Reconnaissance for radioactive deposits in Alaska, 1953

Matzko, John J., Bates, Robert G. · 1955 · Report

During the summer of 1953 the areas investigated for radioactive deposits in Alaska were on Nikolai Creek near Tyonek and on Likes Creek near Seward in

This 1955 document, Reconnaissance for radioactive deposits in Alaska, 1953, is preserved in the Mountain Man Mining Library for research and reference. Original source: pubs.usgs.gov.

(Qoo) Reconnaissance for radioactive deposits in Alaska, 195 3 By J. J. Matzko and R. G. Bates

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A - · ' "· . , t Trace Elements Investigations Report 442 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY

OFFTC IAL USE ONLY Geology and Mineralogy This d oeumen t consists of 29 pages Series A UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY RECONNAISSANCE FOR RADIOACTIVE DEPOSITS IN ALASKA, 1953 By John J. Matzke and Robert G. Bates October 1955 21 1955 U. S. GfOUFGfCAt StmVEY Trace Elements Investigations Report 44 (;vuJ. CAUTION Information contained in this document has been furnished in confidence by all prospectors concerned and shall be handled accordingly within the USGS . ani AEC. The material herein shall not be published without the approval of all prospectors concerned and the u. s. Geological Survey. This prelimin~r.y report is distributed without editorial and technical review for conformity with official standards and nomenclature. It is not for publie inspection or quotation. -~This report concerns work done on behalf of the Division of Raw Materials of the U. s. Atomic Energy Commission. OFFICIAL USE ONLY

OFFICIAL USE ONLY USGS - TEI-442 GEOLOGY AND MI NERALOOY Distribution (Series A) Division of Raw Materials, Denver. o o o o

Division of Raw Materials, Salt Lake Cit.f. o

o Division of Raw Materials, Washington.

o Exploration Division, Grand Junction Operations Office o

Grand Junction Operations Office o

o o u. s. Geological Surveyg Geochemistry and Petrology Branch, Washington. o

Geophysics Branch, Washington. o o

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Mineral Classification Branch, Washington. o

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Mi..11eral Deposits Branch, Washington. o

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A. L. Brokaw, Grand Junction o o

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v. L. Freeman, ?airbanks o o R. s. Velikanje, Juneau o

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TEPCO, Denver o o

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OFFICIAL USE ONLY CONTENTS o o o Introduction.. .. o

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o o Ar eas investigated o o o o o Tyonek area o o o o o

Likes Creek area. o

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o Miller House-Circle Hot Springs area. o

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Gold Bench area o

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o o o Peace River area. o o

Port Malmesbury area. Summar.y and conclusions o

Literature cited

ILIDSTRATIONS Figure 1. Index map of Alaska showing areas examined, 1953 2. Map of part of the Tyonek quadrangle, south-central

Map of the Likes Creek area, Resurrection Peninsula, o

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Map of the Miller House-Circle Hot Springs area, Page Circle quadrangle, Alaska o o

Geologic sketch map of the Gold Bench area, eastcentral Alaska o

Sketch map of headwaters of the Peace River, Candle quadrangle, Seward Peninsula, Alaska o

o Geologic sketch map of Port Malmesbury area, Kuiu

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Table

Table 1. Equivalent arid chemical uranium analyses of samples collected in 1953 o o

Official Use Only

OFFICIAL USE ONLY RECONNAISSANCE FOR RADIOACTIVE DEPOSITS IN ALASKA 9 1953 By John J o Matzko and Robert Go Bates ABSTRACT During the summer of 1953 the areas investigated for radioactive deposits in Alaska were on Nikolai Creek near Tyonek and on Likes Creek near Seward in south-central Alaska where carnotite-type minerals had been reported3 in the headwaters of the Peace River in the eastern part of the Seward Peninsula and at Gold Bench on the South Fork of the Koyukuk River in east-central Alaska, where uranothorianite occurs in placers associated with base metal sulfides and hematite; in the vicinity of Port Malm.esbury in southeastern Alaska to cheek a reported occurrence of pitchblende; and, in the Miller House..Cirele Hot Springs area of east-central Alaska where geochemical studies were made. No significant lode deposits of radioactive materials were found. However, the placer uranothorianite in the headwaters of the Peace River yet remains as an important lead to bedrock radioactive source materials in Alaskao 'fa.ndra cover prevents satisfy~tory radiometric reconnaissance of the area~ and methods of geochemical prospe~ting such as soil and vegetation sampling may ultimately prove more f:rui tfu.l in the search for the uranothoriani te-sulfide lode source than geophysical methods. INTRODUCTION The chief objective of reconnaissance for radioactive deposits in Alaska~ conducted by the Geological Survey on behalf of the Division of OFFICIAL USE ONLY

