevailing 

trend of the bedding in this vicinity, and the vein is evidently of 

the crosscutting fissure type. An adit at an altitude of 2.700 feet 

has been driven 14 feet with the intention of cutting the vein in 

depth. The adit starts in argillite, which contains quartz veinlets 

with disseminated molybdenite. The outcrop of the vein is probably 

not more than 200 feet vertically above the contact with the Texas 

Creek quartz diorite.
MINES AND PROSPECTS 101

The Lake claim lies on the West Fork trail about a mile east of 

Chickamin Glacier, at an altitude of 2,400 feet; It was staked in 

July, 1923. The vein is in the Texas Creek quartz diorite just below 

its contact with the overlying sediments. The vein is exposed beside 

the trail, where it is 11 inches wide, strikes N. 35° W., dips 60° E., 

and is heavily mineralized along the footwall with abundant galena 

and less pyrite. It has not been traced.

MORNING

The Morning group comprises. four claims near the head of the 

West Fork just above Texas Lake, at an altitude of 2,300 feet. 

They are held by Frank Blasher. The country rock is the Texas

Creejs quartz diorite, and the vein consists of quartz 2 to 4 feet 

wide, heavily mineralized with pyrite and with sparse pockets of 

galena. At one end the vein passes into a highly schistose zone several feet thick of quartz diorite moderately impregnated with pyrite 

and containing narrow stringers and knots of quartz. The vein is 

exposed by stripping for 40 feet; it strikes N. 40° W. and dips 

45° NE.

EDELWEISS AND JUMBO

The Edelweiss claim is near Through Glacier, just north of the 

northernmost glacier on its west side. The claim was staked by 

Hummel, Blasher, and Mross in September, 1925. The vein is reported to be 1,500 to 2,000 feet in altitude above the glacier and to consist of quartz with galena and pyrite. A picked sample assayed $32 

in gold and 10.2 ounces in silver to the ton.

The Jumbo group, which comprises two claims, is at a lower 

altitude, just above Through Glacier. It was staked at the same 

time as the Edelweiss and by the same group of men. This property was not visited by the writer after the claims were liocatedL

Mr. W. B. Jewell reports that a number of quartz veins occur 

in graywacke on the mountain slope just northwest of the glacier. 

They strike about N. 10° E., dip steeply, range from 6 inches t/j> 2: 

feet in width, and locally carry shoots mineralized with- pyriteand galena. The graywacke strikes N. 60°-70° W. and' dips- steeply; 

it is cut locally by dikes of highly altered gabbro.

HECKLA

The Heckla group comprises five claims on the mountain slope 

southwest of the junction of Greenpoint and Through' Glaciers. 

It was staked by Hummel, Mross, and Blasher in September,. 1925.
102 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

The vein was not seen by the writer. It occurs in graywacke and is 

reported to be exposed for 75 feet. A ton of ore was broken from 

the surface outcrop and sledged down over the glacier to the West 

Fork trail in September, 1925, for a test shipment to the smelter. 

The ore consists of galena, pyrrhotite, sphalerite, and, chalcopyrite. 

A picked sample yielded $1.60 in gold and 54.3 ounces of silver to 

the ton, 21.6 per cent of lead, 32.1 per cent of zinc, and 4.1 per cent 

of copper.

TEXAS CREEK COMSTOCK (HYDER LEAD) 

LOCATION AND CHARACTER OF THE DEPOSITS

The Texas Creek Comstock group of 20 claims lies on the mountain slope on the south side of the West Fork in the vicinity of the 

two small glaciers between Ferguson Glacier and Hummel Glacier. 

The original claim, the Joe-Joe, was staked on July 15, 1923, by Joe 

Jackson and Joe Neary. In 1926 the name of the company controlling the group was changed from Texas Creek Comstock Mining 

Co. to Hyder Lead Mines (Inc.).

The predominant rocks exposed on the property consist of thickbedded graywacke or waterworn tuff with a little intercalated slate 

forming the upper part of the mountain and a portion of the Texas 

Creek batholith forming the base. (See pi. 10, A.) The character of 

the contact indicates that the batholith has here an upward bulge 

into the graywacke, forming a cupola-like protuberance. On Ferguson Glacier the contact is at an altitude of 3,000 feet; farther west it 

rises to 3,300 feet at the first main gulch and to 3,600 feet on the 

ridge above the first small glacier; it crosses very near the foot of

this glacier; between the two small glaciers it is at about 3,800 feet, 

and on the west side of the second glacier at 3,900 feet; west of the 

second glacier the contact bends sharply to the north and goes down 

to an altitude of about 3,340 feet, where it swings northwest and 

descends still lower. The graywacke here forms the roof of the 

batholith, which plunges to the west. Coarse, breccia-like beds composed of elongate fragments of volcanic rock are common. The 

strike of the bedding is. usually N. 75°-80° E.; the dip is usually 

60° S. but ranges from 50°-80° S. The Texas Creek batholith here 

lias not been carefully examined to determine its composition, but 

it is believed to be quartz diorite. It has an inconspicuous banding 

or a gneissic structure which is about vertical and strikes N. 70° E. 

The Texas Creek quartz diorite sends off dikes into the overlying 

graywacke. Many of these dikes are coarsely porphyritic. Aplite 

and pegmatite dikes are found, in the quartz diorite for 200 feet or 

so below the contact and for, 500 or 600 feet above it.
MINES AND PROSPECTS 103

More than a dozen veins have been (found on the property. They 

have a northwest strike and a steep northeast dip in both the quartz 

diorite and the graywacke and therefore strike uniformly across 

the structure. They also cut across the dikes of aplite and porphyry 

but are themselves probably cut by the dark-gray malchite dikes. 

Some of the veins occur in the Texas Creek quartz diorite, some in 

the graywacke, and some cross the contact and occur in both. As 

now exposed at the surface, the veins in the graywacke are more 

highly mineralized than those in the quartz diorite; most of the 

latter are barren or sparsely to moderately mineralized with pyrite, 

but some contain locally small shoots mineralized predominantly 

with galena.

VEINS ON THE FOBTTTNA CLAIM

On Fortuna No. 1 claim, in the first little gulch to the east of the 

eastern of the two small glaciers, between altitudes of 3,200 and 3,300 

feet, there is a shear zone in the Texas Creek quartz diorite that is 

5 to 10 feet thick and is exposed for a length af 50 yards. This 

zone contains a number of small quartz stringers and in the footwall 

portion a well-defined vein 1 to 3 feet thick, consisting of quartz 

sparsely to very heavily mineralized with pyrite. At many places 

the pyrite crystals are associated with pockets or stringers of calcite 

in the quartz. The vein strikes N. 50° W. and dips 60° E: About 

20 feet above this fissured zone there is another quartz vein, 15 to 

24 inches thick, sparsely mineralized with pyrite disseminated in 

cubic crystals. The veins are at an altitude 300 to 400 feet lower 

than the contact of the Texas Creek quartz diorite and the graywacke.

Two veins that may be parts of a single vein with the southeastern 

portion offset to the wes.t have been traced by several strippings 

from the contact of the Texas Creek quartz diorite with the overlying graywacke, at an altitude of about 3,540 feet, southeastward up 

.the hillside to an altitude of about 3,850 feet. At 3,700 feet a stripping shows the quartz vein 2% feet wide where it crosses an aplite 

dike that is intrusive into the graywacke. The quartz vein carries 

a shoot moderately mineralized with galena and pyrite. At an 

altitude of a little over 3,800 feet an open cut has been made on 

the vein, which is here in banded slate and graywacke, strikes northwest, and dips TO 0 E. For about 50 feet above the open cut the 

rock is a porphyry, part of an upshooting dike from the Texas Creek 

quartz diorite, which lies about 300 fee.t deeper. In the open cut 

there is a vein of quartz a foot wide, very heavily mineralized with 

sulphides. The hanging wall of the vein is not exposed. In the 

porphyry dike the vein splits into a number of stringers throughout 

a width of 20 to 25 feet. For this width the fissured zone is composed of 10 to 15 per cent of quartz in stringers. On the lower side
104 GEOLOGY OF HYDER AND VICINITY, SOUTHEA.STBEN ATiASKA

of the dike two of the larger quartz stringers, which are nearly a 

foot thick, are moderately mineralized. One of these extends across 

,the dike and carries many small shoots of sulphide several inches 

thick in addition to being sparsely mineralized throughout. On the 

upper side of the dike there is a narrow band of slate and graywacke in which the vein pinches to a few stringers, and then an 

aplite dike in which the stringers practically die out. The sulphides 

comprise galena, pyrite, and a little chalcopyrite. Locally there is 

considerable barite.

