Mineral Resources 

of Alaska, 1956 

GEOLOGICAL SURVEY BULLETIN 1058 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1961 
UNITED STATES DEPARTMENT OF THE INTERIOR 

FRED A. SEATON, Secretary 

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director 
CONTENTS 

[The letters fn parentheses preceding the titles designate separately published chapters] 

(A) Reconnaissance for radioactive deposits in southeastern Alaska, 

1952, by J. R. Houston, R. G. Bates, R. S. Velikanje, and Helmuth 

Page 

Wedow, Jr ___________________________ -·- _ __ __ _ __ _ __ __ __ _ ___ _ 1 

(B) Geology and ore deposits in the Reid Inlet area, Glacier Bay, Alaska, 

by D. L. Rossman------------------------------------------ 33 

(C) Geology of Geikie Inlet area, Glacier Bay, Alaska, by J. F. Seitz___ 61 

(D) Geology and coal resources of the Little Susitna district, Matanuska 

coal field, Alaska, by F. F. Barnes and Daniel SokoL___________ 121 

(E) Geology and ore deposits of northwestern Chichagof Island, Alaska, 

by D. L. Rossman------------------------------------------ 139 

(F) Geology and coal resources of the Homer district, Kenai coal field, 

Alaska, by F. F. Barnes and E. H. Cobb______________________ 217 

(G) Geology of the Mount Katmai area, Alaska, by A. Samuel Keller and 

H. N. Reiser__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 261 

(H) Geology of part of the Craig C-2 quadrangle and adjoining areas, 

Prince of Wales Island, southeastern Alaska, by C. L. Sainsbury_ _ 299 

(I) Tofty tin belt, Manley Hot Springs district, Alaska, by R. G. Wayland------------------------------------------------------ 363 

~Reconnaissance for 

. Radioactive Deposits in 

:Southeastern Alaska, 1952 

"' By JOSEPH R. HOUSTON, ROBERT G. BATES, ROBERT S. VELIKANJE, and 

HELMUTH WEDOW, Jr • 

. MINERAL RESOURCES OF ALASKA 

GEOLOGICAL SURVEY BULLETIN 1058-A 

This report concerns work done on behalf 

of the U. S. Atomic Energy Commission 

· and is published with the permission of 

the Commission 

II 

.. 

... UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1958 
UNITED STATES DEPARTMENT OF THE INTERIOR 

FRED A. SEATON, Secretary 

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director 

For sale by the Superintendent of Documents, U.S. Gov~mment Print~ Office 

Washington 25, D. C. - Price 75 cents (paper cover) 

.
CONTENTS 

Page 

Abstract---------------------------------------------------------- 1 

Introduction------------------------------------------------------ 1 

Northern part of Prince of Wales Island and parts of adjacent islands____ 3 

Generalgeology_______________________________________________ 4 

Beddedrocks--------------------------------------------- 4 

Igneousrocks--------------------------------------------- 5 

Structure_________________________________________________ 6 

Salmon Bay area______________________________________________ 6 

GeologY---------------------~---------------------------- 6 

Vein deposits__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1 

Radioactive carbonate-hematite veins____________________ 1 

Rare-earth carbonate veins__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 9 

11ineralogy___________________________________________ 10 

Radioactivity data_____________________________________ 12 

Calculation of reserves in 100-foot section of Paystreak vein_ 18 

Rare-earth oxide data ___ ------_________________________ 19 

Genesis_______________________________________________ 20 

Summary and conclusions ____ ------- ____ -------____________ 23 

Other areas examined__________________________________________ 24 

Taku Harbor-Point Astley district _________________________ ---------- 25 

Hyder area _____________________________________________ .:_________ 25· 

References cited ______________________________________ -----________ 30. 

IndeX------------------------------------------------------------ 31 

m 
ILLUSTRATIONS 

[Plates in pocket] 

PLATE 1. Map of northern part of Prince of Wales Island, southeastern Alaska. 

2. Geologic map of Salmon Bay area, Petersburg quadrangle. 

3. Geologic sketch map of Pitcher Island, Salmon Bay area. 

Page 

FIGURE 1. Map of southeastern Alaska showing localities examined in 

1952------------------------------------------------- 2 

2. Geologic sketch map of Paystreak vein, Pitcher Island______ 8 

3. Geologic sketch map of rare-earth carbonate vein north of 

Salmon Bay _______________________________ ------ ___ _._ 9 

4. Sample location map of Mountain View property, Hyder area_ 26 

TABLES 

TABLE 1. Minerals found in Salmon Bay veins________________________ 10 

2. Data on radioactivity of samples from Salmon Bay area______ 13 

3. Calculation of average equivalent-uranium and equivalentthorium content of a 100-foot section of the Paystreak vein, 

Pitcher Island _______ ----- _____ ---- ___ -- ___ -- _____ --___ 18 

4. Data on rare-earth oxide content of carbonate-vein samples from Salmon Bay area ____________________________ -----_ 19 

5. Data on radioactivity of samples from Taku Harbor-Point 

·Astley district, islands adjacent to northern Prince of Wales 

Island, and Hyder area-------------------------~-------- · 27 

IV 
• 

MINERAL RESOURCES OF ALASKA 

RECONNAISSANCE FOR RADIOACTIVE DEPOSITS IN 

SOUTHEASTERN ALASKA, 1952 

BY JosEPH R. HousToN, RoBERT G. BATES, RoBERT S. VELIKANJE, 

and HELMUTH WEnow, JR . 

.ABSTRACT 

Reconnaissance for radioactive deposits in southeastern Alaska in 1952 was 

centered in three localities: the northern part of Prince of Wales Island and parts 

of adjacent islands, the Taku Harbor-Point Astley district, and the Hyder area. 

Significant concentrations of radioactive minerals were found only in the vicinity 

of Salmon Bay on the northeastern shore of Prince of Wales Island. In this area 

radioactive carbonate-hematite veins occur along the coast for about 8 miles. 

The veins are generally short, irregular, and lenticular, but a few can be traced for 

more than 300 feet between the low-tide line and the forest cover. The width of 

the veins normally ranges from less than 1 inch to 2.5 feet; several, however, are 

5 to 10 feet wide. 

The most abundant minerals in the veins are dolomite-ankerite and alkali 

feldspar with decreasing amounts of red hematite, specular hematite, pyrite, 

siderite, magnetite, quartz, chalcedony, and chlorite. Parisite, bastnaesite, 

muscovite, fluorite, apatite, thorite, zircon, monazite, epidote, topaz, garnet, 

chalcopyrite, and marcasite have also been identified. 

Most of the radioactivity is due to thorium contained chiefly in the minerals 

thorite and monazite. The highest grade grab sample assayed 0.13 percent 

equivalent ur-anium or about 0.64 percent equivalent thorium. The average of 7 

channel samples taken along 100 feet of one of the more radioactive veins was 

0.034 percent equivalent uranium or 0.16 percent equivalent thorium. 

The rare-earth fl.uocarbonates parisite and bastnaesite, occur in small amounts 

in some veins. Four chip-channel samples taken from a high-grade rare-earth 

vein about 1,150 feet long averaged 0.79 percent rare-earth oxides over an average 

width of 7.4 feet. One high-grade grab sample from this vein assayed 5.0 percent 

rare-earth oxides. 

INTRODUCTION 

Most of the reconnaissance for radioactive deposits in southeastern 

Alaska during the summer of 1952 was centered in the northern part 

of Prince of Wales Island and parts of adjacent islands (locs. Gthrough 

M,fig.l). Brief reconnaissance work in 1951 (Houston, 1952,p.13-17) 

had proved the existence of radioactive carbonate-hen1atite veins in the 

vicinity of Salmon Bay on the northeastern shore of Prince of Wales 

Island (loc. G, fig. I), and further geologic work was necessary to determine more accurately the grade, mineralogy, and areal extent of these 

veins. 

1 
2 ~RAL RESOURCES OF ALASKA 

56'n,__ ____________ __, 

Northern part of Prince of Wales 

and parts of adjacent islands 

------------------

EXPLANATION 

Principal area investigated 

0 

localities examined in 1952 

A Taku Harbor-Port Snettisham area 

B Point Astley 

C Salmon Bay area 

D Round Point, Zaremba Island 

E The "graywacke" area along the north shore of Prince of Wales Island 

F Shakan molybdenite deposit, Kosciusko Island 

G The "graywacke" area near Shakan and Shipley Bays, El Capitan Passage, Kosciusko and Prince of Wales Island 

H Baker Island molybdenite prospect 58 • I lead deposit on west shore of Egg Har· bor, Coronation Island 

Kuiu Island zinc deposit 

Totem Bay, Kupreanof Island 

lake Bay, Prince of Wales Island 

Green Monster Mountain, Prince of Wales Island 

Mountain View property, Hyder area 

54'~===::::::;::::==================~~=-d. if::. ±=====t.=:Lt~?: l 134' 

FIGURE 1.-Map of southeastern Alaska showing localities examined in 1952. 

Because the radioactive veins in the vicinity of Salmon Bay occur 

only in graywacke, those parts of the northern and northwestern 

coasts of Prince of Wales Island (locs. E and G, fig. 1; pl. 1) that have 

been mapped as graywacke by Buddington (Buddington and Chapin, 

1929, pl. 1) were also examined. In addition, localities F, H, I, J, L, 

and M (fig. 1), on Prince of Wales Island and adjacent islands were 

visited because previously described mineral deposits at those localities contain mineral assemblages similar to uranium deposits 

elsewhere (Wedow and others, 1951). 
• 

RADIOACTIVE DliBPOSITS IN SOUTHEASTERN ALASKA 3 

Brief reconnaissance exarnina tions were made also in the Taku 

Harbor-Point Astley district (locs. A and .B, fig. 1) and in the Hyder 

area (loc. N, fig. 1) to investigate reported pitchbllende occurrences. 

Joseph R. Houston, Robert G. Bates, Robert S. Velikanje, and 

Helmuth Wedow, Jr., geologists, and Eugene D. Michael, geologic 

field assistant, all of the Geological Survey, made these field investi .. 

gations. The U. S. Bureau of Mines motor vessel, the "Swan II," 

was used as a base for the party in the field frorn early July until 

about mid-September.. Bates and Wedow were with the party for 

about a month in the early part of the summer. Houston, as chief 

of the reconnaissance party, was responsible for the preparation of 

the report. 

Special acknowledgrnent should be made to personnel of the U. S. 

Bureau of Mines who operated the "Swan II" and to personnel of the 

laboratories of the Geologicul Survey at College, JIJaska, and Washington, D. 0., who nutde all of the radioactivity:, fluorimetric, and 

chemical analyses and some of the mineral identifications given herein. 

Mary E. Thompson was the first to identify the rare-earth mineral, 

parisite, in the samples from the vicinity of Salmon Bay. The 

writers are also indebted to Arthur E. Glover, engineer-assayer at 

the Ketchikan assay office of the Alaskan Territorial Department 

of Mines, for cooperation and aid on the work in the Salmon Bay area. 

Qualitative and some seJoaiquantitative determinations of radioactiyity were made in the field with standard commercial portable 

Geiger counters. Some of the counters were nJLOdified to accept 

2- by 20-inch gamma probes as well as the standard 6-inch betagamma probe. The buger probes were used mostly for traversing 

on foot with both the probe and counter lashed to a packboard 

(Wedow, 1951, p. 6). 

This work was done on behalf of the U. S. Atomic Energy Commission. 

NORTHERN PAR'I' OF PRINCE OF WALES ISLAND AND 

PAR'I'S OF ADJACENT ISLANDS 

In May 1950, John Wandve of Ketchikan, .Alaska, submitted 

several pounds of reddish rocks to the I{etchikan office of the Alaskan 

Territorial Department of Mines. Wandve reported that he had 

collected the specimens at Salmon Bay on the northeastern shore 

of Prince of 'Vales Island (loc. C, fig. 1). Tests by Arthur E. Glover, 

Territorial Department of Mines engineer-assayer at I{etchikan, 

indicated that the average radioactivity of the entire sample was 

about 0.01 percent equivalent uranium. 