OFFICIAL USE ONLY Raw Materials of the u. s. Atomic Energy Commission, is the discovery-of high-grade uranium ores. During the field season of 1953 attempts were made to locate reported occurrences of carnotite-type minerals Nikolai Creek near Tyonek and on Likes Creek near Seward in south-central Alaska (Wedow and others, 1952, 20-23, 37-38) and to search for the bedrock sources of uranothorianite associated with base metal sulfides and hematite in placers at the headwaters of the Peace River in the eastern Seward Peninsula (Gault and others, 1953, Po 28-31) and on the South Fork of the Koyukuk River in east-central Alaska (Nelson a:nd others, 1954, Po 48). In addition, a brief search was made for pitchblende reported by a prospector in the vicinit,r of Port Malmesbury, southeastern Alaskao Further search for the bedrock source of uranium in the Miller ~'iiouse..Cirele Hot Springs area of east-central Alaska {Nelson and others, 1954, Po 29-38) was made by using the geochemical prospecting techniques of soil and water sampling (See fig. 1.) The instruments used to detect radioaetivity during the 1953 field season consisted of standard commercial portable Geiger counters modified to accept a variety of probes. (See WedowJl 1951.) Portable scintillation counters were also used. Some of the latter were modified to take re~ cording devices which would permit the observer to obtain a permanent continuous record of variations in radioactivity; this modification was used mostly in airborne and carborne traverses. OFFICIAL USE ONLY

1 15cf Barrow E:lHHHY L I !- JO() 140° FIGURE 1.--INDEX MAP OF ALASKA SHOVv iNG AREAS EX AMINED, 1953 EXPLANATION Areas examined A Tyonek area (fig. 2) B Likes Creek (fig. 3) Miller House-Circle Hot Springs area (fig. 4) D Gold Bench (fig. 5) E Peace River (fig. 6) F Port Malmesbury, Kuiu Island (fig. 7)

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OFFICIAL USE ONIJ:' AREAS INVESTIGATED Tyonek area Samples of limestone containing metatyuyamu.nite, submit·tted in the summer of 1951 to the Geological Survey by H. N. Fowler, a prospector from An~homage, contain as much as 0.92 percent u.ranimn. As originally reported i n 1951 (Tolbert and Nelson, 1951, Po 6 and table 1) the Fowler prospect was thought to be in the Yentna River drainage and north of the mouth of the Skwentna Rivero Additional information obtained by Fowler in the spring of 1952 placed the location of the samples on the Deshka River, about 25 miles south-southwest of Talkeetna. The D~shka site was examined by Nelson (Wedow and others, 1952, p. 20) in 1952 but no uraniferous deposits were found. Further inquiries by Fowler and his associates indi~ated that the samples we·re found in the fall of 1949 by Max Chiekalusian of Tyonek. The location was given as the north side of the valley of a left-limit tributary of Nikolai Creek, 16 miles northwest of 'l'yonek. (See figo 2.) An attempt by Wedow, Fowler and Chiekalusian to visit this site in October 1952 was unsuccessful due to adverse weather c0nditions which also made it unsafe to approach sufficiently close to the site to conduct airborne radioactivity traverses from a light plane. In June 1953, Wed ow and Bates accompanied by Fowler, made another attempt to locate the source or the samples but were again unsuccessful, chief~ because the nearest poin·t of access by light plane to the prospect was a small lake more than 6 miles to the swtheast and the OFFICIAL USE ONLY

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Gr·anrtt> Pt FIGURE 2.--MAP OF PART OF THE TYONEK O UADRA NGLE,SOUTH-cENTRAL ALASKA Showing location of Fowler carnotite prospect

) EXPLANATION Site from which original samples of carnotite-bearing I imestone ore reported to hove been collected in 1949 Other sites at which carnotite is reported to occur 5 M l, c r- -·

