Summary of reconnaissance for radioactive deposits in Alaska, 1945-1954, and an appraisal of Alaskan uranium possibilities
<p>In the period 1945-1954 over 100 investigations for radioactive source materials were made in Alaska. The nature of these investigations ranged from field…
Public-domain full text preserved in the Mountain Man Mining Library. Original source: pubs.usgs.gov.
T67r (/)t(). 577 Summary of reconnaissance for radioactive deposits in Alaska, 1945-1954, and an a:appraisal of Alaskan uranium possibilities By Helmuth Wedow, Jr. sh I 0
' rp '.lnd the U S Geo o ical urv y · Trace Elements Jnyestigations Report 577 UNITED STATES DEPARTMENT _OF:·~ HE INTERIOR GEOLOGICAL SURVEY
OF1t.,ICIAL USE OiiL:(( Geology and Mineralogy Thi9 ctocu:tnent consists of 111 :pages .9 plus 1 figure Series .A UNITED STATES DEPART£·1ENT OF THE mrERIOR. GEOLOGICAL SURVEY SUJ,m.1ARY OF FOR RADIOACTI\"E DEPOSITS OF ALASKAN URANIUM POSSIBILITIES* By Helmuth Wedow, Jr. 14arch 1956 ·Trace Elements. Investigations Report 577 CAUTION Inform.~tion conta5_ned in this docu.ment has been furnished in confidence by aJ..l prospeGtors and companies concerned a..nd shaJ.1 "be handled accordingly iii thin t he USGS and AEC. The material herein shall not be published1 without the approval of" all prQspectors a.r.~.d companies concerned a:n.d th~ U. S. Geological Survey o This preUminary rep.ort is distributed 1d thout editorial a11.d technical review tor conformity with official standards and nomenclature. It is not for public inspection or quotation~ *'This report concerns work ·done on behalf of the Division of' Raw Ma;cer"ia.ls of the U. S. Atomic Energy Co:rrnnission 0 OFFICIAL USE OrlL Y
OFFICIAL USE ONLY USGS - TEI-577 GEOLOGY AND MINERAOLOGY Distribution (Series A) f o_f_c...,.o-=p_i""i""e s · Division of Raw Materials, Austin
Division of Raw Materials, Butte.
Division of Raw Materials, Casper Di v:Lsion of Raw Materials, Denver Division of Raw_ lv'1materials, Rapid ei ty. DiVision of Raw .Materials, Ishpeming Division of Raw Materials, Phoenix. Division of Raw Materials, st. George DiVision of Raw Materials, SaJ. t Lake City
Division of Raw Material-s, Washington E;xplora~ion Division, Grand Junction Operations Office. Grand Junction .Operations Office. U. S. Geological Survey: Alaskan Geology Branch, Menlo Park. Geochemistry and Petrology Branch, Washington Mineral Deposits Branch, Wa$hington A. H Koschmann, Denver
],. R. Page, Washington. R. S. Velikanje, Juneau TEPqo, RPS, Washington, (including master). . OFFic-IAL USE· ONLY ...
OFFICIAL USE ONLY Introduction... o
.,
Summary of re~onnaissance CONTENTS
Southeastern Alaska Soutr.&rn Alaska Southwestern Alaska e
D
&
· - East~central Alaska
West-centra:;L Alaska .. so
.,
Possibilities for uranium and thorium in Alaska . . " Igneous rocks, pegm.atites, veins and related deposits Veins and related deposits . Potentialities :for vein and related deposits on the Potentialities for vein and related deposits in Page Carnotite-type ores in sa.ndstonei3 and limestones. Areas potentially favorable for carnotite-type ores Alaska Peninsula-Cook Inlet area. o
Manley Hot Springs-Rampart area Cantwell area e
o
" Carbonaceaus rocks, phosphorites and other sedimentary rocks. .. Placer deposits Q
Q
Natural fluids. P
Li teratu:re cited. Unpublished reports
Ap:pendi.x--Recormaissance topographic quadrangles of the Alaskan
, ILLUSTRATIONS Page Figure 1 .. Index map of Alaska shoving regions. Ma:p of southeas-tern Alaska showi~g areas a...11d localities :i.investigated $
.,
·oFFICIAL USE ONLY
OFFICIAL USE ONLY ILLUS'l'RATIONS Page Figure, 3.. Map of' djout;n,er:rl Alaska ~howi~g areas and 1oea.li ties o
,
Map of southwestern Alaska showing areas and l.:>calities
o
o
Map of east-~entral Alaska shonng a:reas and 1cali ties
4o 6. Map of west=central Alaska showing areas and loca1i tie~ investigated. ., ..
Map of northern Alaska showing areas and localities invest:;i.gate:d.'
e . .
'. Map showing some of the more significant areas examined for radioactive minerals in Alaska (In envelope) TABLES Page Table l.. Su:mm.ary of reconnaissance for radioactive deposits in southeastern Alaska, 1945-1954.. e
2. Summary of reconnaissance for radioactive deposits in southern Alaska, 1945-1954. o
Summary of reconnaissance :for radioaeti ve ;in southwestern AJ.aska, 1945-1954. .. e
lJ... Summary o:f reconnaissance for radioactive deposits in east-central Alaska, 1945-1954.
_36 5,. Summary of reconnaissance for radioact:Lve deposits in 4,6 Summary of :reconnaissance for radioaet:i,ve deposits in ·northern .Alaska, 1945-1954.. o
o
1. Classifications of radioactive deposits e
Official Use Only
OFFICIAL UC-:\:E: ONLY PJ'JD AN Af'P.Hl;.ISAL Olr ALASKAN UH;\~eJIUN :.POSSIBILiiJ:IES B~r Helrmrth ;~Jcdo1-r , Jr , I n the period 19l1-5~195h over 100 investigations for radioaeti ve source m~rterials -r.vere in JUasJ\:a ,. The nature o;f these investi.,. gat ions range1 from fielc1 e~::runinations of' indj, vidup..l prospects or the anal;y-s:Ls of si.gnificantly radi.oacttve saru:ples su1Jmi tted by }1rospecto:cs t o re con.no.is~3n.nec stw1ies of' large districts,. In thi s 1:::e ri od no deposj:ts of m~aniuJ.'11 OT 'thortu1n that "\rould uar rant com.merq:Lal exploit ation uere discovered,., rrhe investiga:tions' hoi-rever' disclosed that rac1j.active materials occur in \videly scattered areas of Alaska and in Many igneouu :rocLu t.hour!Yhout P.la.skrt are ·vrea1d,y radioact.Jve because of uranium-and thorium-bear_ng accept1sory minerals, such as allanite, a}.xr:.:;ite? monazite, sphene; xenotime, and. zircon; ~ore r9-rely the radioactj.vity of these roeJ:.:s is due to thorianite or thorite and their uranoan variet:i.es , The felsic rocks, for example, granites and syerd tes J are generally Inorc r adi.oacti ve than the maflc ie;neous rocks.. Pegrnatj.tes J loeally , have also r:·:,oved. to be radj_onct;i ve, but they have little comrDercj.B,l sj_gni:f:i.cance" No :primary uranj_um oxic1e rtlinerals have been found 1dent:i.i'led as Ho\·Teve:r-; ce;rt.a.in occuri·ences of secondary uran).um nlj_nerals, chi.efly those OFFICIAL USE ONLY
OFFICIAL USE ONLY of the ~te group, on the Se·ward Peninsula, in the Russian Mountains, and. in the vicinity of' Kodi~ suggest t hat pitehblende~type ores ms.y oceur at depth beneath zones of alteration. Thorite-bearing veine have been discovered on Prince of Wales Island in southeastern Alaska. Although no deposits of carnotite-type minerals have been found in Alaska, several containing such mineraJ.s have been submitted by Alaskan prospec·tors. · Eff"brts to locate the deposits from which these minerals were obtained have -been uhsu.cces sfu.l, but review of available geologic data suggests that several Alaskan areas are potentially favor- ( able f'or carnotite-type deposits. The chief of these areas · is the Alaska PeninsuJ.a-Cook Inlet area which encompasses most of the reported occurrences of ~he prospectors' carnotite-type samples. Alaska is aJ.so potentia.lly favorable :for the occurrence of large bodies of the very low-grade uraniferous sedimentary rocks, such as pho.sphor:ttes and bl.aek shales. 1'b.is type of deposit, however, has not received much study because of the emphasis on the search for bonanzatype h:igb-grade ores. Uraniferous phosphorites similar to those of Idaho, Montana, and Wyoming oecur in northern Alaska on the north flank of the Brooks Range; bl ac:k shales comparable to the uranif'.erous shales of the Chat tanooga f ormation of so·u.theastern United States have been noted along the Yukon River near the international boundary. Placer deposits in Alaska .have some sma.ll potential for the production· of the radioactive elemen.t.s as by:products of gold- and tinplacer mining. The placer area believed to have the relatively greatest potent ial in Alaska lies in the Kahiltna River va.'lley where concentrates
)
I,· . I' '. :' OFf~CIAL USE ONLY ar e 1-r.rtb-vr:a. t o conta:Ln such COlTh..."n.ercial :minerals i~e!fi te, oasis teri te, plati nwu, and gold i n a~dition to uranot horiani te and monazite. T]+e possibilit ies of t he natural fluidE?- water and petro;Leum~-ha:ve not yet been teste in Alaska to any great except. studies of fluids are i n:progres$ t o d~termine whet her they may be used to discover and def'inf? areas potentially favorable for the occur;re:n.Ge of -uranife:rous lodes ., INTRODUCT;I:ON Sipce 1945 the Geological Survey has conducted reconnaissance for radioactive deposits in Alas~a., first on behalf of the Manhattan Engineer District, U s. War Departm~nt, later on behalf of t~e Division of Raw Materi als, U1 S. Atomic Energy Commission~ The pr~ry objective of this reconnaissance has been the search for high-grade uranium ores. Althou~h this search has been largely unsuccesE?ful to date, certain positive leads to high-grade ores occur, and it can by no means be concluc1ed 1 t hat such ores will not be discovered in Alaska¢ : .f T;he chief hindrance to the search for -uranium in Alaska has been the general inaccessibility of much of the Territory, which has an areal
1. ·1 extent ;of about ·one-fifth, that of continental United States (or abo-q.t t he e~hivalent of the states of Arizona, New Mexico, Colorado, Utah, I daho 1 ap.d Wyoming), with the consequent slowness and cost of tra.nsportat:J.on .Anotner detergent has been the lack of detailed maps, both ~eologic and topographic About one~half of Alaska, which has as comple~ a geologic framework and widespread occurre~ces of metallic OFFICIAL USE ONLY '
OFFICIAL USE ONLY minerals as much of westex~ United States, h~s not been mapped geolQgically at a seale greater than 1:1,000,000; most of the remainder is known only from: very general exploratory surveys' with less than 10 percent mapped geologically at a scale comparable to most of the mapping the States. In the years prior .to World War II little was kno'Wtl about the of' radioactive materials in Alaska. Carnotite had been identified in a sample submitted to the as'say office at Fairbanks 1918. This s~le was supposedly found by a railroad construction worker in the vicinity of Healy on the Alaska Railroad, but the exact locality_ is unknown. · Mona.zite was reported by Mertie (1925, p. 260) in concentrates from Ni the g~avels ofBig .Creek in the Cha.ndalar di~trict on the south. flank of the Brooks Range. Milton (Ros~, 1933b, p. 437) tentatively iden.tif'ied monazite in placer concentrates from Valdez Creek near Denali on the _south. f"lank of the Alaska Ran~e. Esehyn.ite, monazite, and xenotime were identi~ fied by Waters (Mertie and Waters, 1934, p. 229, 239-24o) in concentrates from gold-tin placers of the Tof'ty tin belt of the Hot Springs district ' near the junction of the Yukon and Tanana Rivers. In 1932 Wacker (Anon~ous, 1932, p. 7) is reported, to have f'ound a uranium deposit on Martin Arm of Boea de Quadra Inlet in southeastern Alaska. Henry Joesting (1946, personal communication to P. L.- Killeen) of the Territorial Department of' Mines found, about 1941, that some concentrates from placers in interior Alaska were radioaeti ve; the s~ple showing the greatest radioactivity was from Grubstake Creek in the Nenana district on the north flank of the Alaska Range. It contained 1 X lo-9 grams radium per gram ot sample. OFFICIAL USE ONLY
''
,,
f ·-· -· .. '
; t. 1! .,
·
J
· .. , : :pa~. :the . :u.rantuta~ ~asibiliti ot: :Ala~lta ·r:o:r t:ne. M~at;t·~ t :-
· iee·tet.l .n:wne:rou.S · ~eoneenttS:tEf$ .in AJ;:a~ka 'in· ,a· ctb. ·fo't · il'~Q1\~tive ·
' t. ' 't ' - · ' ' ' ; '
'
' J
.. . '"I :
' , , - ·
, ,- ,' : · The Al:aska.· ~ac;.e · Element: ProgrSlit a~· the ~y, , · ·
' ;. - ,
' .;" ' ' · ' r m#e. ~ha.n 600 p!ae~r con- .· · oent.r~i4~&- 111 thti' s, Alaekan, .~tfU~eUons:~ TJte: re~ t.i : ol ~:tlie · stu~y . · ' , · , . ·sou.r¢.e~.,:or ter:t~s 9 · ·. <loll,a- ' ··
' ~a'tl;lf., .itl ·'l±9.~~; : .. mv~;a~1ratio-. w:e,~e · . , '; ' c . " '· , iu,t& ··B~taY.i · li~~:) :; : ~eeJ$t:e.kd · Cl-e~k . . · ··
!
: ;
' .
, ·
ol, ; ''
' l..t'.J
''10,<(0,
··:;.1 .·-tal: ea!le ~wat·..tn - ~a; ot' . ibt!f':~~ M~Q14~/:t;ati4 ·.
· t-- ·- · tpJ;; · :·itazfll · '· ·
·fc) /6Qdi1;i~ :lttid · '·-at, ?;itie ·. · · , 'I . '
OFFICIAL USE ONLY The primary conclusion _.of the field work of 1945 was that Alaskan plaeer.s, in gene·ral, should not : be considered. in the near future as _important for reserves of materials, and that the general emphasis of the Alaskan program of reconnaissance f'or radioactive deposits should be directed toward. the search for bedrock sp~es in ar~a.s wher~: -(l) Radioactive :ndn~raJ.s were known or report~d to be preS.E!l.li; (2) Lode mines and prospects contain minera+s known to occur .in radioa.ct:;lve deposits elsewnere in the world. (3) I~eous rocks of certain a.g~s and petrog~aphic tY,Pes migb.t contain radio~ctive minerals. (4) Black shales and ot~er sedimentary rocks a.r~ possibly radioactive. (5) eoncentrates from creek gravels and placer operations are known to contain radioactive minerals. As much of Alaska is of difficult access, one phase of the Alaskan . reeonnaissan.ce :program was directed toward obtaining information on accessible areas contiguo u.s to the Alaskan b.highway, railway; and riversystems, where no previous information on radioaeti vi ty was av~lal;lle,. selection of other areas for investigation was governed by the five eriteria.set out above. ~cause the res-ults ot the (}eologi~a.l Survey's reconnais~S+lce :prog~am through 1950 had not yet inq.:icated :much promise f'or the oecurrenae of hig.b.~grade uraniUlD. ~re ·deposits .in Alaska, f'ield studies were curtailed pending a reappraisal of' Alaska's uranium possibilities '1'1?-is reapprB.isal cuJJ.nina.ted in a ,re;port (Wedow and othe:rs, 1951) reviewing the geology -~d mineral deposits of the several Alaskan regions in the light of their u.ranium possibilities, these possibilities being based on the fAO'Wn OFFICIAL USE .ONLY
I 'I i: ~JC.Cl.1L.-renee of radioaeti ve :m.a.teria.l.s and geologie criteria SllggeSt~ng the presence ()"£uranium.. !'he geologie erlteria ine1uded: oeeurrenee of silver, and tluo;d:te; an.a., as lesa surely intieative 7 the occurrences of :ouch minerals as arsenopyrite, oorni te, eassi terl te, ehaleopyri te , galena, hel!BB.ti te, molybie.IU. te, p)'rl te, siderite, sphal.eri te, ·and tetrahedri te, and their al.teration produ.~ts. 'fl1e selee.tion of the criteria vas based w on a review of literature pertaining to known domestic and :f'ereign uranium deposits.. Of particular aid vere, reports by Ba.in (1950), Lang (1949a, 19lJ9b, l950) , George (1949), (1934) , anti Bastin ana H1ll (1917) , reports . of the Atomie. E:uergy Commi~sion an.O. Geologie.al Survey. Beeaue
few of Alaska .s mineral deposits have been investigated in detail, ll'l8.1ly of. the 4e:posits are known ou:r from brief reconnaissance studies by Ck!o~ogica.l geologists and u. S.. Bureau of Mines engineers, or from reports by prospectors and mining eom.pan.ies 0 Consequently, the seriptions at the mineral. ~sits may be due to incomplete information rather than a'ba,ence f'rom. tl1e deposit. B:owever, the e0nel.usions reached by the 1950-1.951 reappraisal ot .Alaska 11s ua.nium possibilities indicated that several Al.askan regi~s were favorable for th.e oeeurrenee of' uranium, and several. partie8 tiel.d a~!$Pls possibl.e uraniferous areas du.ring the sumner of 1951 ia the Alaska. Railroad belt, the Gul.f' of Alaska region, southeastern .Alaska, aai the Seward Pem.inn.J.a (Wlrl. te and others, 1952) and during the SlUmBer of 1952 in southeastern Alaska, eastern Alaska, OFFICI.A:L USE . ORY
OFFICIAL USE ONLY and ·the l ower Yukon~Kuskcpkwim region (Wedow and others, 1953). In 1953, reconnaissance of possibly favorable areas was continued by one field party (Mat zko and Bates , 1955) . In 1954, Qne field party investigated areas from wlU.ch pros~etors had. submj. tted radioactive samples (~tzko and Bates, report. in pr~pe.ra.~ion). Since 1951 the Geological Sw;-vey, on behalf of the Atomic Energy Commission, has maintained a laboratory during the summer months on the · campus of the University of Alaska at College near Fairbanks 'fhe eb.ief purpose of this laQoratory is to make ~re~iminary studi~s of the content · and nature of the radioactive material in sattlples submitted by the public and Government agencies. This laboratory is operated in cooperation with t .he University of' Alaska, which has made space and facilities available to the Survey. Anyone in Alaska interested in h~ving sample~ tested for radioa.~ti vi ty may submit the material ei tll.er directly to the -Survey ! labor~~ory or through Survey field geologists or .offices. Various .techniques have been used in the field in the. search for ·I uranium in .Alaska, . In small restricted drainage' basins, whe:r:e much of the bedrock is covered with shielding materiaJ.s such as moss, muek, and tundra, the test1rng of concentrates from creek gravels for radioactivity has been found to be the most sati.sfaetory method of testing for the presence of radioactive deposits in the basin. Hawever, as m9st uranium mineraJ.s both extremely friable and soluble anQ. are li~ely to be destroyed readily by the erosive and eorros:J_ ve aetion of streams, the testi~g of the concentrates should be augmented by the analysis for ura.ni't;UJl in alluvi~ fines, vegeta.t;i.on, res;id.ual boils, and stream waters. OFFICIAL USE ONLY
OFFICIAL USE ONLY vfuer:: mines 7 pros:pe~:;-cs:; ro~v:l cuts J and na:tural outcrops afford access to- .l:ode de:posi t.s and ·bedrock 7 direct radioac!tivi ty tests h~ve been macte ~r;i. th portable detec!tion e112ipment in ·the a11d samples of interest taken for later laboratory examination. In rec~nt years the improvement of' portable equipment :for mea;suring radioactivity, particularly the development of more rugged and more sensitive portable survey meters of various types, has enabled the field geologist engaged in the search for uranium to s1.n tch from the laborious r.tand-count.ing methods of record:ir!{S radioactivity to methods of' continuous traversing.? using ground vehicles, boats, light fixed-win~ aircraft't, and. hel.icopters, as well as the time liPnored .
back-packing method for foot-traverses (Wedow, 1951). . Thus, in the years succeeding the initial field radioactivity studies by the C-.,eological Survey in Alaska during 1945, a number ·pf different techniques have been used to test for the presence of radioactd:ve materials. Although a great variety of materials and types of deposits in widely scattered a~r·. s have been so tested, much of Alaska remains unexamined. However, becaus~ of the econ.om.ic factort3 involved, the primary objective 'I of' the search for ~a.nium in .Alaska must continue to be the discovery of high-grade deposits. The results of the reconnaiss~nce program conducted ·by the Geological Survey on behalf of the Division of Raw Materials of t ,he U. S. Atomic Energy Conmdasion and its predecessor, the Manhattan E.."lgineer D~strict, are summarized by region in the body of this report. In addition, an appraisal of the uranium and thorium possibilities of Alaska by types of deposits is given. OFFICIAL USE ONLY
OFFICIAL USE ONLY For the purpose of this report Alaska. has been di vid~d into six regions (fig. 1) based on arbitrary groupings of' quadrangles of the Alaska reconnaissance topographi c series (seale 1:250,000) The quadrangles ineluded in each region are listed in the appendix. SUMMARY OF RECONNAISSANCE Southeastern Alaska · The results of reconnaissance for radioactive deposits in southeastern Alaska are summa.rized in table 1; the sites of the localities examined are plotted on figure 2. Reeonnaissane~ for radioactive deposits in southeastern Alaska by the Geological Survey did not begin unti l 1949. Tests of shipping eoncentrates and mill tailings from the Alaska-Juneau gold mine at Juneau in 1947 showed a maximwn equivalent-urani~ content of only o·.oo2 percent and analyses of the few samples from southeastern Alaska in the Survey's Alaskan eoneentrate eolleetion likewise showed little or no radioactivity. Howev~~' unverified reports or rumors placed occurrences of radio~etive materials in a number of widely scattered areas of southeastern Alaska, including l localities on the Whiting Rive~, on t~e mainland east of Petersburg, in the vicinity of Chiehago~ at Goddard Hot Sprin~s (Colby, 1942, :P. 175), and on Boca de Quadra Inlet (Anonymous, 1,932, p. 7). Because very little informat ion was available on the distribution of radioactivity in southeastern Alaska and because th~ region is prominent for its metalliferous lode deposits, the objectives of the reeonnaiss~ee party in southeastern Alaska in 1949 were follows: OFFICIAL USE ONLY
H
fi
t , ol r9'
·REGIONS I Southeastern AI aska 2 Southern Alaska 3 Southwestern Alaska 4 East-centra.l ~Iaska 5 West~l Alaska 6 Northern AI ask a Figure t o=-lndex rnap of Alaska showing regions ',
H
txij
t-<
Table I.--Summary of reconnaissance for radioactive deposits In southeastern Alaska, 1945-1954 Location Year of Types of deposits examined or (Reference no. of fig. 2) field work nature of investigation Radioactivltt Remarks References Ketchikan quadrangle Hyder district (I) Silver- lead quartz fissure veins and mineralized Maximum radioactivity of samples Samples collected by TDMI/ in 1950 from West and Benson, 1955 shoots in zone along intrusive contact of Texas taken in 1949 Is about 0.05 Canyon vein contain as much as 0.7 perWe dow and others, 1951, p. 52-56 Creek granodiorite with metamorphic rocks of percent eU. Radioactivity is cent equivalent uranium; pitchblende is Wedow and others, 1953, p. 6, 12 Hazelton group; examined chiefly on due to uranium in iron oxides, believed to be the radioactive mineral . Houston and others, 1954 Mountain View property. galena, sphalerite, pyrite, USGS reconnaissance in 1952 failed to chalcopyrite, molybdenite, and duplicate this s·ampling. scheellte. Tetrahedrite, freiberglte, and fluorite are also present. George Inlet, Fissure veins and replacement zinc deposits In <0.001 percent eU White and others, 1952, p. 15 Ketchikan district (2) siliceous rocks close to granite contact containing chalcopyrite, galena, sphalerite, and pyrrhotite Ketchikan and vicinity (3) Bismuth-bearing gold-quartz veins 0.001 percent eU West and Benson, 1955 Wedow and others, 1951, p. 60 Helm Bay (4) Blsmuth(?)-bearing pyritic gold-quartz veins .001 percent eU Wedow and others, 1951, p. 60 White and others, 1952, p. 15
Gravina Island Hematite-copper sulfide replacement deposits <0.001 percent eU, locally as White and others, 1952, p. 15
(southern end) (5) much as 0.005 percent eU In
felsic volcanic rocks
Craig quadrangle
z
Union Bay area (6) Reconnaissance to find source of tyuyamunlteSample estimated to contain more Geology of area not believed to be favorWhite and others, 1952, p. 13-15 z bearing coal sample submitted by prospector than I percent U; no radioactlvable for this type of uranium occurrence.