JOE-JOE VEIN

The discovery stake on the Joe-Joe vein is on the west side of the 

ridge between the two small glaciers, at an altitude of about 4,500 

feet. The vein probably consists of at least three parts successively 

offset by faults for short distances to the west. If these are considered to be parts of the same vein, the vein as a whole strikes N. 

35°-50° W., dips 80°-60° E., and is exposed for a total difference in 

altitude of 340 feet and a horizontal length of about 200 yards. It 

is a fissure vein in thick-bedded, massive, tuffaceous graywacke, 

whose bedding strikes prevalently N. 80°-85° E. and dips 55°-60° S. 

The gangue is almost wholly quartz, and large portions of the vein 

are barren or but sparsely mineralized with pyrite. The sulphides 

occur in local shoo.ts and comprise galena, pyrite, chalcopyrite, and 

sphalerite, with galena predominant. The largest shoot exposed at 

the surface is near the discovery stake.

Just above the discovery stake the vein is 4% feet wide and consists of quartz heavily mineralized with sulphides throughout. About 

20 yards up the slope, southeast from the discovery stake, there is a

highly fissured zone in graywacke 15 feet or so wide, with many 

sparsely mineralized quartz stringers and a vein of quartz 7 feet 

wide, 15 inches of which is moderately to heavily mineralized. The 

vein strikes N. 35° W. and dips steeply to the northeast. The projected line of extension up the mountain side farther southeast is 

covered for some distance. A quartz vein at an altitude of about 

4,640 feet has been exposed by stripping for a length of 40 feet; 

it is 9 to 15 inches wide and contains a shoot several inches thick 

heavily mineralized with galena and pyrite and showing a trace of 

sphalerite. If this vein is the same as the Joe-Joe it is offset to the 

east, but it is probably a different vein. About 15 feet northwest of 

the discovery stake the Joe-Joe vein is sparsely mineralized and is offset to the west. The part of the vein between this offset and the 

covered portion to the southeast is exposed for a vertical difference of 

60 feet and a length on the hill slope of about 40 yards. A dike of 

malchite with a strike of N. 65° W. occurs along the line of offset, 

then makes a sharp bend and follows the northwest offset extension
MINES AND PEOSPEOTS 105

of the Joe-Joe vein for a distance of 50 yards, striking N. 45° W. 

The vein thus occurs here along the contact between the malchite 

dike and the graywacke. Its contact with the dike is slickensided, 

and for about 35 yards down the hillside it is poorly exposed and at 

places very narrow. For the next 30 feet the vein is exposed by 

stripping and has a width of 2 to 3 feet with a shoot on the footwall 

as much as a foot in width and moderately mineralized with 

sulphides. Below this is an open cut which shows that the vein 

breaks up into moderately mineralized quartz stringers in a fissured 

zone 2% to &y2 feet wide in the graywacke adjacent to the malchite 

dike. Below the open cut the vein is in graywacke for about 25 

yards, with a strike of N. 50° W. and a dip of 70° E. The lower 15 

yards is stripped and shows a quartz vein that has an average width

of about 4 feet and is sparsely mineralized. A small shoot, moderately mineralized with sulphides, occurs at intervals in the hanging 

wall of a portion of the vein below the open cut. The total length 

of this second part of the Joe-Joe vein, as exposed on the surface, 

is about 75 yards. At its lower end, at an altitude of about 4,380 

feet, the vein is again offset to the west, and this third part has.been 

traced by two strippings for 100 yards-and a difference in altitude of 

160 feet. The upper stripping shows a fissured zone 2 to 3 feet wide 

with stringers of quartz and one vein several inches to a foot wide. 

The quartz is mineralized here and there with galena, pyrite, and a 

little sphalerite. The lower stripping exposes a strong quartz vein 

for a length of 30 feet. It ranges from 2 to 5 feet in width and 

is sparsely mineralized with pyrite.

OTHER VEINS

At altitudes of 3,400 to 3,900 feet on the west side of the hogback 

between the two small glaciers, on the edge of the slope above the 

west glacier, there are three parallel veins that strike northwest. 

Beginning with the southwesternmost vein and going northeast each 

has a successively steeper dip to the northeast, which results in their 

joining at altitudes of about 3,800 and 3,480 feet. These veins in 

their upper parts are in the graywacke, but they pass down across 

the contact at an altitude of about 3,820 feet into the underlying 

Texas Creek quartz diorite. They are here called Nos. 1, 2, and 3 

veins for purposes of identification. As exposed within the Texas 

Creek quartz diorite these veins are in general wholly barren or 

sparsely mineralized with pyrite, but in the graywacke they carry 

shoots mineralized with galena and other sulphides. Rarely, very 

small shoots mineralized with galena are found also in the veins 

within the Texas Creek quartz diorite. 

6196 29 8
The lower vein, No. 1, is exposed at an altitude of about 3,820 

feet by an open cut on the slope above the glacier. It strikes N. 

40° W. and dips 50° NE. The deposit here consists of a 7-foot 

fissured zone in graywacke with a vein 14 to 18 inches wide in the 

hanging wall moderately mineralized throughout a length of 25 

feet. At the southeast end beyond the face of the open cut the quartz 

veins pinch out into little stringers a quarter of an inch to 1 inch 

wide. The vein is covered for a space and then 35 feet northwest 

of the face of the open cut it crosses a 4-foot dike of porphyry in 

the graywacke where it is sparsely mineralized. Just beyond, at 

the contact of the graywacke with the mass of Texas Creek quartz 

diorite, the vein is offset about Y feet along a fault that strikes N. 

30° E. In the Texas Creek quartz diorite the vein, for a vertical 

distance of 20 feet below the contact, ranges from 1 to 2*4 feet 

in width and is sparsely mineralized with pyrite and chalcopyrite 

and locally a little galena in the hanging wall. At an altitude of 

about 3,800 feet a narrow stringer connects it with No. 2 vein, 

which at higher altitudes has a steeper dip and lies to the northeast 

and above it. At the junction of the two branches there is a mass 

of calcite with considerable disseminated pyrite. Below the junction the vein bulges to 3 feet in thickness and carries narrow bands 

mineralized predominantly with pyrite but with a little associated 

galena. About 35 feet vertically below the junction the vein splits 

into stringers; the one on the hanging wall is heavily mineralized 

with pyrite. The vein extends down nearly to the foot of the 

glacier, at an altitude of about 3,440 feet, and is from 1 to 2 feet 

in width locally, with included stringers of country rock. Sparse 

small pockets in the vein are mineralized with stringers and disseminations of pyrite.

No. 2 vein is exposed in an open cut on the slope above the glacier 

at an altitude of 3,900 feet. It is in graywacke, strikes N. 30° W., 

and dips 65° NE. The vein is stripped for 25 feet above the open 

cut, is about 20 inches wide, and contains many small lenses or 

stringers of solid sulphide averaging 6 inches in thickness. Galena 

predominates, with a little associated pyrite and chalcopyrite. 