In July 1951, Joseph R. Houston and Helmuth Wedow, Jr., 

geologists, and David L. Norton, geologic field assistant, accompanied 
4 M~ERAL RESOURCES OF ALASKA 

by Glover, spent 1~ days in the Salmon Bay area. Houston and 

,Norton returned for 3 days late in August. The results of the work 

in 1951 have been described by Houston (1952, p. 13-17). Many 

narrow radioactive carbonate-hematite veins were found in the 

graywacke of Silurian age near Salmon Bay. The most radioactive 

sample assayed 0.07 percent equivalent uranium. Tests showed 

that most of the radioactivity was due to thorium. 

In October 1951 Wandve staked two lode claims near the entrance 

to Salmon Bay. In April and May of 1952, Smith, Pitcher, & Co., 

also of Ketchikan, prospected in the Salmon Bay area and along the 

coast to the south. Several new radioactive veins were discovered, 

and 32 lode claims were recorded. 

Because of the marked interest among private prospectors and 

because of the brief reconnaissance nature of the 1951 work, the 

Geological Survey undertook more detailed studies of the Salmon 

Bay area in July and August 1952. Also, because the radioactive 

veins at Salmon Bay were thought to be only in graywacke of Silurian 

age, reconnaissance traverses were made along those parts of the 

northern and northwestern coasts of Prince of Wales Island (pl. 1) 

that had been mapped as graywacke by Buddington (Buddington 

and Chapin, 1929, pl. 1). Additional examinations were made at 

several localities on some of the nearby islands to investigate previously 

described mineral deposits that were reported to contain mineral 

assemblages characteristic of uranium deposits in other parts of the 

world. 

GENERAL GEOLOGY 

Little detailed geologic work has been done in the northern part 

of Prince of Wales Island. Buddington (Buddington and Chapin, 

1929, pl. 1) did reconnaissance mapping in the coastal areas; part 

of his geologic map has been adapted for plate 1 of this report, and 

most of the geology recorded below has been taken from Buddington's 

report. 

BEDDED ROCKS 

The oldest rocks in the area are of Early and Middle Ordovician 

age. They consist of a series of well-indurated graywacke with 

associated dark slate, andesitic volcanic rocks, thin-layered black 

chert, and layers of conglomerate and limestone. 

Overlying the rocks of Ordovician age, probably unconformably, 

is a thick series of sedimentary and volcanic rocks of Silurian age. 

The oldest rocks consist of andesitic volcanic rocks and conglomerate 

with some associated graywacke, black slate, and tuff. These rocks 

are about 3,000 feet thick and are overlain by a massive, relatively 

pure limestone. The fresh rock is white; on weathered surface it 

is gray or grayish brown. Many small randomly oriented fractures 

.
RADIOACTIVE DEPOSITS IN SOUTHEASTERN ALASKA 5 

cut the limestone. These fractures are coated with a thin facing of 

carbonate that usually weathers into a network of veinlets. Thick 

beds of coarse conglomerate and limy argillaceous layers are interbedded with the limestone. The aggregate thickness of the limestone 

and conglomerate is about 4,500 feet. A sequence consisting of 

about 5,000 feet of reddish-brown, gray, and grayish-green graywacke 

and containing a few interbedded conglomerate, graywackelike sandstone, and shale layers overlies the limestone. Much of the rock 

on the northern and western coasts of Prince of Wales Island that 

Buddington mapped as "graywacke" (Buddington and Chapin, 

1929, pl. 1) is actually very limy as indicated by the carbonate 

content of 45 to 90 percent of 3 thin sections examined. Generally 

there is a layer of coarse conglomerate 300 to 400 feet thick at the 

contact between the grnywacke and the underlying limestone. The 

graywacke is the youngest sedimentary formation in the area except 

for unconsolidated glacial material. 

IGNEOUS ROCKS 

A small dioritic batholith, apparently an outlier of the Late Jurassic 

or Cretaceous Coast Ra,nge batholith on the mainland, lies just east 

of Shakan Bay on Prince of Wales and Kosciusko Islands. Buddington 

(Buddington and Chapin, 1929, p. 188, 203) gives the following average composition for diorite and quartzose diorite (quartz diorite of 

present authors) from Prince of Wales Island: 

Diorite Quartzose diorite 

Percent Pereem 

Andesine____________________ 62 Andesine____________________ 56 

Hornblende_________________ 26. 5 Hornblende _____ ------------ 20 

Quartz______________________ 4 Quartz _________________ ----- 9 

Biotite______________________ 3 Potassium feldspar___________ 6 

Potassium feldspar___________ 2 Biotite______________________ 4 

Magnetite___________________ 1. 5 Pyroxene___________________ 2. 5 

Accessories (chiefly sphene, npa- Mngnetite __________________ - 2 

tite, and zircon)___________ 1 Accessories__________________ • 5 

Chapin (1919, p. 89), Mertie (1921, p. 118-119), and Twenhofel, 

Robinson and Gault (1946, p. 21), who have visited the molybdenite 

deposit near Shakan on Kosciusko Island (loc. F', fig. 1; pl. 1) also 

report that this intrusive mass is composed of diorite and quartz diorite. 

A thin section made frmn a specimen collected in 1 H52 near the western 

contact of this intrusion had the mineralogic composition shown below: 

Oligoclase-andesine _______ -· __ _ 

Quartz _________________ --· __ -

Biotite (partly altered to chlorite) _______ ------------·---

Percent 

55 

35 

5 

Alkali feldspar 11 _____________ _ 

Hornblende ________ ---- ____ _ 

Accessories ______________ ----

Percent 

3 

2 

tr 

t Perthite is the most abundant of the alkali feldspars; lesser amounts of orthoclase, albite. and sodic 

oligoclase are present. 

461·398-58--2, 
6 MINERAL RESOURCES OF ALASKA 

As geologists have made few, if any, traverses across the northern 

part of Prince of Wales Island, and prospectors have done little work in 

the area, there may actually be other outliers of the Coast Range 

batholith on Prince of Wales Island besides the one shown in plate 1. 

Lamprophyre and basalt dikes cut the rocks of Paleozoic age of 

northern Prince of Wales Island in many places. They range from a 

·few inches to more than 50 feet in width and many can be traced for 

several hundred feet from the edge of the low-tide line to the forest 

cover. The dikes generally strike between northwest and northeast. 

The most prevalent strike is north-northeast. The lamprophyre 

dikes are probably older than the basalt, dating possibly from a late 

phase of the Coast Range orogeny during Cretaceous or early Tertiary 

time. The basalt dikes are probably of Tertiary age (Buddington and 

Chapin, 1929, p. 230, 271-272). 

STRUCTURE 

Only the broader features of the structural geology of the northern 

part of Prince of Wales Island are known. The major feature is a large 

northwestward-trending anticlinorium that parallels the Coast Range 

batholith. Kashevarof Passage on the east side of the island and 

Port Protection at the northwest corner have been eroded along subsidiary anticlines of this structure. Shakan Bay on the west coast 

occupies a synclinal trough. There are probably several other minor 

anticlines and synclines in the area. 

SALMON BAY AREA 

GEOLOGY 

The Salmon Bay area is on the west flank of the north~northwestward-trending Kashevarof anticline. The regional strike averages 

about N. 15° W. and the dip averages about 45° SW. 

A thick graywacke of Silurian age is exposed along the coast for 

about 3 miles northwest and about 5 miles southeast of Salmon 

Bay (pl. 1). Layers of well-indurated shale, graywackelike sandstone, and coarse conglomerate are interbedded with the graywacke. 

The conglomerate is especially abundant near the base of the graywacke formation where it occurs in a layer 300 to 400 feet thick. 

It is composed of well-rounded pebbles, cobbles, and scattered boulders of a red granitic rock, dark-green greenstone, dark-gray argillite, 

gray limestone, and a red volcanic rock in a matrix of reddish-brown 

graywacke. 

The graywacke of the Salmon Bay area ranges in color from reddish brown to grayish green. The grains range in size from less 

than 0.05 to more than 3 millimeters. The rock is composed of 

plagioclase, microperthite, orthoclase, chert, quartz, carbonate, and 
RADIOACTIVE DEPOSITS IN SOUTH:I!JASTE,RN ALASKA 7 

rron oxides and contains smaller amounts of pyrite, epidote, slate,. 

and volcanic rock fragments. In many places iron oxides give the 

rock a deep hematite--Ted color. The graywacke is well indurated 

and generally occurs in beds ranging from several inches to several 

feet in thickness, but in some places no bedding is visible and the 

graywacke resembles a volcanic rock. 

Many dikes cut the graywacke in the Salmon Bay area. Their 

strikes range from N. ·15° W. to N. 65° E., but north-northwesterly 

and north-northeasterly strikes predominate; the dips are commonly 

very steep. The widths range from a few inches to as much as 50 

feet. The widest dikes are between Bay Point and Point Colpoys 

(pl. 2). Four types of dikes have been identified. Lamprophyre 

dikes of albite-biotite and albite-hornblende are the most common 

types; fairly fresh -look[ng basalt dikes rich in carbonate are a bun dan t; 

one phonolite dike has. been recognized. The exact age of the dikes 

is not known. The larnprophyre dikes n1ay have been emplaced 

during the late stages of the Coast Range orogeny in Cretaceous or 

early Tertiary time. The other dikes are probably of Tertiary age 

(Buddington and Chapin, 1929, p. 230, 271--272). 

No coarse-grained igneous rocks were observed in the vicinity of 

Salmon Bay. Traverses to the west up the major streams revealed 

only more of the graywaeke and one small isolated lens of limestone. 

A few well-rounded pebbles and cobbles of a light-colored hornblendebearing granitic rock ·1:vere found in the stream beds. These could 

have come from an intrusive mass further west, or they may be 

glacial drift derived frmn the Coast Range batholith or one of its 

outlying stocks to the east. A few rounded boulders of granitic 

rock found along the shore are probably glacial drift from the east 

or northeast. VEIN DEPOSITS 

RADIO ACTIVE CARBON ATE-HEMA'I'ITE VEINS 

For about 3 miles northwest and 5 miles southeast of Salmon Bay 

many narrow radioacti ve carbonate-hematite veins cut the graywacke along the coast (pl. 2). A few veins also crop out in the larger 

stream beds west of Salmon Bay. Radioaetive carbonate-hematite 

veins have been found only in the .graywacke. Similar veins in the 

limestone are not appreciably radioactive. 

The largest radioactive vein found to date is the Paystreak vein at 

the north end of Pitcher Island, about 4 n1iles southeast of Salmon 

Bay (fig. 2 and pl. 3). The Paystreak vein strikes N. 3° W. and dips 

70° E. It averages 2.4 feet in width. At extreme low tide about 

100 feet of the vein is exposed. 

The average strike of the radioactive carbonate-hematite veins lies 

between north and northwest, but individual strikes vary greatly. 
8 MINERAL _RESOURCES OF ALASKA 

Radioactive 

rn 

carbonate-hematite 1~oc ~ ~ vein showing dip, dashed g; ' where approximately located .., 

Graywacke 

~51 

Strike and dip of bed 

4561 

• Locality of sample 

APPROXIMATE MEAN 

- DECLINATION 1953 

} 

10 0 

FIOURE)!.-Geologic sketch map.of the Paystreak.vein, Pitcher Island. 

