GEOLOGICAL SURVEY CIRCULAR 196 

PRELIMINARY SUMMARY OF 

RECONNAISSANCE FOR URANIUM 

IN ALASKA, 1951 

By M.G. White, W. S. West, G. E. Tolbert, A. E. Nelson, and J. R. Houston 

HNITED STATES DEPARTMENT OF THE INTERIOR 

Oscar L. Chapman, Secretary 

GEOLOGICAL SURVEY 

W. E. Wrather, Director 

GEOLOGICAL SURVEY CffiCULAR 196 

PRELIMINARY SUMMARY OF RECONNAISSANCE FOR URANIUM 

IN ALASKA, 1951 

By M.G. White, W. S. West, G. E. Tolbert, A. E. Nelson, and J. R. Houston 

This report concerns work done on behalf of the 

U. S. Atomic Energy Commission and is published 

with the permission of the CommiBBion. 

Washington, D. C., 1952. 

Free on application to the Geological Survey, Washington 25, D. C. 

CONTENTS 

Page Page 

Part 1. --Seward Peninsula, by Max G. White Fart 3, --Gulf of Alaska region, by Authur E 

and Walter S. West Nelson and Gene E. Tolbert 

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Abstract ......... o ... o............ .. . 10 

Introduction.- . . . . . . . . . . . . . . . . . . . . • . . . . . 1 

Discussion of data..................... 2 

Introduction.... . . . . . . . . . . . . . . . . . . . . . . 10 

Discussion of data .......... ·. . . . . . . . . . 10 

Peace River area................. 2 

Lost River area. . . . . . . . . . . . . . . . . . 2 

Brooks Mountain area ............. 2 

Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Part 4. --Southeastern Alaska, by Joseph 

R. Houston 

Conclusions.................. . . . . . . . .. 6 Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

Part 2. --Alaska Railroad-Iliamna ;region, 

by Gene E. Tolbert and Arthur 

E. Nelson 

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 13 

Discussion of data................... . 1:3 

Conclusions......................... . 14 

Abstract............................ 7 Reference cited .... ·. . . . . . . . . . . . . . . . . . . . . . 14 

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 7 

Discussion of data . . . . . . . . . . . . . . . . . . . 7 

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

Figure 1. 

2. 

3. 

4. 

ILLUSTRATIONS 

Districts of the Seward Peninsula, Alaska ............... · ................................ . 

Districts of the northern part of the Alaska Railroad-Iliamna region ....................... . 

Districts of the eastern and central parts of the Gulf of Alaska region ..................... . 

Districts of theeentral and southern parts of southeastern Alaska .......................... . 

TABLES 

Table 1. Data on localities examined on the Seward Peninsula, Alaska, 

Page 

2 

8 

11 

14 

Page 

during 1951 ........................................... ;......................... .. . . 3 

2. Data on localities examined in the Alaska Railroad-Iliamna region 

during 1951. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

3. Data on localities examined in the Gulf of Alaska region 

during 1951 ..................... •............ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 12 

4. Data on localities examined in southeastern Alaska 

during 1951. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

PRELIMINARY SUMMARY OF RECONNAISSANCE FOR URANIUM 

IN ALASKA, 1951 

PART 1. --SEWARD PENINSULA 

By Max G. White and Walter S. West 

ABSTRACT 

Reconnaissance examinations for uranium were 

made at nine localities in the York, Nome, and 

Koyuk districts of the Seward Peninsula, Alaska, 

during the 1951 field season. In addition, carborne 

radiometric traverses were made of four roads in 

the Nome and Council districts. O:!ly at Brooks 

Mountain in the York district were uranium-bearing 

deposits found that required detailed study. 

On the southwest flank of Brooks Mountain, 

zeunerite occurs as a surface coating on quartztourmaline veins occupying joint fractures in granite; 

at a second locality, also on the southwest flank of 

Locality 

Brooks Mountain area -----------------

Lost River area ----------------------

Peace River area ---------------------

Potato Mountain area -----------------

Charley Creek bismuth prospect -------

Sinuk River iron area ----------------

Hed and Strand antimony mine ---------

Big Hurrah gold mine -----------------

Quiggley (Gray Eagle) ---------------- antimony prospect. 

In addition to examination of the above localities, carborne radiometric traverses were made along 

the Penny River, Snake River, Osborn, and NomeCouncil roads (fig. 1) in the Nome and Council districts. 

Radiometric traversing on the ground was 

accomplished with standard portable survey meters 

mounted on packboards equipped with interchangeable 

2- by 20-in. gamma and 6-in. beta-gamrr.a probes. 

For all road traverses a gang of six 2- by 40-in. 

gamma tubes, connected in parallel, was mounted 

on top of a jeep and connected to a portable survey 

meter inside the vehicle. The latter type of equip1 

the mountain, zeunerite is disseminated in a highly 

weathered, altered zone of granite near a contact 

with limestone. Preliminary radiometric analyses 

show an average of about 0. 05 percent equivalent 

uranium in the vein material and about 0. 07 percent 

equivalent uranium in the weathered, altered granitic 

zone. 

INTRODUCTION 

Appraisal of Alaskan uranium possibilities 

(Wedow and others, 1951) 1 indicated that a number of 

localities on the Seward Peninsula (fig. 1) were 

favorable for the occurrence of uranium. The nine 

localities examined during the 1951 field season were 

as follows: 

Designation 

District on figure l 

York -------- BK 

York -------- BK 

Koyuk ------- BO 

York -------- CJ 

Nome -------- CK 

Nome -------- CL 

Nome -------- CM 

Nome -------- CY 

Nome -------- cz 

ment was also used for airborne traversing over the 

Sinuk River iron area with the gang of probes lashed 

to the stretcher struts of a helicopter. 