Beneath the open cut the vein is sparsely mineralized and passes 

across an aplite dike, where it splits into a number of stringers 

through a width of 3% feet and forms one-half to three-fourths of 

the total volume. The vein then passes through about 10 feet of 

graywacke, becoming smaller in depth, to a porphyry dike. Only a 

half-inch stringer enters the dike, but about 12 feet below the dike 

quartz begins to come in again, and 25 feet below there is 2 feet 

of milky quartz with a little chlorite and a few pockets sparsely 

mineralized with pyrite and a trace of chalcopyrite. The vein is
MINES AND PEOSPEOTS 107

covered below this along the strike of the band where No. 1 vein 

develops a mineralized shoot. No. 2 vein is 8 to 10 inches thick in 

the graywacke just above the contact with the Texas Creek quartz 

diorite. It is offset by the same fault that offsets No. 1 at the 

contact of the graywacke and Texas Creek batholith. In the Texas 

Creek quartz diorite the vein ranges from several inches to a foot 

in width and is practically barren.

No. 3 quartz vein occurs in the Texas Creek quartz diorite and is 

poorly exposed. It is connected by a narrow stringer with No. 1 

vein at an altitude of about 3,480 feet and dips 60° NE. near its 

junction. About 300 feet in altitude above the junction the vein is 

about 50 feet from No. 2 vein, strikes N. 50° W. and dips 80° NE., 

is 2 to 3 feet wide, and at one spot contains a 1%-foot shoot mineralized with stringers of galena and pyrite. This vein was not traced

upward into the graywacke.

About 50 yards east of the water in the gulch below the west 

glacier, at an altitude of 3,100 feet, a vein of quartz 9 inches to 2*^ 

feet in width is exposed. It strikes N. 30° W., dips 55° E., and 

extends up the hillside for probably several hundred feet. It is 

barren except for small local patches with disseminated pyrite.

On the edge of the bluff face above the west glacier, at an altitude 

of 4,000 feet, a vein in graywacke is exposed for a length of 50 feet 

by stripping and an open cut. The graywacke beds strike N. 75° E. 

and dip 50°-60° S.; the vein strikes N. 10° W. and dips 40° E. The 

vein is 20 to 27 inches thick and consists of quartz with bands moderately to heavily mineralized with galena, pyrite, chalcopyrite, 

sphalerite, and a little pyrrhotite. These sulphides occur in widely 

varying ratios to each other. Some ankerite and a little barite are 

present in a few of the adjacent quartz stringers.

Several veins are exposed along the ridge just west of the west 

glacier. In the first gulch west of the glacier, at an altitude of 3,560 

feet, there is a fissured zone several feet thick in the Texas quartz 

diorite, with several small stringers and a quartz vein 8 inches to 

a foot thick exposed for a length of 150 feet. The vein strikes N. 50° 

W. and dips 45° NE. It consists of quartz with a little chlorite and 

calcite, seams of pyrite, and rarely a little galena. The walls of the 

vein are impregnated with pyrite and weather to a rusty color. At 

an altitude of 3,700 feet in the same gulch a quartz vein in the Texas 

Creek quartz diorite has been traced for 50 feet by several small 

strippings. A band several inches thick along one wall is- heavily 

mineralized with sulphides, predominantly galena, with some associated pyrite and a little sphalerite and chalcopyrite. Pyrite appears 

to predominate in the vein as a whole. A little tetrahedrite is also 

found.
108 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

A short distance west of the west glacier, at an altitude of 4,420 

feet, a vein in graywacke is exposed for 30 feet. The deposit consists of a fissured zone that contains stringers of quartz and a vein 

3 to 10 inches wide; it strikes N. 40° W. and dips 40°-50° E. Some 

of the stringers consist of quartz with chlorite and calcite. Seams of 

pyrite and small shoots of solid sulphides, comprising galena, 

sphalerite, pyrite, and chalcopyrite, occur in the vein. Several hundred feet higher, just at the edge of an ice-filled gulch there is another fissured zone 3 to 6 feet wide in graywacke, with stringers of 

quartz from a fraction of an inch to a foot wide. The quartz is in 

part heavily mineralized with galena and pyrite. The veins are exposed for only a short length, as they pass under the ice in one 

direction and pinch out in the other.

A boulder of graywacke with narrow stringers of quartz carrying 

visible flakes of free gold was found by Mr. Hummel at the foot of 

the west glacier, but the place from which it came has not been 

located.

KENO

The Keno group comprises 10 claims on the west side of Ferguson 

Glacier, at an altitude of 3,800 feet, about V/2 miles south of the 

foot of the glacier. They were staked in 1923. An adit 50 feet in 

length has been driven along a quartz vein in Texas Creek granodiorite. This vein strikes N. 42° W. and dips 70°-80° NE. It ranges in 

width from several inches to 4^ feet, but the average is from 3 

to 4 feet. It has been traced by trenches and natural exposures for1 

a length of 400 feet and a difference in altitude of 300 feet. The 

vein appears to be offset by faulting at its northwest end, just

before it passes beneath a glacier. At the surface one shoot of 

almost solid sulphide 25 feet long and as much as 7 inches wide 

occurs in the vein, usually in its center. Other similar shoots are 

present. Except for these sulphide shoots, the quartz normally 

carries only a little disseminated cubical pyrite, with locally some 

disseminated barite. The sulphide shoots consist predominantly of 

galena but contain also a little pyrite, chalcopyrite, sphalerite, and 

tetrahedrite. The adit has not reached the point below the sulphide 

shoot that is exposed at the surface.

JTJNEAU

The Juneau group comprises two claims at an altitude of 4,100 

feet, about half a mile northwest of the Sunset group. These claims 

were staked by a man named Murphy. A large quartz vein in the 

Texas Creek granodiorite ranges from 3 to 6 feet in width and is 

reported to have been traced by interrupted outcrops for 1,300 feet.
MINES AND PKOSPECTS 109

The quartz is predominantly milky white, with limonite facing 

the fractures and rarely a little stain of malachite. Locally there 

are small shoots heavily mineralized with chalcopyrite. The vein 

strikes N. 40° W. and dips 50° NE. A quartz vein mineralized with 

galena and pyrite is also reported to crop out on these claims.

SUNSET

The Sunset group comprises two claims on the east side of Ferguson Glacier 2^ miles from its foot, at an altitude of about 5,100 

to 5,200 feet. They were staked by Murphy & Stevens. Two mineralized quartz veins are exposed here in the Texas Creek granodiorite, 

near an isolated roof pendant of argillite and graywacke. Both 

veins strike about N. 50° W. and dip steeply to the northeast. Only 

a little surface stripping has been done.

The upper vein appears to be exposed at three different places 

and is thus traceable for a length of about 300 yards. At the southeast end there is a quartz vein a foot wide exposed for 10 yards, 

with local shoots moderately mineralized with galena and pyrite. 

Northwest of this, at the second exposure, a quartz vein has been 

uncovered by surface stripping for 10 yards. The vein ranges in 

width from 1 foot at the southeast end to 3 feet at the northwest. 

On the footwall or in the center there is 6 inches of the quartz 

heavily mineralized with galena and pyrite, and several inches on 

the hanging wall is similarly mineralized. Galena predominates. 

At the northwest exposure there is a shattered zone in the Texas 

Creek granodiorite 20 feet in width, about one-fourth of which 

consists of stringers of milky quartz. At the southeast end of this 

zone there are quartz stringers moderately mineralized with galena 

and pyrite.

The lower vein is 3% feet wide in one place and averages about 3 

feet. It can be traced by interrupted outcrops for 200 yards. Most 

of the vein is barren quartz with locally disseminated cubic crystals 

of pyrite. One lens of pyrite and galena 12 feet long and 4 inches 

wide was observed. Considerable barite is locally associated with 

the galena.

ENGINEER

The Engineer group comprises five claims on the east side of 

Ferguson Glacier about a mile from its foot, at an altitude of 4,000 

feet. They were staked by Dominick Bervaqua in 1924.