30 Feet 

The largest veins, such as the Paystreak, have general strikes of either 

N. 30°-35° W. or north toN. 5° W. A third strike trend lies between 

N. 30°-60° E. The N. 30°-35° W. and the N. 30°-60° E. veins 

were perhaps emplaced along a complementary set of shear fractures 

resulting from the compressive forces that formed the north-northwestward trending Prince of Wales anticlinorium during the Coast 

Range orogeny. '· The average dip is about 70° NE.; however, dips 

range from 45° NE. to 40° SW. The veins range in width from a 

fraction of an inch to several feet, but the average width is 2 to 3 

inches. Few veins are more than a foot wide, most are relatively 

short. Generally only a few feet or a few tens of feet of any given 
RADIOACTIVE DEPOSITS IN SOUTHEASTERN ALASKA 9 

vein is exposed along the beach, but at a few localities individual veins 

can be traced for more than 300 feet. 

RARE-EARTH CARBONATE VEINS 

In addition to the radioactive veins, wider nonradioactive carbonatehematite veins containing small amounts of rare-earth fluocarbonates 

occur in the graywacke of the Salmon Bay area. The width of these 

veins ranges from a few inches to 10 feet and averages about 5 feet. 

Just north of a small cove about 1 mile north of the entrance to Salmon 

Bay (fig. 3 and pl. 2) about 375 feet of a rare-earth carbonate vein is 

exposed at low tide. Thjs vein strikes N. 35° W. and dips 75° NE. 

To the south on Pitcher Island (pl. 3), 3 rare-earth carbonate veins 

are exposed between the high- and low-tide lines. These veins strike 

about N. 60° E. and dip 60°-65° SE. They can be traced fm 200 to 

400 feet along the beach. 

APPRO JOMATE MEA N 

DECLINATION 19 52 

Dense vegetation 

Bose from sketch mo 1952 

f-. 

~ 

~ ~ 

~ 

EXPLANATION 

CJd w 

~ 1-

Lamprophyre dike showing dip < 

_J 

Dashed where inferred ~ 

0 

~ ~ 

Ul 

Ul 

< 

Rare-earth carbonate ~ 

vein showing dip ~ 

Dashed where inferred 

-<:) Graywacke 

}i ~ .4757 

~ Locality of sample 

100 300 Feet 

Geology by R. G. J. R. Houston, and R. S. 

FJG \'RE ? ,-Geologic, sketch map_ of the rare-earth carbonate vein, 1 mile north of Salmon Bay, 
10 rurr.NERAL RESOURCES OF ALASKA 

MINERALOGY 

A grayish-white carbonate of the dolomite-ankerite series is the 

most abundant mineral in the veins at Salmon Bay. Other minerals 

present in appreciable amounts are alkali feldspar, red hematite, 

specular hematite, and pyrite. Locally siderite and magnetite are 

abundant. Small amounts of the following minerals, listed in decreasing order of abundance, have been identified: quartz, chalcedony, 

chlorite, calcite, parisite, bastnaesite, muscovite, fluorite, apatite, 

thorite, zircon, monazite, epidote, topaz, garnet, chalcopyrite, and 

marcasite (table 1). 

TABLE I.-Minerals found in the Salmon Bay veins 

[Mineralogic analyses, Mary E. Thompson, Joseph R. Houston, and Richard Kellagher; spectrographic analyses, Charles S. Annen, J. N. Stich, and Katherine E. Valentine; powder X-ray work, Evelyn Cisney] 

Mineral Occurrence, abundance, and remarks 

Dolomite-ankerite, Ca(Fe,Mg,Mn) (C0a)2 ___ In all veins; makes up about 80 percent of most veins and as much as 99 percent of some veins. Omega indices on 10 different specimens ranged from 1. 720 to 1. 732, values 

which are in the ankerite end of the dolomite-ankerite 

group (Palache and others, 1951, p. 211). However, car- bonate from some samples was identified as dolomite and 

ferroan dolomite by mineralogists of the U. S. Geological Survey Trace Elements laboratory in Washington, D. C. 

Feldspar, alkalic, (K,Na)AlSiaOs _____ ________ The second most abundant vein mineral; makes up about 

10 percent of most veins, but is absent in other veins; 

perthite is the most common type; orthoclase, albite and 

sodic oligoclase are also present; some feldspar is '!lightly sericitized. 

Hematite, red Fe20a------------------------- Small amounts in most veins, usually as narrow bands or as dark reddish-brown radioactive layers along vein walls; 

probably mixed with other unidentified red iron oxides. 

Hematite, specular, Fe20a-------------------- Small amounts in most veins, usually as narrow black 

bands, also as platy aggregates. 

Pyrite FeS2. --------------------------------- In all veins, usually in striated cubes less than 1 mm thick. 

A few cubes are as much as 7 mm thick; apparently a late-stage mineral. 

Siderite, FeCOa------------------------------ Small amounts in many veins; abundant locally, especially near the entrance to Salmon Bay. 

Magnetite, Fe+2Fe+a2of ___ ------------------ Small amounts is many veins, locally abundant. 

Quartz and chalcedony, Si02----------------- Irregular; many veins contain no quartz; generally con- centra ted near the edges of the veins. 

Chlorite, (Fe, Mg)2Al(OH)e(Fe,Mg)a(A1Sia- o,o)(OH)2. Rare; fills cracks in some veins; apparently a late-stage alteration product. 

C~lcite, CaCOa. -------------------------- ___ Rare; most of the carbonate is .ankerite. 

Parisite, (Ce,La)2Ca(COa)aF2---------------- Small amounts in many veins; most abundant in the wide, 

rare-earth carbonate veins; apparently a late-stage mineral usually occurring as a filling in small vugs or along postvein fractures in the carbonate. 

Bastnaesite, (Ce,La) (COa) F ----------------- Rare; identified in the Paystreak vein on Pitcher Island; a late-stage mineral. · 

Muscovite, K(Al,Cr)2(AlSiaO,o) (OH,F)2 _____ Small amounts in many veins but not common; the green (chromian) variety occurs in small but conspicuous con- centrations. 

Fluorite, CaF2. ------------------------------ Rare; local concentrations of purple :fluorite conspicuous in a few veins; more rarely white. 

. ---
RADIOACTIVE DEPOSITS IN SOUTHEASTERN ALASKA 11 

TABLE !.-Minerals found in the Salmon Bay veins-Continued 

Mineral Occurrence, abundance, and remarks 

Apatite, Cas(F ,Cl,OH) (P04)3---------------- Rare; radioactive apatite indentified in sample 4437 (pl. 2). 

Thorite ThSi04----------------------------- _ Trace amounts in most radioactive veins; generally in nar- row veinlets. 

Zircon, ZrSi04- ------------------------------ Rare; trace amounts in some radioactive veins; generally radioactive. 

Monazite, (Ce, La, Y, Th)(P04)------------- Rare; trace amounts in some radioactive veins. 

Epidote, Ca2(Al,Fe)3(Si04)3(0H) ____________ Rare; apparently a late-stage alteration product. 

Topaz, Ah(Si04) (OH,F)2-------------------- Very rare; a few acicular grains were found in the heavy- mineral fraction of sample 4422 from Fishery Island (pL 

2). 

Garnet, (Ca,Mn,Fe,Mg)3(Al,Fe)2(Si04)3----- Very rare; found only in sample 4440 from West Island (pl. 

2). 

Chalcopyrite, CuFeS2------------------------ Very rare; identified in sample 4580 (pl. 2) from small island 

72 mile west of Pitcher Island. 

Marcasite, FeS2------------------------------ Very rare; identified in sample 4437 from Salmon Bay (pL 

2). 

Grain counts on thin sections made from three Salmon Bay veins 

gave the following average mineralogic composition: 

Carbonate _________________ _ 

Alkali feldspar 1 _____________ _ 

Iron oxides _________________ _ 

Percent 

81 

11 

3 

Quartz and chalcedony ______ _ Pyrite _____________________ _ 

Chlorite ___________________ _ 

Percent 

2 

2 

1 

1 Perthite is the most abundant of the alkali feldspars with lesser amounts of orthoclase, albite, and sodic 

oligoclase. 

The grain size of the vein minerals ranges from less than 0.05 

millimeter to more than 1 centimeter; however, most of the carbonate 

grains are 1 to 3 millimeters across. 

Thorite, monazite, zircon, and apatite are the only radioactive 

minerals that have been identified from the Salmon Bay veins, and 

these occur only in traces. There are many radioactive zones in 

which the radioactive mineral or minerals could not be determined. 

These zones contain only carbonate, feldspar, pyrite, and red hematite. 

Hematite and other red iron oxides stain intensely many small open 

fissures which cut the graywacke almost parallel to the carbonate veins. 

There are also reddish-brown hematitic alteration zones along the 

walls of many of the veins. Some of the altereu zones have a glazed, 

slaglike appearance; most of them are less than 1 inch wide. Generally the hematitic zones are more radioactive than the carbonatevein filling. A less intense reddish-brown coloration caused by smaller 

amounts of red iron oxides is common in much of the graywacke 

country rock around Salmon Bay. The dark-red hematitic zones 

adjacent to the veins were undoubtedly formed by hydrothermal 

solutions, but much of the lighter red coloration in the surrounding 
12 MINERAL RESOURCES OF ALASKA 

graywacke is due to iron oxides that were either present in the original 

rock or formed by the oxidation of pyrite. 

The rare-earth fluocarbonates, parisite and bastnaesite, occur in 

small amounts in some of the veins. Parisite is especially abundant 

in a wide vein about 1 mile north of the mouth of Salmon Bay (pl. 2 

and fig. 3). The parisite is light yellowish brown to grayish brown. 

It is a late-stage mineral, generally occurring along postvein fractures 

in the carbonate vein filling. Locally, it lines small vugs as earthy 

subrounded grains about 0.5 millimeter in diameter. 

RADIOACTIVITY DATA 

Most of the veins at Salmon Bay show some radioactivity. The 

equivalent-uranium content of 7 4 samples from the Salmon Bay area 

was determined in the laboratory; selected samples were also analyzed 

for uranium, uranium oxide, equivalent thorium, and thorium dioxide 

(table 2). Sample localities are shown on figures 2 and 3, and on 

plates 1, 2, and 3. 

The maximum equivalent-uranium content of unconcentrated vein 

material from Salri:wn Bay analyzed by the Geological Survey is 0.13 

percent (sample 4443, pl. 2). This sample was collected by a prospector from a hematite-rich zone of wall rock adjacent to a carbonate 

vein. It contained hematite, albite, orthoclase, and some small 

veinlets of thorite. 

Twelve samples (4089, 4090, 4093, 4095, 4428-A and -B, and 4437-

4443, table 2) that were analyzed fluorimetrically for uranium (U) 

showed a maximum uranium content of only 0.003 percent. Five 

other samples (4570, 4571, 4572, 4574, and 4577, table 2) that were 

analyzed chemically for uranium oxide (U 30 8) showed a maximum 

uranium content of only 0.004 percent. The equivalent uranium 

content (eU) of these 5 samples as determined by radiometric assay 

ranged from 0.014 to 0.083 percent, indicating that most of the radioactivity was due to thorium. Thus, it seemed advisable to express 

the assay data in terms of percent equivalent thorium (eTh) rather 

than percent equivalent uranium. 
RADIOACTIVE DEPOSITS IN SOUTHEAS'l'ERN ALASKA 13 

TABLE 2.-Data on radioact£vity of samples from Salmon Bay area 

Sample Locality Type 

Analyses (percent) 

Equiva-! lent Ura- ura- nium2 niuml, 

Uranium 

oxide 

(U30>) 

Equiva- Thorium lent dioxide thorium (Th02) a 

-------------1--------____ , ___ ---------

4089 

4090 

4092 

4093 

4095 

Carbonate vein, Fish- Grab _________________ _ 

ery Island, Salmon Bay (pl. 2). _____ do ______________________ do _______________ _ _____ do ______________________ do. ______________ _ 

Carbonate vein, Prince _____ do _______________ _ 

of Wales Island, about 0. 7 milrs north of Salmon Bay (pl. 