Helicopter support for the investigation of the 

Sinuk River iron area and the Hed and Strand mine 

was furnished by the U. S. Army, 30th Engineer 

Base Topographic Battalion. Daniel Jones, Territorial Department of Mines, and Robert Thorne, 

U. S. Bureau of Mines, accompanied the Geological 

Survey party in these two investigations as well as 

in the radiometric examination of the Quiggley antimony prospect and the Big Hurrah mine. 

1See reference cited. 
EXPLANATION 

- Areas Investigated 

BK Lost River area 

80 Peace River area 

CJ Potato Mountain area 

CK Charley Cr. bismuth prospect 

CL Sinuk River iron area 

C M Hed and Strand mine. 

CY Big Hurrah mine 

CZ Quiggley antimony prospect 

·. 0 25 

Figure 1. --Districts of the Seward Peninsula, Alaska 

Most of the investigations during the 1951 season were of short duration and made in the course 

of a few hours or, at the most, two 9r three days. 

The contiguous Brooks Mountain and Lost River 

areas, were investigated jointly during the latter 

part of July and in August. At the time of the investigation of the uranium prospect at Brooks Mountain, 

the United States Smelting, Refining, and Mining Co. 

was prospecting the site under a lease from the owners, 

George Hellerich of Fairbanks and Associates. There 

was no uranium prospecting at any of the other locations examined, nor was any prospecting for uranium 

reported from elsewhere on the Seward Peninsula. 

DISCUSSION OF DATA 

· Information regarding the geology, mineralogy 

and radioactivity of the various locations investigated 

is summarized in table 1. 

Radioactivity in excess of 0. 004 percent 

equivalent uranium was found at only three of the 

places examined on the Seward Peninsula: (1) in 

the Peace River area, Koyuk district; (2) the Lost 

River area, York district; and (3) the Brooks Mountain area, York district (fig. 1). 

Peace River area 

At the extreme head of Peace River (locality 

BO, fig. 1) uranothorianite, gummite, and thorite 

are associated with chalcopyrite, pyrite, hematite, 

bismuth, and silver in a stream concentrate collected 

by the Geological Survey in 1947. Radiometric 

reconnaissance of the area and a limited amount of 

trenching during late June and early July 1951 failed to 

reveal a bedrock source of the radioactive minerals. 

Detailed mineralogical examination of the samples 

from this locality is being made in the hope that a clue 

to the origin ofthe radioactive minerals will be found. 

Lost River area 

In the Lost River area (locality BK, fig. 1) 

minor amounts of radioactive material occur in 

mineralized portions of rhyolitic dikes and in an 

iron-enriched or replacement zone in limestone. 

The dikes contain up to 0. 01 percent equivalent 

uranium locally and average 0. 005 percent equivalent uranium. The radioactive material is mostly 

in a secondary hematite coating of the dike rock 

formed from the weathering of sulphide minerals. 

An iron-enriched zone in a prospect on the west side 

of Lost River valley has an average content of about 

0. 06 percent equivalent uranium with the radioactive 

· material occurring in limonite, hematite, goethite and 

and mimetite. At this prospect the radioactivity is 

restricted to a zone or pocket about 3 ft wide. No 

extension of this radioactive iron-enrich~d zone could 

be found. 

Brooks Mountain area 

Zeunerite, a hydrous copper-uranium arsenate, 

is the principal radioactive mineral at Brooks Mountain (locality BK, fig. 1). It has been found at two 

places on the southwest flank of the mountain: 

1) Associated with quartz-tourmaline veins 

filling joint fractures in granite on the 

south'west side of the mountain. The 

zeunerite occurs as a coating on both the 
w 

Table 1.--Data on localities examined on the Seward Peninsula, Alaska, during 1951 

Locality 

Potato Mountain area (locality 

CJ, fig. l) 

Brooks Mountain area (locality 

BK, fig. l) 

Lost River area (locality BK, 

fig. l) 

Age and type of rock 

York district 

Early Paleozoic black slate intruded by a large granite por- phyry dike and many quartz veins 

of Mesozoic age. 

Early Paleozoic black shale and 

white limestone intruded by 

Mesozoic granite. 

Early Paleozoic limestone and 

Mesozoic granite cut by rhyolitic and basaltic dikes. 

Significant minerals 

Bedrock: Pyrite, cassiterite 

tourmaline, zoisite, hedenbergite, and fluorite. 

Concentrate from Nortnern 

Tin Co. placer operation on Birch Creek: Cassiterite 

with minor amounts of 

hematite, magnetite pyrite, 

tourmaline, and rutile. 

Mineralized, oxidized granite near contact with limestone: Hematite,tourmaline, 

purple fluorite, and 

zeunerite. 

Marmorized limestone near granite contact: sulfide 

veinlets. 

Quartz-tourmaline veins in 

granite: Hematite and 

zeunerite. 

Granite mass as a whole: 

accessory monazite, zircon, 

tourmaline, and vesuvianite. 

Mineralized limestone: pyrite, arsenopyrite, fluorite, 

cassiterite, and various 

copper minerals. 

Iron replacement zones in 

limestone: Limonite, hematite, goethite, ana mimetite. 

Rhyolitic aikes: cassiterite, 

wolframite, topaz, and 

minor amounts of sulfides. 