to Territorial Department of Mines lty of significance found in area. Semple thought to have been "imported" as part of coal shipment to former cannery in area. Niblack Anchorage area Hematite-copper sulfide replacement deposits <0.001 percent eU White and others, 1952, p. 15 (7) with some galena(?), sphalerite, and jasper North Amo, Moira Sound (8) Silver-lead-zinc vein and replacement deposits <:0.001 percent eU White and others, 1952, p. 16 Doloml area (9) Gold-bearing breccia veins containing tetra- .001 percent eU White and others, 1952, p. 16 hedrite and pyrite Cholmondeley Sound Gold-quartz veins <0.001 percent eU Contain traces of sulfides White and others, 1952, p. 16 area (10) Green Monster Mountain Contact metamorphic deposits containing <0.001 percent eU Wedow ond others, 1953, p. II (II) magnetite and chalcopyrite, and small Houston and others, 1953 amounts of pyrite, pyrrhotite, molybdenite and hematite Kasaan Peninsula (12) do <0.001 percent eU Metatorbernlte and allanite White and others, 1952, p. 16 reported from this area Wedow and others,l951,p.63 Lake Bay (13) Copper-bearing breccia vein containing pyrite, 0.001 percent eU We dow and others, 1953, p. II chalcopyrite, sphalerite, secondary copper Houston and others, 1953 minerals and iron oxides Baker Island molybdenite Silicified quartz diorite cut by narrow quartz 0.001 percent eU Wedow and others, 1951, p. 67 prospect (14) velnlets containing molybdenite, pyrite, Wedow and others, 1953, p. II pyrrhotite, and Iron oxides Houston and others, 1953
Table I.--Summary of rec:onnalssanc:e for radioactive deposits In southeastern Alaska, 1945-1954--continued Location Year of Types of deposits exc.nined or (Reference no. on fIg. 2) field work nature of Investigation Radioac:tivit~ Remarks References Craig quadrangle--continued Egg Harbor, Coronation Replacement deposits In limestone; metallic: <0.003 percent eU Wedaw and others, 1951, p. 67 Island (15) minerals are galena, sphalerite, Iron oxides, Wedow and others, 1953, p. II cerussite, smlthsonlte, hydrozlnc:ite and Houston and others, 1953 possibly tetrahedrite Petersburg quadrangle Groundhog and Glacier Replacement and fissure veins containing .001 percent eU Wedow and others, 1951, p. 60 Basins and Lake claims sphalerite, pyrrhotite, galena, pyrite, White and others, 1952, p. 17 (16) c:halc:opyrite, molybdenite, pyromorphite (?) and fluorite(?) Dunc:an Canal (17) Replacement deposit containing barite and <0.001 percent eU White and others, 1952, p. 17 traces of pyrite, sphalerite, galena and magnetite Woewodskl Island (18) Gold-quartz vein, and replacement deposits .001 percent eU White and others, 1952, p. 17 containing pyrite, c:halc:opyrite, galena, and sphalerite
Round Point, Zaremba Granite Intruding graywacke 0.004 percent eU Radioac:tivlty probably due to c:ommon Wedow and others, 1953, p. 10
n Island (19) ac:c:essory minerals In granite Houston and others, 1953 n
Southwest c:oast, Zaremba Colorless, white, green, and purple fluorite <0.001 percent eU, locally as White and others, 1952, p. 16
Island (20) with fine-grained pyrite in velnlets c:uttlng muc:h as 0.005 percent eU In volc:anlc: roc:ks felsic: volc:anlc: roc:ks
z Salmon Bay area, Prlnc:e of Narrow c:arboncle-hematlte veins containing Maximum content is 0.095 percent Velnsrangein thickness from less than I White and others, 1952, p. 13, 14, 16 z
Wales Island (Exchange small amounts of thorite, monazite, sulfides, eU; average is about 0.03 percent inc:h to as much as 2. feet . Country roc:k Hou~ton, 1952
Cove to Point Colpoys) fluorite and rare-earth minerals eU. As uranium content Is 0.003 Is graywacke whlc:h Is hematltlcally Wedaw and others, 1953, p. 6, 9, 10 (21) percent or less, radioactivity Is altered adjacent to many of the veins. Houston and others, 1953 due to thorium; average Th02 A prospector's sample of hematitlc:ally Bates and Wedaw, 1953, p. 3, 4, 8 content is estimated to be about altered wall roc:k contains as muc:h as 0.1 percent 0.13 percent eU. North Shore of Prlnc:e of Reconnaissance of Silurian(?) "graywacke" 0.001 percent eU Wedow and others, 1953, p. 9, 10 Wales Island (west of Red area for possible extension of thorium-bearing Houston and others, 1953 Bay) (22) veins found In Salmon Bay area El Capitan Passage and do 0.001 percent eU Wedow and others, 1953, p. 9, II Shokan, Shipley, and Edna Houston and others, 1953 Bays, Prlnc:e of Wales and Kosc:lusko Islands (23) Shokan molybdenite deposit, Brec:c:ia zone c:antalning molybdenite, pyrite, 0.004 percent eU Wedow and others, 1953, p. 9, 10 Kosc:iusko Island (24) pyrrhotite, c:halc:opyrlte, sphalerite, malybHo~aton and others, 1953 denite and Iron oxides Totem Bay, Kupreanof Rec:onnalssanc:e to loc:ate possible northwest0.003 percent eU Wedow and others, 1953, p. II Island (25) ward extension of thorium-bearing veins Houston and others, 1953 found In Salmon Bay area; bedrock c:onslsts of Tertiary volcanic: roc:ks Paint St. Albans area, Kulu Quartz-carbonate velnlets c:antalnlng 0.001 percent eU Wedow and others, 1953, p. II Island (26) sphalerite, galena, pyrite, pyrrhotite Houston and others, 1953 and Iron oxides Thomas Bay (27) Fissure vein c:ontalnlng pyrite, arsenopyrite, <0.001 percent eU Wedow and others, 1951, p. 60 c:halc:opyrlte, pyrrhotite(?) and secondary White and others, 1952, p. 17 metallic: minerals
Table I.--Summary of reconnaissance for radioactive deposits in southeastern Alaska, 1945-1954--continued Location Year of Types of deposits examined or (Refer~nce no. Q'l fig. 2) field work nature of invesligotion Radloact I vitl Remarks References Port Alexander quadrangle Port Malmesbury pitch1953 Reconnaissance of possible pitchblende occurCurrent information indicates no May also be location of hematitlcally Wedow and others, 1951, p. 63, 64 blende(?) prospect, Kulu renee reported by D. E. MacDonald significant radioactivity altered samples, found In collections Velikanje, 1953, written communication Island (28) of the Territorial Department of Mines at Motzko and Bates, 1955 the Ketchikan Assay Office, containing Also file data as much as 0.05 percent eU308 as determined by the New York Laboratory of AEC Goddard Hot Springs area, Reconnaissance for radioactive deposits In the Hot Spring waters not significantly Wedow and others, 1951, p. 64 banof Island (29) vicinity of a reported radioactive Hot Spring; radioactive. Heavy-mineral Bates and We dow 1 1953, p. 8 country rock chiefly granitic fractions of granitic rock contain West and Benson, 1955 as much as 0.016 percent eU; radioactivity is due chiefly to thorium In allanite and monazite Saginaw Bay, Kulu Island Chiefly barite, witherite and sphalerite in (0.001 percent eU, locally as Originally reported by Territorial DepartWhite and others, 1952, p. 17 and Keku Islands (30) vein deposits much as 0.005 percent eU ment of Mines as containing radioactivity anomaly of possible significance Sumdum quadrangle
Port Astley (31) Lenticular replacement veins In schist; contain 0.006 percent eU (maximum) Wedow and others, 1951, p. 60 pyrite, sphalerite, bornite, pyrrhotite, galena, Wedow and others, 1953, p. 6, 10
and covellite(?). Also reported to contain
native silver Sitka quadrangle o;
Chichagof and vicinity (32) Gold-quartz lodes In fault and shear zones; 0.002 percent eU (maximum) Wedow and others, 1951, p. 64 z contain common metallic sulfides and gold !:( z Baranof Exploration and Analysis of samples of gold-quartz veins sub- (0.001 percent eU Samples submitted by Moore hod been Wedow, 1953 !:( Development Co. claims mitted by JesseS. Moore, New York City, reported by Ledoux and Co. to contain between Klag Bay and Lake In February 1953 0.014 and 0.021 percent uranium oxide. Anna, Chichagof Island (33) Taku River quadrangle Speel Arm, Port Snettlsham Reconnaissance to locate possible occurrence 0.003 percent eU In quartz Wedow and others, 1953, p. 6, 10 (near Fannie Island) (34) of pitchblende(?) reported by U. S. Bureau diorite country rock Houston and others, 1953 of Mines Limestone Inlet (35) do (0.001 percent eU Wedow and others, 1953, p. 6 Houston and others, 1953 Juneau quadrangle T aku Harbor (36) do I 0.001 percent eU Wedow and others, 1953, p. 6, 10 breccia zone In schist contains pyrite and Houston and others, 1953 arsenopyrite Juneau and vicinity (37) Radioactivity traverses af roads in vicinity of 0.002 percent eU (maximum) Uranothorlanite reported In concentrates West and Benson, 1955 Juneau and examination of mine dumps of from Juneau airport dredging operations Motzko, 1953, written communication several mines In Juneau gold belt Admiralty-Alaska Gold Gold-quartz veins and a copper-nickel lode 0.001 percent eU West and Benson, 1955 Mining Co. claims, Funter Bay 1 Admiralty Island (38)
g ()
0 z !:( Table I.--Summary of reconnaissance for radioactive dePosits in southeastern Alaska, 1945-1954--continued Location (Reference no. on fig. 2) Glacier Bay area (39) Haines- Skagway area (40) Year of field work Types of deposits examined or nature of investigation Radioactivity traversing by geologic mapping party Radioactivity traversing by party Investigating magnetite occurrences In vicinity of Klukwan I/ TOM sample collected by Howard M. Fowler, Engineer, Territorial Department of Mines, Alaska Radioactivity Mt. Fairweather quadrangle No significant radioactivity detected Skagway quadrangle No significant radioactivity detected Remarks Included about 55 miles of road traverses with jeep and about 10 miles of foot traverses . Also underground workings of Inspiration Mine near Summit on White Pass and Yukon RR. References Seitz, 1950, written communication Tolbert, 1950, writte n communication g () :0
0 z !:(
' ! ' I "I '
.., OFFICiAl USE ONlY 2{) ) ~RI se:P:=::e 3::==o so Miles UKON -SHcoLuMillA · EXPLANATION Areas and localities Investigated {numbers refer to areas or localities listed in table 2 of text) INDEX AT LIN FIGURE 2.-- MAP OF SOUTHEASTERN ALASKA SHOWING AREAS AND LOCALITIES INVESTIGATED OFFIC IA L USE
(l) (2) :J!o examine a n:umber \Qf' typieal mineral deposits f~r ratioa~tivi ty. investigate SUCh l:'ellOrled OCCUrnces of radioactive materials or aJlomalies as a ~peared to warrant study .. rences of rs;ili:oacti ve materials to determine whether' field investigations were·warra.ntedo Field investigations- were therefore conduct vicini ties of· silver-lead 4eposi ts near Hyd r (locality 1), bismuth..:. beari-ng gold lodes near Ketchikan (locality 3), the reported radium-bearing hot spring· at GOddard Hot Springs (loeali ty ·.29.~ gold lodes a:t Chiehag~f Juneau (localities 32 and 37), an~ gold and nickel deposits at -Funter Bay (loeB.lity -38). ifieant activity were -collected in the Hyder ~rea. They eoJatain 0. 05 perce 'flle oeeurrenee of ura.ni um on Martit... Arm of B~ca. de Qa.s..dra. Inlet 7 east of Ketchikan reported by Wacker (Anonymous, 1932 7 p. 1) eou.ld not be in a sea.rch by the Territorial West) with directions from Wacker. HcYwever Wac::ker fnibsequ.ently claimed. that the search was not aon.ducted at the co eet locality. As Wacker has no $a:m.ples available for radioactivity test further attempt has been :made to ~~all).ine this prospect. Although no recon.na.issanee wa.s :ma.de s cifically for radioactive t"le:posi ts in southeastern Alaska in 1950 7 ioaeti ""n ty data were obtained i incidental to geologie studies by reg-alar Su.rvey parties in the HainesSkagway area. (locality .40) an.d in the 1rielnity of Glacier Bay (locality 39). OFFICIAL USE ONLY
,'1 OFFICIAL USE ONLY The appraisal of the uranium possibilities of southeastern Ala,ska (Wedow and others, 1951., p. 49-67) in 1950-51 indicated that a number of lode deposits in southeastern Alaska contain mineral assemblages similar to those characteristic of high-grade radioactive depos~ts elsewhere in the world. Most of these deposits are related genetically to the Coast Range batholith. Consequently, in the summer of 1951, a Geological Survey party conducted radioactivity reconnaissance e.x;aminatioiis of 47 lode mines, prospects, and other sites of favorable minera,l assemblages in southeastern Alaska. The chief localities were: the he~titic copper ores on Gravina Island {locality 5) and at Niblack Anchorage (locality 7), silver-lead-zinc deposits on the North Arm of Moira Sound (locality 8) , gold~tetr~edrite-pyrite breccia veins at Dolomi (locality 9), magnetitechalcopyrite deposits on Kasaan Peninsula (locality 12), and the silverlead-~inc ore in the vicinity of Groundhog Basin (local~ty 16). Also investigated in 1951 were a reported occurrence of tyuyamunite-bearing coal Union Bay '(locality 6) and thori'Ulll-bearing hematite-carbonate . veins /· Salmon Bay (J.cali ty 21). The only samples of si~ificance 1"1 were collected from the Sa.llnon Bay area. They contain 0. 095 percent ' I 1) equivalent uranium, and the radioactivity is due principally to thorium. In the field season of 1952 the reconnaissance for radioactive deposits in southeastern Alaska was continued wi the work centering chiefly on the study of the thorium deposits at Salmon Bay (locality 21) and the e.x;amination of geologically similar areas (localities 22, 23, and 25) elsewb.ere on the northe:r;n :part of Prince of Wales Island $D.d parts ot adjacent islands. Other reconnaissance in 1952 included the e.xamination OFFICIAL USE ONLY
OFFICIAL USE ONLY of: molybdenite-bearing lodes on Baker Island (.locality 14) and at Shakan (locality 24), lead deposits on Coronation Island (locality 15) and on the southern end of Kuiu Island (locality 26), copper ores at Green Monster Monntain (1oca.l.ity 1.1) and T.aake Bay (locality 13) 9 three occurrences of pi t;chblende (?) in the Taku Harbor-Port Snettisham area (localities reported by the U 0 S. Bureau of Mines, a silver-copper lode at Point Astley (locality 31), and a pitchblende(?) occurrence on the Mountain View property in the Hyder district (locality 1) reported in 1950-51 by the . Terri to rial Department of' Mines 0 Significant radioactivity was found only at the Salmon Bay and Mountain. 'View properties. The Salmon Bay examination did not reveal any samples higher in radioactivity than those collected the pre-v-ious year. The reported occurrence of pitchblende on the Mountain view property was not found. No major field studies were und~taken in the search for radioactive materials in southeastern Alaska during 1953. However, a brief, but un1 successful, attempt was made to find a reported pitchblende occurrence in. the: vicinity of Port MaJ..:mesbury (locality 28) o:tl Kuiu Island (Matzko ! and Bates, report in preparation)
I t ·:' Southern Alaska The sites of localities studied in southern .Alaska are shown on fi gr,rr~ 3; the data are summarized in table 2. Field investigation for radioac-tiv-e deposits in southern Alaska began ;'in 1945 when preliminary study (Harder and Reed, 1945) of placer concentrates in Alaskan collection.s show·ed that significant amounts of ;I OFFICIAL USE ONLY
t) t-o: w 0: :z t -
t- (1) w z (I) t-z w :::E w w w u
1Bose rrom Alaska Mop B, Edition of 1950 DFFICIAL USE ONLy :24 EXP LANATION Areas and localities Investigated (numbers refer to areas or localities listed in table 2 of text) QUADRANGLE INDEX M idd l ton Isla nd I L---L---L l l 2JOO M ilt USE ONlY FIGURE 3 ·- - MAP OF SOUTHERN ALA SKA SHO WIN G AREA S AN D LO C ALITIES INV ES TI G ATED
Location Year of (Reference no. of fig . 3) field work Nuka Bay area (41) Jakolof Boy area (42) Horner coal field (43) Yakataga Beoc:h area (44)
n
0 z
Hlnchlnbrook Island (45) Western Prince William Sound (46) Likes Creek area, Resurrection Peninsula (47) Moose Pass-Hope area (48) Girdwood area (49) Nlzina district (50) Golconda Creek, Bremner district (51) Table 2.--Summory of reconnaissance for radioactive deposits In southern Alaska, 1945-1954 Types of deposits examined or nature of investigation Quartz fissure veins c:ontolnlng gold, silver, copper, pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, cove II ite, tetrohedrlte and chalcocite Reconnaissance to locate reported radioactive ores Radioactivity traverse of Tertiary coal-bearing sequence In Homer coal field Mineralogic study of radioactive concentrates from beach placers submitted to USGS in Beach sands In Yakataga area Hematite deposits Radioactivity reconnaissance of granitic rocks, adjacent contact metamorphic zones, and various types of metalliferous lode deposits Reconnaissance to locate source of carnotitebearing sandstone sample submitted by prospector Quartz fissure veins and mineralized dikes contolnlng gold, silver, arsenopyrite, pyrite, galena, sphalerite, chalcopyrite, pyrrhotite, and molybdenite Fissure veins similar to those In Moose Pass-Hope area Radioactivity reconnaissance of various rocks and mineral deposits Placer-gold deposit Radiooc:tivitl Seldovia quadrangle 0 .002 percent eU or less 0.001 percent eU in unconcentrat.ed rocks; as much as 0.007 percent In concentrates No significant radlooc:tlvlty detected Bering Glacier quadrangle Concentrates contain as much as 0.32 percent eU; radioactivity due chiefly to three minerals of zircon group, two of which ore thorium-bearing, the other uranium-bearing. The unconcentrated beach sands contain 0.001 percent eU Cordova quadrangle 0.003 percent eU Seward quadrangle 0.003 percent eU or less Samples contain as much as 1.5 percent U; no significant radioactivity detected in the field 0.002 percent eU or less <0.002 percent eU McCarthl quadrangle 0.002 percent eU or less 0.004 percent eU in concentrate Remaks Chromite stockpile may hove been mistaken for pitchblende by prospectors Concentrates supposedly from this area were submitted to the USGS In 1952 and contain as much as 35 percent eU and 19 percent U; the chief radioactive mineral is uranothorianlte References Wedow and others, 1951, p. 109 White and others, 1952, p. 10-12 Moxham and Nelson, 1952b, p. 5 Cobb, 1950, written communication Moxham and Nelson, 1952a, p. 11-14 Motzko, 1953, written communication Motzko and Bates (Report In preparztlon, 1956) Wedow and others, 1951, p. 110 Wedow and others, 1953, p. 13 Wedow and others, 1953, p. 13 Wedow and others, 1952, p. 34, 35 Motzko and Bo tes, 1955 White and others, 1952, p. 10-12 White and others, 1952, p. 10-12 Moxham and Nelson, 1952o, p. I, 3 Moxham and Nelson, 1952a, p. 3
n "'
"' 0 z
Table 2.--Summary of reconnaissance for radioactive deposits in southern Alaska, 1945-1954--contlnued Location Year of Types of deposits examined or (Reference no. on fig . 3) field work nature of investigation Radioactivity Remarks References Valdu quadrangle Valdez-copper Center Radioactivity reconnaissance of serious types of 0.005 percent eU or less Moxham and Nelson, l952a, p. 3, 4 area (52) bedrock and mineral deposits, chiefly gold lodes Anchorage quadrangle Motonusko Volley (53) Radioactivity reconnaissance of various types of 0 .002 percent eU or less Moxham and Nelson, 1952a, p. 6 bedrock and mineral deposits Willow Creek mining Gold-bearing quartz veins 0.004 percent eU or less Moxham and Nelson, 1952o, p. 5 district (54) Fishhook Creek-Arch'angel Radioactive pegmatites Pegmatites overage 0.004 percent Moxham and Nelson, 1952a, p. 7-10 Creek area, Willow Creek eU; heavy-mineral fractions overmining district (55) age 0.33 percent eU; radioactivity is due chiefly to one or more of the following: uranlnite, thorlte, cyrtol ite, allanite g Anchorage-Kuik River Radioactivity reconnaissance of various types 0.002 percent eU or less Moxham and Nelson, 1952a, p. 5 area (56) of bedrock and placer deposits g n
n
Tyonek quadrangle "'
o-
Nikolai Creek area (57) Reconnaissance to locate source of carnotiteSample submitted by prospector Wedow and others, 1952, p. 20-23 z bearing I imestone samples submitted by proscontains as much as 0.6 percent Motzko and Bates, 1955
z pector, Howard Fowler. UJ08; no significant radioactivity
detected In field Mt. Spurr area (58) Study of concentrate and rock specimens Concentrates contain in O.OX range Bates and Wedow, 1953, p. 8 submitted by prospector percent eU; radioactive minerals ore chiefly monazite and zircon Nabesna quadrangle Alaska Highway (59) Granite and schist bedrock Granite contains as much as Wedow, Killeen, and others, 1954, 0.004 percent eU; no significant p. 13-16 radioactivity found In schist Bonanza Creek area , Gold- and silver-bearing galena-pyrite 0.004 percent eU or less Wedow and others, 1953, p. 6, 7 Chlsana district (60) veins and various types of associated bedrock Nelson and others, 1954 Orange Hill (61) Airborne radioactivity reconnaissance of lode No significant radioactivity Wedow and others, 1953, p. 6, 7 deposit containing chiefly copper, lead, detected Nelson and others, 1954 zinc and molybdenum sulfides Nabesna mine (62) Chiefly a gold lode but also containing various <0.001 percent eU Wedow and others, 1953, p. 6, 7 common sulfide minerals. Nelson and others, 1954 Rock Creek area (63) Molybdenite-bearing pegmatite 0.004 percent eU or less Wedow and others, 1953, p. 6, 7 Nelson and others, 1954 Mineral Point area (64) Altered shear zone containing copper, gold, <0.001 percent eU We dow and others, 1953, p. 6,8 silver, and traces of nickel(?) Nelson and others, 1954 Glenn Highway between Tests of concentrates from grovels of streams 0.003 percent eU or less Wc dow, Killeen, and others, Slana and Mineral Lake crossing highway 1954, p. 16-18 (65)
g n
0 z
Location (Reference no. on fig. 3) Silver Creek area (66} Indian group (67} Nelchina area (68) Iron Creek area (69} Cache Creek-Pete rs Creek area (70) "Alaska Highway (71) Richardson Highway between Donnelly Dome and Paxson (72) Table 2.--Summary of reconnaissance for radioactive deposits in southern Alaska, 1945-1954--Continued Year of field work Types of deposits examined or nature of investigation Radioactivity Remarks References Quartz veins, containing silver-bearing galena and tetrahedrite with same gold, cutting diorite Gulkana quadrangle Veins contain <.0 .001 perc<:>nt e U; diorite contains as much as 0.005 percent eU Wedow, Killeen, and others, 1954, p. 16-18 Wedow and others, 1953, p. 6, 8 Nelson and others, 1954 Quartz veins containing silver-bearing galena 0 .004 percent eU or less Wedow and others, 1953, p. 6, 7 and tetrahedrite, cb..aJ..co.p.yrite malachite and Nelson ancl others, 1954 azurite Tests of concentrates from Nelchina placermining district and radioactivity traversing of various types of bedrock in the course of geologic mapping Chiefly replacement deposits containing chalcopyrite, pyrite, hematite, and other copper and iron oxides Investigation of gold-placer deposits containing radioactive minerals Radioactivity tests of bedrock and placers adjacent to highway Test of concentrates from placers of streams adjacent to highway Talkeetna Mountains quadrangle No significant radioactivity detected 0.002 percent eU or less Talkeetna quadrangle Heavy-mineral fractions of concentrates with uranothorianite, monazite and zircon are in the O.OX range of percent eU Mt. Hayes quadrangle Heavy-mineral fractions of concentrates from placers of streams draining areas of granitic rocks contain as much as 0.014 percent eU; radioactivity probably due to zircon 0.004 percent eU or less except for those of Ober Creek which range from 0.003 to 0.001 percent eU; radioactivity due to traces of monazite Healy quadrangle Bedrock source of radioactive minerals not found, but believed to lie in the Alaska Range north of the area; uranothorlanite also occurs in placers of Kahiltna River below Cache Creek Moxham and Nelson l952a, p. 3,4 Weciow and others, 1953, p. 13 White and others, 1952, p. 7-9 Robinson and others, 1946 Harder and Reed, 1945 Wedow, Killeen, and others, 1954, p. 13-16 Obet Creek concentrates also contain traces Wedow, Killeen, and others, 1954, p. IS of fluorite Drazenovlch uranium claims Radioactivity examination No significant radioactivity detected Moxham and West, 1953b, p. 3,7 along Alaska Railroad 4 miles south of Healy (73) Mt. McKinley (74) Radioactivity tests of 50 rock specimens collected by the 1947 Bradford Washburn Mt. McKinley Expedition Mt. McKinley quadrangle A specimen of manganiferous vein quartz contains as much as 0.009 percent eU; granitic rock types contain as much as 0.004 percent eU; remaining specimens are essentially nonradioactive Motzko, 1951
n ;;: "' ,
0 z
g ()
0 z
Location (Reference no. on fig. 3) Mt. Eielson area (75) Kantlshna Hills area (76) Alaska Railroad right-of-way (77) Year of field work Table 2.--Summary of reconnaissance for radioactive deposits in southern Alaska, 1945-1954--continued Types of deposits examined or nature of ·investigation Radioactivity Mt. McKinley quadrangle--continued Replacement deposits containing chalcopyrite, sphalerite, galena, pyrite, and arsenopyrite; the galena and sphalerite are silver-bearing Quartz fissure veins containing silver-bearing galena and tetrahedrite,pyrlte, arsenopyrite, sphalerite, chalcopyrite, and secondary copper and Iron minerals (0.001 percent eU 0 .001 percent eU or less Remarks Seward, Anchorage, Tyonek, Talkeetna, Talkeetna Mountains, and Heoly quadrangles Radioactivity traverse significant radioactivity detected References White and others, 1952, p. 7-9 White and others, 1952, p. 7-9 Moxham and West 1 1953b g () N
Cx>
0 z
OFFICIAL USE ONLY · I radioa;ci;i ve material occur in the Yentna district. The study by Robinson and others (1955) the Cache Creek-upper Peters Creek area (local~ty 70) disclosed that the placers did not contain sufficient amounts of radioactive mineraJ.s to be considered as an immediate source of uranium. The bedrock source of the radioactive minerals was not found. Investigations in southern .4laska were continued in 1946 with examinations along parts of the Alaska Highway (locaJ.ities 59 and 71), along part of the "Tok Cutoff'!, now designated as the eastern section of' the Glenn Highway (locality 65) , and in the Donnelly Dome-Paxson area (locality 72) on the Richardson Highway. No radioactive deposits of sigr~ficance were found. In 1947 study of areas contiguous to the highway system of Alaska was continued with the extension of reconnaissance to the ''southern highway belt. n 'fhe studies included selected localities in the Nizina dist!'ict, Bremner district, Valdez-Copper Center area, Matanuska valley, Willow. Creek mining district, and An.chorage-Knik River area (localities , I 50-54, . and 56 respectively) Again, no significant.ly radioaeti ve deposits were discovered. No field investigations were made in southern Alaska during 1948, but laboratory studies disclosed the presence of radioactive minerals in prospectors' samples of beach placers at Yakataga (locality 44) and traces o± .. radioactivity in spec:tens of vein quartz and granitic rocks ·collected on Moimt McKinley by the 1947 Washb~rn Expedition (locality 74) Radioactive pegma.tites in the Willow Creek mining district {locality 55), found in 1948 by a Survey fiel d party studying the gold lodes of the district, were examined in 19490 The :pegmatites, however, did not contain OFFICIAL USE ONLY
OFFICIAL USE ONLY co:mme:rcia.l ainounts of uranium. or thorium, although the slight radioactivity present was found t o be due chiefly to trace amounts of uraninite, thorite, and aJ..la.rdte. Also in:vest igat ed. i n 1949 was a reported occurrence of pitchblende in the Ja.kolof Bay area {locality 42) on the Kenai Peninsula. No radioactivity of significance was detected ill. this area, and it is thought i;hat the report originated when J;>rospect ors may have mistaJ!en ehromi te for pitchblende in a stockpile on the shore of Jakolof Bay. The only field studies made in southern Alaska during 1950 were limited to a radioactivity traverse along; the right-of-way of the Alaska Railroad (locality 77) and an examination of ~laims staked for uraniUJD. near Healy (locaJ.i ty 73) No anomalous radiat ion was detected. reappraisal of the uranium possibilities of Alaska (Wedow and others, 1951) in 1950-5J. indicated that certain meta.l.l1fero1:lS lode~ in southern Alaska contain mineral asse~blages associated with uranium II ; else'W'liere and hence were favorable for reconnaissance. Field appraisal of some of these favorable deposits was conducted in 1951 included ' loca..l~ties in the Nuka Bay, Moose Pass-Hope, and Girdwood areas (1,9eali ties 41, 48, and 49 respectively) on the Kenai Peninsula; in the Iron Creek (locality 69) of the Talkeetna MOuntains; and in the MOunt Eielson and Kantishna Hills areas (localities 75 and 76 respectively) on the north fl.~ · of the Alaska Range. No radioactive deposits warranting additional study were disclosed. The reconnaissance examination of favorable lode deposits in southern Alaska was extended in 1952 to include selected localities (nos. 6o-64, 66, and 67) in the eastern Alaska Range. In addition to investigations OFFICIAL USE ONLY
OFFICIAL USE ONLY to search spec:if'iea.lly for uraniferous deposits, other C-eological Survey parties made r~dioactivity tests in the N'elchina area (locality 68) and the Prince William Sour1d region ( locaJ.i t .ie s 45 and 46) inc:i.dental to geologic studies. In 1954, samples were collected from the beach sands in the Yakataga area (loca.li ty 44) to determine the extent and concentration of radioaeti ve minerals known to oec:ur in the sands. Preliminary ~s:ul ts on samples obtained at a maximum depth of eight feet indicate that under present -conditions, the beach sands are too low in radioactive black minerals to be a source of uranium, even as a byproduct material (Matzko and Bates, re:po~ in preparation). Southwestern Alaska Southwestern Alaska, which in this report includes mo$t of the lower Yukon-Kuskokwim region, the Alaska Peninsula and the Alel,ttian Islands, has n~t been investigated for radioactive deposits in the same degree as several of the other main regions of the Uerritory, primarily because of its rf!'..moteness, general inaceessibili ty, and general dearth of geologie information on which to base an appraisal of its favorability or lack of favorability for uranium ores. 'I'he suJlmmry data on the limited amount of r econnaissance conducted. in ~outhwestern Alaska. are given in table 3 and tb.;:~ locations of the areas investigated are shown on figure 4. The first known occurrence of a uranium mineral in southwestern Alaska was ~scovered in 1947-48 (Moxham, 1950) when metazeunerite was · identified in a concentrate from a copper deposit at the Konechney OFFICIAL USE ONLY
I · IY w cr <1' IV) w
z 1/) I · w ,.