2). Carbonate vrin, Pt. _____ do _______________ _ 

Colpoys, Prince of Wales Island (pl. 2). 4403-A Carbonate vrin, Fish- _____ do _______________ _ 

rry Island, Salmon Bay (pl. 2). B _____ do ________________ _ Nonmagnetic fraetion of 44()._'1--A. C _____ dn _________________ Magnetic fraction of 

4403-A. 4422-A Carbonate vein, Fish- Grab _________________ _ 

f'ry Island, Salmon Bay (pl. 2). B _____ do ________________ _ 

C _____ do ________________ _ 

D _____ do ________________ _ 

E _____ do ________________ _ 

Fraction of 4422--A less than 2.9 ~P gr. Fraction of 4422-A b<·tween 2.9 and 3.3 spn. 

Moderately magnetic 

portion of fm(·tion of 4422-A greater than 3.~ sp gr. 

4428--A Carl onate vein, small 

Slightly magnetic 

portion of fraction of 4422-A grcat<•r than 3.3 sp gr. Grab _______ ----------- bay 1 mile north rf Salmon Bay (fig. 3). B _____ do __ -------- ____________ do. ____ ------ ____ _ 

4437 Carbonate vein, Salm- _____ do __ --------------

4438 

on Eay (pl. 2). Wall rock adjacent to _____ do._--------------

Paystreak vein, Pitcher Island (fig. 

2). 

4439 Paystrrak vein, Pitcher ChanneL _____________ _ 

Island (fig. 2). 4440 CarbonatP vrin, "\Vest _____ do _______________ _ 

Island (pl. 2). 4441 Fine-!!Tainrd dike rock, Grab _________________ _ 

small island about % mile northwe~t of Pitcher Islands (pl. 

2). 

4442 Coarse-grained dike _____ do _______________ _ 

rock, large island be- tween Fishery and Pitcher Island (pl. 

4443 H~~atitP-rich wall l _____ do _______________ _ 

rock, Fislwry Island, I' 

Salmon Be,y (pl. 2). 4492-A Hemr.titic limestone, _____ do ________________ , 

B ---~::~a~~~:~~~~:~~-~~ __ Frnetion of 4492-A 1

1 

I ;rrPater th:>n 2.n sp gr; concentration 1 mtio 6 1 :l. 

See footnotes at end of table. 

461898-58-8 

0. 017 <O. 001 4 C.084 

.Oi .003 s. 26 .001 

.007 <.001 --------- 4.03 

.OJH <.001 --------- 4.06 

.014 

.020 

.006 

.022 

.008 

.020 

.160 

. 007 --------- --------- --------- ---------

.003 . 001 4 .01 

.002 . 001 4.005 .029 .002 4.14 

.002 .001 4.005 

. 046 . 001 5.20 

. 029 .003 4 .13 

.007 .003 4.02 

.005 .001 --------- 4.02 

.130 . 002 --------- 4. 64 

.001 

.003 
14 MINERAL RESOURCES OF ALASKA 

TABLE 2.-Data on radioactivity of samples from Salmon Bay area-C~mtinued 

Analyses (percent) 

Sample Locality Type Equivalent UraUra- Equiva- Thorium 

nium lent dioxide ura- nium2 

niuml 

oxide thorium (Th02)8 

(UaOs) 

-------1--------------------

4493-A 

4493-B 

Carbonate vein, Prince 

of Wales Island, 

about % mile north of 

Exchange Cove (pl. 

2). _____ do. _______________ _ 

4494-A Altered fracture zone in 

graywacke, Exchange 

Island (pl. 2). 

Grab _________________ _ 

Fraction of 4493-A 

greater than 2.9 sp 

gr; concentration 

ratio 6 1.3:1. Grab _________________ _ 

B _____ do __________________ Fraction of 4494-A 

4495-A Iron-stained zone in 

graywackr, Exchange Island (pl. 2). 

greater than 2.9 sp 

gr; concentration 

ratio 6 3.2:1. 

Grab ___ ----------·- __ _ 

B __ ..• do __________ ------- Fraction of 449/i-A 

4496-A Hematitic limy breccia zone, West Island 

(pl. 2). 

greater than 2.9 sp 

gr; concentration 

ratio 6 2:1. Grab _________________ _ 

B _____ do.---------------- Fraction of 4496-A 

4497-A Carbonate vein, small cove on Prince of 

Wales Island west of 

Thorne Island (pl. I). 

greater than 2.9 sp 

gr: concentration 

ratio 6 1:1. Grab _______________ c __ 

B _____ do _________________ Fraction of 4497-A 

4498-A Carbonate vein, Thorne 

Island. 

greater than 2.9 sp 

gr; concentration 

ratio 6 1:1. Grab _________________ _ 

B _____ do _________________ Fraction of4498-A 

greater than 2.9 sp 

gr; concentration 

ratio 6 21:1. 

4499-A Carbonate vein, Thorne Grab _________________ _ 

Island (pl. I). B _____ do ________________ _ 

4500-A _____ do. _____ --------- __ B _____ do ________________ _ 

4511-A Mafic dike rock, Thorne 

Island (pl. 1). 

Fraction of 4499-A 

greater than 2.9 sp 

gr; concentration 

ratio 6 1:1. 

Grab _______ ----------- Fraction of 4500-A 

greater than 2.9 sp 

gr; concentration 

ratio 6 1.2: 1. Grab _________________ _ 

B _____ do.---------------- Fraction of 4501-A 

greater than 3.3 sp 

gr: concentration 

ratio a 55:1. 

4502-A Marker vein, Pitcher Grab _________________ _ Island (pl. 3). B _____ do ________________ _ 

C _____ do ________________ _ 

Fraction of 4502-A 

gre.atr.r than 2. 9 sp 

gr; concentration 

ratio a 1.3: 1. Fraction of 4502-A 

greater than 3.3 sp 

gr; conrBntration 

ratio a 40:1. 

See footnotes at end of table. 

0. 001 --------- --------- --------- ---------

. 004 --------- --------- --------- ---------

.001 

.005 

.002 

.003 

<.001. --------- --------- --------- ---------

.002 

< .. 001 --------- --------- --------- ---------

<.001 --------- --------- --------- ---------

<.001 

.001 

<.001 

<.001 

<.001 

<.001 

.002 

. 001 

. 053 

.056 

.103, _________ --------- --------- ---------

1 I 
RADIOACTIVE DEPOSITS IN SOUTHEASTERN ALASKA 15 

TABLE 2.-Data on radioactivity of samples from Salrnon Bay area-Continued 

Sample Locality Type 

Analyses (percent) 

Equivalent Ura- ura- nium2 

nium 1 

Ura- I Equiva- Thorium 

nium lent dioxi ttl 

oxide I thorium (Th02)S 

(l'30s) 

-----------1----------·---------------------

4503-A Carbonate vein, south- Grab _________________ _ 

4504 

4505 

4506 

4507 

4.508 

4546 

4547 

4548 

.4549 

4550 

4551 

4561 

4562 

4563 

4564 

4565 

4566 

4567 

456~ 

4569 

4570 

4571 

4572 

4573 

4574 

4575 

4576 

4577 

4579 

east side of Pitcher 1 

Island (pl. 3). 

B _____ !lo ·----------------·· Fraction of 4503-A 

Carbonate vl'in, small 

bay 1 mile north of 

Salmon Bay (fig. 3). 

greater than 2.9 sp 

gr; concentration 

ratio 61.2:1. Chip-channeL _______ _ 

_____ do _______________________ do ________________ _ 

Altered zone adjacent Grab _________________ _ 

to carbonate vein, 

small bay 1 mile 

north of Salmon Bay (fig.3). Carbonate vein, small Chip-channeL _______ _ bay 1 mile north of 

Salmon Bay (fig. 3). _____ do ___________ -"----- _____ do ________________ _ 

Wall rock along barren Grab _________________ _ 

fracture, West Island 

(pl. 2). Carbonate vein, ·west _____ do ________________ _ 

Island (pl. 2). Carbonate vein, small _____ do ________________ _ 

bay 1 mile north of 

Salmon Bay (fig. 3). Fluorite-bearing car- _____ do ___ c ____________ _ 

bonate vein, south of 

Bay Point (pl. 2). Carbonate vein, west of _____ do ________________ _ 

Point Colpoys (pl. 2). Carbonate vein, Bay _____ do ________________ _ 

Point (pl. 2). Paystreak vein, Pitcher ChanneL _____________ _ 

Island (fig. 2). Wall rock adjacent to _____ do ________________ _ 

Paystreak vein (fig. 

2). Paystreak vein, Pitcher _____ do ________________ _ 

Island (fig. 2). Wall rock adjacent to _____ do ________________ _ 

Paystreak vein (fig. 

2). Paystreak vein, Pitcher ____ _do ________________ _ 

Island (fig. 2). _____ do _______________________ do ________________ _ 

Wall rock adjacent to _____ do ________________ _ 

---~:~~1~~~~--~~~1:-~~~~- _____ do_---------------~ Paystrcakvein, Pitcher _____ do----------------

Island (fig. 2). 

=ii=ilt=~~~=i~=.= =;if~~~~= = === =~~======= ==========I Island (pl. 3). ·wan rock inclusion, _____ do ___ ------------- Mmker Vein (pl. 3). 

Marker vein, Pitcher _____ do----------------

Island (pl. 3). Wall rock inclusion, _____ do _________________ 

1 

Marker vein (pl. 3). ::\farker vein, Pitcher _____ do ________________ _ 

---~~:ro-~---~~:~ ___ 3}_-_________ do _________________ \ 

Carbonate vein, small Grab------------------1 

island about ~-1! mile 

northwl'st of Pitcher ' 

I ~land (pl. 2). 

See footnotes at end of table. 

0. 0:31'1 

.002 

.002 

.006 

.002 

.002 

.()(!3 

.009 

<.001 

<.001 

.002 

.006 

.035 

. 003 

.036 

.002 

.020 

.030 

.002 

.003 

.036 

.014 

.049 

. 083 

. 002 

. 057 

.006 

. o;n 

.026 

. 011 

....... +----.... ---.----- ---------

----

---

---------

0. 001 

. 001 

. 002 

. 004 

---------

---------

.004 

---------

5 0.16 ---------

5. 16 --- ·-----

5.11 

5. 17 

5. 17 

7 .07 

7. 23 i . .n 

0.08 

.26 

.48 

5 • 013 ---------

7 .29 .35 

5 . 028 ----

3 .17 

7 .11 .13 

------- ----
16 MINERAL RESOURCES OF ALASKA 

TABLE 2.-Data on radioactiv£ty of Samples from Salmon Bay area-Continued 

Sample Locality Type 

Analyses (percent) 

Equiva- lent Ura- ura- nium 2 

niumt 

Ura- Eryuiva- Thorium 

nium lent dioxide 

oxide thorium (Th02) (U30') 

----------l---------·1----------------

4581 Wall rock adjacent to ChanneL ____________ _ 0. 005 --------- --------- --------- ---------

4582 

4583 

4584 

4585 

4586 

4601 

4602 

4603 

4604 

4605 

4606 

4608 

4609 

4610 

4759 

4761 

4762 

vein, southeast side 

of Pitcher Island (pl. 

3). Carbonate vein, south- _____ do ________________ _ 

cast Ride of Pitcher 

Island (pl. 3). Wall rock adjacent to _____ do ________________ _ 

vein, southeast side 

of Pitcher Island (pl. 

3). 

Carbonate vein, south- Chip-channeL _______ _ 

east side of Pitcher 

Island (pl. 3). ____ .do _______________ . ______ .do _____ --- ___ ---- __ _____ do __________________ Chip-channel (along 

the vein). 

Paystreak vein, Pitcher ChanneL .. ----------- Island (fig. 2). Wall rock adjacent to _____ do ________________ _ 

Paystreak vein (fig. 