Granite: Common accessory minerals. 

Radioactivity 

{percent eU) 

Less than 0.001 

Overall average about 

0.07; best grade may 

average 0.3; scattered 

float specimens con- tain UP: to 2.1. 

Less than 0. 001. 

Average 0.05; scattered 

pieces as high as 1.0. 

Averages 0.003. 

Less than 0.001. 

Average 0.06. 

Average 0.005; locally 

up to 0.01. 

Less than 0.002 
~ 

Table 1.--Data on localities examined on the Seward Peninsula, Alaska, during 1951--Continued 

Loca:City 

Sinuk River iron area (locality CL, fig. l) 

Charle¥ Creek bismuth prospect \locality CK, fig. l) 

Red and Strand mine (locality CM, fig. l) 

Radiometric traverse, Penny 

River road (see fig. l) 

Radiometric traverse, Snake 

River road (see fig. l) 

Radiometric traverse, Osborn 

road (see fig. l) 

Quiggley (Gray Eagle)antimony 

prospect (locality CZ, fig.l) 

Big Hurrah mine (locality CY, 

fig. l) 

Radiometric traverse, NomeCouncil road (see fig. l) 

Age and type of rock 

Nome district 

Veins and stockworks of limonite 

with hematite in early Paleozoic 

limestone; some residual con- centration locally. 

Hydrothermal enrichment of early Paleozoic schist and white quartz 

veins. 

Quartz veins in early Paleozoic 

schist. 

Coastal plain gravels and 

Paleozoic schist. 

Paleozoic limestone and schist, 

and coastal plain and river grav- els. 

--------------do----------------

Quartz veins in Carboniferous 

slate. 

Carboniferous black slate intruded 

by quartz vein. 

Significant minerals 

Limonite, hematite, mag- netite, siderite, pyrolusite, galena, sphalerite, and 

gold; some limonite is 

botryoidal. 

Native bismuth, bismuthinite, 

and small amounts of iron 

sulfides. 

Stibnite, pyrite, and arseno- pyrite. 

Stibnite, pyrite, and arseno- pyrite. 

Stibnite 

Gold, chalcopyrite, pyrrho- tite, and stibnite. 

Nome and Council districts 

Granitic complex of the Cape Nome 

area, Paleozoic(?) schist, and 

coastal plain and river gravels. 

Radioactivity 

(percent eU) 

Less than 0.001. 

Less than 0.002. 

0 .001. 

Schist: 17-22 divisions on 2.0 scale 

Gravelsi 13-15 divisions on 2.0 

All rock types: 12-14 

divisions on 2.0 scalel 

Do. 

Less than 0.001. 

Less than 0.001. 

Coastal plain gravel: 

3-4 divisions on 20.0 

scale.l 

Granitic complex: 6-8 

divisions on 20. 0 

scale.l 

Schist: 5-7 divisions on 20.0 scale.l 

River gravels: 5-ll 

divisions on 20.0 

scale.l 
01 

Peace River area (locality BO, 

fig. 1) 

Koyuk district 

Weathered granitic rock containing decomposed iron-rich zones. Granite: accessory sphene, zircon, pyrite and mag- netite. 

Concentrate from stream 

gravels: Pyrite, chalcopyrite, hematite, ilmenite, 

uranothorianite, bismuth, 

bornite, gold, silver, 

chromite, thorite, gummite, and common accessory minerals from granite. 

Granite: Less than 

0.003. 

Iron-rich zones: Less 

than 0.005. 

Concentrate from stream 

gravels: 0.25. 

lusing gang of six 2- by 40-in. gamma tubes connected in parallel, and attached to a portable survey meter; basic response of this 

instrument is about 8-10 divisions on 2.0 scale and 2-3 divisions on 20.0 scale. 
vein surface and the fracture walls. In 

many places the space between the vein 

and the wall is filled with a mixture of 

hematite and finely divided zeunerite. The 

average radioactivity of the veins is about 

0. 05 percent equivalent uranium, although 

some pieces of high-grade float contain 

up to 1. 0 percent equivalent uranium. 

2) In granite near a granite-limestone contact, 

associated with deep-purple fluorite, brightred hematite and black tourmaline, in a 

6-ft wide zone of highly-weathered, porous, 

oxidized granite. Preliminary radiometric 

data indicate that the richest portion of this 

deposit is across a 4-ft wide central portion 

of the zone. Readings here average about 

0. 3 percent equivalent uranium. Overall 

average content of the entire weathered, 

oxidized zone is probably about 0. 07 percent equivalent uranium. 

Radiometric traversing of the granite and its borders 

failed to locate any primary uranium minerals disseminated in that rock. Accessory zircon and monazite are the only radioactive minerals found in the 

relatively unaltered granite. 

6 

CONCLUSIONS 

It is concluded that possibilities for high-grade 

uranium ore in the areas investigated on the Seward 

Peninsula during 1951 occur mainly at Brooks 

Mountain, where zeunerite is. found in quartz-tourmaline veins and disseminated in an altered granitic 

zone. Continued routine check, however, will be 

made in the Lost River area where underground 

exploration of tin-bearing deposits will expose at 

depth mineralized dikes which at the surface contain 

0. 01 percent equivalent uranium locally and average 

0. 005 percent equivalent uranium. Although radiometric traversing in the Peace River area failed to 

locate a possible high-grade source of uranothorianite 

found in placers, this lead is by no means exhausted 

and private prospecting should be encouraged. 