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OFFICIAL USE ONLY intervening terrain consisted of rough glacial moraine CtCYvered by a dense growth of alder and numerous beaver ponds (fig. 2) o No uraniferous limestone or other radioactive material was fwnd in. the several hours spent on the ground in the prospect areao Airborne radioa~tivity traverses over the area did not locate

anomalies; and Chieka.lucian., who accompanied Wedow in the airborne work, was unable to recognize the precise spot from. which he had obtained the samples. In view of these factors and the difficulty of aeeess to the prospect area, it was decided therefore to curtail investigations until such time as a precise location was given, or helicopter support for a ground party would be available. The project rill be reopened should Fowler obtain additional samples from the area or if helicopter support ean be assured for a period of three to faur weeks, probably in C(')Operation with the Topographic Division of the Geological Survey. Chiekalusians description of the outcrop (locality 2, figo 2) from which the samples were taken indicated that it is approx:imately So feet long and 10 feet thicko He descri.bed the ttyellow rook" to be i.n long lenses as much as 3 inches thiek between thin beds of limestone. Laboratory studies on the available samples have shown that the carnotite is also disseminated in the li.mestoneo (See Wedow and others.P 1952.) No limestone was reported near Nikolai Creek by Geolo gieal Survey reconnaissance parties that passed through the area in 1927 and 1928 (Capps p 1935) o According to Capps (1935) the bluff along the northeast side of Nikolai Creek is composed of Eoeene clay 1 sand and gravel_, and, locally, tuff' and ligniteo These are overlain, in part by Quaternary OFFICIAL USE ONLY

OFFICIAL USE ONLY glacial deposits To the west on the eastern flank of Mount Spurr gneissic granite of Mesozoic age is partially overlain by Tertiary lavas ' and tuff. The anly reported limestone in the general Mount Spurr re gi.on

·'· i s to the west or Mount Spurr in the drainage of the Igitna and Chilligan Rivers.. It is described as a gray, crystalline, thin bedded limestone associated with metamorphosed shale and sandstone. These rooks, together with basaltic lava flows, are of Upper Jurassic or Cretaceous age, and are entirely hr nearly surrolUlded by granitic rocks ef late Mesozoic age. (See Capps, 1935.) Likes Creek area In September 1952, two samples of metatyayamu.nite-bearing sandstone were given to members of the Geological Survey by Marti.t""l Goreson through Russell R. Norton, both of Seward, , Alaskao Analysis of one of the samples indicates 1.5 percent equivalent uranium and 1. 7 percent chemical uranium. These samples were reportedly found in 1949 as float at the .foot of Spoon Glacier (locality 1, fi.g. 3). Spoon Glacier is located on the east side of the valley of Likes Cr-eek on the west side of . Resurrection Peninsula just north of Thumb Cove. In the late fall of 1952, two attempts were made t o locate the bedrock source of the metatyu.yamu.nite or to duplicate the previous samples. The bedrock source of the radioactive minerals was not found and the samples were not duplicated in the field 6 even though the Survey part.y was accompanied by Goreson and Norton on one trip. (See Wedow, and others, 19.52., Po 37-38.) · During July 19.53, Survey personnel spent fou.r days in the area to OFFICIAL USE ONLY

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N l , 'los e lr om Se w o r d , FI G URE 3. --MAP OF THE LIKE S CREEK AREA, RESURRECTION PENINSULA, ALASKA

OFFICIAL USE ONLY the source of the metatyu.ya.unite. This investigation was unsuo- ~essful an.d no anomalous radiation was detected by ground surveys. While in the area, Geological Survey personnel were accompanied by Fred Wo Richardson, a prospector from. Anchorage, who had. a " ~arnotite prospect on the mountain to the west of the divide between Likes Creek and Fourth of July Creek (locality 2, fig .3). Mro Richardson led the Geological Survey party to his prospect and upon examination the nn earnotite00 was found to be weathered yellow-green graywackeo According to Grant and Higgins (1909, 98-107) the bedrock on the west side of Likes Creek is composed. of graywacke with some slate. '!'he bedrock on the east side of Likes Creek is composed of lava flows altered to greenstone and contains several old copper prospects Miller House-Circle Hot Springs area Pla~er concentrates from Portage Creek, a north-flowing stream draining into Medicine Lake, in the vicinity of Circle Hot Springs (figo 4) were reported to contain as mu.ch as 0 oOX percent equivalent ·uranium (WedorA P White, and others, 1954, p. 4-6). Attempts to duplicate these samples in 19.52 were not successful (Nelson and others, 1954, water sample taken in 19.52 from Por·tage Creek, below Heine Carsten11 s :pla~er workings, contained 40.2 parts per billion uranium (Nelson and others 9 1954, Po 34). This is significantly high concentration as the average content of fresh waters is 0.1 part per billion uranium, (Irving May, oral communication). OFFICIAL USE ONLY