2). 

Carbonate vein, north- Chip-channel (along west side of Pitcher the vein). Island (pl. 3). ___ do. --------------- Chip-channeL _______ _ ____ do __________________ Chip-channel (along 

the vein). ____ .do .. ____ .___________ Chip-channeL __ ------ Carbonate vein, small _____ do ________________ _ 

bay 1 mile north of 

Salmon Bay (fig. 3). ___ .do. ___ ._____________ Grab ______ ------------ l<'eldspathic dike, south _____ do ________________ _ 

of Bay Point (pl. 2). Hematitic wall rock _____ do ________________ _ 

adjacent to radioactive fracture, Fishery Island, Salmon 

Bay (pl. 2). Paystreak vein, Pitcher Composite ___________ _ Island (fig. 2). Marker vein. Pitcher _____ do ________________ _ 

Island (pl. il). 

I Radiometric assay by Benjamin A. McCall. 

.064 

.005 

.002 

.003 

.004 

.035 

<.001 

<.001 

<.001 

<.001 

<.001 

<.001 

.001 

.005 

.065 

.033 

.057 

80.16 

8.26 

2 Fluorimetric assay by Mary E. Thompson, Paul D. Benson, H. Kramer, and Audrey C. Pietsch. a Chemical assay by Jesse J. Warr and Harry Levine. 

0.18 

.30 

4 Calculated from the equivalent-uranium content by subtracting the chemical uranium and multiplying the remainder by a conversion factor of 5. 6 Radiometric assay by Benjamin A. McCall, using thorium standards. 6 Concentration ratio is the concentration by weight effected by removal of minerals lighter than the 

heavy-liquid medium used; approximate specific gravity of bromoform 2.9, methylene iodide 3.3. 7 Average of results obtained using methods described in (4) and (B). 

B Calculated from the Th02 content by multiplying by the conversion factor of 0.8788. 

Thorium assays can be made by the conventional wet chemical 

analysis for thorium dioxide (Th02) or by radiometric analysis using 

thorium standards. The. 5 samples (4570, 4571, 4572, 4574, and 

4577, table 2) that \Yere analyzed chemically for uranium oxide and 

radion1etrically for equivalent uranium were also analyzed chemically 

for thorium dioxide. The ratio, percent 'l'h02:(percent eU -percent 

U), was calculated for each of the 5 samples. These ratios ranged 

fron1 5.40 to 6.53 and averaged 5.93. So if any given equivalenturanium assay is multiplied by· 5.93 the result will represent the 
RADIOACTIVE DEPOSITS IN SOUTHEASTERN ALASKA 17 

approximate amount of thorium dioxide in the sample. Inasmuch as 

the ratio Th :Th02=0.8788, 5.93 X 0.8788, or 5.22, is an average factor 

for converting equivalent-uranium assays to equivalent thorium. 

Another method of thorium assay is to determine the thorium 

radiometrically using thorium standards. Ten Salmon Bay samples 

(4090, 4439, 4561, 4563, 4565, 4566, 4569, 4573, 4575, and 4576) were 

assayed radiometrically for equivalent thorium, using thorium standards, and for equivalent uranium using uraniun1 standards. The 

ratio of equivalent thorium to equivalent uranium in this group of 

samples ranged from 3.54 to 6.50 and averaged 4.75, as compared to 

an average ratio of 5.22 determined by comparing equivalent-uranium 

assays with wet-chemical assays for thorium dioxide. These conversion ratios depend on many factors and are only approximate at hestt 

so the number 5 was used as an average conversion factor for the 

Salmon Bay samples. This factor was used in computing some of 

the equivalent-thorium values in table 2 of this report by substituting 

uranium values in the following formula: 

percent eTh= (percent eU -percent U) X5 

The percent uranium (chemical assay) should be subtracted from the 

percent equivalent uranium (radiometric assay) before multiplying 

by the conversion factor. But because the amount of uranium in the 

Salmon Bay samples is small (0.004 percent or less), it can be neglected 

for all practical purposes, and the following formula can be used: 

percent eTh= percent eUX 5 

In addition to radioactivity measurements made in the field and 

in the laboratory, Bates and Wedow made an attempt to deterrnine 

whether the radioactivity of the Marker and Paystreak veins on 

Pitcher Island (pl. 3) could be detected from the air. The equipn1ent 

used in the airborne attempt consisted of a gang of six 2- by 40-inch 

gamma tubes connected in parallel and powered by a standard 

commercial Geiger counter modified to accept such a probe (Wedow, 

1951). The instrument was carried in a 4-place aircraft equipped 

with floats. Flights over the localities of the veins on the northeast 

beach of Pitcher Island were made at 100-, 50-, and 20-foot altitudes, 

successively. No ratemeter readings above background were obtained 

at the 100- and 50-foot levels, and only a very slight increase was 

noted at the 20-foot level. This slight increase, however, may have 

no significance, because it was about equal to or only slightly greater 

than themaximumlimitoffluctuationin theratemeterreadingsfor background. Because of flying hazards at both the 50- and 20-foot levels 

(maximum height of timber on island is about 100 feet), only one run 
18 MINERAL RESOURCES OF ALASKA 

was made at each of the two lower levels. A more sensitive instrument, such as a scintillation counter adapted for airborne traversing, 

probably could detect significant variations in radioactivity over the 

beach on Pitcher Island at the safer 100-foot level of flying. 

CALCULATION OF RESERVES IN 100-FOOT SECTION OF THE PAYSTREAK VEIN 

Because of the low grade and the short, lenticular, irregular nature 

-of the Salmon Bay radioactive carbonate-hematite veins, no attempts 

at systematic sampling were made except on Pitcher Island where 

a 100-foot section of the Paystreak vein, exposed at low tide, could 

be sampled accurately enough to warrant a grade and reserve calculation (fig. 2). 

First, the grade was calculated in terms of percent equivalent 

uranium and was found to average 0.03 percent (table 3). However, 

an expression of the average grade in terms of equivalent uranium 

actually has little meaning because most of the radioactivity is due 

to thorium. Therefore, grade calculations were also made in terms 

of percent equivalent thorium and were found to average 0.16 percent 

(table 3). In these calculations no provisions were made for possible 

wall-rock dilution. 

TABLE 3.-Calculation of average equivalent-uranium and equivalent-thorium 

content of a 100-foot section of the Paystreak vein, Pitcher Island 1 

Distance of Area of Equiva- Area- E1~r- AreaWidth Distance influence influence lent assay assay Sample (fig. 5) (W) between Dt+D,=d WXd=A uranium product thorium product 

(feet) samples 2 2 (square assay (AXper- assay (AX per· 

(D) (feet) (feet) feet) (percent cent eU) (percent cent eU) z eTh) eTh) 

------ 4601.- ------·------ 2.0 24.2 24.2 48 0.035 0.017 3 0.17 0.082 

4561_-------------- 2.8 26.0 25.1 70 .035 .025 4.16 .11 

4439_ -------------- 1. 7 13.0 19.5 33 .046 .015 4 .20 .066 

4563_ -------------- 3.1 19.6 16.3 51 .036 .018 4 .16 .082 

4565_-------------- 2.0 3.2 11.4 23 .020 .005 4 .11 .025 

4566_-------------- 1.8 14.0 8.6 15 .030 .005 4 .17 .026 

4569 ·--~-----------} 4570 ·-------------- 3.3 14. () 14.0 46 •• 028 .013 6.14 .064 

4571 ·--------------

TotaL ______ ------ ---------- ---------- ------------ 286 ---------- 0.098 ---------- 0.46 

l:{A) l:(AXpercenteU) I l:(AX 

cent eTh) 

1 Method modified after Parks (1949, p. 66). 2 Radiometric assay, using uranium standards. a Calculated from the equivalent-uranium assay by subtracting an estimated 0.002 percent for chemical 

uranium and multiplying the remainder by the conversion factor of 5. 4 Radiometric assay, using thorium standards. 1 Sample: 

eU eTh Width 

(percent) (percent) (feet) 

4569~----------------------------------------------------------------- 0. 036 0.17 1. 0 4570__________________________________________________________________ • 014 . 07 1. 8 

457L _____________________ -------------------------------------------- . 049 • 23 • 5 6 Weighted average of samples 4569, 4570, and 4571. 

A . . l:(AXpercent eU) 0.098 

verage grade, eqwvalent uramum= l:A . 286 =0.0003=0.03 percent eU. 

. . l:(AXpercent eTh) 0.46 Average grade, eqmvalent thormm== l:A .... 286 =0.0016=0.16 percent eTh. 
RADIOACTIVE DEPOSITS IN SOUTHEASTERN ALASKA 19 

Reserves of thorium and thorium dioxide per foot of depth (do-wn 

the dip) were calculated for the 100-foot section of the vein. The 

:average specific gravity of the Paystreak vein is 2.94. This givt3S 

10.9 cubic feet of mineralized roc:k per ton or 22 tons per foot of dept:rr. 

'There are, therefore, about 70 pounds of thorium or 80 pounds of 

thorium dioxide per foot of depth for the 100-foot section of the vein 

sampled. 

The extent of the Paystreak vein beyond the 100-foot sampled 

section is unknown. The dense forest cover on Pitcher Island prevents the tracing, either visually or by radioactivity surveying, of 

the vein to the south. No sign of the vein along its projected strike 

eould be seen on the beach on the southeast side of the island (pl. 3); 

hence it is evident that the Paystreak vein does not extend for more 

than 730 feet to the south. Nothing is lmown about the northward 

·extension of the vein, except that it can be seen under water for about 

40 feet at extreme low tide; however, at least another 50 feet of cornparable width and grade can be inferred, and there may be several 

hundred feet more. 

RARE-EARTH OXIDE DATA 

Because many of the Salmon Bay veins contain parisite or bastna,esite or both, chemical analyses for rare-earth oxides were made on 

several samples. The rare-earth oxide analyses are listed in table 4; 

TABLE 4.-Data on rare-earth oxide content of carbonate-vein samples from i~he 

Salmon Bay area 

Sample 

4428-A 

-B 4504 

4505 

4507 

4508 

4601 

4602 

4603 

4604 

4605 

4606 

4608 

4609 

4610 

[Equivalent-uranium analyses, Mary E. Thompson and John J. Matzko] 

Location of sample Type of sample 

Vein about 1 mile north of Salmon High-grade grab ______________________ _ 

Bay (fig. 3). _____ do _____________ --------- ___________ .do _______ ------------- ____________ _ 

_____ do_____________________________ 2.0-ft chip-channel from hanging-walL_ _____ do_____________________________ 4.0-ft chip-channel from footwall (a 

continuation of sample 4504). _____ do_____________________________ 7.0-ft chip-channel across vein ________ _ _____ do_____________________________ 10.0-ft chip-channel across vein _______ _ 

Paystreak vein, Pitcher Island 2.0-ft channel across vein _____________ _ 

(fig. 2). 

-----do ••• -------------------------- Channel across wall rock adjacent to vein. Vein on northwest side of Pitcher Chip-channel along vein _____________ _ 

Island (pl. 3). _ ••.• do_____________________________ Chip-channel across vein _____________ _ _____ do_____________________________ Chip-channel along vein. ____________ _ _____ do _____________________________ 4.5-ft chip-channel across vein ________ _ 

Vein about 1 mile north of Salmon 6.5-ft chip-channel across vein _______ _ 

Bay (fig. 3). ____ .do_____________________________ High-grade grab ______________________ _ Feldspathic dike about ~2 mile Grab _________________________________ _ 

south of Bay Point. 