The source of the uranium in the zeunerite at 

Brooks Mountain is problematical. The mineral has 

been tound at only two places, and although other 

sites on the mountain are geologically similar to the 

zeunerite-bearing sites in almost every respect, they 

were devoid of zeunerite. Most of the many quartztourmaline veins on the mountain contain only a very 

small amount of radioactive material, and no other 

red oxidized zones are more than moderately radioactive. The restriction of the zeunerite to two 

localities indiCates that the uranium may have been 

derived from one or two local primary sources within 

the granite. 
PART 2. --ALASKA RAILROAD-ILIAlVINA REGION 

By Gene E. Tolbert and Arthur E. Nelson 

ABSTRACT 

Radiometric reconnaissance in several districts 

of the Alaska Railroad-Iliamna region during 1951 

found no radioactive material in excess of 0. 002 percent equivalent uranium associated with certain lode 

deposits that ¢e'Jiously were deemed favorable for 

the occurrence of uranium because they contain mineral assemblages similar to uranium-producing lodes 

elsewhere. 

Examination of two prospects in the Fairbanks 

district, upper Yukon region, failed to reveal any 

uranium deposits of commercial importance, although 

argentiferous galena containing up to 0. 01 percent 

equivalent uranium occurs in one prospect. 

INTRODUCTION 

Wedow and others (1951) indicated that several 

areas in districts of the northern part of the Alaska 

Railroad-Iliamna region (fig. 2) warranted investigation 

for uraniferous materials because the mineralogy of 

certain lode deposits of these districts is similar to 

that of known uranium-producing districts elsewhere. 

These favorable lode deposits are as follows: 

1) Silver-lead ores in the Kantishna Hills, 

Kantishna district. 

2) 

3) 

5) 

Silver-copper-zinc ores in the Mount 

Eielson area, Kantishna district. 

Gold-arsenopyrite-bismuth and other 

mineralization in the Nenana district. 

A siiver lode and complex gold-sulfide 

ores in the Chulitna district. 

Hematitic copper deposits in the Iron 

Creek area, Talkeetna district. 

In the summer of 1951 radiometric reconnaissances 

were completed on all the deposits listed above except those in the Chulitna district. Examination of 

the Iron Creek area in the Talkeetn.a district was 

accomplished with helicopter support furnished by 

the U. S. Army, 30th Engineer Base Topographic 

Battalion. 

Also included in this report are data on radiometric examinations of the Anderson and Lindgren7 

Fultz prospects in the Fairbanks district, upper 

Yukon region. The examinations of the two Fairbanks district prospects were requested by the 

Atomic Energy Commission and the Defense Minerals 

Administration for region I, respectively. The 

information on the Fairbanks district was supplied 

to the authors by other members of the Alaskan 

Trace Elements Unit. 

DISCUSSION OF DATA 

No radioactive material in excess of 0. 002 

percent equivalent uranium was found in the deposits 

examined in the Kantishna, Nenana, and Talkeetna 

districts of the Alaska Railroad-Iliamna region. 

Data on these deposits are presented in table 2. 

No radioactive material was found during 

1951 in deposits previously deemed favorable for 

uranium in the Alaska Railroad-Iliamna region. 

Yet to be examined are the Mint silver lode on 

Po:.:tage Creek east of the Alaska Railroad in the 

Chulitna district and the belt of complex gold-sulfide 

lodes west of the Railroad, also in the Chulitna 

district. This belt extends from Costello Creek 

to Long Creek, and reappears on Ohio Creek to the 

southwest. It includes such properties as the Read~' 

Cash, Copper King, Lindfors, Golden Zone, Silver 

King, and Eagle prospects. 

Examination of the Anderson and LindgrenFultz prospects in the Fairbanks districts failed to 

reveal any commercial occurrences of uranium 

minerals, although samples of argentiferous galena 

containing up to 0. 01 percent equivalent uranium 

were found in the Lindgren- Fultz prospect. Pertinent data on these two prospects are also given in 

table 2. 

CONCLUSIONS 

It is concluded from reconnaissance during 

1951 that no high-grade uranium deposits occur in 

association with certain lode deposits ot the Kantishna, 

Nenana, and Talkeetna districts of the Alaska Railroad-Iliamna region previously thought to be favorable for the occurrence of uraniferous materials. 

Further reconnaissance in these districts, ·therefore, 

is not warranted unless the results of private prospecting or further search cf the literature changes 

the outlook for the districts. Yet to be investigated 

in the northern part of the Alaska R8.ilroad-Iliamna 

region, however, are several favorable lode areas in 

the Chulitna district. 
EXPLANATION 

• Areas investigated 

B P Kantishna silver-lead prospects 

BQ Mount Eielson area 

BR Liberty Bell mine and California 

Creek prospects 

C E Iron Creek area 

KANTISHNA 

YENTNA 

106- MILES 

' '--•? 

FAIRBANKS -

FAIRBANKS r ~" 

" 

I 

I , __ ~­

(' 

;' 

VALDEZ CREEK 

INDEX MAP 

,-

Figure 2. --Districts of the northern part of the Alaska Railroad-Iliamna region 
co 

Table 2.--Data on localities examined in the Alaska Railroad-Iliamna region during 1951 

Locality 

Kantishna Hills area, 

Kantishna district 

(locality BP, fig. 2). 

Mount Eielson area, Kantish- na district (locality BQ, 

fig. 2). 

Liberty Bell mine and California Creek prospects, 

Nenana district (locality 

BR, fig. 2) 

Iron Creek area, Talkeetna 

district (locality CE, 

fig. 2) 

Anderson prospect, Fairbanks district. 