w u
a: B R I 8ol'e from Alas a Mop E, Edition of 1946 FIGURE 4 ·-- MAP OF SOUTHWE STERN OFFICIAL USE ONLY EXPLANATION Ale as and local It les inve st i9ote d (numbers refer to areas or loc alities listed In table 3 of te xt) II() KA SHOWING ARE AND LOC ALITI ES INVE STIG ArEO OFFICIAL USE ONLY
g () 1!
0 z
Table 3.--Summary of reconnaissance for radioactive deposits in southwestern Alaska, 1945-1954 Location (Reference no. on fig. 4) Kodiak and vicinity (78) Year of field work Types of deposits examined or nature of investigation Study of uraniferous sample submitted by prospectors in 1953 Radioactivity Kodiak quadrangle Commercial assays show a content of over I percent U; radioactivity due to meta-autunite and metatyuyamunite Iliamna and Lake Clark quadrangle Iliamna Lake-Lake Clark region (79) Russian Mountains area (80) Marshall area (81) Chiefly silver-lead and copper deposits; also tested were various types of bedrock and concentrates of gravels from streams draining the more Inaccessible areas Copper prospects Vein deposits containing molybdenum, copper, and lead minerals and gold; also associated Igneous and sedimentary rocks Maximum radioactivity of rocks and ores tested di d not exceed 0.002 percent eU; maximum radioactivity of gravel concentrates was 0.007 percent eU; traces of radioactivity believed due chiefly to common accessory minerals of granitic rocks Russian Mission quadrangle A concentrate collected in 1944 from the workings on the copper lode of the Konechney prospect contains 0.017 percent eU due primarily to metazeunerite. Field examinations in 1952 found only 0.004 percent eU in quartz monzonite country rock and 0.002 percent eU or less in ore samples, although a trace of metazeunerite was found in one sample from the dump of the Konechney prospect Marshall quadrangle 0.001 percent eU or less Remarks Field investigations did not reveal any significant radioactivity and the uranium-rich samples submitted by the prospectors were not duplicated. References Matzke , 1953, oral communication Motzko, 1955, USGS-P~ii. no. A-1,741 Re-examination of the concentrates in 1953 Moxham and Nelson, 1952l, p. 1-4 disclosed that the radioactivity (0.007 percent eU) in a con~ ·:n trate from the east shore of Lake Clark may be due to traces of a sooty block uro~ ium mineral In 1952 all underground workings were inaccessible Moxham, 1950 We dow and others, 1953, p. 2, 4 West, 1953, p. 5-7 Wedow and others, 1953, p. 2, 4 West, 1953, p. 8-9 g () w
w
OFFICIAL USE ONLY prospect in the Russian ~Iountains (locality 80) .. The sample had been collected in 1944 by a G-te;ologicaJ. Survey p~rty conducting mineral resource investigations in the cent raJ. Kuskokwim region. The problems of accessibility.and logistics, and the scheduling of other ·work elsewhere in Alaska prevented the examination of the Russian Mountains area until 1952, when helicopter-support was available from the 30th Engineer Topographic Battalion, U.. S Army. Unfortunately most of the surf' ace and underground workings at the Koneehney prospect was then inaccessible so that direct examination of the metazeuneri te-·bearing vein could not be made and only traces of meta.zeuneri te "Were found in h.ighly disintegrated material on the mine dumps. The earliest field investigations in southwestern Alaska specifically for radioactive deposits were made in 1949 by Moxham and Nelson (1952b, p. ).-4), in the Iliamna Lake-Lake Clark region (locaJ..ity ,79). The inve.stigation included the examination of' silver-lead and copper lode depos~ts, one of which had been reported earlier to contain uranium .. Also tested were most of the rock types in the more accessible parts of the region as well as numerous concentrates from creeks draining the more inaccessf:ble areas. Only traces of radioactivity were detected and it wa~ concl-uded that the region held little promise for the occurrence of' urard·um minerals. However, re-examination in 1953 of several of the eo~centrates taken along the shore of Lake Clark disclosed that the sl ight radioactivity of a concentrate from a beach deposit on the east shore of the lake in the vicinity of Currant Creek is due to traces of a highly radioactive mineral believed to be sooty pitchblende(?) rather OFFICIAL USE ONLY
OFFICIAL USE ONLY than concentrations of one of the more refractory accessory minerals of granit,ic rocks as had been supposed. An investigation was made in southwestern Alaska cf vein deposits containing molybdenum, lead, gold, and copper minerals in the Ma.rsl').all area (loc~ity 81). These metalliferous lodes had been indicated as favorable for the presence of uranium in the 1950-51 appraisal of Alaskan uranium possibili.ties (Wedow and others, 1951, p. 83, 91), but when examined in 1952 were found to be essentially nonradioactive. In 1953 a :prospector from Kodiak su.bmi tted a sample eontain:i.ng about 1 percent uranium to the Geological Survey (locality 78) Mineralogic analysis· of the sample indicated that the chief uraniferous minerals are
meta.tyuyamtmi te and meta-autunite. The site f'rom which the satnple was taken was reported by the prospectors as just outside the city limits of' Kodiak. A field examination of the sample locality and surrounding area ,· in 1954, however, did not locate any significantly radi<;>aeti ve material (Matzko and Bates, ~pc>:t;t in preparation). East.central Alaska '·' The data. on the reconnaissance investigations for radioactive deposits in east-central Alaska are summarized in table 4; the areas covered by these investigations are shown on figure 5. Although no field tests for radioactivity were made in east-central Alask~ in the initial year (1945) the Alaskan reeoooaissanee program, concentrates from various placer mining districts in the Yukon-Tanana region were collected by R. R. Coa::'cs of the GeologicaJ. Survey specifieflily OFFICIAL USE ONLY
Location (Reference no. on fig. 5) Alaska Highway (82) Glenn (Siana-Tok) Highway from Mineral Lake to Tok Junction (83) Taylor (Fortymile) Highway from Fortymile Junction to Chicken (84) Chicken area (85) s () ·
0 z
Wilson Creek area (86) My Creek area (87) Ben Creek area Copper Creek copper prospect (89) Table 4.--Summary of reconnaissance far radioactive deposits in east-central Alaska, 1945-1954 Year of Types of deposits examined or field work nature of Investigation Radioactivity Remarks Tanacross quadrangle Radioactivity reconnaissance of rocks adjacent Most radioactive rocks are granites to highway which contain as much as 0.005 percent eU which is due chiefly to zircon and allanite Radioactivity reconnaissance of rocks and No significant radioactivity deplacer deposits adjacent to highway tected; maximum radioactivity of placer concentrates 0 .003 percent eU Radioactivity reconnaissance of rocks adjac.ent No significant radioactivity detected, to highway except in vicinity of Mt. Fairplay where granitic rock contains as much as about 0.018 percent eU; radioactivity due chiefly to zircon Eagle quadrangle Radioactivity reconnaissance and tests of Granitic rocks and conglomeratic samples donated by prospectors arkose(?) near Chicken contain as much as 0.005 percent eU; placer concentrates from Atwater Bar on the South Fork of the Fortymile River contain 0.04 percent eU--radioactivity due to uranothorlanlte and monazite Radioactivity reconnaissance to locate pitchPitchblende not found; maximum blende-bearlng vein reported by Charles radioactivity detected is in Fellyez granitic rocks that contain as much as 0.005 percent eU Radioactivity reconnaissance to locate occurPitchblende not found; maximum renee of pitchblende reported by E. D. Manske radioactivity is 0.003 percent eU in granitic rocks; quartz veins containing galena and hematite contain <0.001 percent eU Radioactivity reconnaissance to locate high-grade High grade uranium ore not "yellowish uranium ore" reported by Wm. Ott found; maximum of 0.005 percent eU occurs in felsic igneous rocks; radioactivity probably due to accessory allanite and monazite, as these were identified in concentrates containing O.OX percent eU from placers of creeks draining areas of felsic igneous racks Radioactivity study of "contact" copper deposit Chief anomalous radioactivity is in in highly metamorphosed roof pendant in granite iron-stained rocks along fractures batholith in lime-siliceous rocks, maximum radioactivity Is about 0.03 percent eU--rodioactlvity due to uranium os Impurity in copper minerals References Wedow, Killeen, and others, 1954, p. 13-16 Wedow, Knleen, and others, 1954, p. 16-18 White, Nelson, and Motzko (manuscript in preparation) Motzko, written communication, 1954 Wedow, White, and others, 1954, p. 10-12, 20-21 Wedow, White, and others, 1954, p. 13-18 Wedow, White, and others, 1954, p. 18-19 Wedow, White, and others, 1954, p. 19-20 Wedow, White, and others, 1954, p. 7..,9 g () w
()o 0 z
g ()
0 z
Location Reference no. on fig Fortymile fluorite occurrences Lower Mission Creek area (91) Table 4.--Summary of reconnaissance for radioactive deposits in east-central Alaska, 1945-1954--continued Year of field work Types of deposits examined or nature of investigation Reconnaissance of two fluorite occurrences near Chicken Reconnaissance of Mesozoic(?) granite and its Tertiary sedimentary derivatives Radioactivity Eagle quadrangle-continued Maximum radioactivity 0.003 percent eU Granite averages 0.005 percent eU and arkose derived from the granite average 0.004 pe·rcent eU; biotite is the chief radioactive mineral in the granite and zircon and monazite contain the radioactive elements in the arkose rocks Eagle and Chorley River quadrangles Remarks Fluorite ranges from colorless through green to purple Traces of uranothorianite reported in 1953 in placer concentrate from drainage of Seventymile River Yukon River between Eagle Reconnaissance of sedimentary rocb of Precamorian to Triassic age None of the sedimentary rocks contain more than 0.003 percent eU except for black shale beds Phosphatic pellets from one of the black shale beds contain as much as 0.022 percent eU, 0.019 percent U and about 15 percent P2o5 and Nation (92) Richardson Highway in Harding Lake-Richardson area (93) Miller House-circle Hot Springs area (94) Hope Creek area (95) Steese Highway in upper Chatanika Valley (96) in the Mississippian Calico Bluff formation; two black shale units each averaging about 6 feet thick contain 0.006 to 0.007 percent eU Big Delta quadrangle Radioactivity reconnaissance of rocks adjacent to highway Reconnaissance for radioactive deposits associated with granitic rocks Reconnaissance for radioactive deposits associated with granite and reported quartz-pyrite-fluorite veins Radioactivity reconnaissance of rocks adjacent to highway Maximum radioactivity in area found in granitic rocks tha1 contain about 0.005 percent eU; the chief radioactive minerals zircon and allanite(?) Circle quadrangle Granitic rocks contain as much as 0.007 percent eU; concentrates from placers contain in O.OX range percent eU; chief radioactive minerals are uranothorianite, allanite, sphene, purple Fluorite, scheelite, malachite, zircon, and at one locality an unidentified yellow-green secondary uranium mineral Granites contain as much as 0.004 percent eU; float fragment of limonite-hematite granitic breccia contains O.<l5S percent eU Granitic rocks contain as much as 0.005 percent eU, graphitic schist as much as 0.003 percent eU and ather schist 0.002 percent eU or iess; a dredge concentrate from placers on Nome Creek contains 0.012 percent eU probably due to thorium In traces of monazite A water sample from Portage Creek contains as much as 40 parts per billion uranium Review of the mineralogy Indicated purple fluorite at the head of American and Sourdough Creeks References Wedow and others, 1953, p. 13 Wedow, 1954 Motzko, 1953, written communication Wedow, 1954 Wedow, Killeen, and others, 1954, p. 11-13 Wedow, White, and others, 1954, p. 4-6 Wedow and others, 1953, p. 3, 5, 6 Nelson and others, 1954 Motzko and Bates, 1955 We dow and others, 1953, p. 3, 5 Nelson and others, 1953, p. 25-29 Nelson, West, and Motzko, 1954 Wedow, Killeen, and others, 1954, p. 8 g () w
'l
0 z
g ()
0 z
location (Reference no. on fig. 5) Alaska Railroad right-of-way (97) Liberty Bell mine (98) California Creek prospects (99) Ester Dome area (100) Pedro Dome are a (101) Melba Creek bismuthbearing gal d lode prospect (102) Tolovana mine on Willow Creek (103) Cleary Hill mine (104) Anderson prospect (105) Fox Creek silver-lead prospects (106) Elliot Highway (Fox to Livengood) (107) Table 4.--Summory of reconnaissance for radioacti ve ckposits in east-central Alaska, 1945-1954 --continued Year of field work Types of deposits examined or nature of investigation Rodiooctivity traverse Gold-bearing quartz veins with arsenopyrite, pyrite, chalcopyrite, and bismuthinite Two prospects: I) quartz veins containing stibnite, pyrite, and chalcopyrite; and 2) quartz vein containing silver-bearing galena Radioactivit y Fairbanks quadrangle No significant radioactivity detected 0.002 percent eU or less 0.002 percent or less Fairbanks and Livengood quadrangle (Fairbanks district) Chiefly gold-lode prospects Chiefly gold, tungsten, and antimony lode prospects; granitic rocks, schist, and placer concentrates also tested Gold-lode prospect reportedly containing bismuth minerals and considered to be a possible source of radioactive bismuth nuggets in placers of Fish Creek; deposit consists of quartz veins cutting a fine-grained biotite granite Gold-bearing quartz veins containing minor amounts of arsenopyrite and stibnite Gold-bearing quartz veins containing minor amounts of arsenopyrite and stibnite Sheared quartz vein in granitic rock containing gold and several of the common sulfides Silver-bearing galena In quartz-carbonate veins cutting highly weathered granitic rock Radioactivity traverse of Precambrian and Paleozoic rocks adjacent to highway Maximum radioactivity detected was 0 .005 percent eU No significant radioactivity detected; maximum eU percent obtained in bedrock was 0.003 In granodiorite from Pedro Dome and in sulfide-enriched limestone on Seattle Pup 0 .002 percent eU or less 0.003 percent eU or less 0.003 percent eU or less Maximum of 0.006 percent eU in granitic rock Samples of galena normally contain less than 0.01 percent eU, but locally contain as much as 0.03 percent eU In weathered pockets Livengood quadrangle Samples collected contain a maximum of 0 .003 percent eU, Birch Creek schist .004 percent eU, Middle Devonian and Carboniferous dark shale Remarks A 3-pan concentrate from Buzzard and Iron Creeks divide submitted by a prospector contains 0.015 percent eU with traces of platinum Prospect stoked in 1951 by Messrs. Lindgren and .Fultz as a silver-uranium deposit; as DMEA application for Government aid was turned down the claims were ollo"!ed to lapse. U.S. Geological Surv"y work in 1952-53 consisted of applying geochemical prospecting techniques to the study of the prospects to determine whether such techniques could be used in the reconnaissance for uranium deposits in Alaskd References Moxham and West, 1953b White and others, 1952, p. 7-9 White and others, 1952, p. 7-9 Motzko, 1953, written communication Wedow, Killeen, and others, 1954, P· 3-8 Wedow, Killeen, and others, 1954, P· 3-8 Wedow, White and others, 1954, p. 1-2 Wedow, White, and others, 1954 P· 2 Wedow, White, and others, 1954, P· 2 White and others, 1952, p. 7, 9 White and others, 1952, p. 7, 9 Motzko, 1953 and 1954, written communication Wedow, Whlte,and others, 1954, 2
Location Year of (Reference no. on fig. 5) field work Livengood district (108) Manley Hot Springs-Ranpart 1948 district (109) Grant Creek area (110) g n
Yukon River traverse (Ill) 0 z
Porcupine and Coleen Rivers (112) Chandalor mining district (113) Gold Bench area, South Fork of Koyukuk River (114) Table 4.--Summary of reconnaissance for radioactive deposits in east-central Alaska, 1945-1954--continued Types of deposits examined or nature of investigation Radioactivit~ Remarks Livengood quadrangle--Continued Radioactivity reconnaissance of lode prospect, Source of euxenite-polycrase bedrock, and placer deposits with particular mineral not found; maximum radioemphasis on source of euxenlte-polycrase activity detected in bedrock was mineral found in placers on Goodluck Creek 0.005 percent eU in granite on Livengood Ridge; traces of monazite found in placers of Ruth Creek Tanana quadrangle Radioactivity reconnaissance of lode prospects No significant bedrock source of and bedrock types of district with emphasis on radioactive minerals located; concolbalt-bearlng silver-lead lode, and granitic centrates from placers generally rocks; also to locate source of ellsworthite, contain O.OX percent eU; granitic eschynite and columblte found in placers of rocks contain as much as 0.004 Tofty tin belt percent eU; silver-lead lode material contains O.OOX percent eU. Reconnaissance to locate source of pitchblende Source of pitchblende not located, reported by Walter Fischer no significant radioactivity detected in areal traverse. Tanana, Livengood, and Beaver quadrangles Radioactivity traverse of rocks adjacent to river No significant radioactivity detected except in a monzonltlc rock from a locality about 30 miles below Rampart; It contains 0.008 percent eU Coleen quadrangle Radioactivity traverse of sedimentary rocks adSilurian black shale contains a maxifacent to lower Coleen and upper Porcupine mum of 0.005 percent eU, CarbonifRivers and reconnaissance of granitic rocks erous black shale - a maximum of along [nternationol Boundary north of Rampart 0.003 percent eU, Precambrian shales - House a maximum· of 0.005 percent eU; granitlc rocks contain as much as 0.006 percent eU which appears to be due chiefly to traces of unidentified uranium minerals Chandalar quadrangle Rodl.ooctivlty reconnaissance of metalliferous Vein deposits contain 0.001 percent veins for possible uraniferous deposits; also or less eU; placer concentrates attempt to locate source of monazite In placers contain as much as 0.05 percent eU, due chiefly 1to thorium In monazite Wiseman quadrangle Radioactivity reconnaissance to locate bedrock Bedrock source not found; grovel consource of placer uronothorlonl~e and associated centrates contain as much as 0.18 sulfides percent eU References We dow, Killeen, and others, 1954, p. 8-11 Wedow, White , and others, 1954, p. 2-3 Moxham, 1954 Wedow, Killeen, and others, 1954 p. 33-36 White, St.ovens, an-! Motzko (report in preparation) White, 1952a White, 1952b Wedow and others, 1953, p. 3 Nelson and others, 1954 White, 1952b Wedow and others, 1953, p. 3 Nelson and others, 1954 Motzko and Bates, 1955 g n w
'()
0 z
0: ) n. w 0: z I.JJ
..J h.l w
8ose from Alaska Mop B, Edition or 1950 OFFICIAL USE ONLY FIGURE 5 - ·MA P OF EA ST- CE NTRAL AL S A SHOWIN G ARC AS AND L O C ALITI ES INVE STI G ATED OFFICIAL USE ONLY EXPL ANATI O Areas and loca lities inv stigot d fer to areas or loca lities listed in table 4 of te t) QUADRANGLE INDEX 2 00 Moles J
f'or rati~aeti vi ty tests. Hewever Jl rA~ne @f tb.e eonetentrates eolleeted in 1945 shoved appreeiab~e amotm.ts of raiii~ae~i vi t;r or aey areas favorabl.e Harder a:ad Reed (1945). In 1946 reeonnaissaaee vas directed toward the ~earth for radioactive district (loea.lities 100 and. .101) al.ong the Steese Highvay (locality 96) P the Livengood district (locality loB) j tUOng the Riellardson Highway in the Harding :take-f;tieha.rdson are·a ·(locality 93) and along a part of the Alaska Highway (loea..ti ty 82) Also investigated in 1946- vas a reported pi tehblen.de oecur:renee in the Graat Creek area (l~eali ty 110) north of the Yukon River west of Tanana. lione of the 1.946 investigationB di6e~osed commercial deposits of radioaeti ve materials, al. though minor amou.Bts ot uranium. and t tho~um, oeeurring ehief'ly as im.pufiti~ .® in aeeess10ry 'mineral.s of grauitie roeks, were f'ouna to be in the an;-as investigated. Alaska during +947. Ill 1948, investiga.titl!U3 were made in the Eagle-Dation. area (localities 91 and 92), aloq the Porcupine- sad e~leea . Rivers _(locality t
112) and in the. Maaley Rot Spri~g~-Rampa.rt di~triet (1reality.l.09). Seetioms of sedimentarY rocks, ehietl.y ft'Jf Preeambrlau u.S. Pale~zei~ age 1 :many· thousa.n.U of :feet in ~cones&l were traver~ed for rati®aeti"f'ity along the Yukoa River between Eagle and Nation (locality 92) and along and Coleen Rivers (loeaJ..i ty 112) Tile major sedimentary r,oek types of interest in these areas were radioactive black ~hales of Paleo;oie age similar to OFFICIAL USE OBLY
Official Use Only
f .ormatiol!S in the United. States tha.t eonta.in large reserves ot low-grade uraniferous: material.; and ·Precambrian red beds, 'Which at one loeaJ.i ty in northwestern Canada contain deposits with monazite and pitchblende or ura.ninite (Rabbitt, 1947; Lang, 1952, p .. 63, 65). On the other hand, none of the Precambrian strata traversed contained ra.dio$etive .materials similar to those found in beds of comparable age in C~&Aa. Grardtie rocks of Mesozoic(?) age in the lower Mission Creek area (locality 91.) near Eagle contain minor amounts of the radioelements in such accessory· mineral.s as biotite, zircon, a.nd monazite, whereas in similar rocks along the international boundary north of' the Porcupine lli ver :tloeali ty · 112), the radioactivity is due to trace amounts of unidentified uranium minerals. The investigation. in the Manley Hot Springs-Rampart di~trict {l.oeal.i ty 109) wa.s primarily eoneerned with the examination of a eobal tsiJ. ve.r~lead lode deposit gn Hot Springs Dome a."l.d the search for the bedrock source of uraniferous minerals associated with cassiterite and gold in the : placers of the Tofty tin belt. The eobalt~bearing lode proved to be essenti.aJ.ly no:nradioaeti ve and the source of the uran~ferous minerals in the placers eou1d not be located. Reeorma.issuance parties in the field during 1949 conduete:d studies . at a number of widely scattered areas in eftle~~-t~- (:~b~:u' fte'Se' ' ·[;:~s c. ~:Jtu.dies included: ·· radioaeti vi ty traverses along the Yukon Bi ver (loeali ty 29) and along the Elliott Highway (l.oeali ty 107); the search for the bed-· roek sources of uraniferous minerals identified in eoneentDates from placers in. the Livengood area (locality 1o8) and in the Miller House-Circle Hot OFFICIAL USE ONJ:,Y
OFFICIAL USE ONLY Springs area (locality 94); the in,vestigation of favorable met~life:rous lodes in the FairbarJ\:s di.strict (localities 102-104) and on Copper Creek (locality 89) in the Eagle district; the search for re,ported occurrences of high-grade u.ranimu ores in the Fortymile district (loeaJ,.i ties 85-B8) .. Although no deposits warranting e:xploration discovered, minor amounts of" the radioelem.ents were found in most of the ,localities studied, chiefly in the accessory minerals of granitic rocks. The recognition of uraniferous fluorite in granitic rocks of the Miller HouseCircle Hot Springs area vas of specific note and the occurrence indicated the need for f1l,ture study. In 1950, reconnaissance in east-central Alaska was ·11m1 teO. to radioactivity traverses along the right-of-way of the Alaska Railroad (locality <J7) and along the southern half of the Taylor (Fortymile) Highway (lo~ cality 84). No significant radioactivity was detected along the railroad, but along the Taylor High:way granitic rock were found to contain minor amounts of uranium, chiefly in ac.eessory zircon.. Reeonna.issuance in 1951 consisted of the exa;rnination of 9everal possibly favorable ·lode deposits in the Fairbanks region (localities 98, 99, 105, and 106). None of these deposits exhibited radioactivity of interest except for the silver-lead deposit at the head of Fox Creek northeast of Fairbanks (locality 106). However, the radioactivity at this prospect was not sufficient to grant a DMEA loan requested. by the prospectors who noted the radioactive galena. At th,is locality the radioactivity of silver-bearing galena veins is due chiefly to minor a.mounts of urar...ium generally concentrated in weathered pockets in, :massive OFFICIAL USE ONLY
OFFICIAL USE ONLY ,. ! l!l pieces of ore. Although not of commercial significance, the deposit is unique in that 1 t was t.he first uraniferous vein depo.si t f'ou..11d in the Fairbanks distrieto Search for radioaci.;i ve deposits in east-central Ala.-ska. was continued in 1952 with the- investigation of reported. fluorite occ~crences in the Hope Creek area (locality 95), Mil.ler House-Circle Hot Springs area (locality 94) and in the Fortymile district (local.ity 90); the search for the bedrock source of placer monazite and the testing of meta.ll.:ferous lodes in the Chandalar district (locality 113); and a brief search for the bedrock source or placer u.ra.nothorianite and associated sulfides at Gold Bench on the South Fork of the Koyukuk River (locality 114). In addition to · the above, samples were take.n at the Fox Creek silver-lead deposit (locality 106) for preliminary tests to determine whether geochemical techniq,ues eoul.d be applied to the search for uranium in the dee:ply weath~red tundra. ... covered terrain of interior Alaska. Again, no deposits worthy . of exploitation were discovered. Of note, however, was the reeogji nition of an unidentified secondary yellow~green uranium mineral in granite a.nd ura.nothoriani te in placers on Portage Creek in the Miller House-Circle Hot Springs area. The preliminary geochemical tests at the Fox Creek silver-lead deposit indicated that such teeb11j ques were feasible and that mi~or var~ations in uranitun generally followed variations in the lead and zinc content of the residuum overlying the veins. In 1953 brief' additional studies w·ere made in the vicinity of Gold Bench, at the Fox Creek silver~lead prospect, and in the Circle Hot Sprlngs area (Matzko and~ Bate~, 1955). The re ~:n.il.ts of these studies OFFICIAL USE ONLY