Equivalent uranium 

(percent) 

0.003 

.002 

.002 

.002 

.002 

.002 

.035 

<.001 

<.001 

<.001 

<.001 

<.001 

<.001 

.001 

.005 

Rar1•-

eart:t1 

oxides 

(percent)l 

5.0 

1.2 

• 73 

.67 

.83 

.84 

.36 

.09 

.09 

.19 

.29 

. 72 

• 78 

1.95 

.07 

1 Includes Th02 which in these samples is negligible exeept for sample 4601 which contains about 0.2 per- cent Th02 as calculated from the equivalent-uranium ana.lysis. 
20 MINERAL RESOURCES OF ALASKA 

the localities of the samples analyzed are shown in figures 2 and 3, 

and plates 2 and 3. One vein about 1 mile north of the entrance to 

Salmon Bay was particularly high in parisite. Five chip-channel 

samples (4504, 4505, 4507, 4508, and 4608) were taken across this 

vein at irregular intervals along a strike distance of about 1,150 feet. 

They average 0.79 percent rare-earth oxides for the average vein 

width of 7.4 feet. One high-grade grab sample from the vein assayed 

5.0 percent rare-earth oxides (table 4 and fig. 3). 

GENESIS 

Most of the Salmon Bay veins have sharp, clean walls; wall-rock 

inclusions are not abundant, but they do occur locally. A few veins 

show alternating narrow bands of vein material and wall rock. Some 

of the veins have an en echelon arrangement. There is evidence of 

some replacement, but open-space filling appears to have been the 

dominant process involved in the introduction of the vein fillings. 

The restriction of the radioactive veins to the graywacke at Salmon 

Bay is probably due to the fact that magmas and hydrothermal 

solutions of the proper composition existed in that area at a time 

when there were fractures in the graywacke in which the mineralized 

solutions could be deposited. The graywacke probably played no 

part in localizing the veins other than serving as a fairly competent. 

rock that maintained open spaces much better than the other rock 

types in the area. 

At one locality on the southeast shore of Pitcher Island (pl. 3) ·a . 

narrow radioactive carbonate-hematite vein appears to cut one of 

the wider nonradioactive rare-earth fluocarbonate veins, suggesting 

that the radioactive veins are younger than the rare-earth veins. 

Lamprophyre, basalt, and phonolite dikes are the only igneous 

rocks exposed in the Salmon Bay area. The nearest plutonic rocks 

are of dioritic composition and are almost 10 miles to the westsouthwest (pl. 1). There are some Tertiary volcanic rocks, on 

Zaremba Island 4 to 6 miles northeast of Salmon Bay. 

Many of the carbonate veins are closely associated with the lamprophyre dikes. The wide rare-earth carbonate vein loca_ted about 

1 mile north of Salmon Bay (fig. 3) and one or two other carbonate 

veins cut lamprophyre dikes. The veins commonly pinch down to 

an inch or less in width through the dike, then widen out again to 

their normal width in the graywacke. , Several lamprophyre dikes 

(fig. 3) end abruptly against the carbonate veins. Probably the 

lamprophyre dikes and the wide rare-earth carbonate _veins are 

genetically related although no definite evidence for this has been 

found. The lamprophyre dikes, in turn, may be genetically related 
RADIOACTIVE DEPOSITS IN SOUTHEASTERN ALASKA 21 

to a phase of the Late Jurassic or Cretaceous intrusive rocks 

(Buddington and Chapin, 1929, p. 230). 

The Salmon Bay rare-earth fiuocarbonate veins have some similarity to the rare-earth fluocarbonate deposits at Mountain Pass, San 

Bernardino County, Calif. The California deposits probably are 

genetically related to the "differentiation of an alkaline magma from 

shonkinite to syenite to granite with a carbonate-rich end product 

containing the rare elements" (Olson, Shawe, Pray, and Sharp, 1954, 

p. 1). The lamprophyre dikes at Salmon Bay 1nay be associated 

with alkalic rocks which have not yet been exposed by erosion. 

Inasmuch as the region immediately west of Sahnon Bay has never 

been mapped geologically, it is possible that there are also some 

undiscovered alkalic intrusive rocks near the carbonate veins. Thin 

sections from three different lamprophyre dikes in the area showed 

the following mineralogic composition: 

Sample 4757 (fig. 3) 

Percent 

Albitic plagioclase______________ 49 

Carbonate____________________ 21 

Altered hornblende_____________ 19 

Epidote ______ --------_________ 5 

Percent 

Pyrite ______ -----_____________ 3 

Iron oxides____________________ 3 

Analcite _____ -----_____________ tr 

Sample 4758 (fig. 3) 

Percent 

Brown and green biotite_------- 48 

Albitic plagioclase______________ 28 

Carbonate____________________ 22 

Percent 

Ilmenite_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2 

Apatite ______ ----------------- tr 

Sample 4760 (pl. 2) 

Percent 

Hydrobiotite and "sericitic" ma- terial_______________________ 51 

Biotite________________________ 25 

Albitic plagioclase______________ 15 

Percent 

Carbonate____________________ 6 

Opaques (magnetite, pyrite, ilmenite)_____________________ 3 

Analcite ___________________ --_ tr 

In addition to the lamprophyre dikes some basalt dikes occur in the 

Salmon Bay area. About 70 feet of one such dike is exposed on 

Pitcher Island between the Paystreak and Marker veins (pl. 3). 

Megascopically the rock is dark and fresh looking; it effervesces in 

hydrochloric acid. A thin section (sample 4578) shows a poorly 

defined diabasic texture. Plagioclase in lath-shaped crystals and 

ferroan dolomite (Palache and others, 1951, p. 211) are the main 

constituents. The original ferromagnesian minerals have been 

completely altered, but the original presence of olivine is strongly 
22 MINERAL RESOURCES OF ALASKA 

indicated. The rock is probably an olivine basalt that has undergone 

considerable deuteric alteration. The mode is as follows: 

Sample 4578 (pl. 3) 

Percent 

Plagioclase (average Ans0)_______ 45 

Carbonate____________________ 35 

Magnetite_____________________ 14 

Percent 

Chloritic material______________ & 

Quartz ___ --------_____________ trOlivine(?) ____________ -----____ tr 

.A thin section of rock sample 4441 (pl. 2) collected by Glover from 

a dike on a small island a short distance northwest of Pitcher Island,. 

was examined by Richard Kellagher of the Geological Survey laboratory in Washington, D. C. Kellagher identified the rock as an 

aegirite-analcite phonolite consisting chiefly of sanidine, analcite, and 

aegirite with small amounts of leucite and sodalite. No other phonolite dikes were recognized in the area, but more detailed studies would 

probably disclose some. 

The relation of these basalt and phonolite dikes to the carbonatehematite veins is obscure. Perhaps the narrow radioactive carbonate· 

veins are genetically associated with one of these sets of dikes while 

the wider nonradioactive rare-earth :fluocarbonate veins are related tothe Jamprophyre dikes. 

Thorium-bearing veins somewhat similar to the Salmon Bay veins 

have been discovered recently along shear zones in the Wet Mountains of Colorado. "Pre-mineralization basic dikes" (Christman, and 

others, 1953, p. 1) are closely associated with these veins; however,. 

the relationship between the dikes and the thorium veins is thought to· 

be "purely structural" (idem, p. 6). 

The so-called carbonate-hematite veins at Salmon Bay may actually 

be carbonatites, that is, carbonate-rich rocks derived from a carbonate 

magma or from carbonate hydrothermally redistributed from sedimentary limestone beds. The association of lamprophyres, phonolites,. 

olivine basalts, and dikelike carbonatite bodies is entirely logical from 

a petrogenic standpoint, although authorities do not agree on the 

exact processes involved. Rock assemblages having similar bulk 

chemical compositions have been described from several parts of the 

world (Turner and Verhoogen, 1951, p. 334-342; Barth, 1952, p. 213-

216; Hatch, Wells, and Wells, 1949, p. 241-243). 

The Salmon Bay veins could be interpreted as mobilized or hydrothermally redistributed sedimentary limestone beds derived from the 

relatively pure limestone that underlies the graywacke in the vicinity 

of Salmon Bay (pl. 1) or from the limy graywacke itself. Such an 

origin would require some outside source of magnesium and iron for 

the dolomite-ankerite that constitutes about 80 percent of the veins . 

.Also, aluminum, silicon, sodium, and potassium in excess of the small 

amounts carried in the relatively pure limestone would be required for 
RADIOACTIVE DEPOSI'l'S IN SOUTHEASTERN ALASKA 23~ 

the alkali feldspar which makes up about 10 percent of the veins. The 

remaining 10 percent of the Snlmon Bay veins consists of iron oxides 

and sulfides and small amounts of many other minerals listed in table 1. 

A hydrothermal origin for these minerals seems probable. The pyrite 

in particular appears to be hydrothermal. Almost invariably it occurs 

in small striated cubes that apparently were formed by late-stage 

replacement solutions. The rare-earth fluocarbonates appear to be 

definitely hydrothermal. They are late-stage minerals occurring along· 

postvein fractures in the carbonate and as small, subrounded aggregates in vugs. Another feature that is also definitely hydrothermal is 

the widespread hematitic alteration adjacent to most of the veins. 

Detailed geologic mapping along the shore of Prince of Wales Island 

from Point Colpoys to Exchange Cove (pl. 2) at low tide would undoubtedly solve many of the problems concerning the origin of the 

carbonate veins and their relationship to the different dikes. 

SUMMARY AND CONCLUSIONS 

The surface of the radioactive carbonate-hematite veins in the 

vicinity of Salmon Bay contain only traces of uranium. Most of the· 

radioactivity is due to thoriun1 contained in the minerals thorite and 

monazite. Red hematite, zircon, and apatite also contain small 

amounts of thorium. The thorium content of the veins is too low to· 

be of commercial interest at the present time. 

Judging from the surface mineralogy of these veins, the authors do· 

not think it probable that the veins would show any significant in-· 

crease in uranium tenor with depth. The thorium is contained in 

minerals into whose crystal structure uranium enters to only a very 

limited extent. So, unless some undetected radioactive mineral that 

forms an isomorphous series between a pure thorium end member 

and a pure uranium end member is present, there is little likelihood of 

an increase in uranium content with depth. 

The rare-earth fluocarbonate veins are low grade and relatively 

small. They rank far below the California deposits in both grade and 

tonnage, and at the present time they offer no commercial possibilities. 

OTHER AREAS EXAMINED 

The radioactive carbonate veins at Salmon Bay occur only in graywacke. Similar veins in the underlying limestone are not appreciably 

radioactive. Therefore, in order to exhaust all possibilities, radioactivity traverses were made along those parts of the northern and 

northwestern coasts of Prince of Wales Island (loc. E and G, fig. 1; 

also see pl. 1) that had been mapped as graywacke by Buddington 

(Buddington and Chapin, 1929, pl. 1). Only a small part of this. 

work was done on foot. The greater part was conducted by cruising: 
24 MINERAL RESOURCES OF ALASKA 

.close to the shore in a skiff. If any signs of the hydrothermal hematitic 

alteration common to the veins at Salmon Bay or other evidence of 

possible mineralization were seen the party went ashore and made a 

radioactivity examination with Geiger counters. A few barren calcite 

veins were found in the graywacke; some epidote-garnet-calcite veinlets were found near igneous contacts; one small galena-bearing 

veinlet was found near Tokeen on Marble Island. None of the 

·samples collected assayed greater than 0.001 percent equivalent 

uranium. It should be pointed out that most of the rock in this area 

that was mapped as graywacke (pl. 1) by Buddington is actually very 

limy. Three thin sections made from specimens collected from the 

"graywacke" areas on the northern and western shores of Prince of 

Wales Island contained from 45 to 90 percent carbonate. 

As the Salmon Bay veins may be related genetically to the batholith 

near Shakan (pl. 1) or to similar smaller intrusive masses, a number 

-of mineral deposits definitely known to be related to these masses were 

-examined. These deposits included the molybdenum prospect at 

.Shakan, Kosciusko Island (loc. F, fig. 1), a zinc prospect near Point 

St. Albans, Kuiu Island (loc. J, fig. 1), an old lead prospect at Egg 

Harbor, Coronation Island (loc. I, fig. 1), and the Baker Island 

molybdenum prospect (loc. H, fig. 1). No radioactivity in excess of 

.0.004 percent equivalent uranium was found at any of these localities. 