1~. S cole 19§1 MAG"' E.Tic l I NA T !Ol

J d rid e Sample location '. · WI,,

' ! :.. , j, . -I . FIGURE 4.--MAP OF THE MILLER HOUSE-ciRCLE HOT SPRINGS AREA, CIRCLE QUADRANGLE, ALASKA w

OFFICIAL USE ONLY Bedrock., plaeer and water samples were collected by the Geologi~al Survey reconnaissance party in this area in 1953o Only three samples were collected that contained more than 0.005 percent equivalent urani1.llllg sluice concentrates from Deadwood Creek and Portage Greek ~ontained Oo008 and Oo006 percent equivalent uranium respectively; and a sample of crushed granite from the divide between Portage Creek and Half Dollar Creek contained 0.007 percent equivalent uranium (table 1). A traverse made with a portable Geiger counter on the cleaned bedrock of Heine Carsten's placer ground did not indicate any radioactivit.r anomalies A small piece of granite rock with purple fluorite was found loose in the bedrock. Of the ten water samples collected for uranium analysis in the area in 1953 only two contained high concentrations of uranium (table 1). All of the 1953 samples taken for uranium ana~sis were collected in 500 milliliter po~ethylene bottles, but three samples analyzed for total heavy metal content were collected in l gallon pyrex bottles (table An attempt was made to duplicate the high uranium water sample which was collected in a pyrex 'bottle in 19.52. Also, to determine if a:ny appreciable loss in uranium occurred in samples not acidified, duplicate samp~> ,was ~ollected at one locality on Portage Creeko R., G. Milkey (1953, p. 12) has indicated that no uranium solution with a pH of less than h.2 (acidic) decreased significantly in concentration. He also states that for solutions of the same concentration greater losses o:f uranium occur in polyethylene bottles than in pyrex · bottles. This occurs because~ in addition to losses through ion exchange and hydro~sis~ uranium is also lost by Van der Waalns adsorption which OFFICIAL TJSE ONLY

OFFICIAL USE ONLY varies directly with the degree of roughness of the surface to which the uranium solutions are exposed. Polyethylene bottles have a rougherl' and hence a larger attracting surface and, therefore~ will tend to adsorb more uranium than the smoother surfaced pyrex containers. Thus, non-acidified samples that are allowed to stand in polyethylene bottles may give misleadingly low results. Milkey' s findings are apparently borne out by the analysis of the duplicate samples collected in polyethylene bottles on Portage Creek in 1953 o The analyses show that the sample (53AMz 7A) acidified with about 2 ml of concentrated hydrochloric acid contained 15 parts per billion uranium 'Whereas the non-acidified sample (53AMz 7B) contained 14 parts per billion uranium. This is a significant difference when it is noted that present fluorimetric analyses for uranium are sensitive to Ool part per billion. The difference in uranium content between the water samples containing 40e2 parts per billion uranium (1952) and 15 parts per billion uranium (1953) is probably due principally to the effects of the sluicing operation on Portage Creek, at the time of collection of the 1952 samples. West .(Nelson, and others, 1954, p. 34) has suggested that a possible explanation for the high uranium sample at Carsten's placer gold property is due in part to the sluicing operation which caused an increase of solids in suspension in the creek, and the probable more rapid solution of uraniferous material in the area. A water sample taken at Martin's workings on Portage Creek, a. mile and a half upstream from Carsten's workings contained only 1.7 parts per billion uranium The uranium eon tent of the water at Carsten's camp is about eight OFFICIAL USE ONLY

OFFICIAL USE ONLY times greater than at Martin's camp, which suggests that a source of uranium must lie along the drainage between the two camps. Further water sampling at regular i:ni;ervals between the two camps might aid materially in locating the source of the uranium. Gold Bench area A concentrate obtained in 1952 from gold-placer mining operations at Gold Bench (fig. 5) on the South Fork of the Koyukuk River contained 0.18 percent equivalent uranium. (See Wedow and others, 1953, p. 3.) Laboratory studies showed that the chief radioactive ~ineral is uranothorianite. As hematite and traces of gold, bismuth, copper, lead, tin, and tungsten minerals are associated with uranothorianite in the gravels at Gold BepchJ. it is believed that the radioactive miner~s may have been derived from a lode source in the drainage area above Gold Bench. The source of the gold mined from the gravels at Gold Bench is unknown, although Maddren (1913 1 Po 106) suggests that the source area of the gold is in the mountains on the south side of the South Fork of the Koyukuk River. The field party in the area during 1953 attempted to locate the lode source of the uranothorianite. Because of the wide-spread cover of tundra, gravel, and moss over most of the area, the method of testing placer concentrates for radioactivity, similar to that developed by West and Matzko (Gault and others, 1953, p. 21-27) on the eastern Seward Peninsula, was adopted to search for the source of the uranothorianite. Special attention was paid to those streams draining into the South Fork of the Koyukuk River from the south. Gravels from all streams draining into the South Fork for OFFICIAL USE ONLY