The vein is in the Texas Creek granodiorite, with included blocks of 

sediment very near the contact of the batholith with the argillite and 

fine-grained graywacke. It strikes N. 30°-40° W., dips 60°-T5° NE.,
110 GEOLOGY OF HYDER AND VICINITY, SOUTHEASTERN ALASKA

and is exposed by a series of surface strippings for a length of 75 

yards and a difference in altitude of 200 feet. The vein ranges from 

1 foot to &y2 feet in width but is generally from 2 to 4 feet. It consists of quartz with local shoots moderately to heavily mineralized 

with sulphides. An adit 30 feet long has been driven on the vein, 

In this adit the quartz is sparsely mineralized with blebs of chalcopyrite, cubic crystals of pyrite, little pockets of galena, and rare 

grains of scheelite. The walls are slickensided. About 20 feet above 

the adit, in an open cut, the vein is 3 feet wide. A foot of the hanging wall is heavily mineralized with pyrite and galena and a little 

chalcopyrite, and the remainder of the vein is sparsely mineralized 

with pyrite cubes and chalcopyrite blebs. The heavily mineralized 

shoot is short and passes into quartz moderately mineralized withi 

pyrite and chalcopyrite along both the dip and the strike. The hanging wall here is an included block of graywacke that appears like 

greenstone. An open cut 40 feet above the adit exposes a fissured 

zone in the granodiorite 10 feet wide, with the main quartz vein near 

the footwall and occasional quartz stringers in the upper part. In 

the hanging-wall part of the main quartz vein there is a small shoot 

5 inches wide and 5 feet long that consists of chalcopyrite and pyrite.

At an altitude of 150 to 170 feet above the adit a good ore shoot 

has been revealed by two strippings. The northwestern stripping 

exposes the vein for a length of 25 feet, where it has an average width 

of about 3% feet and contains a shoot 1 to 4 feet wide, heavily mineralized with galena and pyrite. To the southeast about 18 feet of the 

vein is covered,, and then another 35 feet is exposed by stripping. 

The vein here ranges from 2 to 4 feet in width, and the mineralized 

shoot from 1 foot to 2% feet. The sulphides are galena and pyrite 

in about equal amounts. The wall rock of this part of the vein is a 

block of graywacke included in the Texas Creek granodiorite.

Assays of seven specimens from the mineralized shoots show gold 

to range from 0.04 to 0.64 ounce ($0.80 to $12.80) to the ton, silver 

from 7.6 to 26 ounces to the ton, and lead from 11.3 to 55.3 per cent.

NORTH STAR

The North Star claim lies at an altitude of 3,850 feet, southeast of 

the foot of Ferguson Glacier. It was staked by Dominick Bervaqua, 

The vein is a fissure vein in graywacke. It strikes N. 40° W. 

and dips 70° E. The graywacke strikes N. 60° E. and has a vertical 

dip. The vein is only about 50 yards, measured on the surface, from 

the contact of the graywacke and Texas Creek granodiorite. It is 1 

foot to 2% feet wide, is exposed for a length of 50 feet, and consistsof quartz with local shoots of galena and a little associated pyrite.
MINES AND PROSPECTS 11 I 

JUMBO MINING

The Jumbo mining group comprises six claims on the south slope 

of the West Fork of Texas Creek, between altitudes of 3,500 and 

4,000 feet, about halfway between Casey and Ferguson Glaciers. 

The claims were staked by Kennedy & Provinse in 1925. The. country rock is graywacke, y/hich forms a downward-projecting tongue 

into the granodiorite of the Texas Creek batholith. The strike of 

the beds is N. 85° E. and the dip is vertical. The contact with 

the batholith at the lowest points is at an altitude between 3,000 

and 3,200 feet. Mineralization has occurred along a shear zone 

striking N. 30° E. and dipping 75° E., which extends between altitudes of 3,100 and 4,100 feet. The vein consists of a breccia of graywacke with quartz stringers ranging from 1 foot to 3y2 feet in width. 

These stringers, which carry the greater part of the sulphides, range 

from 1 inch to 2 feet in width and are well mineralized locally, 

though no seams of solid sulphide more than 2 inches wide were observed. The graywacke in the shear zone is impregnated with pyrite 

and a little chalcopyrite. The sulphides of the vein are mainly 

galena, pyrite, and chalcopyrite. They are not continuous but occur in local shoots. The vein follows the general trend of an aplite 

dike.

Another narrow fissured zone strikes into the larger zone. It 

trends north and dips 75°-80° E., is 10 inches wide, and has 6 

inches of quartz mineralized with galena, pyrite, and a little chalcopyrite and sphalerite.

COMMONWEALTH

The Commonwealth group is about 14 miles in a straight line 

southwest of Hyder, on a creek about 3 miles north of Cascade Creek, 

west of Kound Point, on Portland Canal. The prospects lie within 

a narrow belt of limestone and schist included in the quartz monzonite of the Coast Range batholith. The metamorphosed sediments^ 

are several hundred feet thick and include interbedded quartzite, 

dark-gray micaceous schist, and impure crystalline limestone. The 

belt is exposed in a gulch about a mile up the creek from the coast. 

A narrow dike of mica lamprophyre is exposed at several places in 

the gulch; it cuts both the quartz monzonite and the crystalline 

schist series. At an altitude of 580 feet an adit has been driven on. 

this dike for 80 feet, the intention being to crosscut and sample the 

walls for evidences of mineralization in the schist. The dike is in 

quartz monzonite at the portal, but crosses into the schist a short 

distance within the adit. It strikes N. 30° E. and has an average 

width of 6 to 7 feet. The walls of the dike at the inner end of the
112 GEOLOGIC RECONNAISSANCE ALONG CHIOKAMIN RIVER

adit consist of micaceous schist and masses of epidote of contactmetamorphic origin. Above the adit a thick bed of quartzite with 

disseminated pyrrhotite is exposed, dipping about 40° NE. Between the quartz monzonite and the quartzite there is a pocket-shaped 

aggregate of quartz, garnet, and epidote. On the west side of the 

gulch a pegmatite dike lies along the footwall of the extension of 

this mass. At one locality west of this gulch seams of sphalerite 

occur in an epidotic rock. The limestone contains nodules of pyroxene, much disseminated tremolite, some quartz, and seams, masses, 

and disseminations of pyrrhotite. An 11-foot adit was driven in 

the limestone on the east side of the gulch and exposed a small 

stringer of quartz reported to yield gold. A dike of mica lamprophyre is again exposed in the gulch at an altitude of about 860 

feet, where an open cut has been made along it. The rocks of this 

belt of schist and limestone have been metamorphosed by the intrusive quartz monzonite; the garnet-quartz-epidote masses are typical 

of such metamorphism. Weathered pyrrhotite gives the rusty color 

to the surface outcrop. Molybdenite and seams and disseminated 

deposits of sphalerite and sparse chalcopyrite occur locally. No 

mineralized shoot of any size has been found, and extensive underground workings here appear wholly unwarranted unless something 

more promising can be discovered by surface prospecting.

GEOLOGIC RECONNAISSANCE ALONG CHICKAMIN

RIVER

The writer is indebted to his assistant, W. B. Jewell, for the data 

on which the following report on the geology and topography along 

Chickamin Kiver is based.

GEOGRAPHY

Chickamin River is one of the larger rivers of southeastern Alaska. 

It flows from Chickamin Glacier, which lies about 30 miles from the 

coast, and empties into Behm Canal about 16 miles south of Unuk 

River and 70 miles north of Dixon Entrance. Leduc River and 

Chickamin South Fork, its two main tributaries, join it a few miles 

.above its mouth. The small bay into which the river flows is being 

gradually filled with sand and silt brought down by it. (See pi. 3.)