Lindgren-Fultz prospect, 

Fairbanks district. 

Geology 

Quartz fissure veins in preCambrian Birch Creek 

schist. 

Devonian argillite, limestone, .slate,and schist 

intruded by granodiorite; ore occurs as replacement bands in calcareous rock. 

Quartz stringers in preCambrian Birch Creek 

schist and Paleozoic(?) 

Totatlanika schist. 

Andesite flows of unknown 

age and Triassic sedimentary rocks intruded by Mesozoic granodiorite; ore occurs as banded replacements in andesite. 

Sheared quartz vein in 

granitic rock. 

Quartz-carbonate veins along fracture systems in a highly weathered granitic rock. 

Mineralogy 

Silver-bearing galena and tetrahedrite, pyrite, arsenopyrite, sphalerite, and chalcopyrite, 

with malachite, azurite, and 

limonite in oxidized portions of 

veins. 

Chalcopyrite, galena, sphalerite, pyrite, and arsenopyrite 

in quartz-epidote gangue; the 

galena and sphalerite contain 

silver in solid solution. 

At Liberty Bell mine--arsenopyrite with minor amounts of 

pyrite, chalcopyrite, bismuthinite, and free gold in 

quartz gangue; at California 

Creek prospects--stibnite, py- rite, and chalcopyrite at one prospect, and silver-bearing 

galena at other prospect; quartz 

gangue at both prospects. 

Chalcopyrite, pyrite, and specular hematite with minor amounts 

of arsenopyrite, bornite, 

azurite, malachite, limonite, 

and quartz. 

Gold and several of the common sulfides. 

Argentiferous galena, limonite, 

quartz, and carbonate minerals. 

Background 

reading 

2 on 2.0 

scalel 

2 on 2.0 

scalel 

2-4 on 2.0 

scalel 

2-4 on 2.0 

scalel 

12-15 on 2.0 

scale2 

2-3 on 2.0 

scalel 

4-5 on 2.0 

scalel 

lusing a 2- by 20-in. gamma probe attached to a portable survey meter. 

2using a probe consisting of six 2- by 40-in. gamma tubes attached to a portable survey meterfor airborne traversing. 

Equivalent 

uranium 

(percent) 

0.001 or less 

Less than 0.001 

.002 or less 

.002 or less 

Less than o.oo6. 

Less than 0.01; 

locally to 

0.025 in weathered pockets. 
PART 3. --GULF OF ALASKA REGION 

By Arthur E. Nelson and Gene E. Tolbert 

ABSTRACT 

No radioactive material in excess of 0. 002 percent equivalent uranium was found durin1} 1951 in a 

reconnaissance of possibly favorable lode deposits 

in the Nuka -Bay, Moose Pass-Hope, and Girdwood 

areas of the Gulf of Alaska region. 

INTRODUCTION 

In an appraisal of the uranium possibilities of 

Alaska, (Wedow and others, 1951) lode deposits of 

several districts in the Gulf of Alaska region 

(fig. 3) appeared to warrant examination for radioactive materials, as these deposits contain mineral 

assemblages similar to certain types of uranium 

deposits elsewhere. These lode deposits in the Gulf 

of Alaska region were the silver-lead lode on Eagle 

River in the Anchorage district, the silver-bearing 

galena-pyrite-arsenopyrite-quartz fissure veins at 

Nuka Bay on the south coast of the Kenai Peninsula 

(Nuka district), and a reported occurrence of fluorite in auriferous quartz-sulfide veins on Passage 

Canal in the Wells district. 

Radiometric reconnaissance completed in the 

Gulf of Alaska region during the 1951 field season 

was as follows: 

1) Examination of metalliferous lodes at 

Nuka 'Bay and radiometric traversing 

by small boat of rocks exposed along 

most of the shore of Nuka Bay (locality 

CB, fig. 3). 

2) Examination of many lodes in the Moose 

Pass-Hope area including the silver-lead 

deposit on Bear Creek; carborne radiometric traverses were made of roads and 

trails, and airborne (helicopter) traverses 

were made of otherwise inaccessible localities; all traverses, however, being incidental 

10 

to the investigation of the lodes (locality 

cc, fig. 3). 

3) Examination of lode deposits in the Girdwood 

area including an unsuccessful search for the 

silver-lead prospect on Eagle River and airborne (helicopter) traversing of many 

inaccessible mineralized and oxidized 

zones incidental to transportation to and 

from ground investigations (locality CD, 

fig. 3). 

The helicopter support for these operations were 

furnished by the U. S. Army, 30th Engineer Base 

Topographic Battalion, with field headquarters at 

Seward. 

The investigation of the reported fluorite occurrence on Passage Canal was postponed until another 

field season because weather conditions would not 

permit airborne operations iri the Passage Canal area 

at a time when personnel and equipment were available for the reconnaissance studies in the Gulf of 

Alaska region. 

DISCU$SION OF DATA 

No radioactive material of significance was 

found in the course of reconnaissance investigations 

in the Gulf of the Alaska region during 1951. A 

summary of such data as were obtained is given in 

table 3. 