Scale 3 miles

1~51 MII~NE TIG <ION G eol ogy adapted from U. S. G. S. Bull. 532 FIGURE 5. --GEOLOGIC SKETCH M/JSJ OF THE GOLD OENCH AREA, EAST-cENTRAL ALASKA. LEGEND D QUATERNARY Silt, sand, gravel, c lay, Pl e isto - cene till and glacial outwash, Recent stream and residual deposits UPPER CRETACEOUS Sandstone, shale and conglomerate, I imestone, calcareous sandstone and arkose with some igneous rocl.-s MISSISSIPPIAN Slate, chert, I imestone and diabase with undifferentiated greenstone; inc ludes ultra-basic igneous rocks, tuffs, and alteration products e Sample location

Mining camp

OFFICIAL USE ONLY a distance of 7 miles upstream and 2 miles downstream were sampled. Neither the lode source of' the ura.nothorianite was located nor was any significant radioactivity noted Chemical determinations of three water samples from tributar.y streams in the Gold Bench area (table 1) indicate a high of Oo2 parts per billion uranium for one of the samples; and, the other two samples contain 0.1 parts per billion uranium. The uranium content is probably lower than normal for the streams sampled because heavy surface runoff caused by practically contifluous rain during the reconnaissance would tend to dilute the uranium content of the waters. Sample Noo :x-4 x. 7 Table lo--Equivalent and chemical uranium analyses of samples collected in 1953. oOOl oOOl ·ereent) chemical Deseri tion and location Port Malm.esbury Silieifi.ed graywacke with limonite and sulfides Diorite intrusive Replacement vein material of quartz and pyrite containing gold, silver, lead and zinc Silicified graywacke interbedded with marbleized limestone Mafic dike "Pods" containing pyrrhotite 3 specular hem~tite and chalcopyrite Diorite intrusive OFFICIAL USE ONLY

Sample No. 1;- h817 h821 ·4825 h827

53AMz 1 53AMz 4 53AMz 7A 53AMz 7B 53AM~ 12 .5.3AMz 17 53AMz 18 53AMz 20 53AMz 21 . .53AMz 22 OFFICIAL USE ONLY Table I.--Equivalent and chemical uranium analyses of samples collected in 1953-~Continuedo .ooB .ooh .oo6 .oo5 .ooh Deseri tion and location Miller House-Circle Hot Springs 0.3x1o-7 1. 7xlo-7 15xlo-7 J.hxlo-7 o.2xlo-7 3xlo-7 5xlo-7 hxlo-7 1.3xlo-7 , o.hxlo..,.7 Bottom Dollar Creek, .?-pan concentra:te. Mafic dike ;;n Portage Creek Portage Creek, upstream from Heine Carsten's placer mine, weathered granite bedroom Deadwood Creek near Switch Creek, grani-te bedrock. Mouth of Switch Creek, h-pan concentrate. Deadwood Creek, sluice box concentrate. Last left limit tribut~ to Deadwood Creek, porphyritic granite. Near schist-granite contact on last left limit tributar,y to Deadwood Creek~ 4-pan concentrate. Irrlependence Creek:.tJ sluice box concentrate Miller House Granite Creek, granite float. Miller House Granite Creek, 4-pan concentrate. Portage Creek (H. Carsten), sluice box concentrate. Portage Creek, bedrock sample eonta.i.ns purple fluorite. Switch Creek, sluice box concentrate Switch Creek, near mouth, granite bedrock. Last left limit t.ributary to Deadwood Creek~ rock samples from near znouth of t.ributa17. Bottom Dollar Creek. Portage Creek, on Hank Martin's placer property. Portage Creek, on Heine Carsten's placer property, acidified. Portage Creek, on Heine Carsten's placer property, not acidified. Circle Hot Springs from hot springs side of hill Poulder Creek Bedrock Creek Albert Creek, about 3 miles northeast of Central House on. Steese hwy, off fig. h Miller House Granite Creek. Faith Creek, about 56 miles southeast of Central House on Steese hwy$ off fig. h.. OFFICIAL USE ONLY