The main valley of Chickamin River is broad and flat. The river 

flows in a braided channel with numerous rapids, sloughs, and shifting sandbars. It is subject to sudden floods, and log jams are common. The river is navigable with a small boat and outboard motor 

for about 25 miles, from Behm Canal up to the foot of its canyon, 

but only with great difficulty and through the exercise of exceptional 

skill. The canyon is about 12 miles below the foot of Chickamin
GEOGRAPHY 113

Glacier; it is about a mile long and has a maximum depth of 50 feet. 

The river boils through it in a series of small falls and rapids. This 

canyon is the result of the river being forced against the steep southeast wall of the valley by a great rock slide from the mountain on 

the northwest.

A foot trail was built by the United States Forest Service in 1923- 

from the lower end of the; canyon 13 miles to the foot of Chickamin 

Glacier, but it is now overgrown with tall ferns and bushes. Landslides, windfalls, and brush have made it impassable in places. 

Tripods have been erected on Chickamin Glacier to mark the best 

route to the West Fork of Texas Creek, but many of them fall after 

a short time. In 1924 the Forest Service built two stretches of foot 

trail, about 2 miles apart and each about 3 miles in length, starting 

from a cable crossing over Leduc River about li/2 miles above its 

junction with the Chickamin. There is a Government cabin at the 

foot of the canyon and another at the foot of Chickamin Glacier.

The flats in the lower valley of Chickamin River are heavily timbered with tall spruce trees 3 and 4 feet in diameter. A few hemlocks 

and cottonwoods are present, together with the usual jungle-like 

underbrush of devil's-club, blueberry, salmonberry, and willow. In 

protected areas, where the slopes are not too steep, the forests extend 

continuously up to altitudes of 3,000 feet and over. The valleys of 

the tributary creeks are all heavily forested. The river flat abovethe canyon is covered with dense underbrush but with very few trees,, 

chiefly cottonwoods, some of which are 1 foot in diameter. The slopes 

of the upper part of the valley are covered in protected places as high 

as 3,500 feet with large hemlock and spruce trees and scattered 

cedars.

The topography along the entire length of Chickamin River is 

extremely rugged. (See pi. 10, B.) The mountains rise abruptly 

above the valley floor to heights of 4,000 ,to 7,000 feet. Practically 

all these mountains up to 6,000 feet are well rounded, but those over 

7,000 feet in altitude are serrate. There are no long, continuous 

ridges; the rounded peaks are separated by steep-walled valleys. 

Many of the higher peaks are covered with fields of snow or ice. 

The slopes up ,to 3,000 feet in altitude are everywhere extremely 

steep, at some places 50° or more. Some of them are bare of vegetation and have been grooved and fluted by ice action. Along the sides 

of the main valley are many U-shaped hanging valleys, from each 

of which pours a creek in a series of falls and rapids that may have 

an aggregate drop of as much as 1,000 feet. Steep cones of rock 

debris and snow are found at the mouths of many of the gulches.

Chickamin Glacier heads against glaciers .that flow toward Nass 

River. It flows slightly west of south to a point near the head of
114 GEOLOGIC RECONNAISSANCE ALONG CHICKAMIN RIVER

the West Fork of Texas Creek, where it turns sharply toward the 

northwest. A large tributary, Through Glacier, joins Chickamin 

Glacier from the south-southwest at this turn. Through Glacier is 

fed by many tributary glaciers and is continuous across a divide 

(see pi. 14, B) with a glacier that flows for 15 or 20 miles to the 

southwest.

A broad terminal moraine 30 feet high extends across the valley 

4,600 feet downstream from the present front of Chickamin Glacier. 

(See pi. 14, A.) This moraine is now covered with alders several 

feet high. Robert Andrews, of Hyder, states that in 1902 the glacier 

stood within a very few fee.t of the moraine. Malcolm Smith reports 

that the glacier retreated 600 feet between 1923 and 1925.

GEOLOGY 

GENERAL FEATURES

The Chickamin River Valley cuts completely across the great 

Coast Range batholith. On the southwest flank of the batholith 

for 2 miles up the valley from Behm Canal the rocks consist of 

crystalline schist and injection gneiss with sparse intercalated beds 

 of marble. These rocks may be grouped together under the general 

term "metamorphic complex," as they represent sedimentary beds 

which have been recrystallized under stress and have in part been 

injected with aplite and pegmatite veins given off by the underlying Coast Range batholith. The beds may belong to the Prince 

Rupert formation (Carboniferous or Triassic) as mapped by Dolmage 30 to the south in British Columbia, but this assignment is far 

from certain. On the northeast flank of the batholith, along Chickamin Glacier and 3% miles below its foot, the rocks consist of 

tuffaceous graywacke with intercalated slate and quartzitic beds 

that probably belong to the upper division of the Hazelton group. 

The Coast Range batholith, between the metamorphic complex on 

the southwest and the little-altered beds of the Hazelton group on 

the northeast, has a width in this area of about 30 -miles. The 

batholith comprises a narrow band of quartz diorite on the southwest, a broad belt of granodiorite in the core, and' a broad belt of 

quartz monzonite on the northeast. Throughout the batholith there 

are varying amounts of crystalline schist, the inclusions ranging in 

size from small shreds to large blocks several miles long. Near the 

included fragments pegmatite and aplite dikes are common, and 

there are all gradations between clean intrusive rock and crystalline 

schist. A series of dikes of dark fine-grained lamprophyre of the

^Dolmage, Victor, Coast and islands of British Columbia between Douglas Channel and 

the Alaskan boundary: Canada Geol. Survey Summary Rept. for 1922, pt. A, pp. 9-34, 

1923.
METAMOEPHIC COMPLEX , 115

variety spessartite cut all the other rocks throughout the length of 

the valley and have a remarkably uniform northeast strike.

On Portland Canal, to the southeast, quartz diorite forms the 

southwest border of the batholith and quartz monzonite the northeast border; but the core of the batholith there consists of granodiorite interbanded on a broad scale with quartz monzonite and a 

little quartz diorite. Along Stikine River, to the northwest, as on 

Chicfcamin River, quartz diorite forms the southwest border of 

the batholith, granodiorite the core, and quartz monzonite the northeast border. The occurrence of quartz diorite 5 to 15 miles wide, in 

the southwest border of the batholith, of granodiorite 15 to 25 miles 

wide in the core, and quartz monzonite 8 to 15 miles wide in the 

northeast border portion therefore seems to be a general relation 

through at least 150 miles of the length of the batholith.

Westgate 31 states that the batholith is not a simple body resulting from a single intrusion but a " composite batholith " that consists 

of materials of different composition intruded in two or more distinct stages of an eruptive period. On the southwest border, in the 

vicinity of Behm Canal, he reports the series to consist of

(1) an earlier darker gueissoid diorite, more contorted and rustier in outcrop 

1han the later rock, and (2) a light or dark gray gneissoid diorite, often banded 

and contorted but even then appearing massive in the ledge, which is by far 

the most abundant type. * * * The transition from one variety to the

 other is sometimes through a belt of several hundred feet. On one side we 

have the later diorite; then isolated masses of the earlier rock, which be-

 come more and more abundant until they make a breccia cemented by intersecting veinlike bands of the later rock; then these bands die out and there 

5s the continuous mass of the older rock.

The rock referred to b}^ Westgate as diorite is described by him 

elsewhere more .specifically as quartz diorite.

The writer has not seen such definite evidences of successive intrusions within the Coast Range batholith as those described by West- 

.gate. but' he has no doubt that the batholith is composite and that 

there were successive intrusions of magma.

METAMORPHIC COMPLEX

The belt of the metamorphic complex adjacent to Behm Canal 

consists principally of hornblende-quartz-biotite schist with sparse 

beds of marble. Locally the rocks have been converted into injection 

gneiss by the intrusion of abundant veinlets of pegmatite, aplite, and 

.glassy quartz. The rocks weather a reddish brown. The foliation 

strikes generally N. 35°-45° W. and dips steeply, though variably, 

to the northeast. The innumerable pegmatite dikes that cut the

31 Westgate, L. G., The geology and mineral resources of the area east of Behm Canal 

{unpublished manuscript).
116 GEOLOGIC BECONNAISSANCE ALONG CHICKAMIN HIVEE

schist are composed of quartz, hornblende or biotite, and feldspar. 