OFFICIAL USE ONLY emphasized. the need and desirability of using waterJ soil, and plant sampling techniques i n deeply weathered areas coYered by muck, tundra, and vege.lGation. West-central Alaska Su~aries of reconnaissance investigations for radioactive deposits in west-central Alaska are given in table 5. The locations of the area investigated are shown on figure 6. The search for radioactive deposits in west~central Alaska was ini tia·ted in 1945 with the investigation of placers containing radioactive minerals. Investigations in the northeastern part of the Seward Peninsula were made in the Sweepstakes Creek area, of the Bucklan.dKiwalik district (locality 135) and in the Candle Creek area {locality 137) ., Investigations in the western part of the peninsula were made at Ear Mountain (locality 139) and~ Cape Mountain (locality 141) in the York district. Also in 1945, R. E. WaJ.lace of the Geological Su_T"Vey collected additional concentrates in the Nixon Fork-McGrath area specifically for radioactivity studies. ~though the investigat:i.ons in the Sweepstakes Creek area failed to locate the bedrock source of the chief radioactive mineral--uranothorianite-- in the placers, the data obtained suggested that its source was probably in the granitic rocks underlying Granite Mountain in the northern part of the area. Similarly, the bedrock source of uranothorianite in the Candle Creek placers could not be located, but the source is believed to be in altered felsic rocks on one of the he~water tributaries of the creek. OFFICIAL USE ONLY
Table 5.--Summary of reconnaissance for radioactive deposits in west-central Alaska, 1945-1954 Location Year of Types of deposits examined or (Reference no. on fig. 6) field work nature of Investigation Radioactivity Remarks References McGrath quadrangle Candle Creek (115) PI acer concentrate Maximum 0.003 percent eU; trace White and Killeen, 1953, p. 16, 18 of monazite(?) reported lditarod quadrangle Vicinity of Flat (116) Reconnaissance to loc:~te bedrock source of Radioactivity due chiefly to uran- White and Killeen, 1953, p. 1-15 radioactive material previously found in iferous zircon, on accessory mini acer concentrates eral in monzonite that averages about 0.004 percent eU; concentroles may contain as much as 0.1 percent eU but generally only O.OX percent eU Julian Creek (117) PI acer concentrate Concentrate contains about 0.03 Source of monazite probably in fDrphyritic White and Killeen, 1953, p. 16, 18 percent eU due chiefly to monagranite dikes that cut country rock in zite drainage basin of ,;reek Moore Creek (118) Placer concentrate Contains 0.001 percent eU Concentrate consists chiefly of chromite White and Killeen, 1953, p. 16, 18 g with traces of cinnabar, scheelite, and pyrite g n
Medfra quadrangle n t:
Nixon For~ district (119) Reconnaissance to locate source of uranothorianRocks from contact deposits contain Parisite also occurs in the altered contact White and Stevens, 1953, p. 10-19
m ite found in placers and examination of as much as 0.05 percent eU, due zone 0 z gold-copper lodes chiefly to thorium in allanite and
idocrase; source of uranothorianite z not found although additional con-
centrates containing as much as 0.26 percent eUwere collected Ophir quadrangle Cripple Creek Mountains Placer concentrates Maximum 0.003 percent eU White and Killeen, 1953, p. 16-18 (120) Unalakleet quadrangle Mcleod molybdenite Molybdenite-bearing quartz vein Vein contains maximum of 0.001 West, 1954, p. 9-10 prospect (121) percent eU; wall-rock (rhyolite porphyry) contains 0.003 percent eU Ruby quadrangle Poorman area (122) Search to locate source of uraniferous mineral Source not found; placer concen- White and Stevens, 1953, p. 9 of spinel group found in placer concentrates roles contain as much as 0.056 from upstream part of Solomon Creek percent eU Long are a ( 123) Search to locate source of uranothorite found Source of uranothorite found as accesT:-.e uranothorite of one sample contains White and Stevens, 1953, p. 4-9 in placers sory in granite on Birch, Straight, as much as 8.2 percent U and Flint Creeks; gr .. mite contains as much as 0.008 percent eU; concentroles from placers contain as much as 1.6 percent eU
g n
0 z
Table 5.--Summary of reconnaissance for radioactive deposits in west-central Alaska, 1945-1954 --continued Location (Reference no. on fig. 6) Ruby area (124) Yukon River traverse (125) Year of field work Types of deposits examined or nature of investigation 1?49 Radioactivity traversing of roads and examinations of silver-lead lode on New York Creek Radioactivity traverse of rocks adjacent to river Radioactivity Ruby quadrangle--continued No significant radioactivity detected; maximum eU content of silver-lead lode is 0.003 percent Ruby and Melozitna quadrangles No significant radioactivity detected Norton Bay, Solomon, and Bendeleben quadrangles Darby Mountains (126) Big Hurrah mine (127) Quiggley antimony prospect (128) Cape Nocne ar;,a (129) Nome-Council road (130) HeJ and Strand mine (131) Charley Creek bismuth prospect (132) Snake River, Penny river, and Osbom roads (133) Radioactivity reconnaissance Gold-bearing quartz vein containing chalcopyrite, pyrrhotite, and stibnite; intrude black slate of Paleozoic age Stibnite-bearing q~artz veins Granitic rocks reported to contain allanite Radioactivity traverse of bedrock adjacent to rood Quartz veins cutting schist of Paleozoic age; metallic minerals chiefly stibnite, pyrite, and arsenopyrite Quatz veins and adjacent schist containing native bismuth, bismuthinite and iron sulfides Radioactivity traverse of bedrock adjacent to roads Radioactivity in area appears to be re lated directly to areas of granitic rock; concentrates from placers of creeks draining areas of granitic rock contain 0.01 to 0.1 percent eU; radioactivity due chiefly to sphene, allanite, and zircon, locally to monazite, uronothorionite, and on unidentified uranium-titanium niobote mineral Solomon quadrangle <0.001 percent eU <0.001 percent eU Solomon and Nome quadrangles Only traces of allanite found; heavy-mineral fractions of granitic rocks contain as much as 0.012 percent eU which is attributed to U and Th in sphene and zircon No significant radioactivity detected beyond that previously noted in the Cope Nome area (see locality 129) Nome quadrangle 0.001 percent eU 0. 002 percent e U or less No significant radioactivity detected Remarks Concentrates locally contain traces of cassiterite, topaz, fluorite, and various sulfides References White and Stevens, 1953, p. 3,4 White and Stevens ( manuscript in preparation) West, 1953 White and others, 1952, p. 4 White and others, 1952, p. 4 White, West, and Motzko, 1953, p. 5-8 White and others, 1952, p. 4 White and others, 1952, p. 4 White and others, 1952, p. 4 White and others, 1952, p. 4 g n
0 z
0 z !:( Location (Reference no. on fig. 6) Sinuk River iron deposits (134) Buck I and-Kiwal ik district (135) Peace River area (136) Candle Creek area (137) Serpentine-Kougarok area (138) Table 5.--Summary of reconnaissance for radioactive deposits in west-central Alaska, 1945-1954--continued Year of field work Types of deposits examined or nature of investigation Veins and stockworks of limonit-e with hematite in limestone of early Paleozoic age; contain traces of magnetite, siderite, pyrolusite, galena, sphalerite, and gold; purple fluorite reported at one locality Search for bedrock source of uranothorianite found originally in placers on Sweepstake Creek; search later extended to area along divide between Buckland and Kiwolik Rivers Search for bedrock source of uranothorianite associated with sulfides (see locality 135) found in placers on a head-water tributary of the Peace River Investigation of uranothorianite-beoring placers Investigation of radioactivity anomaly found with airborne equipment Search for bedrock source of radioactive minerals found in placer concentrates and the investigation of a granitic intrusive for possible radioactive lode deposits Radioactivity Nome quadrangle--continued (0.001 percent eU Candle quadrangle Concentrates from systematic sampling of creek grovels in the Bucklond-Kiwalik district generally contain O.OX percent eU; locally eU content is O.X percent and concentrates from various phases of placer-mining operations is XX .0 eU. Radioactivity is due chiefly to uranothorianite although uraniferous thorite, gummite, orangite, hydrothorite, allanite, sphene, and zircon also contain radio-elements and contribute to radioactivity of concentrates Concentrates contain as much as 0.8 percent eU or about 10 times the eU content of the average uranothorionitebeoring placers in the BucklondKiwal ik district. Candle and Bendeleben quadrangles Bedrock source not found; radioactive concentrates generally contain O.OX percent eU, although one contains 5.0 percent eU and 3.8 percent U Granitic talus contains about 0.006 percent eU Bendeleben and Teller quadrangles Remarks Source of radioactive minerals not found, but is believed to be in the granitic rocks as the radioactive minerals are restricted to gravels of streams draining areas containing such rocks. Although the distribution of the uronothorianite is widespread, its concentration and association with metallic sulfides in placers at the head of the Peace River is a significant lead to a possible lode source . (See locality 136.) Brief reconnaissance in 1951 failed to locate bedrock source of uronothorianite although it disclosed that gummite, believed to be a decomposition product of the uranothorianite, occurs in inti mate association with tetradymite, galena, and pyrite. Private prospecting in 1953 with a bulldozer did not locate a possible lode source for uronothorianite, gummite and sulfides; however the trenching program was not completed and the results are inconclusive · Radioactivity of placer concentrates and granite is due to zircon, sphene, allanite, hydrogoethite, and two unidentified · radioactive secondary minerals. Radioactivity of granite chiefly in late-stage differentiates which average 0.008 -percent eU References Wedow and others, 1951, p. 33,34 White and others , 1952, p. 4 Harder and Reed, 1945, p. 5, tables I and 2, appendix I Gault and others, 1953, p. 1-10, Gault and others, lcJ53, p. 28- 31 Motzko and Bates, 1955 Harder and Reed, 1945, p. 14, tables I and 2, appendix I Gault and others, 1953, p. 11-14 Motzko, USG S-PRR: A-1, 734 Moxham arid West, l953a g n :; ,
0 z !:(
£ n
0 z
Table 5.--Summary of reconnaissance for radioactive deposits in west-central Alaska, 1945-1954--continued Location (Reference no. on fig. 6) Ear Mountain area (139) Year of field work Types of deposits examined or nature of investigation Investigation of placer deposits containing radioactive minerals and search for bedrock source of such minerals Potato Mountain area (140) Search for radioactive deposits associated with fluorite-bearing tin deposits Cape Mountain area (141) Brooks Mountain area (142) Lost River area (143) Teller and vicinity (144) Search for bedrock source of radioactive minerals found in tin-bearing placers Metazeunerite occurrences in granite Search for uraniferous deposits possibly associated with tin deposits Reconnaissance of placer-gold mining area Radioactivity Teller quadrangle Radiouctivity of placer concentrates is as much as O.X percent eU but is due chiefly to monazite and zircon; these minerals occur as accessories in granite. A uraniferous lode deposit traced over a distance of more than 5,000 feet from float was trenched at two places; the lode consists of a hematitic tourmolinized mafic dike. Channel samples across the lode in widths up to 8 feet contain 0.01 to about 0.05 percent eU. A copper uranite, possibly metazeunerite or metatorbernite has been identified in some samples 0 .001 percent eU Monazite and hematite are uraniferous; the monazite probably occurs as accessory mineral in granite, the hematite has formed by the oxidation of pyrite found in the contact zone; other thorium-bearing minerals probably also occur in the placers Metazeunerite (previously identified as zeunerite) occurs with hematite in a lens-shaped body of altered coarsegrained granite at a granite-limestone contact. Although selected specimens of the deposit contain more than 2 percent U, the average content is between 0.1 and 0.2 percent. Metazeunerite also occurs as surface coatings of tourmaline veins cutting the granite and as traces in a base-metal lode also at the granite-limestone contact No uranium deposits of commercial interest discovered; tin-bearing rhyolitic dikes contain as much as 0.01 percent eU; a packet of iron oxides, not exceeding a few cubic yards In size, in limestone contains about 0.06 percent eU No significant radioactivity detected except minor amounts in granite boulders from gravels on Gold !lin; a heavymineral fraction of one granite ·boulder contains 0.017 percent eU due chiefly to radio-elements In allanite and z~con Remarks Tin-bearing lodes also occur associated with the granite stock at Ear Mountain; the minerals at these lodes and in the contact between the granite and limestone country rock inc I ude: vesuvianite, fluorite, topaz, cassiterite, tourmaline, arsenopyrite, pyrite, chat copy rite, and pageite Pyrite, cassiterite, sphalerite, and fluorite also occur in the tin deposits af the area The chief occurrences of metazeunerite (Foggy Day prospect) was explored by the U. S. Smelting, Refining, and Mining Co. with a 20-foot deep trench. The lens-shaped body was about 15 feet in diameter and 4-5 feet thick. Although the lens was removed during 6xploratlon radioactive hematitic stringers in the bottom of the trench indicate a possible downward extension of the uraniferous zone. The radioactive samples containing O.OX percent eU from the Greenstone lode found In 1950 by scanning old collections could not be duplicated because workings on the lode had caved. References Killeen and Ordway, 1955 Wedow and others, 1951, p. 29-31 Wedow and others, 1951, p. 28-29 White and others, 1952, p. 3 We dow and others 1 1951, p. 31-32 Killeen, 1945, oral communication West and White, 1952 Wedow and others, 1951, p. 26-28 White and West, 1953 Wedow and others, 1951, p. 22-25 White, West, and Motzko, 1953, p. 1--4 £ n
0 z
I · J) Cl: n (Y z J) z "
l.IJ u
EXPLA ATIO Aroas ond localities investigated (numbers re fer to an~oo or loca lities lisr" d In table 5 of text) QUADRANGLE INDEX 6os. rom AlaJka Mop 8, Edit ion of 1950 NOR ALASKA SHOWING AAEAS AND LOCALITIES INVESTIGATED F 1 G U R E 6 - -MAP OF WEST - Cf TRAL OFFICI l U E 0 y too M otts
OFFICIAL USE ONLY The in:vestigation.s at. Ea,r Mountain disclosed that the radioactivity of the placers there i s due cr.iefl y to radioelements in monazite and zircon which occur as accesso:riea i n the granite s·(z:v::k forming the mountains. Although the ra.d.ioacti vi ty of the placers at Ear MotLn:tain pro,red to have essentially no significaxice, the 1945 reCOll11'laissanee discovered the presence of uraniferous lodes consisting of hematitic tourmaline~quartz veins associated 1rl th tourmaJ.inized mafic d.i.kes. One the radioactive vein-dike zones crosses the top of Ear .Mo'Wltain with a nor .. cheasterly trend. It is traceabl e chiefly by float f'or over 5, 000 :t:eet. At one locality near the top of Ear Mo1mtain it is 8 feet wide. A hemati tie subzone about 18 inches wide in the central part of the 8-foot zone was the most radioactive part and contains Oo045 percent equivalent uranium and 0 &035 percent uraniLtmo Selected fragments of the radioactive rock contain as much as 0&18 percent equivalent uranium;!) The ura..'"liu..m occurs chiefly as copper ura.nite, probably metatorberni te or :meta.zeu.nerite, and as an impurity in the hematite. The brief investigations at Cape Mountain in 1911,.-5 and later mineralogic studies indicate ·t.hat the radioactivity of the placers is due to uranium and thorium chiefly in monazite and zircon which were originally accessory constituents of the granite underlying the moQ~tain. Hematite in the placers is also slightly uraniferous and was probably derived from the oxidation of :masses of pyrite found in and near the ('!Ont.aA'!t of the granite w:i th the lime~ stone country rock. The discovery of a uraniferous lode in assccia·tion with granite at Ear Mountain in 1945 suggested that other, similar deposits :may occur in the vicinity of other gra..r..i tie bodies elsewhere on. the Seward Peninsula. OFFICIAL USE ONLY
OFFICIAL USE ONLY Consequently, in 1946, en investigation was made in the Serpentine-Kougarok area (loeaJ.ity 138) centering chiefly around the granitic body at Serpentine Hot Springs. The ehie:f' =ca.dioaeti vi t;y found in this area was that of the granite itself and placers derived by the natural concentration of the radioaeti ve accessory minerals in the granite. A brief reconnaissance ~conducted in the mining area in the vicinity of Teller (locality 144) disclosed no radioactive materials of commercial significance. , Reconnaissance was continued in the Buekla.nd-Kiwa.lik district {locality 135} v.t. th studies in the Quartz Creek area which lies to the north of the Sweepstakes Creek area investigated in 1945. Uranothorianite w~s again identified as the chief' radioaeti ve mineral in the placers and was traced from gravels into slope wash high on the north flank of Granite Mountain. Although the ac;tuaJ. bedrock source was not found, it is believed to be concentrated in specific zones of segregation within the granitic rock. In 1947 twc m.ajor .field investigations were cond~cted in west-central Alaska: (1) The examinatf:on of granitic bodies in the vicinity of Flat (locality 116) to determine the possibilities for bedrock concentrations of radioaeti ve minerals previously known only in placers. The chief radioactive mineral proved to be uraniferous zircon which occurs as an aeeessor:r constituent of a quartz monzonite stock, and hence coul.d not be considered as a eommereiaJ. source of uranium. {2) The extension of reconnaissance in the Buckland-Kiwalik district {locality 135) to all as yet uninvestigated areas between Sweepstakes Creek on the eouth to Clem Mountain on the north~ Because of the vide-spread cover of tundra and taJ..us most of this investigation again had to be limited to the testing OFFICIAL USE ONLY
OFFICIAL. USE ONLY vf' plaA::e:r concentrates rather ·!fhan direct radioaeti vi ty traversing ·~:ri th portable SiXJ.,""Vey meters . The reconnaissance showed that radioactive placers were limited to streams whose drainage areas were underlain at least in part by granitic rocks 0 Later, mineralogic studies :reveal..l.ed that urano~ thorianite, the most ~-portant uranium mineral founti in the BucklandKiwalik district, is localized in placers en Sweepstakes Creek, Quartz Creek and Peace River on the slopes of Granite MOuntain; in the Connelly Creek-Hunter Creek area; and on the south slo:pe of Clem Mountain.. The most important of these localized occurrences is believed to be one at the head of Peace River where uranothorianite and ~1mite are associated with copper sulfide and other metallic minerals in gravels of a restricted drainage basin near a. syeni te ... andesi te contact. Concentrates from these gravels contain as much as o.8 percent eq'Uivalent uranium and are about 10 times more radioactive than similar concentrates from the average ·uranothorianite-bearing placers elsewhere in the district. In addition to these investigations the party working near Flat collected samples for examination from Candle Creek, Ju.lian Creek 11 Moose Creek, and the Cripple Creek Mountains (localities 115, 117, 118, and Field studies in 1948 were limited to a reeonnaissane.e of the Darby MolUltains (.locality 126) 0 As in the Buckland-Ki:wa.lik district investigated in 1945-47, the chief source of radioactive minerals proved to be in. the . granitic rock;s of the area. Although most of the radioactivity detected appears to be due largely to radioelements in such accessory mineraJ.s of granite as sphene, al.lani·te, zircon a.rtd monazite, local con~ centrations of uranothorianite and uraniferous niobate minerals were found OFFICIAL USE ONLY
OFFICIAL· USE ONLY ereeks draining .areas of granitic rocks. The association of topaz, fluorite, eassiterite with the uranium minerals suggests that the source might be related to -possible tin-bearlng lodes in or near conta.cts of the granitic intrusi·ves with the country rock. In 1949 field studies in west-central Alaska consisted of reconnaissance in the Nixon Fork and Ruby-Poo~ districts (localities 119 and 122-124) and traversing along the Yukon River (locality 125). In the Nixon Fork district thorium-bearing mineraJ.s occur locally in altered rocks at a limestone-monzonite contact and may be related to gold-copper ores found along the same contact. The source of uranothorianite occurr~ng in placers of streams crossing the contact was not found but is believed to be localized along the contact like the deposits of gold-copper ores and other thorium-bearing minerals. In the Ruby-Poorma.n district the chief radioactive mineral. found is uranot~orianite which oecurs as an accessory constituent granite in the vicinity of Lo:ng. Nq significantly ra.dioaeti ve deposits were found in the reconnaissance traverse along the Yukon River. No reconnaissance was made in west-central Alaska during 1950. However, scanning of old Survey collections and the receipt of uraniferous samples fro~ a prospector pointed up the need for investigations in the Brooks Mountain-Lost River area (localities lll-2 and 143) on the Seward PeJ).insuJ..a (Wedow and . others·, 1951, p. 22-28, 32) In 1951 radioactivity investigations in west-central Alaska. were eonc.entrated in the Brooks Mountain-Lost River area, although brief examinations were a.J.so made at several plaees in the Nome-Council area. OFFICIAL USE ONLY
OFFICIAL USE ONLY (liOCali t:Ltr'*s 127, 128, 130-134) and at the headwaters of the Peace River (locality 136) .. At Brooks Mou.n.tain prospectors had discovered a small body of :metazeuneri te ... ·oearing altered grani tie I'Ock that contained between 0.1 and 0.2 :percent uranium with selected specimens of ore containing over 2 per""' een.t uranium.. Minor a.n.d traee amounts of metazeuneri te were found at several other sites in the same general vicinity. Although no deposits of possible commereiaJ. interest were located in the Lost River area~ it was found that tin-bearing ltlikes were slightly uraniferous. :None of the other localities examined on the Seward Peninsula in 1951 indicated sufficient amounts of radioactiv~ty to be of further interest except at the head of the Peace River, where additional reeonnaissanee vas made to find the source of uranothorianite, gummite and metaJ.lic sulfides known in placers. Aga:i.n however, the source could not be loe.ated, but sueh info:r1l'J.ation as eou.ld be obiiained substantiates the belief that a copper-uranium lode may occur in that vicinity. The MeLeod molyodenite prosp~ct (locality 121) 1ifas the only site tested f or radi.oacti vi ty in west-central Alask,a during 1952. J:o sign.i~ ficant radioactivity was detected at the prospeet. In the early part of the summer of 1953, a private party prospec~ted at ~the hea.d of Peace Rive:r (loeal.ity 136) for the ura.rd;mn lode indicated by the previous inva:srtigations. No lodra deposit was found by this pros- · p~cting, but as mechanical difficulties prevented completion of exploration such negative results as were obtained are far f'rom conclusive. OFFICIAL USE ONLY
OFFICIAL USE ONLY .. investigation was made in 1954 of a rad.ioacti vi ty anomaly near Candle (loea.lity 137), l ocated during an a.irp].a.ne traverse over the area. ~ne souree of ·the radioactivity was determined to be granitic float, which contains about 0.006 percent equ.ivaJ..ent uranium, that occurs as an island in an otherwise tundra-covered area (Matzko and Bates, re:PQrlin preparation) Northern Alaska Very f'ew radioactivity investigations have been made in northern Alaska., primarily because of its remoteness and inaccessibility. What 1i ttle information is available has been accumulated chiefly through the analysis and study of samples collected by geologists of the Navy Oil Unit of the Geological Survey in the course of the investigation of the resources of' Naval Petroleum Reserve No 0 4 and adjacent areas on the north flank of the Brooks Range. In addition, a spot examination vas made 1949, at the request of' the Atomic Energy Commission, of a reported:uranium occurrence in the vicinity of Sh:QD:gnak on the Kobuk River. ' The results of these studies are given in table 6; the localities are shown on figure 7. ,, i· uranium deposit'' in the vicinity of Shungnak, reported by A. G. FergusQn of' Kotzebue to the Atomic Energy Commission in 1949, proved to be only slightly rad:ioaeti ve. The ra.dioaeti vi ty was due to uranium occurring as an impurity in metallic minerals at an old copper prospect on Ruby- Creek (loeaJ.ity 145) . A:f"ter t~e recognition of phosphate in rock samples from the Anaktuvuk River area by A. E. Glover of the Territorial Department of' Mines in 1948, OFFICIAL USE ONLY
g () 1!