Sample Noo S3AMz 40 53AMz 46 53AMz 47 OFFICIAL USE ONLY Table 1 .~-Equivalent and chemical uranium analyses of samples collec"ted in 1953 ... -Continued. Uranium. equivalent .oo1 .oo1 lxlo-1 2xlo-1 Deseri tion and location Gold Bench From southeast tribut~ary .stream to Fork, Koyukuk River and across from Gold Bench, .5-pan concentrate. Taken abou. t 1 mile upstream from sample 4831, 5-pan concen·trate. Taken about ! mile upstream from sample 4831, 5-pan concentra't,e. From gravel bar, South Fork Koyukuk River, 6-pan concentrate. From unworked bench gravels at Gold Beneh, 6-pan concentrate. From first southeast tributary to South Fork Koyukuk River, above Gold Bench, 6-pan concentrate. From second southeast tributary to South Fork Koyukuk River, above Gold Bench, .5-pan coneentr·ate, From high slope drainage upstream and above sample location 4838, 2-pan concentrate. Northwest bank of South Fork Koyukuk River, about 2 miles upstream from Gold Bench, crushed bed rock sample of black slate interbedded with sandstone. Taken from first northerly tributary to South Fork Koyuku.k River, upstream froo Gold Bench, 5-pa.n concentrate; . Taken from third southeast tributary to South Fork Koyukuk River, upstream from Gold Bench- 4-pan concentrate. From Grayling Creek-9 4-pan eonc.entrat,e Taken from first southeast tributary Sooth Fork Koyukuk River, do"Wnstrea.m from Gold Bench~ 2-pan concentrate. From high bench just west of Gold l?eneh, .5-pan concentrate. About 3 miles upstream from Gold Bench and on South Fork Koyukuk River, fossiliferous black shale. Same locality as sample No. 4838g acidified Same locality as sample No. 4844J acidified Same locality as sample Noo 484.5, acidified. OFFICIAL USE ONLY

Sample Noo. h894 OFFICIAL USE ONtr Table le--Equivalent and chemical uranium analyses of samples collected in 1953--Continued. Uranium (peree~t) equivalent chemical Deseri tion and location Peace River Bottom of trencH No. weathered bedrock. Trench No. 1, we~thered bedrock Bottom of test pit in trench No. bedrock From 5 foot deep pit in trench No. bedrock. Prospect pit on divide north of trenches 5 and 6. Peace River area Reconnaissance for radioactive deposits in the Buekland-Kiwalik divide area of the Candle quadrangle, Seward Penj.nsula, in 1947, by West and Matzko (Gault and others, 1953, p. 21-27), disclosed significant amounts of uranothorianite in concentrates from placers in .the headwaters of the Peace River (fig. 6). The equivalent-uranium content of these concentrates ranges from about 0.2 to 0.8 percent or roughly 10 times that of other uranothorianite-bearing concent~ates from the eastern Seward Peninsula. In addition to uranothorianite, gwmmite~ tborite, copper sulfides, iron oxides, molybdenite, gold, silver, bismuth, and other heavy minerals were identified in the samples. The gummite is probably an alteration product of the uranothorianite. The placers from which these concentrates were obtained lie near a granite-andesite contact in a restricted (one-half square mile) drainage casino The friable gummite further bears out the belief that the heavy minerals in these placers could not have traveled far from their bedrock source. OFFICIAL USE ONLY

Explanation

Early Tertiary granitic rocks Early Tertiary granitic dikes Q Pre-cretaceous andesitic rocks ' Bui I dozer trench -

Prospect pit Sam~le location Scale I MILE

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' FIGURE 6.-- SKETCH MAP OF HEADWATERS OF THE PEACE RIVER, CANDLE QUADRANGLE, SEWARD PENINSULA, ALASKA