The feldspar includes both oligoclase and potassic varieties. Biotite 

flakes as much as 3 inches in diameter and hornblende crystals as 

much as 2^ inches long are common. Biotite is much more abundant 

than hornblende. Garnets are plentiful in some parts of the schist.

A large block of schist nearly 2 miles wide and 4 miles long occurs 

within the quartz monzonite near the canyon. It makes up most .of 

the mass of the mountain 4,000 feet in altitude just north of the 

river and extends across the river. It is sparsely mineralized locally 

with the iron sulphides, pyrite and pyrrhotite. This large block 

has a north-south trend. It is not so intensely altered as the rock of 

the metamorphic complex on the southwest, and the bedding is quite 

apparent on the top of the mountain.

Along Behm Canal the metamorphic complex includes also quartzitic beds, amphibolite, and calcareous schist.

On the southwest border of the batholith the contact between the 

quartz diorite and the schist is a zone more than a mile wide rather 

than a sharply defined line. In this contact zone the amount of 

intrusive material increases toward the northeast and the schist 

inclusions become fewer and fewer. The belt of quartz diorite is 2 

to 3 miles wide. The number of samples collected here was not sufficient to afford data on the average composition of the belt; for this 

reason the average composition of quartz diorite, as given in the 

table on page 118, is that1 of samples from the western portion of the 

Coast Range batholith along Stikine River, where the rock is similar 

to that on Chickamin River. Locally the percentage of quartz varies; 

it may be as much as 30 per cent. Hornblende may be practically 

absent. The plagioclase is usually andesine, locally oligoclase, and 

ranges from 50 to 65 per cent. The potassic feldspars range from 

1 to 8 per cent and include microperthite, microcline, and orthoclase. 

The orthoclase is usually minor. The accessories include magnetite, 

apatite, titanite, and a trace of zircon. The biotite and hornblende 

occur usually in practically equal abundance.

The core of the batholith in the vicinity of Chickamin River is 

composed of granodiorite, which forms a belt 13 to 14 miles wide 

from the quartz diorite northeast to a line about 4 miles below the 

mouth of Indian Creek. Throughout this belt there are large areas 

of rock that shows a marked gneissic structure and banding and in 

part resembles injection gneiss. This structure has probably resulted from the partial or complete disintegration and assimilation 

of belts of schist by the intrusive magmas and pegmatitic solutions. 

Small inclusions of schist are abundant. Some of the larger in-
COAST RANGE INTEUSIVES 117

elusions are altered to great masses of garnet and epidote, locally 

with disseminated pyrite and pyrrhotite. Locally the granodiorite 

gives place to quartz diorite, but these areas of quartz diorite are 

generally small, and many of them are in the vicinity of schist inclusions. Some of the gneiss resulting from the interaction between 

the granodiorite magma and the schist has the composition of quartz 

diorite. The average mineral composition of the granodiorite, as 

determined by Kosiwal analyses on specimens from 10 different 

localities, is given in the table as No. 2. The potassic feldspars 

include microcline, microperthite, and orthoclase, but the orthoclasa 

is relatively sparse. The accessory minerals comprise magnetite, 

titanite, and apatite. The plagioclase is predominantly andesine, 

commonly of a sodic variety. 

The northeastern part of the batholith from a line about 4 miles

below Indian Creek to the eastern contact, a distance at right angles 

to the banding of 8 to 14 miles, is composed of practically massive 

medium-grained quartz .monzonite very similar to that near Hyder. 

The average mineral composition, as determined by Eosiwal analyses 

on specimens from eight different localities along the river, is given 

in the ta£>le as No. 3. The plagioclase in the quartz monzonite is 

oligoclase. The potassic feldspar includes microcline, microperthite, 

and subordinate orthoclase. The accessories include magnetite, 

titanite, and apatite. Schist inclusions and pegmatite stringers occur, 

but they are relatively sparse aside from the large block of schist 

near the canyon referred to above.

The average composition of two specimens of pegmatite is given in 

the table as No. 4. These pegmatites occur within the core of granodiorite and grade into coarse-grained mas&es resembling the quartz 

monzonite of the adjacent belt on the east.

It seems probable that the quartz monzonite is a later intrusion 

than the granodiorite, though belonging to the same magmatic epoch. 

No positive evidences of intrusive relations were seen, however, though 

in a hurried reconnaissance they might easily be overlooked.

The lamprophyre dikes cut the batholithic intrusions. They are 

fresh in appearance, black to dark greenish, and brittle. Under the 

microscope they are found to consist usually of needles of brown 

hornblende and very sparse biotite in a dense macrocrystalline aggregate of highly altered plagioclase with small amounts of potassic 

feldspar and interstitial quartz. They usually contain also abundant 

grains of well-crystallized magnetite. The plagioclase is largely 

andesine, with small amounts of labradorite. The hornblende generally forms from 20 to 30 per cent of the rock and is extensively 

altered to chlorite. The plagioclase is much altered to sericite and 

carbonates. All the lamprophyre dikes examined were of the variety
118 GEOLOGIC RECONNAISSANCE ALONG CHICKAMIN RIVER

spessartite except one, which contained abundant biotite and only 

sparse brown hornblende. The dikes are relatively narrow, few 

being more than 4 to 6 feet wide, and they have a remarkably uniform 

strike. Of the many observed only one had a strike that varied much 

from N. 50° E.

Mineral composition of Coast Range intrusives along Chickamin River

1. Average of 5 specimens of quartz diorite 

from western part of batholith along 

Stikine Eiver. ... .......................

2. Average of 10 specimens of granodiorite 

from core of batholith along Chickamin

3. Average of 8 specimens of quartz monzonite from eastern part of batholith along 

Chickamin Eiver ... ..............

4. Average of 2 specimens of pegmatite in 

granodiorite along Chickamin Eiver.....

Andesine

61

^n

Oligoclase

37

26.5

Potassic feldspars

2

14

33

25.5

Quartz

18.5

'21

24

45

Hornblende

11

5

.2

Biotite

6.5

4.3

3

Accessory minerals

1

1

1.5

Trace.

STRUCTURE

The prevailing trend of the Coast Range batholith is northwest. 

Along Chickamin River, especially in its lower portions, the foliation 

of the metamorphic complex in the main belt and in the larger inclusions has a strike that ranges from N. 5° W. to N. 50° W. with an 

average of N. 30° W.; its dip, though variable, is generally about 50° 

NE. The northeast dip is also common to the foliation of the Coast 

Range batholith itself.

On the northeast flank of the batholith the contact of the quartz 

monzonite with the graywacke is irregular and crosses more than 

it parallels the strike of the strata. A large block of graywacke 

forms a deep reentrant into the east border of the batholith along 

Chickamin Valley, forming Banded Mountain and extending to a 

point about 3^ miles below the terminus of Chickamin Glacier. The 

beds in this block strike predominantly N. 60°-90° W. Close to the 

contact the dips are vertical; farther away they are southwest.

The rocks of the Coast Range batholith, especially on the southwest, have a gneissoid structure. The character of this structure is 

such as to suggest either that it has arisen from flow in the yet 

unconsolidated magma and is primary or that it is due to inheritance 

from reaction with schist inclusions. The texture of the rock is the 

result of crystallization on cooling and not of dynamic action. The 

quartz monzonite shows only a slight gneissic structure and much less 

abundant inclusions of schist. No evidence of crushing of the mineral grains of the intrusive rock was seen under the microscope. The
METAMORPHISM 119'

quartz and locally some of the feldspar show strain shadows, but 

that is all.