0 z
Location (Reference no. 001 fig. 7) Ruby Creek copper prospect (145) Brooks Range phosphate (146) Mount Michelson area (147) Year of field work Table 6. --Summary of reconna1ssance for radioactive deposits in northern Alaska, 1945-1954 Types of deposits examined or nature of investigation Copper prospect reported to contain uranium; deposit consists of sulfides, oxides and carbonates filling fractures in a narrow zone cutting brecciated limestone Uraniferous phosphate rock interbedded with organic shale and limestone of the Mississippian Lisburne group . Investigations made by members of the Navy Oil Unit of the Survey coincidental with other work Examination of granite and placer samples collected in 1948 by Navy Oil pen;onnel of the Survey Radioactivity Ambler River quadrangle Maximum radioactivity of average ore is 0.007 percent eU; radioactivity is due to uranium in sphalerite, iron oxides and copper carbonates; the sphalerite is the chief radioactive mineral and contains 0.013 percent U Chandler Lake quadrangle Remarks Samples contain as much as 10 percent copper On Kiruktagiak and Tiglukpuk Rivers The phosphatic facies of the Lisburne limea zone of oolitic phosphatic shale stone extend over a wide area in the cenand I imestone is about 40 feet thick . tral part of northern Alaska; pre I iminary Random samples taken at this locality data from field work in 1953 indicates that in 1949 average 0.015 percent eU, the beds are not likely to be sufficiently 0.013 percent U, 31.95 percent P20 thick for commercial interest. The occurand 0.11 percent V205 The highes? renee of phosphate rock in northern Alaska U content, 0.21 percent, is in a bed was first recognized by A. E. Glover of 1/2 -foot thick at the base of the zone. the Territorial Department of Mines in a The phosphate beds at this and other sample submitted for assay by an Eskimo localities were sampled in detail in 1953. from the Anaktuvuk River Mount Michelson quadrangle Gneissic granite contains up to 0.008 percent eU; the heavy-mineral fractions of several samples average 0.052 percent eU and 0.03 percent U with an average concentration ratio of about 30:1; the uraniferous mineral is biotite Fluorite, molybdenite, pyrite, and hematite occur as accessories in the granite; these minerals as well as traces of galena and scheelite have been identified in concentrates from placers of streams draining areas underlain by the gneissic granite References White, 1950 Wedow and others, 1951, p. 113 Patton and Motzko, (manuscript in preparation) White, l952b, p. 1-7 g ()
0 z
t - ot) t-a: 0 a. w a: z c ;:: <II w
C/1 t-z w l:
w (.)
t-
BoW! from Alosko Mop B, Edit ion of 1950 QUADRANGLE INDEX J 20 0 Mi tu j F IG URE · -- MAP OF NORTHERN ALASKA SHOWING AREAS AND LOCALIT IES INVESTIGATED OffiCIAL USE ONlY 0 c E: 4 sa EXPLANATION c;::J 147 Areas ond localities Investigated (numbers re fe r to are as or localities liste d In table 6 of te xt) OFFICIAL USE ONLY
OFFICIAL USE·ONLY studies by geologists of the Na,r,y Oil Unit showed that the phosphate rock extends over a ~:JJ'ide area aJ.ong the :n.orth flank of the central part of the Brooks Range (locality 146) and north of the Brooks Range. The deposits are Mississippian in age and are comparable to the Permian phosphorites of the northwestern United States litho logically and in their content of' phosphorous, vanadium, and u.rani u:m.. Not enough work has done to determine if' there is a large enough tonnage of phosphate rock in northern Alaska to be of potential commercial value. The phospha.te rock would have to contain at least 24 percent P205, the minimum grade minable in the northwest phosphate fields (in 1956). Study of specimens of granitic gneiss collected in 1948 near MOunt Michelson (locality 147) indicatea that the raCO.oaetivity of' this rock is due chiefly to ura.?J.iferous biOJ(;i te associated with fluorite, hematite, and sulfide minerals. '·I POSSIBILITIES FOR URANIUM AND THORIUM IN ALASKA I, 'I ., Ty:pes of radioactive deposits Uranium and thoriu:m occur in many rocks of' widely diverse origins, and almost all types of geologic processes involved in the emplacement, deposition, e..alteration, and disintegration of rocks have played a part in the formation of concentrations of these elements. Many attempts have been made to classify radioactive deposits. The general order of classification of radioactive deposits depends largely upon the local emphasis placed on the importance of one or a few types of deposits. Thus, . in Canada a classification group containing pitch;tende-bearing OFFICIAL USE ONLY
OFFICIAL USE ONLY ve;i:r1~3 is ·rJf' greater im~rtance than one containing carnotite-bearing sandstones; ·~whereas the re'trerse is currently true in the United Stat~s. Thus, al$o, di_seu.ssiorJS of radioac:ti ve de:posi ts in Brazil and Ceylon, for example, might well treat thoriu:m=bea.ring pla.eers as· hav,.ng greater signif'ieanee than other types of deposits eontaining th.e radioelem.ents. In general, most of the elas~ifieations in use today are mainly related either to the genesis or to the geologie environment of' the deposits. Com ... monly, the most acceptable,· and usable classification is somewhat arbitrary and uses either the genesis or environment, {whichever is more sigzrl.fieaf).t), or both The inter:r:elationsb.ip ·of' genesis and environment and the problems of classification are well demonstrated by the five recent elassifieations of other writers shown in. table 7 0 For the purpose of this report the author follows the classification used by Butler but with minor modifications. (See table 7.) :Many of the more significant deposits con·taining uranium. and thorium in Alaska ar~ discussed by type of deposit and, in. some eases, are compared to deposits in continental United States to enhance the discussion. Igneous roeks, ~patti tes, veins and related dePf?Si ts Igneo'?s rocks Mo~t igneous rocks are wea.kl.y radioactive because of trace amounts of uranium or thorium or both, tb.B:t occur ehiefl.y as impurities in. the eo:mmon aeeessory mineral.s, such_ as alla:ai te, apatite, monazite, sphene, :xenotime, and zircon. The grani:tie rocks, that i ·s, the felsic types, are generally more radioactive than the maf'ie types. OFFICIAL USE ONLY
n
0 z !( George (1949, p. 10-18) I) Pegmatites a) Microl ite-pyrochlore pegmatites b) Uraninite pegmatites c) Rare earth pegmatites 2) Hydrothermal veins a) Chiefly pitchblende deposits of four types depending on associations with various types of metallic and gangue minerals b) Uraninite deposits (Katango) 3) Disseminated deposits a) Granitic rocks and metamorphosed equivalents 4) Sedimentary deposits a) With uranium minerals as cementing constituent (typified by carnotite de.posits in sandstone) b) Placers c) Phosphate rock and black shales 5) Carbonaceous deposits a) Petroleum, oil shales, asphaltlte, and other carbonaceous materials Bain (1950, p. 289) I) Primary deposits (Pegmatites (High temperature fissure veins (Mesothermal fissure veins 2) Sedimentary deposits (Bituminous and phosphatic shales (Alluvial or placer deposits (Carnotite-bearing sandstones 3) Oxidized deposits (Precipitated almost in situ (Precipitated by an alkaline rock or soil (Precipitated in playa or playa-like deposits Table 7 .--classifications of radioactive deposits Lang (1952, p. 13) I) Granitic deposits 2) Pegmatite deposits a) Granite pegmatites b) Pegmatitic schist deposits, migmatites, etc. c) Diorite pegmatite, etc . d) Calcite and calcite -fluorite pegmatltes 3) Hydrothermal deposits a) Uraninite-bearing veins b) Pitchblende-bearing veins, stringer-systems, etc., with simple or complex mineral associations c) Disseminated or replacement deposits 4) Sedimentary deposits 5) Secondary deposits 6) Placer deposits Kaiser and others (1952, p. I) I) Deposits with structural control a) Veins, breccias, and pipes b) Disseminated deposits associated with fractures c) Pyrametasomatic deposits d) Pegmatites 2) Deposits with stratigraphic control a) Phosphates b) Black shales c) Limestones and dolomites d) lignites e) Deposits in sandstones f) Surficial or caliche deposits Butler (1952, p. 9) Wedow (this report) I) Igneous rocks, pegmatites, I) .Igneous rocks, pegmatites, veins and related deposits veins and related deposits 2) Deposits in sandstone of 2) Carnotite-type ores in sandcarnotite, copper-uranium, stone ond I imestone and other minerals 3) Carbonaceous rocks, phos3) Other consolidated sedimenphorites, and other contory rocks solidated sedimentary rocks 4) Placers 4) Placers 5) Natural fluids 5) Natural fluids
n
0 z !(
OFFICIAl, USE ONLY Butler (1952, p. 12) re~:ports that the Geological Survey has tested at least 100 bodies of igneous rocks in continent~ United States. He states that a few igneous roekf;, partictilarly the late::-atage magmatic differentiate, contain a.s mueh as o.oo8 ·to 0.015 percent ~ran.ium and that numerous grar..i.tic roeks contain as much as 0.005 to 0.01 uranium. He further states that many gr&~tes and related rock types are more radioactive than previou~ly reported in the literature. Tests -of' numerous igneous rocks of' Alaska have shown that most grani tie rocks in the Terri tory contain 0. 002 to 0. 008 percent equivalent uranium. This radioactivity is due generally to one or more of' the common accessory minerals mentioned above Locally, however, the ra.dioaeti vi ty is or is believed to be caused by minor amounts of' uranothoria.nite, thorianite, uranothorite, thorite, gummite, clarkite(?), uraniferous bio.ti te, uraniferous fluorite, and unidentified secondary uranium minerals. The work of Moxham and West (1953a.) during 1946 in tlle Serpentine Hot Springs area of the Seward Peninsula lends support to the hypothesis (Phair, 1952) that uranium and thorium tend to eoncent:r:ate loeally in the late-stage magmatic differentiates of' gran:i tic roeks. At Serpentine Ho't Springs fine-grained felsic dikes and pegmatitie veins cut the normal facies of their parent granitic rock. The felsic dikes and pegm~titic veins locally contain as much as 0.015 percent equivalent ur8,Jliu.m and Ov032 percent equivalent uranium respectively and both average about 0.009 percent equivalent uranium in contrast to an average of about 0.005 percent equivalent uranium. for the normal granite. OFFICIAL USE ONLY
OFFICIAL USE ONLY The genera.lly low radiQa.cti vi ty of gr&'1.i tic rocks, both in A.la$ka and -elsewhere, indicat es that they cannot be seriously considered as commercial sources of uranium and thorium, although they will likely be among the most f'requently reported ''discoveries" by prospectors because of their relatively large siz~ and rather widespread occurrence. However, the local coneentr~tion of uranium and assoeiat ed sulfide minera~s in a granitic rock, might indicate alteration of the rock by hydrothermal solutions. Further search sbould be made in the vicinit~es of such occurrences to determine whether uraniferous vein and related deposits were also formed as a result of the passage of hydrothermal so~utions. In addition, tne possibility should not be ovet·looked for the discovery of large lowgrade igneo11s bodies, perhaps averaging only a few hundredths of a percent uranium, from which the urani1lm mineral could be extracted by ~imple physical methods to obtain a high tenor concentrate. In such a case the ura.ni1k mineral would ~so have to be a type from which the uranium could be ext:;racted by simple leaching . methods. ' Pegma.tites Although pegmatites in the United States, Canada, and other parts of th~ 'WQrld commonly contain uranium and thorium minerals as accessory constituents,they r~rely are sufficiently rich to ~ne for these elements alone. The only significant world production of uranium and thorium trom pegmati tes, as far as is known, has been in Madagascar, where the principal minerius are eu.xenite and betafite {Page, 1950; Lang, 1952, p,. 14-16). OFFICIAL USE ONLY
OFFICIAL USE ONLY 1ieti..!tly ra.dioaeti ve pegme:t:.i tes b...aye been reported at many loeali ties in .Alaska. At two loealities, ura.niuxn antd thorium mineral.s have been as :e,t least part of ·the source of the radioaeti vi ty in pegm.a ... <!vi tes. Reeonn.ai~H~anee of' the area (Moxham and West, l953a} in the western part of the Seward Penin~ula disclosed that secondary uranium minerals are the eau.se of the radioactivity of pegm.atites closely associated with other late-stage vari~~ts of the granite at Serpentine Hot Springs. The :pegma:tites eonta.i:n as mueh as 0.032 percent eqtlivalent uranium and· were generaJ.ly the most radioactive of all the rocks tes·ted by Moxham and West (l953a) in the area. Investigation in 1949 of radioactive pegmatites in the Willow Creek gold-mining district (Moxham and Nelson~ l952a, p. 7-10) near Palmer n(!:rth of Anchorage indicated that th.e radioactivity (0.002-0.007 percent equival.ent uranium) of these pegmatites was due primarily to trace amounts of uraninite, thorite, eyrtolite (altered zircon), and allanite. ·further studies of pegmati tes in Alaska will doubtless find additio~al deposits of this type containing traces of various uraniumand thoriu..rn-bea.ring minerals. It is likely, a.lso, that the bedrock sou.rce of eertain radioacti·ve minerals in placers--for example, the esehyni te, ellsvorthi te, a.u.G. coll:rJnbi te in the tin placers at Tofty in the Hot Springs-Rampart district (Moxham, 1954), the euxenite~ polycrase mnerru. identified in a placer concentrate from Goodluek Creek in the Livengood district (Wedow, White, and others, 1954~ Pe 2~3), and the occ~eenee of a ursniferous niobate mineral in the stream gravels of Clear Creek in the Darby Mountains (West, l953)~--ma.y prove to be pegma.tites. OFFICIAL USE ONLY
OFFICIAL USE ONLY In general, the of pegmatite inYestiga.ticnl by the Geologlcal Su vey in continental United States (Page, 1950; Butler, 1952, p 13) show"'ed that the uranium content of pegmatites is similar to that of the closely all,ied grani tie rocks. Butler (1952, p. 13) eon.clud.es: t~eea.use ·they (uraniferous pegmati tes) are relatively sm..all bodies ef low average grade, they would be only insignificant sources of uranium or thorium." Radioactive :pegmatites f'ou.nd in northern Saskatchewan, Canada, are · usually fine grained, rich in biotite and dark quax~z, and eontain mo~b- ,deni te as a minor accessory. The mineralization may be eoneentrated along structural zones. Pegmatite bodies containing large tonnages of' slightly below ore grade ( 0. 08 percent U 308) have been f'ound in the Cha.rlebo~s Lake area in Canada, aud other areas of commercial importance are expected to be found as prospecting is intensified (:M.awdsley, 1955, p. 53-56). Veins and related deposits Vein and related deposits of urar.:ium and thorium are perhaps the most sou.ght after deposits of' these elements in Ala~ka. because of the potentialities for high-grade, bonanza occurrences. T"ne emphasis on the search for such hl.gh.-grade ores in Alaska, perhaps eJ..most to the exclusion of consideration for types of deposits, is obviously neeessary because of the inter-related economic considerations of mining and transportation costs, aceea~ibili ty, and so forth . The best known and perhaps most spectacular vein and related depos:i ts of uranium in the world inelude the pitchblende deposits of OFFICIAL USE . ONLY
OFFICIAL USE ONLY the Great. JBear Lake a.rea in Ca.naa..a, the Katanga region in. the Belgia.""l Congo, an.d the regiorH~ of . Saxony and Czechoslovakia in hope. . Similar deposits, but much smaller in extent Y are known in the United States, mostly in the F.!ront Range :mineral belt of Colorado, also in other western states (Kaiser and others, 1952). studies by the Geological Survey· and Atomic Energy Commission ia. recent .years have gained much in:formation on the origin, spatial relationships, and mine:rtal associations in vein and relatai deposits . This in:rormation is su.mmarized by Butler (1952, p. 14-16) as follows: nThe (vein and -related) deposits include pitchblende-bearing geld-silver and base-metal veins in the Front Range, Colo.; copper and tin-bearing structure-s in the Majuba Hill mine, Nev.; veins of secondary uranium minerals in the White Signal district, N. Mex., and the Marysvale district, Utah; ur&"litml-bearing silicified zones in the Boulder batho;Lith in the Clancy district, Mont.; pi tehblende in pyrometasomatic deposits in the Franklin limestone·' Warren County, N. J.; uraniferous fluorite veins in the . Ja.mesto'Wn district, Colo., and in the Thomas Range, Utah; thoriumbearing veins of rare-earth minerals in the Clark Mountain district, Calif. and thorite-bearing veins in Custer County, Colo. -- to name but a few. "Pitchblende is the principal uranium mineral. in many of the vein de:posi ts studied by the GeologicaJ. Survey. Brightly colored secondary uraniUm. minerals, :principally phosphates, silicates, vanadates, carbonates, and suJ..fates, are the prineipaJ. uranium mineraJ..s in others. "Pitchblende occurs in many veins as grains, nodules, or disseminated masses forming bigh~grade pods or shoots separated by l~ger masses of essentiaJ.ly barren vein material. Many of the uraniferous shoots in deposits of the Front Range, Colo. , are only- smaJJ. parts of' extensive fraeturee containing deposits of other metallic mineraJ.s, principally those of gold, silver, lead, and zinc :f"or which the veins were originally mined 0 1 Assemblages of these minerals, and of cobaJ. t- and nickel~be.a.ri;ng minerais, smoky quartz, and dark-purple fluorite occur with much of' the pi.tehblende and are Vi:Muable guides to new oceurre.nces of uranium. "Many of the deposits of secondary uranium :minerals are the result of weathering of deposits of primary uranium mineraJ.s. ~eir form and distribution are, therefore, analogous to those of the d.eposi ts of :primary minerals from which they were derived. On the other hand, be ... cause the minerals are formed by supergene processes, their distribution OFFICIAL USE ONLY
OFFICIAL USE ONLY i controlled in part. by :factors that were not present at the time of deposit:i.on of the primar y minerals. As a result , the seeond,ary minerals in some deposits represent an outward displacement of uranium into rocks surrounding the :places where. primary ura.ni:mn oxide originaJ.ly was de ... posi tecL Wb.ere such d.ia:perBa.l has occurred the deposits are showy but of lower-grade than the primary deposits from which they were derived . Some deposits of secondary mi~erals, t here ore, are indieati ve of higher-grade dep.osi ts of primary uranium minerals beneath the zone of secondary minerals, or horizontally back from the outcrop of that zone in some of the sandstone-type deposits. Deposits of secondary minerals are known, however, in several places where :primary uranium minerals have not yet been found, f'or example, the Yellow canary claims, Daggett County, Utah, in the White Signal district, N. :Mex. , and at Ma.juba Hills, Various criteria have been used in the selection of areas for reconn.a.issuance. (See p. ll.) Beca:use there were no vein occurrences of uranium minerals known in Alaska before 1945, except for rumors and unverified reports from prospector sources, reconnaissance for high-grade vein deposits eenteted chiefly on (1) areas where radioactive minerals and associated meta.:Liiferous minerals occurred in placer deposits and (2) metaJ.liferous lodes .that contained mineral assemblages similar .to those of uranium deposits elsewhere in the world except f'or the uranium minerals themselves. With the exception of a highly radioactive, blaek, cubic uraniumbearing mineral ( uranini te?) closely associated vi th rutile in a metlUliferous vein in the Hyder district (West and Benson, 1955) of southeastern Alaska, no ores containing primary uranium minerals have been discovered in Alaska. However, possible primary minerals such as te, uranothorla...l'li te, and thoriani te have been identified in concentrates from . placers in the northeaster-n :part of the Seward Peninsula (Gault and others, 1953), on the South Fork of the Koyukuk River (Nelson and others, 1954; Matzko and Bates, 1955), and in the drain:age basin of the Kahiltna River {Robinson and others, 1955). Relatively large OFFICIAL USE1 ONLY
OFFICIAL USE ONLY g_uw..ti ties . of uranothoria.ni te have been ident:i.fied in beach concentrates of' 'the Yakataga district and traces of sooty pitchblende(?) have been recognized in a concentrate :from a beach deposit on tlle southeast shore of Lake Clark (Matzke , 1953, oraJ. communications). Because these oxide :minerals are friable a.nd soluble, they probably have not been tr~sported a:n.y great distance, and, hence, have a nearby bedrock source. In a.ddi tion, these uranium- and thorium-oxid.e minera~s are generaJ.ly closely associated in the concentrates with metallic minerals, chiefly base-metaJ_ sulfides, and thus may have originated in radioactive vein deposits. Although little is knoWn of the occurrence of primary uranium oxide deposits in Alaska, the application of the various criteria used iri the search for vein deposits of uranium and thorium and the investigation of leads developed from samples submitted by prospectors have led to the disCOT/ery' of several occurrences of secondary uranium minerals, chiefly copper urani·tes. The general nature of thest: s.econdary occurrences strongly suggest that primary uranium ores may be found at depth. ~~Brooks Mountain _{West and White, 1952) in the York tin district of the Seward Peninsula, metazeuneri te occurs with hematite in a highly oxidized lens-shaped body of pegmatitic granite at the contact between a gra.ni te stock and limestone, and as· surface coating on a :r~w of the qua.rt~.!.tourmaline ve~ns that cut the gra.ni te. Specimens of .·the metazeunerite-bearing pegmatitic lens contain over 2 percent uranium, but the average grade of the lens is only between 0.1 and 0.2 percent uranium. 'fhe meta.zeuneri te-bearing tourmaline veins contain ov..ly about 0 05 per- ' . cent uranium. The spatiaJ. relationships and mineral content of the main OFFICIAL USE ONLY
·oFFICIAL USE ONLY pegmaJci tic metazeuneri.t e-'Qearing lens strongly s~gest that the deposit was f"or.m.ed from :mineralizing solutions following zo:q.e of structural weakness in pegm.at i tic gra.ni te aJ.ong the gra.n1r te-liluestone contact. If the solutions carrying the uranium were of a.ll ascend,i~g hydrotnermal nature, then it is likely that other pockets or lenses of uranium ore, possibly containing primary mine:-als, will be found at gre_ater depths along an ore shoot. At Ear Mountain, also in the York tin district and. a.pprc>~im&tely 35-4o :miles northeast of Brooks Mountain, oeeurrences of metatorberni te were discovered in 1945 by KiUeen and Ordway (1955 ) in a hemati tieally a1 te:r,-ec:l quartz vein-mafia like zone. The float trace of t4is zone extends f'Qr over 5,000 feet across the granite stock at Ea~ ,Jpl;UJtain. An 8-f'oot width of the zone, including portions of the gr8.111 te wa.ll rock, at one point contained o.ol pe;reent uranium; 1.5-fo_ot l'ed. oxidized zone within. the lo~ at this same poin.t contained 0.035 percent ura.niwn. Furtber surface . exploration followed by drilling o;r other subsurtaae ~xploration is necessary at Ear MOuntain to determine whet~er the oc~urrence of :minor Blilounts of' secondary uranium minerals at the surf'~ee are i;adicati ve of higher grade uranium ores at depth. Another oeeurrenee of meta.zeunerite which "(!Jay have s;ignific~ee as a lead to primary vein ores is at the Konechney copper prQspect 1rn th~ Russian Mountains of the Kuskokwim region. 'l'b.e was f'~rst iientif,ied in a samp~e from the prospect collected by the Geologi~al Survey in 1944 (Moxham, 1950). However, when a field · exalJlin~tion of the prospect waa:? made ia 1952 by West (1954), all opening$ at tl:;te prospect OFFICIAL ONLY ' '
OFFICIAL USE ONLY were inaccessible and study of the radioactivity at the prospect was re stricted to dump material. Traees of metazeuneri te were recognized in only one dlllllP sample collected in 1952, and it is possible that highly soluble secondary uraniUJD. minerals originally in the mine d11Ill,p may have · been leached by the pereolation of' aciilie ground vater. Thus the possibilities f'or the occurrence of' primary ore~ at the Kteneehney prospect are still undetermined. As mentioned above, the only kno-wLI lode occurrence of a primary ur-dlium mineral in Alaska is in tlle Hyder district (West and Bell.Son, 1955), on the east side of the Coast Range batholith, near the Alaska.~ British Columbia boundary. This occurrence is a highly radioactive, black ,cubic uranium mineral. closely associated with rutile in a vein on the Mountain View property. The samples in which it was found contained approximately Oa05 percent equivalent uranium,; other uraniumbearing minerals in these samples include molybdenite, pyrite, and pyrrhotite. The chief values of the ores in the Hyder district are gold, 'silver, and lead, with tungsten, zinc, and mol ybdenum locally abundant. The deposits in ·this district appear to be at least superficially simi1ar to lodes occurring on the east side of the CQast Range batholitk in British Columbia. They contain uraninite in association with me·tallic sul.fides and gold and silver (Lang, 1952, p. 4o-46). The occurrence of the black :primary(?) uran.i um mineral on the Mountain View properly, thus, lends support to the belief of the auth~r that the Hyder district is favorable for the occurrence of primary uranium. ores, although much more intensive prospecting in the district is necessary before any OFFICIAL USE ONLY
OFFICIAL USE OM."¥ fi.n.al eonc::J.usiOJ!S on the potenti&]..ities Qf the di~trict ea.n be reae~ed. The miner al deposits of most of the regions and districts ot Ala$];{a are ,gener~y as yet poorly kno'Wll except for reports from prospectoJ;"S or the· .. brief reconnaissance studies by personnel of Gove;r:-mn.ent agencies. It is the general lack of detail on the mineral content, structure, and,. orl,gin. of :many o:f the reported mineral deposits that prevents · speculation as to precise localities at wich to prospect for vein deposits of ur~ium.