CONCJ,USIONS 

In conclusion, the mineral assemblages at the 

lode deposits examined in the Gulf of Alaska region 

during 1951 do not appear to be favorable for the 

occurrence of high-grade uranium ores. No further 

work in the areas examined is warranted unless the 

results of private prospecting develops positive 

information on the uranium possibilities of these 

areas. 
f---' 

f---' 

N 

EXPLANATION 

- Areas investigated 

C B N uka Bay area 

CC Moose Pass-Hope area 

CD Girdwood orea 

CORDOVA 

0 50 100 MILES 

I I I I I I I 

~ ~ 

I 

r 

I 

I 

l 

Figure 3. --Districts of the eastern and central parts of the Gulf of Alaska region 

\ 

I 

I 

\ 

I 

INDEX MAP OF ALASKA 

' 

\ 

\ 

I 

\ 
I-' 

()V 

Table 3.--Data on localities examioed in the Gulf of Alaska region during 1951 

Locality 

Nuka Ba¥ area, Nuka district ~locality CB, 

fig. 3) 

Moose Pass-Hope area, 

Hope district, locality 

cc, fig. 3) 

Girdwood area, Anchorage district (locality CD, 

fig. 3) 

GeolO£Y 

Quartz fissure veiris in 

Mesozoic slates arrd gray- wackes. -

Quartz fissure veins and 

mineralized acid dikes in 

Mesozoic slates and gray- wackes. 

Fissure veins in an argil- lite and graywacke series on Mesozoic age asso- ciated with quartz diorite 

dikes, sills, and plugs. 

Mineralogy 

Gold, silver, copper, pyrite arsenopyrite, chalcopyrite, sphalerite, galena, covellite, 

tetrahedrite, chalcocite; gangue includes quartz. 

Gold, silver, arsenopyrite, py- rite, galena, sphalerite, chalcopyrite, pyrrhotite, mo- lybdenite;gangue includes quartz. 

Gold, silver, pyrite, arseno- pyrite, marcasite, sphalerite, galena, chalcopyrite, molybdenite; gangue includes quartz. 

lusing a 2- by 20-in. gamma probe attached to a portable survey meter. 

2using a probe consisting of six 2- by 40-in. gamma tubes attached to a portable survey meter. 

Background 

reading 

l-3 on 2.0 

scalel 

10-12 on 2.0 

scale2 

2-4 on 2.0 

scalel 

11-14 on22.0 

scale 

2-3 on 2.0 

scalel 

12-15 on 2.0 

scale2 

Equivalent 

uranium 

{percent) 

0.002 or less 

.002 or less. 

Less than 0.002. 
PART 4. --SOUTHEASTERN ALASKA 

By Joseph R. Houston 

ABSTRACT 

Radiometric reconnaissance during the summer 

of 1951 o.f 47 abandoned lode mines and prospects 

in the predominantly mesothermal mineral belt in 

the central and southerri parts of southeastern Alaska 

revealed radioactivity in excess of 0. 005 percent 

equivalent uranium at only one locality. In the 

vicinity of Salmon Bay on the northeastern end of 

Prince of Wales Island several narrow, steeplydipping, carbonate-hematite veins contain up to 

0. 07 percent equivalent uranium. No uranium minerals have been identified yet, and laboratory tests 

for uranium ·are negative or only weakly positive. 

INTRODUCTION 

Alaskan uranium possibilities, as appraised 

by Wedow and others (1951) included a number of 

areas in southeastern Alaska (fig. 4) in which the 

mineral assemblages of various lode deposits are 

similar to those characteristic of uranium deposits 

in other parts of the world. Many of these areas 

were visited during the summer of 1951. Investigations were concentrated in the central and southern 

districts of southeastern Alaska (fig. 4) because it 

was thought that the mesothermal mineral deposits 

there were more likely to contain conventional 

uranium deposits than the higher temperature goldquartz deposits in the Juneau and Chichagof districts 

to the north. 

The field party engaged in these reconnaissance 

investigations consisted of J. R. Houston, geologist, 

and D. L. Norton, field assistant. Pertinent information on the Salmon Bay area, the north end of 

Kuiu Island, and the Union Bay "carnotite" occurrence was furnished to the party by memb~rs of the 

Territorial Department of Mines through Leo H. 

Saarela, Territorial Commissioner of Mines. 

A. E. Glover, Territorial Department of Mines 

assayer-engineer at Ketchikan, accompanied the 

party in the reconnaissance of the Salmon Bay area 

and the Union Bay "carnotite" occurrence. 

Radiometric traversing in the areas investigated was done with standard makes of portable 

survey meters equipped with interchangeable probe 

attachments consisting of 2- by 20-in. gamma and 

6-in. beta-gamma tubes. A gang probe of six 

2- by 40-in. gamma tubes, connected in parallel, 

and also interchangeable with the other probes used 

on the portable survey meters, was used for shoreline traverses by small boat. This large probe was 

13 

also used for airborne traversing, incidental to 

flying for transportation and other reconnaissance 

purposes. The background readings in the areas 

investigated were approximately 2-4 divisions on the 

2. 0 scale for the portable survey meters when using 

the 2- by 20-in. gamma probe, and 2-4 divisions on 

the 0. 2 scale when using the 6-in. beta-gamma probe. 

DISCUSSION OF DATA 

A total of 47 abandoned mines and prospects 

was visited. The mineral association in some of 

them is so similar that for the purpose of this summary they have been consolidated into 16 areas. The 

pertinent data on each area are summarized in table 

1, and the location of each area is shown on figure- 4. 

All 16 areas are indicated in the above-mentioned 

appraisal of Alaskan uranium possibilities as being 

favorable for the occurrence of uranium. 