OFFICIAL USE ONLY A brief reconnaissance of the area in 1951 by West (Gault and others, 1953, 28-31) indicated galena, sphalerite, pyrrhotite, eovellite, and fluorite in addition to those minerals previously identified. The intimate association of pyrite, sphalerite, chalcopyrite, and galena in discrete grains in the placers, but not in the granite country rock, may indicate a possible lode source for the sulfides. The occurrence of gwmmite with tetradymite, galena, and pyrite suggests that the radioactive minerals occur with the sulfides in a lode deposit. During the 1947 reconnaissance a placer-sampling technique was employed. In 1951, hand trenching by the field party to locate the lode source of the minerals was not satisfactory due to frozen ground and excessive flow of ground water. Bedrock was reached in only h of 16 pits put down. Additional work on the project was recessed pending the availability of a bulldozer or the development of new sampling techniques. In July 1953, the Geological Survey was informed that two men from. Nome~ Elmer Straub and William Munz, were prospecting with a bulldozer for uranium in the areao A small field party was immediately sent to the area to determine the possibilities for putting a larger party into the area to work with the prospectors and to take advantage of the heavy equiPment presento Upon arrival it was found that the bulldozer had broken down and the prospectors had abandoned their efforts, In all, six trenches were put in before the equipment became unoperative. Bedrock was reached in only one of these trenches. Contrary to the recommendations of West· (Gault and others, 1953, 28-31), none of the trenches were cut traJfrerse to the stream at the point where the most radioactive samples were found in 1947 OFFICIAL USE ONLY

OFFICIAL USE ONLr and 19.51. All the trenches are on the north bank of the stream normal to the direction of flmJ on 200-foot centers and about 0.2 mile downstream from the l ocation of the most radioactive samples. Bedrock was reached in only one or possibly two trenches and it is believed that the results of the prospectors were inconclusive. As no heavy equipment would be available to continue the trenching, it was decided not to bring a field party into the area but to attempt to reach bedrock by deepening parts of the trenches. Pits were dug, or deepened so that bedrock was reached in three of the six trenches. The maximum equivalent uranium content of the bedrock samples was 0.003 percent. Samples were also taken of a ~ineralized zone in the bottom of a placer cut on Bear Creek at Porter's Camp. Analyses indicate as mucp as Oo02 percent equivalent uranium. No uranium minerals were identified but alpha plate studies show that the major source of the radioactivity is an opaque, non-crystalline material. Port Ma~esbury area In 1948 and 1949, the Alaskan Territorial Department of Mines scanned all of its file samples for radioactivity. One sample which showed considerable radioactivity was sent in 1949 to the Atomic Energy Commission in New York for analysis. The Commission's New York laborator,y reported that the sample (406-K) contained 0.05 percent uranium oxide equivalent and described it as "altered iron-stained siliceous rock with veinlets of calcite, pyrite, and a dark red mineral, possibly hematite"e~ At the time the source of the sample was unknown. {See Wedow, White, and Moxham, 1951, Po 63-64.) OFFICIAL USE ONLY

OFFICIAL USE ONLY In September 1953 Mr. Donald MacDonald, fonnerly of Petersburg, Alaska called at the Geological Survey in Washington, D. c. Mro MacDonald identified a specimen of the radioactive iron-stained rock as part of a sample that his father, Gordon MacDonald, had sent in the early 1930 1s to the Territorial Department of Mines in Ketchikan believing that it contained cinnabar o Donald MacDonald stated that the sample came from the tidal zone along the shore between the north and the south arms of Port Malmesbury, Kuiu Island,. southeastern Alaska (fig. 7). Gordon MacDonald and his partner, John Luderman, also reported two sulfide-bearing quartz veins that cut across a creek draining into the head of Port Malmesbury from the northeast Donald MacDonald visited the area in 1939 and collected additional samples from the veins. He states that tQ.e veins which occur in a dark graywacke (?) are 8 inches wide and 6 feet apart. An assay of one of the veins by the Territorial Assay Office at Ketchikan gave a value of $S per ton for gold, and $35 per ton for silver. The metallic minerals in the vein are galena, pyrite, and a heavy black mineral which occurs as blebs in the vein quartz. MacDonald believes the black mineral to be pitchblende for the following reasons: (1) Samples of the veins showed strong radioactivity when tested with a gold leaf electroscope; (2) (3) a borax bead test for uranium was positive; and the possibility that the fogging of the film in his camera was due to the fact that the camera had been laid on the vein and carried .for some hours in a pack with the samples. OFFICIAL USE ONLY

Camp J...7S Strike and dip

X-1 Sample location Geology adapted from U. S.G.S. Bull. 800 FIG URE 7. --GEOLOGIC SKETCH MAP O F PORT MALME SBURY AREA, KUJU ISLAN D