However, sa,n~ gener~i ties the, . Peninsula and otf!er regiQns will be presented. Potential~ties for vein and related deposits on Sevtard Peninsula.~·Th.e . : . · ' .; I) Seward Peninsula is prob~bly one of the most likely regions of Alaska to contain vein deposits of Uranium. The mineralization in the York tin dist"riet of the western part of the peni:p.sula suge;ests a para].lel with the ur~ium-tin mineralization of Cornwall; England, and in the .Er~gebirg~ of ~ony and Czeeb.oslova.kia. The simd.larity of th~ occurrences <?f ura.nj,.um, tin, and other metals in the Yor;k district to the occurrence of' these metals at Ma.juba Hill, Nevada (Thurston and Trites, 195,2) of' the secon.da.ry uranium deposits at Brooks and Ear Mounta1-ns to the occurrence of secondary uraniu:m mineraJ.s overlying pr~mary uraniwn O:xide ores . Marysv~e, Utah {Taylor and oth~rs, 1951) shoul.d aJ.so be noted. 1'lle metalliferous deposits in the York distri~t are closely assoeiat~d with stoek-like intrusions of gra.ni te and genetically related mineralized.· dikes. In addition to uranium and tin, these deposits also contain many .·of the other base metals associated elsewhere with uranium deposits. It is quite conceivable, :therefore, that more extensive prospecting followed OFFICIAL USE ONLY
Official Use Only
York dist:rict. metals . that . may. be associated with l"M.ranium ores. An example is the east-west belt of' various base me·tal prospects that lies a short distan.ee north of Nome. Although brief studies w""i.th negative results were made in this belt in 1.951 (White and others, 1952, :p .. supplemental to investigations in the York tin di~trict, i .t . can yet be considered somewhat :favorable on the basis of the widespread metallization. Examples ·of similar areas even more poorly kno'Wll but believed to be favorable are in the ~einity of Bluff, where gold-pyrite=arsenopyrite ores in schist and limestone appear to have been hematitically altered, and in the area of the Bendele ben Mountains, where metallic deposits of all sorts have been rumored to occur but which is essential.ly unknown geologically. ;, Perhaps the most significant lead to a possible primary vein or related deposit in the northeastern part of the Seward PeninsuJ...a (Gault and others"' 1953, Po 28~31) is the occurrence of uranothorianite and gumn.i te with i;ron oxides and various metallic sulfides in placers at the · head of the Peace River. These placers occ~ in the gravels of a small (1/2-squ.are mile) drainage basin near a syenite-andesite contact. centrate:s from these placers contain as mueh as 0.8 percent equivalent . urardutn. and are about 10 times more radioa.eti ve than uranothoriani te=bea.r ... ing concentrates obtained elsewhere in the eastern part of the Seward .Peninsula. The gumn.i te, no:r.mal.ly a. very friable, soluble mineral, is believed to be a decomposition product of the uranothoria.nite and occurs OFFICIAL USE ONLY
OFFICIAL USE ONLY in in.tin.tate mineral aggreg~tes with some of the metallic sulfides
fact that the gummite and copper sulti~es in the concentrates h~ve not been found among the heavy-mineral accessories of ;he sye~te suggests that t~eir source is 'in a eopper-.uranilllll lode, poss;i.bly a vein, located som.ewh~re in the l/2-square mile area lying upstream: trom th~ topogr.aphically highest placer concentrate sample. Some :~private prospecting w~s attempted on the Peace River site during 1953 (Matzko and Bates,. 1955), but th~ results were far from eonelu~i ve, and the potent;Lali ties of the headwa~ers of the Peace River remain to be dete~ned. In general, the whole of the Seward Peninsula can be ~onsidere¢ a poss;i.ble uraniferous province, wherein the best potential is for vein and deposits. In addition, however, low concentrations of uranium are scattered through many of the igneous rocks of the peninsula and could be the.: ultimate source of uranium in possible ~andsto~e-type deposits in ; i the elastic sedimentary roeks of the peninsula and eontiguQus regions. Pcbtentia.lities for vein and related deposits in other .re§ions.--Other .! ' possible uraniferous vein provinces in Alaska are more poorly defined than the po~sible Seward Peninsula province. N~xt in order of ~~anee, however, is that of the eastern border of the Coast Range batholith in southi eastern Alaska, but only a small part of this potential p~ovinee lies with ... in Alaska where the eastern border of' the batholith cuts aeross the Hyder district (loe. l, fig. 2). Although the better potential.! tie$ for uranif'.- eros veins in southeastern Alaska appear to lie in the .Ryder district, the only significant lode deposits of thorium yet found in are on the western side of the Coast Range batholith in the vicinity of S~on OFFICIAL USE ONLY
OFFICIAL USE ONLY Bay on Prince of Wales Island (Houston and others, 1954.) 'f,here numerous steeply dipping, narrm.if, ra.dioa.cti ve carbonate-hematite veins may represent 8ll extremely late stage of the Coast Range intrusion or perhaps an even later stage of igneous activity. The thorium-bearing minerals in these veins are thori te and monazite and to a lesser extent he:mati te The rare-earth minerals, bastnaesite and parisite, also occur in some of the SaJ..mon Bay veins. In general/the thorium-rare ts at this loca:,lity appear to be too low in size and grade to w~rraut e:)tploitation under present economic eond.i tions. The pos$ible province of sandstone-type deposits in the Alaska Pen~ insula~Cook Inlet region, discussed later in this report, the occurrence of sooty pitchblende(?) in a beach placer concentrate in the Clark area, and the reported occurrence of meta-autunite in t~e vicinity of Kodiak suggest that this region is also a general uraniferous province. Such reconnaissance of vein and lode deposits in the region as has. been comp~~ted revealed little or no radioactivity the sites ot the depQsits tested. On the other hand, the Alaska Peninsula.-C9ok Inlet ;re·gion is a relatively large area, in which mu~h of the geology is known only from broad scaJ..e reconnaissance studies. It would be unwise, therefore, to eliminate this region from serious consideration for additional prospecting and reconnaissance. The Lower Yukon-Kuskokwim Highlands region is anQther potential. uraniferous province as suggested by the occurrence of metazeunerite in the Ru$sian Mountai~s, the ;minor amounts of uranium in the a,ceessory zircon of monzonite in the vicinity of Flat, the uraninite an~ OFFICIAL USE ONLY
OFFICIAL USE ONLY ll.ran.otho:t .. ianite in the placers, the thorium-bearing mineraJ.s in the eontact gold-eo~per deposits in the Nixon Fork area, and the presence of uranothorite in the Ruby-Poorma.n area. Whether or net signif'meant radioactive deposits aetual1y do oeeur in the belt occupied by the aforementioned scattered occu,rrences will, of course, only be determined by intensive prospecting. Perhaps one of the ID:Ore likely sites in this belt at which to begin this prospecting is at its northeaStern end in the Cosna-Nowi tna region, wbere granitic rocks are reported to intrude volcanic racks, chiefly of rh:Y_Olitic composition. This area. lies roughly mid-way between the Kuskokwim Mountains and Ma.nJ.ey Hot Springs-Rampart sandstone""type provinces,. which will be discussed later, on the same structural trend. Li ttl.e is known of . this region geologically except for a report by Eakin (1918). In a.ddi tion to the potentiaJ. provinces suggested above, there are many other localities which have not yet been investigated and in which uranium· might occur. The most significant of these is the Copper River region which was touched on brief'ly by Moxham (Moxham and Nelson, l952a) in 1947. Many of" the copper and other metallic deposits in this region are ot difficult access but may warrant examination for radioactive minerals. Because of the ruggedness of the region as well as the difficulties of access, any ground studies there may well be preceded by scouting many of' the mineral. occurrences with scintillation-detection equipment mounted in light aircraft . Of specific interest in the Copper River region, for e.xa.m.ple, are argentiferous tetrahedri te-bearing quartz vein deposi,ts on the Kotsina River in the Kuskula.na district and vein(?) fillings of OFFICIAL USE ONLY
I ; ,I OFFICIAL USE ONJ;,Y stibrrl te, :pyrite, ~ol,ybden,ite, and cinnabar on R~x Creek in the Nizina distr;f.~·t.. (See Wedo~r and others, 1951, p,. 107-108.) Ca.rn.oti te-t:ype ores in sandstones and liJ:n~stQUres Carnotite-type deposits .~n sandstones have been the el:def sources of' uranium in the TJnited States. The principal. production :ta.as come from deposits of the well-known Colorado Plateaus but other deposits are. kn.ow.n in Wyoming, Idaho, Nevada, Texas, Oklahoma, South :Dakota, Pennsyl va.nia and New Jersey. i'h.e ea.rnoti te-type deposits of. the Co~o:rado Plateaus oceur chiefly in Triassic and Jura,ssic rocks, but elsewhere they are found in rocks ranging in age from Paleozoic to Tertiary (Fiseher, 1950; Butler 1 1952, p. 17, 18; Kaiser and others, 1952, p. 26-29). Carnotite in sandstone is also reported in Russia (l3ain, 1950, p. 286). {U. though carnotite is the principal mineral of these deposits, !I~ various copper-uranium and uranium-van~um minerals, ura.ni:u oxide (pitehbl~nde?), ura.n;i.ferous asphaltite, and compJ..ex secondary uranium 'i' miner¥s ar:e abundant locally. The deposits are found chiefly ticuli;tr beds of non:mari~e sandstone, a.1 though some oeeur in :mudstone. These deposits commonly contain about 0.1 to 0,. 5 pereen~ uran.ivm but Srre generally small and have an erratic distribution. Similar deposits in conglomerate and l~stone are also known and are becoming m<;>re U!:port~t / as the search for uranium continues. ~ittle is known about the possibility for carnotite-type deposits in Alask~. It was thought originally that little likelihood existed tor their oeeurrenee in. the Territory because of the securing effect of the OFFICIAL USE. ONLY
OFFICIAL USE ONLY . extensive glaciers that covered much of Alaska during Pleistoqene time. However·, as mentioned in the introduction of' this report, a ~ample of carnotite ore, believed to have come f'rom the vicinity Qf Healy on the Railroad, was a.n.aJ..yzed in the assay office at Fairbanks in l-918. As yet unverified reports of carnotite (?) in the vicinity of Nome on tl).e Seward Peninsula have been obtained from mine operators' records filed with .the Survey around 1915. More recently, ~om Jones, a prospeet<;>r at Seward, indicated that he and a pa+tner had found a rieh Ca.I1J.otite sandstone occurrence in Alaska but would not. divulge its source nor su~ mi t samples for study (We dow and others, 1952, P.~ 37 ... 38) , because he claimed it was near a rich gold-placer prospect which had not yet been staked. In June 1951 a sample ot u carnotite" was submitted by Mr. Ube of Ketchikan to the Assay Office of the Terri to rial Depa.rtme~t of Mines at Ketel';likan. The specimen consists of coaly material and a strongly radio~ active yellow mineral., which was later identified as tyuyamuni te in the Survey laboratory. The ·coaly material also contains considerable ur~um .A1. though the sample was not an.~yzed quantitatively for uranium, a. rougll. estimate from radiomet~ic tests indicates a uranium content in exc~ss of 1 percent. The. sample had been found a.s u:f'loat" on the east sbore ot Union Bay, Cleveland Peninsula, southe~stern Alaska :r;1ear a f'o:rmer cannery site. Reconnaissance along the east shore of to locate the source of the specinlens was unsuccessful. In. general, the geology of the Union Bay area does not appear to be favorable f'or the oectUTanee of carnotite-type ores, particW.a.rly where associated with coal. The rocks OFFICIAL USE ONLY
I,. I· OFFICIAL .. USE ONLY ot~ the area are largely ma£ic and ul trama.fic rocks intrusive into highly metamorphosed sediment ary roeks. Tertiary elastic se~ments crop out along · the beach of Union Bay several. miles north of the old cannery site· and are reported to contain minor amounts of bituminous materiaJ.. . Field radioactivity tests of all rock types were consistently low. It is pos- .· sible that the ''aarn.otite n specimen. b~d been. nimporledtf from western United state·s or British Col:umbia. in a shipment of eoaJ. to the . old. cannery (White and others, 1952, p. 14 ... 16) or that it was transported to the site of discovery by glaciers from a source elsewhere in southeastern Alaska. In 1951 samples of metatyuyannmite-bearing limestc:>ne containing 0.6 percent uranium oxide were submitted to the Survey by N. FOwler C?f Anchorage. Mfneralogic studies of the samples show that the only uraniferoup · ¢n,.eraJ. they contain is metatJ~Uya.muni te which eecurs both concen- ·lj: trated.: on the bedding surfaces of' and disseminated through a thin-layered ' ; . . limestone. This occurrence of' a earnoti te-type mineral a.ppea~s to be .. , unique, although the specimens have some resemblance to the tyuyamuniteI' bearing limestone near Grants, N. Mex. (Rapaport, 1952). According to the Indian who collected Fowler's sample in 1949, the outcrop from which it was obtained is about 50 feet long and 10 feet high, and the ''yellow roek" .oceurs in lenses as much as 3 inches thick between thin beds of limestone.. In 1952 and 1953 brief but unsuccessful attempts were ;uaade to locate the site of this oeeurrenee. Information obtained to date indicates that the Fowler prospect i$ on the north side of the valley of a smail left-limit tributary of' Nikolai Creek. This locat~on is OFFICIAL USE ONLY
OFFieiA.L USE ONLY about 17 miles northwest Tyonek amd abeut 65 miles west of Anchorage. No bedr~ek was obse!""*,Ye1i at this site as most of the area. is covered by th:iek depth;lsi ts . of' g~aeiaJ. debris and a dense growth of vegetation. However, several mile~ northwest of' the reported site of the uraniferous limestone lies a thick sequence of' Eocene clastic eoaJ..-bea.ring strata and bedded volcanic rocks, in whi<:h the Indians say are other occurrences of t'yellow rock'' similar to the samples submitted by Fowler (Wedow ap.d -othera, 1952, p. 20-23; Ma.tzko and Bates? 1955). In 1952 two sma.ll specimens of ''ca.rnotiten-bea.ring sandstone were suomi tted to the Survey by Martin Gore son through Russell R. Norton, both of Seward. 'fhese specimens were reportedly found in 1949 by Goreson as nfloa.tu at the foot of Spoon Glacier in the val.ley of Likes Creek on the west side of Resurrec-tion Peninsula about ·10 miles southeast of Seward. Attelllpts in the f'aJ.l o:r 1952 to locate the seuree of the "carnotite" or at l.east duplicate tlle float material fai.led because of' adverse weather conditions. eb.emieal analysis of the least radioactive of the two specimens shows a. content of l. 7 percent uranium. Mineralogic study indicates t:P,a.t the uca.rnotite" is aetu.aJ..ly :meta.tyu.ywrru.nite and· that other vanadium minerals are also prese:o.t. (~e Wedow and others, 1952, p. 34, 35.) In' 1.953 another attempt to find the source of' the uraniferous ~andstone was unsuccessful (Ma:t;zko and Bates, 1955). lfhe aJ..leged carnotite site is untierla.in by a sequence of lava flows now altered to greenstone (Martin, Johnson, and Grant, 1915, pl.. 3) Clastic sedimentary rocks are reported to be ·interbedded with the greenstone in minor amounts, and nearby· is a thick sequence of quartzite, slate, graywacke, and water laid tuff' OFFICIAL USE ONLY
OFFICIAL USE ONLY t' (M~rtin, eJohnson, and Grant, 1915; p. 2.17, 223-226). ·Early in 1953 a~other c~otite occurrence on Resurrection Peninsula was report~d to the Survey by Fred Richardson of Anchorage The site of this oceurrence was at the head of Likes Creek, but upon field examination proved to be iron-stained graywacke (Matzko and Bates, 1955). In late 1953, Leo Mark Anthony, instructor, Mining Extension School, University of Alaska, submitted a radioactive sample given to him by prospectors from Kodia'k (loeali ty 78) The sample, reported to be from Pillar M:nmtain about 1 mile south of the tovm. of Kodiak., c_ontains up to 1 percent uranium. Meta.tyuya.unite and meta·-autunite, the -principal source of the radioactivity, occur in sandstone and along cleavage planes of feldspar (Matzke and Bates, report in preparation). The general distribution of the foregoing reported occurrences of carnotite-type minerals, several of which are partially substantiated by s~~les, and the occurrence of sooty pitchblende(?) in a beach placer on LB.ke Clark suggest that a possible uraniferous province is present in southern and southwestern Alaska. Data are far too meager at present, however, to indicate :that carnotite-type deposits have any commercial potential in Alaska. The locations of the reported occurrence~ must be sought, and, if foundJ the geologic settings must be studied in order to establish the criteria to be used in the search for similar deposits nearby:; as well as elsewhere in the Terri tory. It is likely that after the physical aspects of several Alaskan ''carnotite n occurrences are known, geologic guides to prospect:Dng for such ore deposits can be established, in a fashion similar to the guides developed in the OFFICIAL USE ONLY
OFFICIAL USE ONLY Colo;rado Plateaus (McKay, 1955; Weir, 1952; Reinhardt, 1952a and 1952b) The list of guides suggested by Reinhardt (l.952b, p, 7) are given below. Guides attributed to sedimentation processes Pres~nee of fo~sil stream channels 2, Tlliekening of sandstone lenses 3. Interfingering of Jplldstone and sandstone lenses Presence of carbonaceous material Guides attributed to postsedimentation process~s · 1. Proximity of ore 2. Relation to ·mountain masses an,.d large folds Blea~hing of sandstone Bleaching of mudstone &djacent to sandstone lenses 5. Presence of yellow iron-oxide stains 6. Presence of bleached mudstone pebbles in the sandstone lenses 7. Etched and corroded sand grains Meanwhile, in considering the statements of ~iser and others (1952, p. 26-29) on the oecurrenee of uranium in sandstone and applying the guide~ suggested by Reinhardt for the occurrence of carnotite-type deposits on the Colorado Plateaus to the general geologie of Al.a.$k$. (&nith, 1939, ~1. 1; Payne, 1953) certain areas in the Territory '' may tll tima,tely prove to be uraniferous provinces of the ~a.ndstone-tY,J?e. The more significant of these areas are discussed below. Areas potentially favorable fo~ carnotite-type ores Alaska Peninsula ... Cook Inlet area.--The belt of Jurassic-CretaceousTertiary sedimentary roeks along the Alaska Peninsula ana in the Cook. Inlet region, parts of which have long been considered loeaUy favorable for the oeeurrence of petroleum, consists chiefly of folded and faulted eE>:nglomerate, sandstone, and shaJ.e The rocks are largely marine in OFFICIAL USE ONLY
I., OFFICIAL USE ONLY origin an'd are :probably the seaward extensions of' large deltaic deposits 7 although some fresh=water or terrestrial deposits are also reeognized. They are local~y intruded b y small :masses of ig.aeou6 r~ck:s, chiefly ;of interm.eiliate types l$UCh as quartz diorite and andesite. Some of these igneous rocks are Late Cretaceous or early ~er~iary in age~ others are late Tertiary or Quaternary and are closely related to the prominent volcanic activity characteristic of the Aleutian region. Many of the coarser clastic beds are lenticular and interfinger ~th tne finer elastics. Local tmconformi ties have been recognized. Carbonaceous material is prominent throughout the stratigraphic section, locally in sufficient quantity to · form coal beds. Oil seepages and residue patches also occur in the vicinity of several of the anticlinal structures. (See Smith and Baker, 1924; Smith, W. R., 1925; Mather, 1925; Moffit, 1927; Capps, 194o.) The possible province may be extended to include the graywacke- ! Slate . sequence of Mesozoic age that occurs in the Kenai Peninsula (Martin, Johnson, and Grant, 1915} and on the island.s of the Kodiak group (Capps, 1937) .. The enlarged pro"Vince thus includes the reported occurrences of carnotite=t;y:pe minerals near Kodiak, Tyonek and Seward. '.ft.1.e pro11'inee consists primarily of the western parts of the Matanuska and Chugach .Mountains geosynclines suggested by Payne (1953). ·Kuskokwim Mountains are·a -The belt .of Upper Cretaceous sedimentary rocks in the Kuskokwim Mountains (Smith, P. S., 1939, pl. 1) consists o:f conglomerate, sandstone, and shale of both marine and fresh-water origin.. Rocks of both origins contain abundant detri.taJ. OFFICIAL USE ONLY
OFFICIAL USE ONLY cari:lo:naJ.:eous ma:teriaJ.. They overlie earlier Mesozoic(?) and PaJ.e,ozoic rocks ·u."!colu'orma.bly and are int.rude by Late Cretaceous or early Tertiary stoc~s and dikes of a varie .. cy of granitic rock. :types. In some areas, particu~arly in tl~e vicinity of the intru.sives, the Cretaceous· clastic strata are higlily def'ormed and m.etrunorphosed, but as a rule they are only openly folded (Mertie and Harrington, 192!t.) No ea.:rnoti te-type :minerals are known or have been reported in the area. However, a. few .i.ntrusi ves both in the area and around its periphery, have been studied. and shown to contain minor amounts of radioactive minerals as accessories. At several localities the contact zones of the intrusives also -contain radioactive minerals, and at one locaJ.i ty me.tazeuneri te has been identi-· fied in a copper-bearing vein cutting a granitic stock (Maxham, 1950; Wb.ite and Killeen, 1953; White and Stevens, 1953; West, 1954). This ·belt of Cretaceous clastics and its attendant int.ru.si ves coincides for the most part with the southwestern part of the Kuskokwim geosyncline of Payne (1953). Manley Hot Springs-Rampart area.--Cretaceous clastic rocks are present in the Hot Springs-Rampart area where they appear in the Tofty . segment of the Kuskokwim geosyncline (Payne, 1953) They are in.tr:tded by gra.ni tic rocks in which radioel.e:m.ents oect~r, chiefly in such accessory mineraJ.s as zircon and monazite. In addition, placer deposits of 'the area locally contain columbi te, el~sworthi te, eschyni te, end xenotime, all of which very likely had their bedrock source in deposits related to the intrusives. (See Eakin, 1913; Mertie and Waters, 1931~; MJ~..ham, 1954.) OFFICIAL USE ONLY