No radioactive material in excess of 0. 005 percent equivalent uranium was found in southeastern 

Alaska during 1951 except in samples taken from 

narrow, steeply-dipping, carbonate-hematite veins 

in the Salmon Bay area (locality CA, table 4, and 

fig. 4). These samples contain up to 0. 07 percent 

equivalent uranium. Most of the veins are less than 

5 in. wide, but at one locality about 3/4 mile north 

of the mouth of Salmon Bay, a vein 6- to 10-ft wide 

is exposed for more than 100 yd. The vein material 

consists chiefly of carbonate gangue but also contains 

small amounts of red hematite, specular hematite, 

and pyrite, and locally, purple fluorite, feldspar, 

chalcedony, mica, galena, chalcopyrite(?), an unidentified green micaceous mineral, and an unidentified yellowish-white mineral. No radioactive minerals have yet been identified in the vein samples; 

it is likely that the radioactive elements may be 

proxying for iron in the hematites or carbonates. 

The reported occurrence of "carnotite" at Union 

Bay on the Cleveland Peninsula (locality BT, table 4 

and fig. 4) is presumed to be in error. The 11 carnotite" sample, submitted to the Ketchikan Assay Office 

of the Territorial Department of Mines and examined 

there by the author in June 1951, proved to be 

coaly material containing tyuyamunite. The uranium 

content of the sample was estimated to exceed 1 percent. As mafic and ultramafic rocks, and low- to 

middle-grade metamorphic· rocks constitute the bed..; 

rock in the vicinity of Union Bay, the geology of the 

area is not favorable for the occurrence of tyuyamunite 

in association with coal material. More likely, the 

tyuyamunite specimen has been "imported" in a 
N 

1 

INDEX MAP OF ALASKA 

.. 

BT 

BU 

BV 

BW 

BX 

BY 

BZ 

CA 

CF 

CG 

CH 

CN 

co 

CP 

CQ 

CR 

0 

EXPLANATION 

Areas Investigated 

Union Bay "carnotite" 

Gravina Island 

Niblack Anchorage area North Arm Moira Sound 

Dolomi area 

Cholmondeley Sound .area 

George Inlet 

Salmon Bay area 

Groundhog Basin 

Thomas Bay 

Kuiu Island 

Helm Bay 

Duncan Canal 

Woewodski Island 

Zaremba Island 

Kasaan Peninsula 

10 20, 30 MILES 

Figure 4. --Districts of the central and southern parts of southeastern Alaska 

shipment of coal from western United States or 

British Columbia to an old salmon cannery site which 

is located about 300 ft from the spot where the uraniferous sample was reported to have been found. 

CONCLUSIONS 

The supposedly favorable areas in southeastern 

Alaska examined during the summer of 1951 apparently have no potentialities for the occur:rence of highgrade uranium ores except for the Salmon Bay area 

on Prince of Wales Island. Further reconnaissance 

is needed in the vicinity of Salmon Bay before the area 

can be either designated as a potential uranium 

district or eliminated from future consideration. Also, 

yet to be investigated are favorable silver-bearing 

lodes on Whiting River and at Point Astley in the 

northern part of southeastern Alaska, and an occurrence of pitchblende(?) in the Hyder district recently 

reported by the Territorial Department of Mines. 

REFERENCE CITED 

Wedow, Helmuth, White, M. G., and Moxham, R. M., 1951, Interim report on an appraisal of the uranium possibilities of Alaska, (Trace Elements Memorandum Rept. 235 in open files of U. S. Geol. Survey). 

14 
1-' 

CJl 

Locality 

George Inlet (locality BZ, 

fig. 4) 

Gravina Island (southern 

end) (locality BU, fig. 2) 

Helm Ba¥ (locality CN, 

fig. 4) 

Union Bay "carnotite" 

(locality BT, fig. 4) 

Niblack Anchorage area (locality BV, fig. 4) 

Table 4.--Data on localities examined in southeastern Alaska during 1951 

Geology Mineralogy 

Ketchikan district 

One deposit is a mesothermal 

fissure vein in black phyllite 

close to a granite contact; the 

other deposit is a fairly hightemperature filling and replacement in black phyllite, close to a granite contact, and closely 

associated with a garnet-rich 

"aplite" dike. 

Mesothermal filling and replacement along shear zones in andesitic metavolcanic rocks, volcanic 

breccias, "granite", and rhyo- lite. 

Mesothermal filling and replacement along a well-defined fracture zone in green schist and 

greenstone. 

Low- to middle-grade metasedimentary rocks, mafic and ultramafic rocks. 

Pyrite, sphalerite, galena, chalcopyrite, pyrrhotite, "limonite", traces of 

secondary copper minerals; gangue includes quartz, carbonate, alkali 

feldspar, chlorite, sericite, biotite, 

garnet, graphite, green muscovite. 

Pyrite, specular hematite, chalcopyrite, 

bornite(?), "limonite", malachite, 

azurite, chrysocolla, barite, witherite(?); gangue minerals are quartz with some carbonate. 

Pyrite, chalcopyrite, gold; gangue includes quartz, sericite, talc, and 

graphitic material. 

No ore deposits found; sample submitted 

to Territorial Department of Mines as from Union Bay consists of tyuyamunite 

in coaly material with a uranium con- tent estimated to exceed l percent. 

Wales district 

Fairly high-temperature replacement deposit in greenstone, green 

schist, and other metasedimentary 

rocks. 

Pyrite, magnetic specular hematite, 

chalcopyrite, sphalerite, galena(?), 

seconaary copper minerals; gangue includes quartz with some carbonate and 

jasper. 