Four other outlying areas were also examined briefly. The shoreline of Totem Bay, Kupreanof Island (loc. K, fig. 1) was examined to 

.determine if the northwestward-trending veins at Salmon Bay continued on the north side of Sumner Strait (pl. 1). No evidence of the 

thorium-bearing veins was found. Samples of the andesite country 

:rock on the shore of Totem Bay assayed only 0.003 percent equivalent 

uranium. A brief examination was made also in the vicinity of 

Round Point, Zarembo Island (loc. D, fig. 1) to discover if any 

radioactive mineral deposits were associated with a small granitic 

intrusive there; only small epidote veinlets were found. The granite 

.at Round Point assayed 0.004 percent equivalent uranium. Finally, 

brief examinations were made at Lake Bay (loc. L, fig. 1) and Green 

Monster Mountain (loc. M, fig. 1) to determine whether copper 

·deposits at these localities showed any significant radioactivity. Field 

measurements and analyses of samples indicated that the copper 

·deposits tested do not contain more than 0.001 percent equivalent 

uranium. 

The studies mentioned above indicate that the radioactive carbon-

.ate-hematite veins of the graywacke area at Salmon Bay do not 

-extend beyond the region along the northeast coast of Prince of Wales 

Island between Exchange Cove and Point Colpoys. It is not likely 

-that the area extends very far inland to the west because the gray-
RADIOACTIVE DEPOSITS IN SOUTHEASTERN ALASKA 25 

wacke is succeeded in that direction by massive, relatively pure 

limestone; no appreciable radioactivity has been found in carbonate 

veins that occur in limestone or carbonate-rich wall rocks on the· 

northern part of Prince of Wales Island. 

TAKU HARBOR-POINT ASTLEY DISTRICT 

In the course of travel from Juneau to the Salmon Bay area brief 

reconnaissance examinations were made at a copper prospect near 

Point Astley (loc. B, fig. 1), and at the sites of reported pitchblende· 

occurrences in the vicinity of Taku Harbor, Limestone Inlet, and 

Port Snettisham (loc. A, fig. 1). 

The country rocks in these localities include green schist, green,. 

gray, and black slaty phyllite, and minor amounts of limestone and 

schistose chert. These rocks were intruded by quartz diorite of the 

Jurassic or Cretaceous Coast Range batholith (Buddington and 

Chapin, 1929, pl. 1). 

At Point Astley metallic minerals occur in lenticular replacement 

veins that strike N. 0°-30° W. and dip to the east about 70° parallel 

to the schistosity of the country rock. The veins contain pyrite, 

sphalerite, bornite, pyrrhotite, galena, chalcopyrite, malachite, covellite, and chalcocite in a gangue of quartz, carbonate, and impregnated 

schist. Buddington and Chapin (1929, p. 327) reported traces of 

native silver from this locality. 

Slight radioactivity was noted at one point in a short adit driven 

through a mineralized zone 10 to 15 feet wide. Sample 4558 (table· 

5) taken across a 2-foot part of this zone assayed 0.006 percent 

equivalent uranium. No radioactive minerals were identified. 

Reconnaissance with Geiger counters in the vicinity of reported 

pitchblende occurrences at Taku Harbor, Limestone Inlet, and Port 

Snettisham (loc. A, fig. 1) revealed no appreciable radioactivity. 

No metallic minerals were observed except at the Taku Harbor· 

locality where pyrite and arsenopyrite occur in a breccia zone and 

in the adjacent country rock. The maximum equivalent-uranium 

content (samples 4555 and 4556, table 5) was 0.003 percent. 

HYDER AREA 

The Hyder area (loc. N, figs. 1 and 4) at the head of Portland 

Canal is very highly mineralized. Several marginal gold-silvercopper-lead-zinc-tungsten properties have been exploited on the American side of the international boundary line; the famous Premier· 

mine, only a mile northeast of the boundary in British Columbia, 

produced gold, silver, copper, lead, and zinc for many years. All 

these deposits have mineral assemblages somewhat similar to those, 

found in uranium lodes in other parts of the world. 
:26 ~ERAL RESOURCES OF ALASKA 

' , 

I 

I 

I 

I 

...... , "' ,';--,!!~lt '1 

: ....._ C 9roil 

: dvrQ.s:. 

'c ?; 

1000 0 

EXPLANATION 

Approximate position of contact between Texas Creek granodi· orite and Hazelton group 

A 

Gray Copper vein 

B 

Ruby Silver vein 

c Canyon vein 

D 

Silver Falls vein 

4743 • 

Locality of sample 

2000 Feet 

FIGURE 4.-Sample location map of the Mountain view property, Hyder area. 
RADIOACTIVE DEPOSITS IN SOUTHEASTERN ALASKA 27 

TABLE 5.-Data on radioactivity of samples from the Taku Harbor-Point Astley 

district, the islands adjacent to northern Prince of Wales Island, and the Hyder area 

4552 

4553 

4554 

4555 

4556 

4557 

4558 

4559 

4726 

4729 

4734 

4737 

4739 

4741 

4742 

4743 

4745 

4746 

4747 

4748 

4749 

4750 

4753 

4754 

Location Type of sample 

Taku Harbor-Point Astley area 

East side of Taku Harbor (loc. A, fig. 1) about Grab sample of massive sulfide 

300 ft. south of cannery dock. float. 

From mineralized zone, east side of 'I'aku Har- Grab sample of sulfide from minbor (loc. A, fig. 1) about 450ft. south of can- eralized zone. nery dock. 

From a narrow vein about 300 ft. south of Grab sample of sulfide vein rna- sample 4553. terial. 

North side of Limestone Inlet (loc. A, fig. 1) Grab sample of fine-grained gran- about midway between the mouth and the itic dike. 

head of the inlet. ____ .do.------------------------- ____ .. ______________ .do ________________ --------- ___ _ ____ .do .• ___ --- _______ -------- _______ .. ______________ .do _______________ ------- ___ ----

Point Astley (loc. B, fig. 1), from a short adit Grab sample from a 2-ft. section of 

driven across a mineralized zone 1(}-15 ft. a mineralized zone. wide. 

Islands adjacent to northern Prince of Wales Island 

Round Point, Zarembo Island (loc. D, fig. 1) __ McGill zinc prospect, southeast side of Kuiu 

Island about H-1! miles north of Point St. 

Albans (loc. J, fig. I). 

Shakan molybdenite prospect, Kosciusko 

Island (loc. F, fig. 1). 

Baker Island molybdenite prospect (loc. H, 

fig. 1). 

Northwest comer of Edna Bay, Kosciusko 

Island (south of loc. F, fig. 1). 

From the middle of Totem Bay, Kupreanof Island (loc. K, fig. 1). 

The Lake Bay copper prospect, Prince of Wales 

Island (loc. L, fig. I). 

Green Monster Mountain, Prince of Wales 

Island (loc. M, fig. 1). 

Grab sample of granite ___________ _ Grab sample of sphalerite-bearing 

vein material. 

Grab sample of molybdenite- bearing vein material. 

Grab sample of granite containing molybdenite-bearing quartz 

veinlets. 

Grab sample of iron-stained, argil- laceous limestone. _ Grab sample of "dacite" country rock. 

Grab sample of pyrite-chalcopyrite vein. 

Grab sample of chalcopyrite-bear- ing contact metamorphic ore. 

Hyder area (fig. 4: loc. N, fig. 1) 

Canyon vein, Mountain View property, Hyder Grab sample of vein materiaL •••. area. 

Stations 59 and 90, Skookum tunnel, Moun- Grab sample from Skookum tun- tain View property, Hyder area. nel. 

Southeast end of the drift on the Gray Copper Grab sample of vein material (unvein (USGS station 21), Skookum tunnel, concentrated). 

Mountain View property, Hyder area. Upper Silver Falls tunnel, Mountain View Grab sample of fluorescent rna- property, Hyder area. terial. 

Near footwall of Silver Falls vein, about 10(}-150 Grab sample of vein materiaL. ____ ft. above the upper Silver Falls tunnel, 

Mountain View property, Hyder area. Surface cut in the Ruby Silver vein, Mountain Grab sample of thin yellow coat- View property, Hyder area. ing from outcrop of vein. 

Near the floor of the Skookum tunnel between Grab sample of fluorescent rna- stations 55 and 6(}-25, Mountain View prop- terial. 

erty, Hyder area. Bankovich prospect at an altitude of about Grab sample from vein outcrop ___ 5,000 ft. on "Hyder Lead J\1ountain", south 

side of the West Fork of Texas Creek, about 

9 miles west of Mountain View property, 

I 

Equh:alent 

uramum 

(percent) 

<0.001 

<.001 

.001 

.003 

.003 

.002 

.006 

0.004 

.001 

.004 

.001 

.001 

.003 

.001 

<.001 

0.004 

.004 

.035 

.006 

.005 

.003 

.004 

<.001 

Hyder area. Surface cut in the Gray Copper vein, Moun- _____ do _______________ --------------1 <.001 

tain View property, Hyder area. 
28 MLNERAL RESOURCES OF ALASKA 

Investigations were centered on the Mountain View property which 

is about 5 miles north of Hyder. The area immediately surrounding 

this property is underlain by the Texas Creek granodiorite of Jurassic 

or Cretaceous age that intrudes greenstone, tuffaceous graywacke,. 

volcanic breccia, slate, argillite, quartzite, and limestone of the 

Hazelton group of Jurassic(?) age (Buddington and Chapin, 1929). 

The ore deposits on the Mountain View property are near the contact of the granodiorite and the Hazelton group. They consist of 

mesothermal fissure veins containing in decreasing order of abundance: 

pyrite, galena, sphalerite, pyrrhotite, molybdenite, scheelite, arsenopyrite, magnetite, specular hematite, tetrahedrite, proustite, chalcopyrite, chalmersite, marcasite, anglesite, malachite, azurite, covellite, 

and "limonite." The gangue consists of quartz, calcite, barite, ankerite, sericite, and chlorite. 

Early in the summer of 1949, Howard M. Fowler, a former mining 

engineer for the Territorial Department of Mines, detected radioactivity anomalies on the Mountain View property. Later in the 

summer of 1949, W. S. West and P. D. Benson of the U.S. Geological 

Survey, who were based in southeastern Alaska, conducted a radiometric reconnaissance in the Hyder district (West and Benson, 1955) 

with special emphasis on the Mountain View property. No deposits 

of commercial interest were found although radioactive material is 

widely distributed on the Mountain View mining property. The 

maximum equivalent-uranium assay on unconcentrated material was 

0.049 percent on a sample from the Skookum tunnel of the Mountain 

View mine. No primary uranium minerals could be identified. 

Chemical analyses, however, showed definite uranium; thin coatings 

of a yellowish stain, tentatively identified as uranium sulfate, were 

found at one locality. Positive qualitative tests for uranium were 

obtained from pyrrhotite, molybdenite, pyrite, galena, iron oxides, 

and a few other minerals. 

During the summer of 1950 Howard M. Fowler collected a pitchblende-bearing sample from the Canyon vein on the Mountain View 

property. Because this sample was reported to have assayed 0.7 

percent equivalent uranium oxide, a brief reconnaissance of the 

Canyon vein and the underground workings on the Mountain View 

property was made by the authors in 1952. 