The beds must have been folded in part before the intrusion of the 

Coast Range magmas, which appear to have in part penetrated the 

earlier rocks along these structural planes. On the southwest the 

magmatic residual solutions permeated and very intimately injected 

the beds and, aided by the intense heat, changed them to crystalline 

schist and injection gneiss. On the northeast, although the intrusion 

of the magma appears to have been guided by the older structure of 

the beds, in the Hyder district at least the contact line shows the effect 

of block fracturing rather than penetration along bedding or foliation 

planes.

METAMORPHISM

On the southwest border of the Coast Range batholith in the latitude of Chickamin River there is a belt 35 miles wide, measured at 

right angles to the strike, composed of crystalline schist and phyllite 

with numerous bodies of intrusive quartz diorite. On the northeast 

side of the batholith, however, the area of metamorphosed rocks is 

relatively small and the metamorphism is of the local contact type. 

The beds of the Hazelton group adjacent to the quartz monzonite 

have locally been mashed, or more commonly foliated and recrystallized, but for only a few hundred feet from the contact in 

many places and rarely for more than a quarter of a mile; though 

slight crinkling, pencil structure, or intensification of slaty cleavage may extend to greater distances.

The Wrights 32 have ascribed the greater metamorphism on the 

southwest to deeper burial at the time of the intrusion of the igneous 

masses. Schofield 33 thinks that the difference is due to the shape 

of the batholith its vertical relations to the country rock combined 

with a subsequent tilting of the Coast Range block. The writer is 

of the opinion that the great belt of metamorphic complex on the 

southwest is due to contact metamorphism on a regional scale consequent upon the proximity of the Coast Range batholith, which must 

everywhere underlie it at no great depth, as indicated by the abundant protrusions or cupolas of igneous rock that are exposed at the 

present surface. The contact on the northeast side may, on the 

other hand, be approximately vertical, as Schofield suggests, and 

therefore plunge down so abruptly that the zone of metamorphism 

is very narrow. The zone of metamorphism is similarly narrow 

north of Juneau, where the west border of the Coast Range batholith 

is doubtless very steep. There seems to be no necessity for assuming

82 Wright, F. E. and C. W., The Ketchikan and Wrangell mining districts, Alaska: 

U. S. Geol. Survey Bull. 347, pp. 67-68, 1908.

88 Schofield, S. J., and Hanson, George, op. cit., pp. 65-66.
120 GEOLOGIC RECONNAISSANCE ALONG CHICKAMIN RIVER

a tilting of the Coast Kange block to explain the phenomena. The 

moderate metamorphism of the block of schist near the canyon of 

Chickamin Kiver and of a similar block of country rock along Iskut 

Eiver, both within the core of the batholith, in contrast to the extreme metamorphism of the belt of country rock on the southwest 

border of the batholith, however, is not satisfactorily explained by 

any of the suggestions made.

MINERALIZATION

A few of the glassy quartz veins near the contact of the Coast Kange 

batholith with the metamorphic complex on the southwest contain 

small amounts of pyrite and molybdenite. Low yields in gold are 

also reported from them. About 2y2 miles up the South Fork, 

above its junction with Chickamin Kiver, there is a large shear zone 

approximately 100 feet wide. It strikes N. 50° W. and dips 50° NE. 

This zone is mineralized with narrow veinlets of solid pyrite, and 

examination with .the microscope revealed small amounts of chalcopyrite and magnetite. The rock of this zone weathers to a rusty 

color by which it can be traced for miles across the country, with a 

difference in altitude of at leas.t 4,000 feet. In certain bands of the 

metamorphic complex within the batholith there are disseminated 

sulphides consisting of pyrite, pyrrhotite, and chalcopyrite, but 

nothing of apparent value has been found within them. If prospecting is carried further, however, the schist blocks and their vicinity and the shear zone should be examined.

PROSPECTS 

GNAT

Four miles from Behm Canal, on the north side of the river, there 

is a glassy quartz vein averaging 8 feet in width in the granodiorite. 

It strikes N. 30° W. arid dips 60° NE. The vein is slightly mineralized with pyrite and molybdenite on the hanging wall. The claim 

is reported to have been staked in 1900, but no work has been done 

on it.

GLACIER

The Glacier group consists of seven claims on the north side of 

Banded Mountain, at the foot of Chickamin Glacier, at an altitude 

of 1,200 feet. They were located in 1923 by Andrews & Schonburg, 

of Hyder. The deposit consists of numerous narrow quartz veins 

ranging from 2 inches to a foot in width, in graywacke, with some 

andesitic tuff and breccia. Bands of barren country rock usually
PEOSPECTS ' 121

intervene between adjacent veins, which may be several feet apart. 

The veins are heavily mineralized with coarsely crystallized pyrite 

and small amounts of pyrrhotite, chalcopyrite, and very rarely 

galena. Most of the veins seem to occupy two main sets of cross 

fissures; one set strikes N. 50° E. and dips 45° SE., the other strikes 

N. 20° W. and dips 45° NE. The beds strike east and dip 60° S. 

The veins are cut by a dike of lamprophyre 3 to 4 feet wide. The 

development work consists of 25 feet of stripping and 8 feet of 

tunnel. There is a log cabin on the property. Assays have shown 

80 cents in gold and 6 ounces of silver to the ton and 3 per cent of 

copper.