Equivalent uranium 

(percent) 

Less than 0.001. 

Less than 0.001; 

locally up to 

0.005 in felsic 

volcanic rocks. 

Less than 0.001. 

Less than 0.001. 

Less than 0.001. 
a; 

Table 4.--Data on localities examined in southeastern Alaska during 1951--Continued. 

Locality 

North Arm, Moira Sound (and 

Dora Lake area) (locality BW, fig. 4) 

Dolomi area (locality BX, 

fig. 4) 

Cholmondeley Sound area (includes Kitkun Bay) (locality BY, 1'ig. Ll-) 

Kasaan Peninsula (locality CR, fig. 4) 

Salmon Bay area (locality C 

CA, f;ig. 4) 

Zaremba Island (locality CQ, fig. 4) 

Geology Mineralogy 

Wales district (continued) 

Mesothermal filling and replacement deposits along shear and 

breccia zones in argillaceous and siliceous limestones and 

marbles interbedded with thin 

green schists. 

Mesothermal filling and replacement in siliceous and argilla- ceous limestone. 

Mesothermal fLlling along a welldefined fault cutting argilla- ceous and siliceous limestone 

and green schist. 

Mainly contact metamorphic deposits near the contact of 

dioritic, and granodioritic stocks with graywacke, slate, 

and impure limestone; also one magmatic segregation deposit and one mesothermal fissure vein. 

Mesothermal fissure veins 

cutting graywacke, sandstone, 

shale, and limestone breccia; 

mafic and felsic dikes also 

cut these sedimentary rocks. 

Sphalerite, pyrite, chalcopyrite, 'galena, 

oxidized copper minerals; gangue includes quartz and carbonate. 

Pyrite, tetrahedrite, chalcopyrite, galena, "limonite", malachite, azurite, 

gold; gangue includes quartz with some carbonate, chlorite, sericite, and clay minerals. 

Small amounts of pyrite, chalcopyrite, 

galena sr.ecular hematite(?), sphale- rite(?~, 1

limoni te", traces or' secondary copper minerals; gangue includes 

quartz with some carbonate, sericite, 

and clay minerals. 

Magnetite, pyrite, chalcopyrite, spec- ular hematite, bornite, molybdenite(?), "limonite", covellite, malachite, 

azurite; gangue includes epidote, garnet, calcite, hornblende, quartz, feldspar, chlorite, and talc(?). 

Red hematite, specular hematite, pyrite, galena, chalcopyrite(?), "limonite"; 

gangue includes carbonates with minor 

purple fluorite, feldspar, and mica. 

Wrangell district 

Epithermal fillings along small 

shears cutting basaltic, andesitic, and rhyolitic volcanic 

rocks. 

Colorless, white, green and purple fluorite, and fine-grained pyrite; 

gangue includes carbonate, qhalcedony, and quartz. 

Equivalent uranium 

(percent) 

less than 0.001. 

Less than 0.001. 

Less than 0.001. 

Less than 0 .001. 

Up to 0.07. 

Less than 0.001; 

locally up to 

0.005 in felsic 

volcanic rocks. 
~ 

Groundhog Basin (includes 

Glacier Basin and Lake 

claims) (locality CF, 

fig. 4) 

Thomas Bay (locality CG, 

fig. 4) 

Woewodski Island (locality 

CP, fig. 4) 

Duncan Canal (locality CO, 

fi,g. 4) 

Kuiu Island (includes 

Saginaw Bay and Keku Islets) 

(locality CH, fig. 4) 

Wrangell district (continued) 

In Groundhog and Glacier Basins 

the ore occurs in high-temperature replacement veins in 

schists and gneisses that are cut by aplite, quartz porphyry, 

and granite sills and dikes; at 

the Lake claims the ore occurs in a mesothermal fissure vein in 

phyllite; all of the mineralized areas are very close to a quartz diorite stock. 

Pyrrhotite, dark sphalerite, galena, pyrite, chalco~yrite, molybdenite, 

pyromorphite(?), "limonite"; gangue 

includes quartz, biotite, hornblende, 

chlorite, epidote, pyroxene, actinolite, garnet, and apatite. 

Petersburg district 

Mesothermal fis~ure vein along a well-defined fault which cuts 

quartz-biotite-hornblendemuscovite-garnet schist and 

gneiss. 

Pyrite, arsenopyrite, chalcopyrite, pyrrhotite(?), ''limonite", trace of 

secondary copper minerals; gangue includes quartz with graphitic seams. 

Kupreanof district 

Mesothermal filling with some re- placement in andesitic lava, 

schist, slate, and graywacke. 

Mesothermal replacement in schisttose chert and andesitic volcanic rocks. 

Epithermal filling and replacement in andesite, rhyolite, basalt, 

basalt, graywacke, conglomerate, 

sandstone, slate, phyllite, limestone, and dolomite. 

Pyrite, chalcorryrite, galena, sphalerite, chrysocolla, 'limonite"; gangue includes 

quartz with some carbonate. 

Barite, scattered pyrite, traces of 

sphalerite, galena, magnetite; gangue 

includes quartz and graphite. 

Barite, witherite, sphalerite?! pyrite, marcasite, galena, "limonite', manga- nese oxides; gangue includes calcite, 

quartz, chalcedony, and clay minerals. 

Less than 0.001. 

Less than 0.001. 

Less than 0.001. 

Less than 0.001. 

Less than 0.001; 

locally up to 

o.oos. 

INT .-DUP. SEC., IIASH., D.C. 2 B ~ 4