OFFICIAL USE ONLY !.t<?'twer Y~on-Koyukuk area. --A sequence of about 8, 000 ·feet of' Upper Cretaeecn.:ts r oGks is one of' the dominant features of the Koyukuk geosyn., eline (Payne, 1953) . The sequence consists of both marine and fresh water conglomerates, ~andstones, and shales. Almost aLl beds contain detrit al plant materia.l which locally in the fresh-water emits is abunda.n.t enough t o form coal beds. Most of the coarser elastic · reeks are gray but ~ocally are bla.ek where carbonaceous material is abundant. other beds a:re :reddislJ,. or reddish brown. The Cretaceous strata are intruded by Late Cretaceous or early Tertiary ign~ous rocks of felsic and i nte:mediate types in the form of large dikes or sills aad stocklike bodies. The rock types. i;include soda granite, quartz diorite and · diorite. Later Tertiary effusi ves are also common; these are gener~y basal tie in character., a.l though dacites and · andesites are reported in the SQuthe:rn :part of the area. The Cretaceous rocks f'or the most part have ~een thrown into relatively broad open f'olds; some taul ting is recognized. Stronger deformation with attendant metamorphic effects oeeur :in the vicinity of' the intrusives (Smith and Eakin, 1911; ·Smith, P. s., 1913; Harrington, 1918). No uranium minerals are known either in the clastic rocks or in the associated intrusives. However, Uranium occurs around the periphery of tb.~ geosyncline in aeees:sory mii:terals of g:r1mi tic . rocks, in the heavy sands of placers, and at one locality, in minor amount in a sulfide-bearing breccia vein (White, 1950; Ga.W.. t and others, 1.953, White and Stevens, 1953; West, 1954). · · Ga.newell. a;r:ea The Cretaceous Cantwell ·formation in the central part of' tb.e. Alaska Range conrs~st s of massive conglomerate with OFFICIAL USE ONLY
OFFICIAL USE ONLY ir::.terbe~d~d sandstone, graywacke~ ·· a.rgilli te, shale, _ud slate . qarbonaceout? ma.terie.l is <::o~n, particularly in the shale beds. . The colors of the for.mation a,r~ co:mmonlJt-:gray to drab but locally. are bright red to broVt.rn. In some localitie·s· considerable thicknesses of volcanic tufts · a.nd flows are interbedded with the clastic sediments. ·,!'he lavas appear to be chiefly· a.nd,esi tes although rhyolite and basalt aJ.so occur~ structure of' the Cantwell formation is characteriz"- for the most part · - by broad open f'olds with some :faulting Locally, however, 1 t is ·highly d.is"'climbed a.nd considerably metamorphosed. Large bodie.s ·of intrusive . granitic· rock are a prominent feature of the area. Some· of these in:tru~ .- sives cut the· Cantwell formation and are probably the parent magma from> :, - whieh smaller dikelike bodies of felsic rocks were formed (Mof'fi t ., ,1915; ·
Capps, ·194o) . No radioactive minerals are known· in the Cantwell ;area, although, the _so-called Healy carnotite (p. 30 ) may be from this area. The story. o_f · the Healy Ca.I1lOtite is best related i:q the .Ua.ska Territorial Department of Mines monthly bulletin :for February, 1954; it is gi'ven below . . i ''Since radioactive minerals became im:,portant, there has been· a story' circulating of a carnotite occurrence along the Alaska Railroad somewhere in the vicin:i ty of Healy. The TDM · q.as answered numerous inquiries, both verbal and by correspon~ence, on the subject. Many samples · have be~n sent in from t:Q.e area. for radioa.cti ve testing and · identification, and claims · have been staked on the assumption that radioacti ves were :,present. Thus :far, nothing significantly ra.dioactiye has been found in the district~ 9.qThe probable source of the story is contained in the old records tlie College Assay Offiee, vhere · it is revealed that George Gotto of' Nenana, a railroad worker, sent in a very small sample of mater;ial in 1918 ' that was identified as carnotite by the assayer. as sayer added to h+s report that the sample was too :for positive-tests and ~sked C,-otto for more. Repeated requests for more of the material ':and OFFICIAL USE ONLY
OFFICIAL USE ONLY inf:oi"'lJJ.at,ion on the location ·;of; i t!SI origin were never answered. Gotto died in 1921. It leaves the que~rtion unanS'were. as to whether the assayer might have be~n mistaken, or whether the sa:m,ple might have 'been imported ±"rom · somer~:t.b.ere else. t1So:n:te of~ · -Gett;cl"1 ir former fri.ends an.d many otb.er people are still eonvineed. the. carnotite is there. <me group t-ras so insistent that samples brought, from. the area 't!Yere c·arnoti te that they refu..se~ to accept the assayer's negative report and sent the samples ron in to the AEC in Wa~hing ton ·wnere they received the same results. Some people have been fooled by a variety of yellow al:m11 that occurs in the district.. Geological Survey men covered the railbelt with super-sensitive Geiger eqtJ~pment, but found nothing of importance. nin s:pi te o:e all t.he above evidence to the contrary, the story may· still be tru.e. Carnotite cot:.Ud possibly exist in the Healy district. Perhaps an airborne scintillation survey such as those being widely performed in Ca.nada would settle the question to everyone's satisfaction. n Daring the . smnmer of 1951 a sample o:f meta.tyuyamunite.;.bearing limes:tone was sub:netted to the Fa.urban.ks.Radioaetivity Testing La.bora- ,tory 'by H. N. · Fowler of .lmehorage The sample contained 0. 6 percent urallium oxide. · As originally reported (Tolbert and Nelson, 1951, p. 6, 'I 9) in' ·1951 the Fowler prospect was supposed to be loea.ted near the Yem.t:aa River north of the mouth of' the Sk'w'entna B1 ver. Information. obtained dtir:tng the following 'Winter by however, placed the location on the Deshka. River, about 25 mi~es south-southwest of Talkeetna. The Deshka site ·was examined briefly in Ju.ne 1952, by combined airborne ·I and ground techniques. No uraniferous limestone was found, nor were 'any radiosJc~tivity anomalies discovered. However}) late in the summer of 1952 addi tiona.l inqu~ries by Fowler and .his associates revealed that na.ti ve from ·Tyonek had folliD.d the sample in 1949 on a small tri buta.ry of' Nikolai Creek (locality 17) (Wedow and others, 1952, p. 20-23). An attempt to visit this loc:a.li ty was made ir:~. October 1952, but was unsuccessful be_,:· cause of adverse weather conditions. T'he. Nikolai Creek area was again
OFFICI.AL USE ONLY vlsitea. briefly in June 1953. No uraniferous limestone was observed and no anomalous radioactivity noted. Because most of the area is concealed by glaci3.:l debris and tense _vegetation, the few negative restU.,ts in the reconnaissance of the Nikolai Creek area are not conclusive and furt~r search is warranted. In 1952 while attempting to obtain additional infor.mation from a prospector at Seward on the location of a reported carnotite occurrence (Wedow and others, 1952, p .. 3'7-38) the author was shown a sa.mpJ,.e of carnotite. by another prospeetor and told that it had been found in "the valley ot Likes Creek (locality 7) on Resurrection Peninsula, so~th east of Seward (Wedow and others, 1952, p. 34-35). Attempts to locate this site in September and October 1952 were hampered by adverse weatb.e:r. Additional reconnaissance on Resurrection Peninsula in 1953 found no radioaeti ve materials. It is now believed that the sample may not have come from Resurrection Peninsula, but that a yellowish ~Pi-~" dote:,iraek and graywacke in the vaJ..ley of Likes Creek were, mistaken for carnotite. However, the ori,~in Qf the uraniferous sandstone sample ~st be explained and the fact that the uranium mineral is chiefly metatyuyamuni te, a relatively rare m.inera.:;L and the same as in the uraniferous limestone reported to be from the i'yonek area men.:. · ! other areas.--Ma.ny ot.her areas in Alaska llU9.Y have possibilities for the l ceurrence o:l;' carnoti te-t:ype mineraJ.s. However, until 1110re i:lll'or- :ma.tion is available about the reported occurrences of carnotite and relateti minerals and the possibilities tor local uranium source rocks, it OFFICIAL USE ONLY
'I il ! ' OFFICIAL USE ONLl is needless to speeul.ate further as to where such miner~s could be foll1fld in tbe Territ~ry Carbonaceous rocks, phosph~ori tes, ani other ·sedimentary rocks Uraniu.m. oeeu.rs in earbonaeecnas rocks, phosphorites, and other sedimenta.r·y r·oeks in relatively minor amounts in many parts of the world (McKelvey and Nelson, 1950; Bain, 1950). studies in continental. United States have i1;1dicated that blaek shales, lignites, and phospllorites commonly contain 0.005 to 0.05 percent u.ra:niu:m,~but rarely as :much as O.l percent ura.nimn. The radioactive black shales are donlinantly marine in origi:o_ principally of P~eozoie age, and ocetir for the most part in eastern aad central United States. (See Kaiser all.d othe~s, l952, p. 31-35 ) Elsewhere in the world uraniferous carbona.e~ou.s rocks are known I, in Swe~en and Russia (McKelvey and Nelson, 1950, p. 37-39; a.Ild Bain, 1950, p. 290~292, 310-313, 320). Uraniferous phosphorites .range from Paleozoic to Cenozoic in age. The principal deposits in the Vnited States occur in the Pe~a.n Phosphoria formation .of the northern Roeky Mountains and the ' f Pliocene Bone Valley fo!"lllation of .Florida. Similar phosphorites but of Cretaceous and Eocene age have been repo~ed in Russ~a, Egj'pt, Tunisia, Algeria, and Morocco (McKelvey and Nel~on, l950, p. Lt.o-42). ne most significant concentrations of uranium in coal appears to be in: certain T~rtiary li~nites in the Dakotas, Montana, and Wyoming. geologie relationships of the lignite suggest tllat its uranium may have been leached from nearby volcanic rocks and deposited in the lignite by suriaee waters (Kaiser and others, 1952, Po 3l-35). OFFICIAL USE ONLY t i
OF"FICIAL USE ONLY :;Lnasmuch as the ·maj _or objective o:f reconnaiss-ance for uranium in Alaska has been the search for high-grade ores, little effort has been ;made to in.,restiga:te the possibilities fo1 uraniferous carbonaceous rocks, pho.s:phori tes, and coals, with ~the .e9.u.ence t hat data · the radioactivity of these rock ty:pes are quite meager. In 1948, however, ree~nnaissance traverses through Precambrian and Paleozoic seetio:p.s, .thousand.ds of feet thick:; along the Porcupin~ River (White, J.952a) and in . the E~le-Nation area along the Yukon River 1954) in east-central Alaska reveaJ..ed that certain beds of' MississiJ?pian black shales· conta.~n as much as 0.009 percent equivalent uranium and in general are cQniparable to similar deposits in continental· United States. other carbonaceous shales have been tested at random elsewhere in the Territory in eonnection with other investigations but do not contain more than o.oo4 pereent equivalent uranium as estimated from field observations. The ouly known uraniferou.s phosphorite oeeurs in the .firuk.tagia.k.;. Chandler Lake area on the north flank of the Brooks Range in northern Alaska~ It lies in the Mississippian Lisburne limestone and. is almost identical in lithologic character 'With the Permian phosphorites of the Pacific Northwest. The uranium content is as much as about 0.02 percerl:t, and in general the higher urani-um values follow a high P205 content
.ll"., {See Wedow and others, 195l, p. 113; Patton, 195,:) A small amount 9f uraniferous phosphatic material also occurs as nodules in the Mississippian black shales the Eagle-Nation area (Wedow, 1954;, p. 3-5). Such coal .deposits as have been tested in Alaska have shown no radioactivity comparable t o that exhibited by the lignites of 'the OFFICIAL USE. ONLY. . ·-
OFFICIAL USE ONLY Dakotas, Montana, and Wyoming. The deposits tested include the bituminous and a.nthrae~te c:Jials of Ma.tan.uska valley, the lignites of the Homer area., .,a.nd scattered mino~ occurrences in ea.st~centraJ. Alaska. The ·maximum radioactivity obser~ed was 0.003 percent equivalent uranium in a coked coal. near Chicke_n in the Fortymile district (W~dow, White, and others, 19547 p. 20-21). It is essenti~lly impossible to assess t:tte potentia.litief3 of Alaska for significant deposits of uraniferous ca.bona.eeous sha.l~s, ;Phosphor:i tes, and coals on the basis of the limited data. now available' .The oecurrrnce of uraniferous blaek shaJ.e at two localities in east-eentraJ. Alas~a and :phosphorite in north~rn Alaska, all in . rocks of essentiaJ.ly the same part of the Mississippian ~ystem, suggests that sedimentary rocks of this system where exposed..· in intervening and adjoining areas of' the northeastern part of the 'i'erri tory are likely to be favorable sites . f'or the occurrence of uraniferous orga.nie deposits o:r :marine er:i.gin. Sueh areas would include those mentioned bY. Mertie (1933, p. 423) along the international bol;,Ul.dary north of the Yu.kolit River, by Smith (1939, p. 30-32) in the Brooks Range. f'rom Cape . Lisburne on the l:f'est to the C~ ning River region in the east, and byNof'fit (1938, p .. 22-29) in the Cb.itina valley .Among the geologie guides suggested "Qy Duncan (1954, 21, 22) in the search for u.ra.nifero·!ls black shales are two that may w~ll be appl_ied to Al~s~a. These are as follows: Look for black shaJ_e zones that interfinger· with or are overlain by slightly radioactive volcanics or their tuffs. n7. Examine marine aeposi ts containing black sha.les that appear to have been deposited during periods of exte~~ive volea.n.ism. Some OFFICIAL USE ONLY
OFFlCIAL· ONLY fine-textU+'ed siliceous sediments such ·as cherts, radiolarites, novae- ·~ulit,e~9 and diatomites with black shale wraps we:re de-. :posited· where u,usual a.:mounts of" siliceous volcanic material. were supplied to oce.an waters. Such deposits might contain unusual amounts of the uncommon metals ' including uranium. Kno"Wll u..raniferous shale ·depqs:lts associated w'j,th cherts include the Phospb.ori~ formation, Chattano<;>ga. shaJ_e and shales in the Gardner formation." Sedimentary deposits meeting the condi tiona set out tl:).e guides quoted above are widespread in Al.a~ka. Black $hales associated with volcanias, at leas·t in part silicic (rhyolitic or felsic), are known in almost ev~ry rock system of the Terr~tory. A few exam~le$ ar~: (1) Red and green volcanic breccias and tuffs interbedded With Devonian bl~ck slate and limestone on the southwest coast of F.rince of Wales Island in southeastern Alaska (Buddington _and Chapin, 1929, p. 96) (2) Also in southeastern Alaska on the, ~northern :part of Kuiu Island .Permian black shale and sandy limestone are intimately associated with pandstones· and .conglomerate containing cobbles and pebbles of various rock types in~luding red rhyolite'· white chert and red jasp~r; and with rhyol.it~c of red, white, and green hues as well as with more mafic volcani as cut by many veinlets of bright red jasper. . Carbon! zed plant remains aN abundant in the sandstones (Buddington and Chapin, 1929, p. 119, 120). Black carbonaceous shales with associated cherts and cherty limestone of the Triassic McCarthy formation i n the Copper River region (Mo:t~fi.t, 1938, p. 58, 59) {4) Permian(?) and Triassic black argillites with ~ssociated vole~c$ and ah~rts in the Chulitna district of the Alaska Railro~ region (Ross, 1933a, p. 294-3Q2). OFFICUL USE ONLY
OFFICIAL USE ONLY Interbedded carbonaceous shales and volcanic tuffs and conglomerates · o:r Tertiary age i:n the An.ia.kchak di.strict in the Alaska Peninsula (Knappen, 1929.9 p. 195). Placer deposits · In general only abrasion-resistant and j_nsoluble minerals accumulate in placer deposits. Thus, most uranium minerals, because of their rel- . ~tively high degree of solubility and friability, are not found in placers. ~he exceptions to this ·generalization include the occurrence 9f highly resistant or refractory minerals, such as zircon, which normally originate as accessories in igneous rocks and contain minor amounts of urani~ and thorium. On the other hand, many thorium-bearing minerals are tough and resistant and hence relatively common in placers; in fact, most of the world production of thorium has been from monazite-bearing placers. In continental United States placer monazite has, been. mined · ' I ' exten~!vely in Idaho, some production is reported in Florida, and significant quantities are known to occur in the Carolinas. At the outset of the Alaskan Trace Elements Program of the Geo- . logical Survey in 1944 placer concentrates in tne Survey's Alaskan collections were scanned for radioactivity as a means of -rapidly finding possil:)le leads to sources of fissionable materials, chiefly uranium. The resul. ts of the. scanning (Harder and Reed, 1945) showed that some placers m:i,ght . be of some promise, but field investig~tions in· 194~ .. indicated that Alaskan placers were not likely to serve as signif'iea,nt rese:r"res of uraniu,m.. The general emphasis of the program was therefore OFFICIAL USE ONLY
OFFICIAL USE ONLY a.i~cte:d chiefl y ·to the ch for high-grade uranium lode deposits. HoweverJ because one of the ·techniques used in the search for lode sources ·was the testing of the heavy-mineral concen-t:rates of ~luvial. deposits, much data have been accumulated on the radioactivity and mineralogy of pl acer deposits in Alaska. Revie·w of the data, collected. over the years~ shows that there are further exceptions to the generalization that uranium minerals are unlikely .to accumulate as . placers. ·. In general, the concentrates from most Alaskan placers and other alluvial deposits are· either only weakly radioactive or essentially nonradioactive, that is, they contain from less than 0.001 ·to 0.009 percent equivalent uranium. Some concentrates, however, particularly those fram .several gold-placer operations, wherein the degree concentration is extremely high contain as much as 80 percent equivalent uranitun. Such amounts of radioactivity are, of course, extremely rare, but concentrates containing from several hundredths to several tenths of a percent equivalent . uranium are relatively connnon in Alaska. The most significant areas from which such radioactive concentrates may be obtained are at Cape and Ear Mountains, at Serpentine Hot Springs, in the Darby Mountains, and on the Buck.l.and-Kiwa.lik divide on t~e Seward Peninsu1a; at Flat, Nixon Fork, and in the vicinity of Long in the Lower region; on the Kahiltna River and some of' its tributaries, and in the vicinity of Yakataga in southern Alaska; and on the South Fork of the Koyukuk River and in the C.Thlandalar, Circle~~ Eagle, and Fortymile districts of east-central Alaska. . The uranium and thorium in most of OFfiCIAL USE ONLY
OFFICIAL USE ONLY the railioa.ctive placer eoneentrates occur chiefly as illlPU+ities in · allanite, a:pati te, monazite, sphefl.e, xenotime, and zircon. These minerals have been derived chiefly from the igneous rocks in which they occur as accessory minerals.. Locally, however, the uranium and thorium in the p~acers occur :· in suqh minerals as uranini te, thoripi te, 'Q.raQ.o-, thoriani te, thori te, gUmmi te, a.nd other mineraJ.s not normally a.b.le to withstand the abrasive processes concommitant with the forma~i9n of placers.. It · is likely, therefore, in most cases, that the more fria"ble and soluble uranium minerals found in placers have not been transported any great distance. Wb.ere these miner~s, particularly the oxides, occur in placers -in the headwater portions of streams, especially in association with other minerals colimloil.ly occurring in uranium lode deposits elsewhere, they strongly suggest that a significant "bedrock source may found in the drainage area upstream from the placer deposit. was formerly thought unlikely that significant quantities of uraniUm. could be obtained from placers.. A recent study of the "radio.;.. ! active black'' mineraJ.s occu.tTing in the .monazite placers of Idallo indieat~s a ~ssibility that significant quantities of urani~~ght be obtained as a byproduct in the production ot niobium and tantalum (:Mackin and Sc~dt, 1953). The radioactive black minerals 'are chiefly oxides ot niobium, ta.ntaJ..u.m, and titanium with smaJ.l amounts of uranium, thorium, and rare-earth elements, for exam~le, s~rs~ite, eschynite, and eolu;mbi te.. The presence of other possible commerei~ miq,erals _such as. monazite, cassiterite, ilmenite, gold, and platinum in the same placer as uranifero~s minerals also enhances the value of the concentrates and OFFICIAL USE ONLY
OFFICIAL USE ONLY :make the byp'rodu.ct production · o.t: ·uran.ium possible. With :reri.ewed i nterest .in .the possibility for production of uranium . from placers, one natu:t;ally t~s to Alaska because of' its pa~t and present: prominence as a :producer-of placer gold. What then are the. :potential.i ties for uranium and thorium placers in Alaska? ! . review of the known oceurren,ces of thorium-bearing mixterals in Alaska was made in 1952 (Bates fmd Wedow, 1953). This review PQinted out that there :was the possibility that thorium-bearing minerals migl;lt be produced as a byproduct of gold or tin mining in at least six widely · scattered areas of the Territory. These areas are as follows: Major thorium-bearing LocaJ.ity minerals 1. Tobin Creek-Big Creek area, Chandalar district, ·east-central Alaska 2. Manley Hot Springs district, east-central Alaska Long area, Ruby-Poorman district west-c~ntral Alaska Nixon Fork area, west-eet+tral Alaska Buckland-Kiwalik district, west-central Alaska (Seward Pe:n.insula) Cape Mountain area( west-central Alaska (Seward Peninsula) Monazite Columbite Ellsworthite Esehynite Monazite Xenotime Thorite Uranothorianite Ura.nothoria.nite 'I'horite · Monazite xenotime To the area listed above should be added the vicinity of Cape Yakataga on the· Gulf of Alaska in southern Alask~ where uranothorianite was identified as the ehief radioactive miner~l in a beach concentrate sample containing as nrach as 35 percent e·qv.i valent uranium (Matzko, OFFICIAL USE ONLY .