OFFICIAL USE ONLY Robert Velikanje1 geologist from the Geological Survey's Juneau office, made two short tr·ips into the area with MacDonald in the fall of On the first trip the party was in the area only 3 hours and used their time to familiarize themselves with the area to aid them in planning the requirements for a several days reconnaissance of the area at a later date. Two weeks later the same party again visited the area and remained there one week. Bad weather and the lack of a small boat, however, prevented the party from searching tor the quartz veins reported at the head of the bayo The outcrops that MacDonald stated were the source of the red radioactive float rock on the beach had been covered by slides and could not be examined. No samples collected in the area in 1953 contained more than 0.001 percent equivalent uranium. In the spring of 1954l Donald MacDonald returned to Port Malmesbury and collected additional s~ples. These samples, tested by c. Lo Sainsbury, geologist in the Juneau, Alaska, office of the Geological Survey, were not radioactive. Later in the summer, additional samples collected by MacDonald also did not contain any radioactivit.y. MacDonald then stated that for financial reasons he was abandoning the search. In the late fall of 1954, Ro So Velikanje and Robert Thorne, engineer, U. So Bureau of Mines, Juneau, Alaska, spent several days in the area to evaluate the sulfide veins. They carried Geiger counters but did not locate any radioactive~ anomalies. OFFICIAL USE ONLY

OFFICIAL USE ONLY SUMMARY AND CONCLUSIONS In 19.53 the Geological Survey conducted reconnaissance for high-grade uranium ores in six widely scattered areas in Alaska. The areas were selected primarily on the basis of the reported locations of high-grade ore samples submitted qy prospectors and the occurrence of uranothorianite with associated sulfides in creek placers. No high-grade bodies of ore were found during the brief reconnaissances conducted in each area. It is ·unlikely, however, that the samples submitted by the prospectors were ~imported" to Alaska, and the prospectors have been urged to continue their searches for new samples of interest and to submit more information on the precise location of the samples they had submitted. The lode sources of the uranothorianite could not be located, but further reconnaissance, particularly in the headwaters of the Peace River on the Seward Peninsula, using geochemical techniques will be needed before these radioactive placer occurrences can be eliminated from further consideration OFFICIAL USE ONLY

OFFICIAL USE ONLY LITERATURE CITED Capps, s. R., 1935, The southern Alaska Range: Uo S. Geolo Survey full 862. Gault, H. R. and others, 19539 Reconnaissance for radioactive deposits in t he northeastern part of the Seward Peninsula~ Alaska$ 1945-47 and 1951: u. S. Geolo Survey Circo 250. Grant u. s., and Higgins, D. F., Jr. 1909, Notes on the geology and mi ner al prospects in the vicinity of Sewardg Kenai Peninsula (Alaska)~ U 9 So Geol~ Survey Bull. 379-Co Maddren, Ao Go, 1913, The Kqyukuk-Chandalar region, Alaska: U& S. Geolo Survey Bull. 532. Milkey, R. Go, 1953, Stability of metallic ions in dilute so1utiong Anal. Chem., v. 2, Noo 11, 1954, Po 1800-1803. Nelson, A. Eo 1 West Wo s., and Matzko, J. Jo~ 1954, Reconnaissance for radioactive deposits in eastern AlaskaD 1952: u. So Geo1~ Survey Tolbert.o Go E., and Nelson, A. E., 1951, Preliminary summary of reconnaissance for uranium in the Alaska Railroad-Iliamna region during 195l g Uo So Geolo Survey Circo 196. Wedow, Helmuth, Jr., 195ll' Adaptation of portable survey meters for airborne reconnaissance with light planes in Alaska: U. s. Geol ... ~urv~y TEM~'323,. issued by· tr.s Atomi .c~Energy Comril.o Tech,9 I:rafo ... vervl ce , Oa k RJ_dge. Wedow Helmuth, Jr$, and others, 1952J Preliminary su~ary of reconnaissance for uranium and thorium in Alaskab 1952g U$ s, Geolo Survey Circo 248o , 1953, Prel~inar,r summary of reconnaissance for

uranium and thorium in Alaska,p 1952: u. s_. Geole Survey Cire o 248o Wedow~ Helmuth, Jro, White, Mo G.,D and others, 1954, .Reconnaissance for radioactive deposits in east-central AlaskaD 1949: Uo So Geolo Survey Circo 335e Wedow$ Helmuth, Jro 1 White,o Mo Go, and Moxham 0 Me, 1951, Interim report on an appraisal of the uranium possibilities or Alaska: U. So Geolo Survey Trace Elements Memo,o Repto 235~ (Open-file Repte) OFFICIAL USE ONLY

Plates & figures from the original