No appreciably radioactive material was detected in the Canyon 

vein. The maximum assay of the samples from this vein was only 

0.004 percent equivalent uranium (sample 4743, table 5, fig. 4). One 

slightly radioactive area found by West and Benson in 1949 in the 

Skookum tunnel at the southeast end of the drift on the Gray Copper 

vein was rechecked in the 1952 investigation. An unconcentrated 

sample from this locality (sample 4746, table 5; fig. 4) assayed 0.035 
RADIOACTIVE DEPOSITS IN SOUTHEASTERN ALASKA 29 

percent equivalent uranium. No uranium mineral was identified. 

The radioactivity apparently emanated from molybdenite, pyrrhotite, 

and pyrite. Chemical tests by the U.S. Geological Survey laboratory 

have shown that these sulfides contain traces of uranium and that 

the molybdenite is the most radioactive. In this connection it is 

interesting to note that very fine grained uraninite has been described 

from the Victoria deposit near Hazelton, British Columbia about 100 

miles southeast of the Hyder area. The uraninite is in microscopic 

grains associated with molybdenite, gold-bearing arsenopyrite, cobalt 

sulfarsenides, and hornblende in lenticular hydrothermal veins a few 

inches to 4 feet wide (Stevenson, 1951, p. 353, 362). Three other 

deposits showing similar mineralization occur in southern British 

Columbia. In all four of these places, Stevenson found that molybdenite is the sulfide most commonly associated with the uraninite. 

A dark-green fluorescent conting was noted underground in several 

places near the bottom of the walls of the Skookum tunnel and the 

upper Silver Falls tunnel. The color of the fluorescence is similar to 

that of the uranium mineral autunite, but the mineral is not appreciably radioactive. The fluorescent mineral from the Skookum and 

Silver Falls tunnels was identified optically as opal (silicon dioxide) 

by the Geological Survey laboratory in Washington, D. C. The 

fluorescence is probably due to a trace of uranium present as an 

impurity in the opal. Fluorescent silica containing traces of uranium 

has been described from the ViTgin Valley in northwestern Nevada 

(Staatz and Bauer, Jr., 1951, p. 2) and from the Monument Valley 

area in Utah. It has been identified in several other localities in the 

Western United States. The color of the fluorescence ranges from 

pale yellowish green to deep green as the uranium content increases. 

The surface outcrops of the Ruby Silver vein on the Mountain 

View property have thin coatings of a yellow stain similar in color 

to some of the secondary uranium minerals. Samples of this material 

collected by Arthur 0. Moa, n1anager of the Mountain View property, 

were studied by the Geologicttl Survey laboratory. The coatings are 

not appreciably radioactive when tested with a Geiger counter. An 

X-ray diffraction pattern gave d-spacings similar to those for hydromica and the clay mineral kaolinite. Similar material collected by 

West and Benson in 1949 gave positive qualitative tests for uranium 

and was tentatively identified as a secondary uranium sulfate. It 

was impossible to collect enough of this n1aterial for positive 

identification. 
30 MINERAL RESOURCES OF ALASKA 

REFERENCES CITED 

Barth, T. F. W., 1952, Theoretical petrology: New York, John Wiley and Sons, 

387 p. 

Buddington, A. F., and Chapin, Theodore, 1929, Geology and mineral deposits of 

southeastern Alaska: U. S. Geol. Survey Bull. 800, 398 p. 

Chapin, Theodore, 1919, Mining developments in the Ketchikan district: U.S. 

Geol. Survey Bull. 692-B, p. 85-89. 

Christman, R. A., Heyman, A.M., Dellwig, L. F., and Gott, G. B., 1953, Thorium 

investigations in 195Q-52, Wet Mountains, Colorado: U.S. Geol. Survey Circ. 

290, 40 p. 

Hatch, F. H., Wells, A. K., and Wells, M. K., 1949, The petrology of the igneous 

rocks: lOth ed., London, Thomas Murby and Co., 469 p. 

Houston, J. R., 1952, Southeastern Alaska, in White, M.G., West, W. S., Tolbert, 

G. E., Nelson, A. E., and Houston, J. R., 1952, Preliminary summary of 

reconnaissance for uranium in Alaska, 1951: U. S. Geol. Survey Circ. 196, 

17 p. 

Mertie, J. B., Jr., 1921, Lode mining in the Juneau and Ketchikan districts: 

U. S. Geol. Survey Bull. 714-B, p. 105-128. 

Olson, J. C., Shawe, D. R., Pray, L. C., and Sharp, W. N., 1954, Rare-earth 

mineral deposits of the Mountain Pass district: U. S. Geol. Survey Prof. 

Paper 261, 75 p. 

Palache, Charles, Berman, Harry, and Fronde!, Clifford, 1951, Dana's system of 

mineralogy: 7th ed., v.2, New York, John Wiley and Sons, 1,124 p. 

Parks, R. D., and others, 1949, Examination and valuation of mineral property:: 

3d ed., Cambridge, Addison-Wesley Press, 504 p. 

Staatz, M. H., and Bauer, H. L., Jr., 1951, Virgin Valley opal district, Humbolt 

County, Nevada: U.S. Geol. Survey Circ. 142, 7 p. 

Stevenson, John S., 1951, Uranium mineralization in British Columbia: Econ~ 

Geol., v. 46, no. 4, p. 353-366. 

Turner, F. J., and Verhoogen, Jean, 1951, Igneous and metamorphic petrology:: 

1st ed., New York, McGraw-Hill Book Co., 602 p. 

Twenhofel, W. S., Robinson, G. D., and Gault, H. R., 1946, Molybdenite investigations in southeastern Alaska: U.S. Geol. Survey Bull. 947-B, p. 7-38. 

Wedow, Helmuth, Jr., 1951, Adaptation of portable survey meters for airborne 

reconnaissance with light planes in Alaska: U. S. Geol. Survey Trace Elements Memo. Rept. 323, issued by U.S. Atomic Energy Comm., Tech. Inf. 

Service Ext., Oak Ridge, Tenn. 

Wedow, Helmuth, Jr., and others, 1953, Preliminary summary of reconnaissance 

for uranium and thorium in Alaska, 1952: U.S. Geol. Survey Circ. 248, 15 P~ 

West, W. S., and Benson, P. D., 1955, Investigations for radioactive deposits in 

southeastern Alaska: U. S. Geol. Survey Bull. 1024-B, p. 25-44. 
INDEX 

Page 

Alkali feldspar ________________________________ 10,23 

Annell, Charles 8., analyst___________________ 10 Anglesite_ ___ ___ ___ _ ___ _ _ ___ __ __ __ _ ___ ___ _ _ _ 28 

Apatite _______________________________________ 10, 11 

Arsenopyrite __ ------------------------------_ 25, 28 Azurite_______________________________________ 28 

Basalt dikes ________________________________ 6, 21-·22 

Page· 

Matzko, John J., analyst_____________________ I!} 

Mountain View property _____________________ 28,29· 

Molybdenite_-------------------------------- 28,29 

Molybdenite deposit, Kosciusko Island, composition ____ ---------------------- 5· 

Monazite _____ ------ ________ ------------------ 10, 11 

Muscovite ______________________ ------------__ 1(}· 

Bastnaesite ___________________________________ 10,12 Ordovician age, rocks_________________________ 4-

Bedded rocks_________________________________ 4:-5 

Benson, Paul D., analyst_____________________ 16 Parisite_- --------------------------------- 10, 12, 20· 

Bornite_______________________________________ 25 Paystreak vein _______________ 7, 8, 13,16, 17, 18, 19, 21 

Pietsch, Audrey C., analyst__________________ 16 

Calcite __ ------------------------------------- 10 Pitchblende ________________ ------------ ______ 25,28 

Canyon vein _________________________________ 26,28 Prince of Wales Island, structural geology____ 6 

Chalcedony __ -------------------------------- 10 Proustite_ ____ _ ___ _ _ _ _ ___ __ __ _ ___ __ ___ _ _______ 28. 

Chalcocite____________________________________ 25 Pyrite ____________ ---------------------- 10, 23, 25,28 

Chalcopyrite_-------------------------------_ 10, 25 Pyrrhotite ____________________ -------- ________ 25, 28 

Chalmersite_ -------------------------------- _ 28 Chlorite______________________________________ 10 Quartz __ ------------------------------------- 10 

Cisney, Evelyn, analyst______________________ 10 Quartzose diorite, Prince of Wales Island, 

Coast Range batholith_______________________ 6, 7 composition _____________________ _ 

Copper--------------------------------------_ 24, 25 Covellite _____________________________________ 25,28 Radioactive deposits ________ 2, 4, 7-9, 12-18,20,22,24 

Radioactivity, data on samples_______________ 27 

measurement from aircraft________________ 17 Diorite, Prince of Wales Island, composition __ 

Dolomite-ankerite ____ -------------------- ___ _ 10 Rare-earth oxides _____________________________ 19-20 

Ruby Silver vein _____________________________ 26,29 

Epidote ____________________ --------------- ___ 10, 24 

Equivalent thorium _________________ 12,13-16,17,18 Salmon Bay area, geology __ ------------------ 6-7 

Equivalent uranium __________________________ 3,l2, vein deposits _____________________________ 7-23 

13-16,17, 18, 19, 24, 25, 27, 28,29 Scheelite __ ------ _________ -------------------- 28 

Siderite ________________________ -----------____ 10 Fluorite _____________________________ .. _______ _ 10 Silver ______________________ ---------------___ 25-

Galena __ --------------------------------- ____ 25, 28 

Gamet._------------------------------------- 10 

Silver Falls vein______________________________ 26 

Sphalerite __________________ ----------- _______ 25, 28 

Stich, J. N., analyst__________________________ 10 Glover, Arthur E., acknowledgment__________ 3 

Gold_________________________________________ 25 Taku Harbor-Point Astley district_ __________ 25,27 

Gray Copper vein ____________________________ 26,28 Tertiary rocks________________________________ 20 

Graywacke, radioactive veins_----------- 2, 4, 20,24 Tetraheclrite__________________ ________________ 28 

Hazelton group _______________________________ 26,

28 Texas Creek granodiorite ____ ----------------- 26,28 

Hematite __________________________________ 10, ll, 28 Thompson, Mary E., acknowledgment_______ 3 H t J h R 1 t 10 analyst_ _______________________________ 10, 16,19 

ous on, osep ., ana ys ------------------ Top::tz________________________________________ 10 Hyder area _______________________________ - 25-26,27 Thorite _______________________________________ 10, 11 

Igneous rocks ________________________________ 5-6,20 Thorium _____ --------------------------- 4, 16, 22,23 

Thorium dioxide _____________ ------------- 13-16,17 

Kashevarof anticline __ ----------------------_ Kellagher, Richard, analyst_ ________________ _ 

Kramer, H., analyst_ ________________________ _ 

10 Uraninite_____________________________________ 29 

16 Uranium_--------------------------- 12,13-16,23,29 Franium oxide _______________________________ 13-16 

Lamprophyre dikes_--------------------- 6, 7, 20,21 Uranium sulfate _________________ ------------- 29 

Lead ____ ------------------------------------_ 25 

Levine, Harry, analyst_______________________ 16 Valentine, Katherine E., analyst_____________ 10 

Localities examined_----------------------- 2, 24-25 ve.in deposits, genesis ________ ----------------- 20-23 

Limestone ________________________________ 4, 5, 25, 28 mine-ralogy _____________________ ---------- 10-12 

Limonite_____________________________________ 28 radio:.tctive c::trbon'1te-hematite._ 7-9, 18, 20, 22, 24 

rare-earth carbonate ___ ----------- 9,19-20,21,23 

McCall, Benjamin, analyst___________________ 16 

Magnetite _______ -------------- __ ---------- ___ 10, 28 Warr, Jesse J., analyst________________________ 16 

Malachite_---------------- ___________________ 25, 28 

Marca~ite __ ---------------------------------- 10,28 Zinc ____________________________ ------------__ 25 

Marker vein _______________________________ 15,17, 21 Zircon __________________ ------- _______________ 10, 11 

31 U.S. GOVERNMENT PRINTING OFFICE: 1958