6196 29 9

INDEX

Acknowledgments for aid. ............. 2,112

Alaska-Premier claims, description of____ 85-86 

Anglesite, occurrence of. ........._...... 51

Ankerite, occurrence of.----------_._..-. 52

Arsenopyrite, occurrence of _.__...... 51

Assays of ores........... ............ 65,70,92,95

Azurite, occurrence of... .. 52

Barite, occurrence of.._....__._ 51

Bartholf claims, description of_______ 92-93 

Basaltic dikes, occurrence of........_ 37

Bibliography of the district........._...... 3-4

Bishop claim, description of.. __. _.. . 67 

Blasher claims, description of._______ 100 

Border claims, description of.... _____.. 90

Boulder batholith, Mont., comparison with

silver-lead deposits of _.. . 57-58

Boundary Glacier, features of. . .. 10,13

view up, plate showing.... _ 24

Boundary granodiorite, contact metamorphism produced by.............. 38,39

description of...................... 32-33,58-59

mineral deposits in. .... 55 

Butte claims, description of.. . .. 81

Calcite, occurrence of..... . 52

Cantu claims, description of.... . 91-92

Casey Glacier, features of..... ..._ 11

Chalcopyrite, occurrence of... ... 50 

Chalmersite, occurrence of...-.--.._ 50 

Chickamin claims, description of..._ .. 100 

Chickamin Glacier, features of....... 11,13,113-114

plates showing_.....___.._____ 24,72

Chickamin River, view at head of.-.__.... 72

Chickamin River Valley, geography of _- 112-114 

geology of.............--..-.---..-..-- 114-120

mineralization in....------.-........-.. 120

plate showing......... , 24

sketch map of.. _ . 8 

Cirque, glacier occupying, plate showing.... 8

Climate of the district....-,--. .. ... 5-6

Coast Range, mountains of, plates showing.. 8,24 

Coast Range batholith, features of.... . 13-14

metamorphism by..------__...... 119-120

prospecting in......... .... 62

structure of....-...........-.......---. 118-119

Coast Range intrusives, description of..... 116-118

Commonwealth claims, description of..... 111-112

Contact metamorphism, effects of..._...-. 37-39 

Covellite, occurrence of...-. . 50 

Crest claims, description of............... 81-82

Cripple Creek claims, description of.... 83-84

Cross vein, prospecting on.... .. .... 78-80

Daly-Alaska claims, description of__._'.. 86-88 

sketch map of..__-..--....-.__...-. 72

Double Anchor claims, description of........ 98-99

Drainage of the district._________... 9-10 

Dugas claims, description of ._______ 99

Edelweiss claim, description of.. ____. _ 101 

Engineer claims, description of.. _____ 109-110 

Evening Star claim, description of........... 94

Faults in the district...__.___.._.... 42 

Ferguson Glacier, features of________ 11,13

plate showing....._... ..._..... 24 

Field work, record of. ____________ 1-2 

Fish Creek claims, description of..__..... 68-71

sketch map of..____...______ 72 

Forest growth, plate showing .. ____.. 8 

Fortuna claim, veins on.______.__ 103-104 

Freibergite, occurrence of..__..__........ 50-51

Galena, occurrence of____...______ 49 

Geology, general features of___ _ ___.. 13-17 

Glaciation in the district..._____.___ 10-13 

Glacier claims, description of _______ 120-121 

Gnat claim, description of _______. __ 120 

Gold, occurrence of.____________. 48-49 

Gold Cliff Premier claims, description of.... 90

Granodiorito porphyry dikes, description of- 33-34 

Gravel, deposits of........................... 39-40

Graywacke-slaty argillite, features of........ 19-22

Greenstone of the district, features of.... _ 18-19

Hazelton group, prospecting on.__. ____ 59 

rocks of ............................... 17-22

Hcckla claims, description of.. ______ 101-102

Hidden Glacier, features of.. _____... 11

head of, plate showing__.__......... 8

History of the district..___________ 1,2-3 

Hobo claims, description of....._____... 84-85

Homestake claims, description of._........ 94-95

Howard claim, description of... _____... 76 

Hummel claims, description of...___.... 98

Hyder, plate showing..__________... 8 

Hyder Jumbo claims, description of.. _.... 72

Hyder Lead Mines (Inc.), claims of....... 102-108

Hyder batholithic intrusions, nature and

extent of .................... 29

Hyder quartz monzonite, aplite dikes associated with.._.......... .... 35

contact metamorphism produced by..... 38-39

description of............... .......... 29-32

features of. 58-59

o mineral deposits in.._................. 55

Hydor Skookum claims, description of....... 72

Ibex claims, description of.............. 96-97

Ickis vein, prospecting on.....-_.......... 78

Indian Creek, valley of, plate showing _. 24 

Intrusive masses, relation of mineral deposits

to... ..- 53-55

Iron Cap claims,-description of....__...... 98

123
124 INDEX

 Page 

Jewel!, Willard B., acknowledgments to__ 2,112 

Joe-Joe vein, description of.. _______ 104-105 

Joints in the rocks__.__ _ ____ ___ 42 

Jumbo claim, description of...._______ 101 

Jumbo mining claims, description of..___ 111 

Juneau claims, description of_______ 108-109

Keno claims, description of.________ 108

Lake claim, description of. ..._....._... 101

Lamprophyre dikes, nature and occurrence

of...-......-..-.......... ..... 36-37

Last Shot claims, description of__...._. 75-76

Liberty claim, description of.____.___ 93-94

Limonite, occurrence of-___....__...... 52

Lindeborg vein, prospecting on...____. 80-81

Location of the district...._............... 1,4

Lucky Boy Extension claim, description of. 67

Magnetite, occurrence of...___.___... 51 

Malachite, occurrence of_____. _____ 52 

Malchite dikes, nature and occurrence of . 35-36 

Map, geologic, of the district___._ In pocket, 

topographic, of the district. ____ In pocket. 

Marcasite, occurrence of_._____..._ 50 

Metamorphic complex, features of.___.. 115-116 

Mineral deposits, classification of._........ 42-44

relation of, to the intrusive masses_._ 53-55 

search for..- .._ _ . 58-63

Minerals, classification of,-.....______. 48

content of valuable metals in... _ __. 48 

metallic, interrelation of__--....--._. 52-53

undetermined, occurrence of-..___.. 52 

Molybdenite, occurrence of. _________ 50 

Monarch claims, description of... __. __ 74-75 

Morning claims, description of__....._. 101

Morning Star claim, description of_____ 94 

Mountain View claims, description of....... 63-67

sketch map of.........._.._..___ 72

Ninety-six claims, description of.______ 93

North Star claim, description of. ______ 110

Nothiger claim, description of..._ ... 94

Porphyry dikes, relation of Canadian ore

bodies to..___________ 54-55 

Portland Canal, sketch map of upper part of. 8 

Portland claims, description of..-._-- _-.. 84 

Prospecting, notes on____.....__..... 58-63

Proustite, occurrence of.___________ 51 

Pyrite, occurrence of...------___.. .__ 49

Pyrrhotite, occurrence of... ____'____ 49

Quartz, occurrence of.____._______ 51

Relief of the district..___________.. 7-8 

Ridges between glaciers, rocks of.._____ 19-22 

Riverside claims, description of._.____ 77-81 

Roads in the district____....._--...-. 4-5

Salmon Glacier, features of.....__...__ 10

foot of, plate showing._______.__ 24

Salmon River, features of.__...___... 9

valley of, plate showing .........-..... 8

Salmon River district, B. C., formations in.. 17

Scheelite, occurrence of.___________ 52

Schofield, S. J., and Hanson, George, quoted. 19,

42-44,54

Silver, occurrence of__...--...-..-..._ 49 

Silver Bar claim, description of._. . . 93 

Silver Bell claims, description of..-...-..._ 97 

Silver Coin claim, description of.......... _ 95

Silver King claims, description of.__.__ 99-100 

Silver Star claims, description of..... ____ 97

Sixmile claims, description of --------'........ 76-77

Smith, Philip S., Foreword._.___.__ vn 

Specularite, occurrence of____....____ 51

Sphalerite, occurrence of ..-..-..-_...... 49-50

Steamship communication with Hyder______ 5

Stewart, B. C., location of.___..-..___ 5

meteorologic observations at.......__.. 6

Stoner claims, description of___._____ 89r-90

sketch map of--..._-...-...--......-.- 72

Stoner-Clegg-O'Rourke claims, description of. ' 88 

Streams in the district.__._.__...__ 9-10 

Structure of the rocks.....__'..........__ 40-42

Sunset claims, description of....._.___.. 109

Tetrahedrite, occurrence of.......... __... 50-51

Texas Creek, features of......___._._ 9

West Fork of, glaciers on, plate showing. 24 

view in valley of. -. _..--- _ 8 

Texas Creek batholith, aplite dikes associated with...................... 28-29

comparison of deposits of, with silver-lead 

deposits of the Boulder batholith, 

Mont............................ 57-58

contact rnetamorphisin not produced by. 37 

dikes associated with...._....___ 28

diorite contact facies of..________ 27 

granodiorite core of....--___._.___ 25-27

nature and extent of._....._..__.. 22-25

quartz diorite border facies of. _. ___ 27 

relation of mineral deposits to_.._... 53-54 

structure of__ --. .._ - 41-42

Texas Creek Comstock claims, description

of.............................. 102-108

Texas Creek granodiorite, features of.__ 58-59,60

Texas Glacier, features of.___.____ 10-11,13

Through Glacier, features of...___.___ 114

plate showing______. ______.. 24

snow field at head of, plate showing.__ 72

Thumb Creek, features of.-__._____ 9-10

Titan claims, description of..---------_.--. 72-74

Topography of the district.__________ 7-l'5

Vegetation of the district....._.____.. 6-7

Veins, influence of temperature and pressure

in formation of...________ 55-57 

position and nature of......._..___. 46-47

strike and dip of_____________ 44-46 

type of. . 44

Victoria claims, description of..__..._.. 67-68 

Virginia claims, description of.. __. _..... 88-89

sketch mapof.__....___...._.... 72

Water power in the district_________ 7

Westgate, L. G., acknowledgment to.___ 2

quoted........ 2-3,19,42-44,44,69,71,86,8", 115

Younger Coast Range ' intrusive rocks,

features of..............._..... 59

mineral deposits in..____,___..... 55

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