OFFICIAL USE ONLY 1953, person.:a.l communication); and, al.so, the ~iltna River placers in the Yentna district of southern Alaska where a placer drill-hole sample fro:m ~ed Hill :Bar contains a suite of heavy mineral~ as follow:B . (Robinson others, 1955, a.p:pendix): Ilmenite :Monazite Zircon Magnetite Platinum Seheelite Uranothorianite Percent Garnet Cassiterite Sphene Rutile Hornblende Gold Biotite Percent · ·tr · tr tr tr Evaluation of ra.d:inactive placer deposits (IG.ine, 1952) has been under . study by the U. S. Bureau of Mines on behaJ.£ of the U. s. Ato~e Energy COmmission. Whether it will be economical to mine raitioactive miner~s from placers will be determined by such factors as: (, (2) (3) {4) Tenor of the depos_it (that is 7 pounds of. t'bl.a.ek sand'' or marketable minerals per cubic yard of gravel) Total yardage of gravels to ensure a relatively long-term period of mining (that is, reserves) Water supply and accessibility Climatic conditions of the region, particularly as they affect the ·length of season during ·which mining operations . can be conducted. Whether or not Alaskan radioa.cti ve placers meet the necessary condi tions :for eommereia.l production has yet to be determined. The subject is .currently under review by the U. S. Bureau of Mines with the epoperation of the Geological Survey. The preliminary conclusions. of the author at this time is that the_ Kahiltna Biver placer~ are perhaps the most likely, OFFICIAL USE ·ONLY
OFFICIAL USE ONLY of all the known plaeer occurrences of uranium~ and thoriu:m. ... bearip.g minera~~ , in Alaska, to meet most of the requi.rements governing commercial exploitation. Sui.ficient yardages of gravel and adequate water are avail.- able du:r-ing the open season to support possible dredge operations. The tenor of the gravels is enha11ced. by a wide variety of such commercial. minerals as ilmenite, cassiterite, platinum, and gold, in addition to the rad:i.oacti ve mineral.s--monazi iie and u.ran.othoriani te. The sites of the placers, which stretch along the Kahiltna from near its mouth on the Yentna Rive·r at least to the mouth of Cache Creek, are accessible by shaJ.low-dratt river boats f'rom the Susi tna and Yentna. Rivers. The placers are also,. accessible by tractor from the "Petersville Road'' which originates on the west bank of' the Susitna River opposite the town.of Talkeetna, a station ·. on the Alaska Railroad, and ~?tends · to the ·Cache Creek' placergold camp. However, mueh. geological and mineralogical stu.dy of Kahiltna placers will be necessary before it can be determined whether these placers are sufficiently rich and economically feasible to mine
·. Natural fluids Some natural fluids such as water and petroleum locally are radioactive. Although it is generally be·lie ved that the radioactivity of the flUids is due primarily to radon a.nd its daughter products, uranium also accounts for a slight amount of the radioactivity. Recent work by the Geological Survey on uranium in water (Fix, 1954) ana in petroleum (13rickson, .Myers, and Horr, 1954) shows that local, relatively large a.m.ounts of uranium in natural fluids and their residues may be of OFFICIAL USE ONLY
OFFICIAL USE ONLY significance in the search.£h for new uranium deposits if not as source materials tb.emsel ves ., According to Fix (1954, p ll), most waters con~ tain less than 1 part per b-illion. uranium; hence, " water containing 1 o 0 ppb U is considered . anomalous -and 1.worthy of addi t:i.onal investigation to determine the cause." Since 1952 the Geological Survey has been attempting to adapt the geochemical technique of analyzing water samples as another tool in prospecting for uranium :i.n Alaska. Local conditions have limited studies to the Circle Hot Springs area where from one locality on Portage Creek sample~ were o-btained which contain from 15 to approximately 4o parts per billion uranium. It is believed that this anoma.lous· coridi tion. :may be due to a nearby bedrock deposit of uranium. (See Nelson and others, , 1954; ~tzko and Bates, 1955.) Considerably larger numbers of samples are needed for experimental j! purposes, both in the Circle Hot Springs area as well as in other areas of Alaska known to contain uranium minerals, before a satisfactory routine technique can be perfected that takes into consideration such peculiarities as permafrost and low volume ground water circulation. The studies of Erickson, MYers, and Horr (1954) on samples of crude oils, natural asphalts, and petroliferous rocks showed that uranium and a vide variety of other metals commonly associated 'With ura.n.ium in lode deposits are consistently present, locally in relatively large concentrations, in these types of carbonaceous materials. The uranium content. of the samples they studied was as much as 0.064 parts per :million in crude oil' 62' 500 parts per million in the asphalt' and OFFICIAL USE ONLY
OFFICIAL USE ONLY 6'1' parl per :million i n oi l extracted from petrollferous roeks. Analysi.s of the ash of these samples for uranium showed as much as 0.014 percent , for the crude oil ash 7 10 per~ent or more in the ash of the asphalts, and o.48 percent in the ash of the oil of the· petroliferou.s rocks. Erickson, Myers, and Horr concluded that the uranium and other metals "occur as metallo-organic compounds and are concentrated in the heavy asJ?baltic portion of the petroleum. n They state further that tb.~ uranium and other metals ve_ry likely were concentrated during the formation of the oil and that natural a~phal ts and pet:r:oliferous rocks might be the source material of the uranium and other metaJ.s in some of the uranium deposits. They also point out "that many uranium deposits occur on the flanks of breached anticlinal structures whicn have served as tra~s for the accumulation of petroleum during geologic time.n As far a.s is known only one sample of petroliferous material from ALaska' has been analyzed for uranium. I_n 1953 a sample of crude oil from a seep in the Yakataga district of the Gulf of Alaska region was obtained from Don J. Miller of the Geological Survey. The ash of this oil contained 0.014 percent ura.r.ium; however, more samples of oil from the Yalta:taga district must be collected for an~ysis before the significance of this one relatively high uranium oil sample ean be f~ly evaluated. , Meanw:b..ile, attempts are being ·maa.e to obtain other s~ples .of oil from the Yakataga. field as well as from other Alaskan petrolelllll fields~ particularly aJ.ong the Alaska Peninsula and in the Coo~ · Inlet region, to analyze for uranium and other heavy metals. Particular attention :sho~d be paid to t;he crude oils and petrol:t:ferous rocks of OFJFICIAL USE ONLY
OFFICIAL .USE ONLY the Irdskin Peninsula and in ~he Pual.e Bay-Wide Bay area of' the Alaska Pe·ninsu.la. If' the petrol:;Lferous materials of these areas prove to be significantly uraniferous, . such i.nfor:mation will, lend support to th~ hypothe~is that the Alaska Peninsula-Cook Inlet .region has p~tentialities for the . occurrence of carnotite-type deposi tB (p. 81). CONCLUSIONS Although no primary deposits of high~grade uranium a.n.d thorium ores have been found in Alaska to date, many areas in the ~erritory are yet favorable for the occurrence of' these ores. Although there is little likelihood that a:ny occurrences of low-grade igneous bodies and the spotty pegmatitie deposits will ever be of commercial significance, nevertheless the potentialities of' the low-grade igneous bodies with their extremely large tonnages should not be overlooked should the radioaetirtty of some such bodies be due to uranium in one of the pri~ry oxid~ mineraJ..s easily concentrated by simple physica1 methods. Vein and related deposits and deposits of the carnotite-type ores perhaps have the greatest potential insofar as pessible Alask~ pro-
duetion is concerned. The Seward Peninsula, the Lower Yukon-Kuskokwim Highlan.ds region~ and southeastern Alaska are the most likely regions in whieh . vein and related deposits might be found. In the first two . o:f tllese regions seeo:t:ldary uran.i:u.m minerals have been found closely associated with deposits of other metals, and it is possible that primary uraniferous ores oeeur at depth. In southeastern Alaska a mineral tentatively id~ntified as pitchblende occurs .in a metalliferous OFFICIAL USE ONLY
OFFICIAL USE ONLY vein in the Hyder district and thorite and monazite have been found in carbonate-hematite veins on Prince of Wales Island, and, although most of' the · other mineral deposits t ested show no evidence of sig:r...ificant radioactivity, :much of this highly mineralized region has not been prospected .. Se-veral sa.mples submitted by Alaskan prospectors have. contained carnotite-type minerals. Most of these are reported to be from the Alaska Peninsula-Cook Inlet region of southern and southwestern Alaska. These samples and the geologic setting of the region indicate that the Alaska Peninsula-Cook Inlet region is perhaps the most favorable in - Alaska for the occurrence of carnotite-type deposits. other belts of clastic sedimentary rocks, chiefly in southwestern and west-central Alaska, are also believed to be favorable for the occurrence of · carnotite-type ores. Urar1iferous phosphorites and black shales have been noted at several localities in Alaska and other areas are believed to be favorable for this type of low-grade deposit. In general, however, present economic considerations would very likely prohibit deve~opment of such deposits. Inasmuch as Alaska has produced considerable gold and some· tin from placers, the Territory ha.s a .small potential for . the production of urc;miu:m. a.:Q.d thorium as a by:product of the placer min;i.ng. The plac·er area believed to have the_ greatest potential is in the K~ltna Valley 'Alaska; placer concentrates from this area eqntain such connnerciar minerals as .ilmenite., cassiterite, platinum, and gold OFFICIAL USE ONLY
OFFICIAL USE ONLY in a.ddi t ion ·to uranothorian.i te and m.nazi te. Water and petroleum--the natural fluids--show same promise in Alaska as indicators of possible ·uraniferous localities and possible uraniferous ;provinces, but nmeh stu.dy on techniques of' sampling as 1rell· as on inter~ p,relation of' .data will be necessary before routine methods can be · developed · LITERATTJRE CITED Bain, G. W. 51 1950, Geology of the fissionable ;ma.teria.ls: Eaon . Geology, v. 45, p. 273-323. Bastin, E. S., and Hill, J.. M., 1917, Economic geology o:f Gilpin County and .adjacent parts of' Clear Creek and Boulder Counties, Colorado: U. S. Geol. · Survey. Prof'. Paper 94,. 3 79 p. Bates, R. G~, and Wedow~ Helmuth, Jr., .1953, Preliminary summary review of' thorium-bearing mineral oec·urrenees in ·Alaska: U. S. Geol. Survey Ci7e. · 202? · 13 p. Buddington 7 A. F., and Cha.p~n, Theodore, 1929, Geology and mineral · . ·deposits of southeastern Alaska~ U .. s. Geol. Survey Bull. 800, 398 p. Butl.er 1 A. P. , Jr., 1952, The GeologicaJ. Su.r"trey' a work on the geology . of ,ur.;tnium and thorium ~eposits: u. ·s. Geol. Survey TEI-207, 26 issued by u . s. AtQmic Energy Comm.. T~ch. In.f. Service, Oak Ridge. Cap:p~, .s. R.~; 1937, Kodiak and adjacent islands, .Alaska: . u. s. Geol': Survey BuJ.l. 88o-c, p. lll-184. · 194o, Geology of the Alaska Railro~ regio:o.: u. S .. Geol. Su:rvey Bull. 9J7, 201 p. Colby, ~Ierle, 1942, Guide to Alaska: New York, The Maemilla.tt :Company. Dvncan, D. C., 1954, Compiled by, Reconnaissance investigations for uranium in black shale deposits of the western states during ':l951 and 1952: U. s. Geol. S~ey TEI-381, :89. ; i;?~11SJQ. by t,he. 1l.., ~s: .Atomic Energy Comm. Tech. Inf. Service, Oak Ridge. Eakin, 'H. M., 1913, A geologic reconnaissance of a part of the Rampart .quadrangle, Alaska: U. S. Geol. Survey Bull. 535,. 38 OFFICIAL USE ONLY
OFFICIAL USE ONLY Eakin, :EL M., 1918, The Cosna-Nowitna region, Alaska: U. s. Geo1. Sur~ey BUll. 667, 54 p. Erickson, R. Lo, Myers, A .. T., and Ho;rr, C. A., ~954, !fhe association . ot l1:17aniurn and other metals with crude oils, asphal. ts, and petrol.ferous _rocks~ Amo Assoc.. Petroleum Geologists Bull. , v. 38, p. 2200-2218 ' Fischer, R. P., 1950, Uranium-be-aring sandston~ deposits of the Colorado Plateau: Econ. _Geology, v. 45, p. 1-11~ Gault, H. R., Killeen, P. L., West, W. S., and otb.ers, 1953, Reconnaissance for radioaet:f,. ve d~posi ts in the northeastern part of the Seward Peninsula, 1945-47 and 1951: U. s. Geol. Survey Circ. 250, 31 p. George, D 'Arcy, 1949, Mineralogy of uranium- and thorium-bearing minerals: U. S. Atomic Energy Commission, RM0-563, 198 p., 1950, issued by U. s. Atomic Energy Comm.. Tech. Inf. Service, Oak Ridge. Harrington, G. L., 1918, The Anvik-.A.ndreafski region, Alaska: U. S. Geol. Survey Bull. 683, 70 p. B;e.ss, F. L., 1934, The radium and uranium ores of the Katanga region · (a, digest of a paper by J. t'flhoreau and others) : U. S. Bureau of Mines , Minerals Yearbook 1934, p. 498.,·502 .. Kaiser, E. P., and others, 1952, Selected papers on ur~ium. the United States: U. s. Geol. Survey Circ·. 220, 35 p. Killeen, P. L., and Ordway,'. R. J., 1955, Radioactivity investigations at E;ar M<;>untain, Seward Peninsula, Alaska., 1945: U S. Geo;L. Survey Bull. 1024-c, p. 59-94. K:n.appen, R. S., 1929, Geology and mineral resources of the .Aniakchak d,istriet (Alaska): U. S. Geo1. Survey Bull. 7'17-F, p. 161-227. Lang, A. H., 1949a, Notes on prospecting· for uranium in Ca.pada: Canada GeoJ,.. Survey Paper 49-4, 22 p. 1949b, Uranium discover;i.es in Canada.--1948-1949: Paper presented at Lo:ndon conference on radioactive raw mate:r;-ials, . September 19490 1950, Summary account of' Ca.nad~an uranium aeposi ts: ·. -a~di"'!""an Mini1;1g _and Metallurgical Bull., v. 43, p. 426~:4-33. 1952, Canadian deposits of' uranium and thorium (interim
Ca.n.~da Geol. Survey, Econ . Geology Series, No. 16, 173 p. OFFICIAL USE ONL~
OFFICIAL USE ONLY McKay, E.. J., 1955, Criteria for 011tlinfng areas" favorable for ur-aniUil1 · deposits in parts or .Colar?do . and.~~ utah: . U S., ... Qeol . ." ;
" : " McKelvey, V. E., and Nelscm., J. M., 1950, Chara.cteristies of marine l.U""anium-bearing sedimentary rocks: Eeon~ Geology, v. 45, p. 35-53~ Macki11, H. J .'1 and Schmidt, D·. L., 1953, Reconnaissance geology of placer 4e:posits containing radio~etive :minerals in the Bear V'aD.ey district, Valley County, Idaho: U. s. G-eol. Survey open file report; Geo1. Soc. America Bull., v. 64, p. 1549 (abs.). Martin, G. c., Johnson, B. L .. and Grant, u. s., 1915, Geology and mineral resources o:f' Kenai Peninsula., Alaska: U. S. Geol. Survey Bull. 587 ,;· 243po Mather, K. F .. , 1925, Petroleum on Alaska PeninsuJ.a: Mineral resources of the Kamishak Bay regi9tn·· (Alaska).: _U. S. Geo1. Survey Bull. 773-D, p. 159-181 .Mawdsley, J. B., 1955, "R~dioactive pegmatites _of Northern Saskatchewan: Mertie, J. B., Jr .. 1925, Geology a."tld gold placers of the Cha.ndalar district, Alaska: u. s. C-eol. Survey Bull. 773-E~ p. 215-263. 1933, The Tatonduk-Nation district (Alaska): Geol. Survey Bul.l. 836-E, .P 337-443. Mertiel, J. B. , Jr.; and Harrington, G. L., 1924, The Ruby-Kuskokwim region, Alaska: u. S. Geol. Survey Bull. 754, 129 p. Mertie, J. B., Jr., and Waters, A. E., Jr_., 1934, Mineral deposits of ·the~ R.a:m.part and Hot Springs dis~ricts, Alaska, by J. B. Mertie:, Jr.; Placer .concentrates of the Rampart and Hot Springs districts, by A. E. Waters, Jr.: U. S. Geol. Survey BuJ.1. 844-D, p. 163-246. Moff'i t, F. H., 1915, The Broad Pass region, Alaska, with sections on Quaternary deposits, igneous rocks, and glaciation, by J. Pogue: u. s. Geol . Survey Bull. 608, SO p. · 1927, The Iniskin-Chinitna Peninsula and the Snug Harbor district, Alaska: U. S;, Geol. Survey B-ull. 789, 71 p, 1938, Ge~logy of the Chitina Valley and adjacent area, Al~ska: U-. S. C-.eol . Survey BtU.l. 894, 137 p. Moxham, R. M., 1954, Reconnaissance f'or radioactive deposi~s in the Manley Hot Springs-Rampart district, east-cent~al Alaska, ·1948: u. s. _Geol. Survey Circ. 317. 6 p. · OFFICIAL USE ONLY
OFFICIAL USE ONLY ~foxhrun 5 R. M., and Nel.son, A. E., 1952a, Reconnaissance for radioactive ct,~]'~Vsits in south=eentral Alaska, 1947-49: u. S. Geol. Survey Cire. 184, 13 Po 1952b, Reconnaissance for radioaeti ve deposits in tn.e : · . ~C~ook Inlet region, Alaska, 1949: U. S. Geol. Survey Circ. 207, 7 Moxham, R., ,M., and West, W. S., 1953a, Radioactivity investigations in the area, Seward Peninsula, Alaska, 1946: U. S. Geo~" Survey Cire. 265- ll .Po Nelson, A. E., West, w. s., and Matzko, J. J Q, 1954, Reeonnai~san.ee. for radioactive deposits in eastern Alaska, 1952: U. S. Geol. Survey Cire. 348,. 21 p. Page, L. R., 1950, Urani~ .. in,.:pegmatites: .Eeon. -Geelogy, v. 45, p. 12~34. Palache, Charles, Ber.man, Harry, and Frondel, Clifford, 1951, The system of mineralogy of James Dwight Dana and Edward Salisbury Dana., Yale University 1837-1892: v. 2, 7th ed., John Wiley and Sons, Inc., New York.
Payne, G., 1953, Mesozoic and Cenozoic Tectonic Elements of Alaska: U. S. Geol. Survey Preliminary Map. (Advance Edition ) ~r, George, 1952·, Rad.ioacti ve Tertiary porphyries in the Central -I. Gi ty district, Colorado, and their bearing upon pi tehblende deposition: U. s . . Geol. Survey TEI-247, 5Jp~. " issl!ed _by.JJ .. S ,At-omic En.e;rgy Comm. Tech. Inf. Serviee, Oak Ridge. Rapaport, Irving, 1952, Interim report on the ore depos~ts of the . Grants district, New · Mexico: U. S. Atomic Energy Commis.sion 1031, 19:cP., _iss.ued by' U-.}3.; .. Atomic._)?4Jergy Comm.Tech. Inf.Service,Oak Ridge. Reinhardt, E. V., 1952b, Practical guides to uranium ores on tb.e . . Colorado Plateau: U. S. Atomic Energy Co:mm.., RM0-1027, 13 ::_p...,Jis~~d ~~ergy Comm. Tech. Inf. Service, Oak Ridge Robinson, G. D~, Wedow, He,l.muth, Jr., and ·Lyons, J. Be,· 1955, Radio"" activity investigations in the Ca.ehe Creek area, Yentila district, Alaska, 1945: U. S. Geol . Survey Bull. 1024-A, p. 1-23. Ross, C. P., 1933a, Mineral: deposits ·near the West Fork of the Chulitna River, Alaska: u. S. Geol. Survey Bul.+. 8~-9-E, p·. 289-333. 1933b, The Valdez Creek mining distrlet, Alaska: U. S. ae - s:--urvey :aull. 8ll9-H, p. 425-468 , , OFFICIAL USE ONLY
OFFICIAL USE ONLY Smith, P. S. 1913, The Noatak ... Kobuk region, Alaska: U. So Gaol,. Survey Bull.. 536, 160 p .. , 1939, Areal geology of Alaska U. · S. Geol. Su:rvey Prof. Pa~r 192, 100 p., Smith, P. 's., ~d. Eakin 7 R. It,, 1911, A geol,ogie recQnnaiss~ce _in south:'"' eastern Seward Peninsula aTJ.d the Norton Bay ... Jlul.ato region, Alaska: . U. S., Geol." Sl?..rvey Bul.l. 449, 146 p. Sm,i:t;h, ·w .. R .. , 19257 The Cold ~ay-KabJai distriet (Alaska): U. s. Geo;l. SurveY, Bull. 773-D, 183~207. Smith, w. R., and Baker, A. A., 1924, The Co1dBa.y-Chign.ik distric"l!, · Alaska~ U. s. Geol. Survey Bull. 755-D,. p. 151-21.8. Taylor, A. 0~, and others, 1951, Geology and uranilml deposits of Marys- · vale, Utah: U, S. Atomic Energy Coimnission RMO.:.S96; 29 p., issued by U. So Atomic Energy Comm. Tech. Inf. Service, Oak Ridge~ Tolbert, G. E., and Nelson, ·A Eo, 1951, Preliminary ~tllDlilS.ry of recon~ na.issa.n.ce f'or uraniUlii. in Alaska, 1951, Pto 2, Alaska RailroadIliamna region: u. s. Geo1·. Survey Circ. 196, p'. 7-9. · · Wedow, Helmu.th, Jr. , 1951, Adaptation of portable survey :J;D.eters for airborne' reconnaiss~ce w.ith +ight planes in ~aska: U. So Geol. Survey TEM-323, i issued by U. S. Atomic Energy Commission 'f~,<!h. Inf Service, Oa.k Ridge, .10 p. 1954, Reconnaissance for . radi'oaeti ve deposits in the E~a-g"""'!!-le- , -~N~a;~t-=-i-o-n area, east-eentral Alaska, 1948: u. S. Geo:t.. Survey Circ ;. 316, 9 p. Wed01i, Hellnu,th, . Jr. , Killeen, P. L. , and others, 1954, Reco~aissa.ri.ce for radioactive deposits in eastern interior Alaska, 1~46: u. S. Geol . Su;riley Circ. 331, 36 p. Wedow, Helmuth, Jr., West, W. S.·, Nelson, A. E~, and others, 1953, ·. P:r~li:minary S'tl'llil1lal7 of reconna.issa:o.ee for uranium and thorium .in Alaska, 1952: U. S. Geol SurVey Cire 248, 15 p. Wedow, He:Lmuth, Jr., White, M. G., and Moxham, R. M., 1951, . Interim report on· ari appraisal of the uranium possibilities of Alaska: ·u. S. Geo1. Su.rvey.open file report Trace Elements Memo Rept. 235, '124 p. 0 '
Wedow./ Helmuth, · Jr., White, M. G., and, others·, 1954, Reconnaissance for radioactive deposits in east-central. Ala.s~a, 1949: u. 5. Geol. Survey Circ 335, , 22 p. · OF,FICIAL USE ONLY
OFFICIAL USE ONLY ·weir, D,. B . , 1952, Geologic guide's to prospectir.tg for ea.:rnoti te deposits O:ti. Colorado Plateau U. Geol . Su...1"'Vey Bull. 988-B, p. 15-27. WestP w·. S., 1953, Reconnaissance for radioactive deposits in the Dar-by Mountain~, Se1ilard Peni.nsula, Alaska, 1.948: U. S. Geol. Survey · Circ. 300, 7 p. 1954, Reeonndissance for radioactive deposits in the lower u.skok'rim region, Alaska, 1952: u . s. Geol. Survey Circ. 328,. lOp. West, w S., aad Benson, P. B., 1955; Investigations for radioactive de~posit s in southeastern .Alaska: U. S. Geol . Survey Bull. West, W . s., ~ite, M. G., 1952, The occurrence of zeunerite at Brooks Mountain, Seward Peninsula, Alaska : U. S. Geol . Survey Cire. 214, 7 Po White, M. G., 1952a, Reconnaissance for radioactive deposits along. the upper Porcupine and lower Coleen Rivers, northeastern Alaska: U. S. Geol. Survey Circ .· 185, 13 Po 1952b, Radioact ivity of selected rocks and placer .eonaentrates from northeastern Alaska: U. s. Geol. Survey Circ. 195-; 12 p. White, M. G., others, 1952, Preliminary su.m:mary of reconnaissance for urani'tim in Alaska, 1951: U. S. Geol. Survey Circ. 196, 17 Po White, M. G., and Killeen, P. L., 1953, Reconnaissance for radioactive d~posi ts in the lower Yukon-Kuskokwim Highlands region, Alaska·, · 1947: U. S. Geol. Survey Circ. 255, 18 p. White, NI. G., and Stevens, J . M., 1953, Reconnaissance for radioactive deposits in the Ruby-Poorman and Nixon Fork districts, west~eentral Alaska, 1949: U. S. Geol . Survey Circ . 279, 19 p .. White,. M·. G., and West ., W. s., 1953, Reconnaissance for ·'l tir~niri.ril . in the Lost River area, Seward P ninsula, Alaska, 1951: U. s. Geol. Survey Circ. 3l9, 4 pt) White, · G., West, W. S., ·and Matzko, J. J. , 1953, Reconna.issanee for radioactive deposits in the vicinity of Teller and .Cape Nome, Seward Peninsula, Alaska, 1946->4-7: U. S, Geol. :Survey Circ.· 244, 8 p .. Anonymous ; 1932, Eugene :wacker, Ketchikan, Ala.ska, _is···report·ed 'Eo have found uranium ino . o conrrner·cial quantity on Martin Arm Boca de Quadra Inlet (news item)~: Ivlining Truth, v. 17, no. 17, p. 7. 'OFFICIAL USE ONLY
OFFICIAL USE. ONLY UNPUBLISHED REPORTS ' ' . Fix, P. F .. 7 1954, Uranium· in natural waters~ U., So Geol .. Survey 'l'~ace E~e:rn~nts Memo " Rept o 78 3 o ' Harder, J.. 0. J and Reed, J 0 C .. , 1945, Preliminary report radioactivity of some Alaskan placer s,a.Jnples: Uo S. Geolo Survey Trace Ele.ntents Inv. Rept.. 6· .. Houston, J. R o , 1952, Interim report on the radioaeti ve carbonate- ' hematite veins near Salmon Bay, Prince of Wales Island, so"Q.theastern Alaska: U., So Geol 0 Survey Trace'' Elements MeJno Rept. 356. Houston, ·J. B.. , Velikanje, R, S. , Bates, R. G. , Wedow, Helll;ruth, Jr. , 1955, Reconnaissance for radioactive deposits in southeastern Alaska, 1952: U. So Geol.. Survey Trace Elements Inv. Rept 293. Judd, Eo K., 1944, Outlook for uranium in Alaska: Ue:S.:, At.omic Energy Commo BM0-191, 37 Union .Mine~ Development Corp. IO.ine, 1114. H., .1952, Evaluation of monazite pla~er deposits: U . S. Bur. Mines. U. S. Atomic Energy Commission RM0-908, I8 :t:>o, issued:':'bj- :t~e U S.:: ftt.omic Energy Comm. Tech. Inf. Service, Oak Ridge. · Matzko,, J. J.,. 1951, Radiometric examination of rock specimens from · Mount McKinley, Alaska: u. s. Geol. ·Survey Tra.ee Elements · Inv. Be:pt lJ _45C. Matzko, J. J., Bates, B .. G., 1955, Beconna.issa.nee for radioactive deposits in Alaska, 195 3: U. S. Geol. Survey ~ace Elements Inv. Rept. 442. '"""'l:"""-~_(In preparation), Reconnaissance tor radioactive deposits in'. Alaska, 1954: · Trace Elements Preliminary ReconnB.issa.nce Reports, PBR:, A-1737-1741. jl Mo;th.am,;· B. M., 1950, The occurrence of zeuneri te in the Ru~sian Mountains, Alaska, interim -report: U.. S 0 Geol. Surtey !rrace Elements Inv. Rept. 57-D. Mo~, R. !9lo; · and 1les1;, W. S., l953b, A radiometric traverse along the .A.laska Railroad: U.. S" Geol. Suryey Trace Elements Memo. Rept. 330. Patton, W .. W., Jr., 1955, Pho~phate deposits in northern Alaska: U. S. Geol. Survey Open-File Report. Rabbitt, J,.. C. , 1947,- Interim report on thorium-bearing limestone from Great Slave take, Canada: U .. s. Geol. Survey Trace Elements Memo. Rept. 50. OFFICIAL USE ONLY
OFFICIAL USE ONLY Re·in.hardt E. V e; 1952a, 'l;'he distribution of' uranium ... vanadiwn deposits in the Colorado Plateau ·relative to Tertiary intrusive masses: U., SQ Atomic Energy Comm., RM0-816. .· Skidmore,. J .. . H .. , 1944, Preliminary reconnaissance survey of' A1as~an plac~r deposits: ·~tt.o 'f : & 4,bemi.c_ Effergy. i~- - RMO~l92, .bO A:p~., ·V!UD Miaes Corp. ,. R. Ho, ap.d Trites, Ao ·F., Jr., 1952, The .uraniU111, tin,- and copper deposits at ~ju.ba Hill, Pershing County, Nevada: U. S. (ieol . Survey Trace Elements . Inv. Rept. 171. · Wedow, Helmuth, Jr , 1953, Analysis of samples from properties of the Baranof ~lora.tion and Development Company, C:b.ichagof Island, southeaster.n Alaska: · u .. S. Geol. Survey Trace El~ments Memo. Rept. White, M. G· . , 1950, Examination for radioactivity in a copper-lode prospect on_ R~by Creek, Kobuk River Valley, Alaska: u; S. Geol. Survey Trace Elements Inv. Rept. 76-A. White, M.G., Nelson, A. E , and , Ma,t~ko, J. J., (In preparation), Radio:trJet.ric investigations along the , T~ylor Highway and part of the Tanana R.iver, . Alaska: · U. s. Geol. · Surve.y · Tra.ee Elements Me~o. 'Rept. 329. · · White, M. G., stevens, .J,. M., and Matzke, ;I. J., (In preparation) :, Radioactivity ~raverse along the YUkon River between. Ft.. Yukon and ;Ruby, Alaska, 191t-9: U .. S. Geol. Survey Trace Elements Memo. Rept. 35,'lo APPENDIX Reconnaissance topographic qU;adrati~es of the Alaskan regions Southeastern Alaska Atlin · . Bradfield Canal Di xon Entrance Juneau Ketchikan· Mt. Fairweather Petersburg Po:rt; Alexander Prince Eu;pert Sitka SQutheastern Alaska--Continued Skagway Sumdum Ts.ku River S9uthern Alaska OFFICIAL USE ONLY AnehQra.ge Bering -Gl:aeie;r · Blying SoundCordova
Southern 'Alaska-Conti:nued Healy Icy Bay Kenai McCarthy Middleton Island . Mt~ Hayes Mt. MeKinl,ey Mt. St. Elias· I, Na1:$sna Seldovia Seward Talkeetna Talkeetna mts. Tyonek Valdez Yakutat Southwestern Alaska Adak Afognak Atka At"fu Baird. Inlet Bethel Bristol Bay ~pe'Mendenhall Chignik Dillingham FSJ.se Pass Ft . .' Randall Gareloi .I. Goodnews · Hagemeister I. Hooper· Bay Iliamna Kiiguyak Karluk. Katmai Vol. Kiska Kod:i.ak Kuskokwim Bay Lake Clark Lime Iliils M~rsha.ll Naknek Nunivak I. OFFICIAL USE .O:Jn,Y . Southwestern Alaska~.coAtinued Nushagak Bay Port Moll~r Pribilof' I. Rat Islands· Russian Mission St. Matthew Samalga. I. Segaa.m Simeono:r I. Sleetmute Stepovak Bay Sutwik I. Taylor Mts. Trinity Islands Ugashik Unlnak U:p:alaska Unimak East-central Alas~a Beaver Bettles Big :Delta Black Rive:r Chanda.lar Charley River Christian Circle· Cole en Eagle Fairba.nk:s Fort Yukon Kantishna. River Livengood Tanacross Tanana Wiseman West-centr~ Al,aska Bendele ben Black Candle Holy Crosp Hughes Iditarod Kateel OFFICIAL . USE ONLY
OFFIC~ USE ONLY -~le st~e:e;nt:r~ Alaska-~ContinueQ. Northern ~aska-·Continued Kotzel:>ue Kwiguk Me Grath Medfra Mel6zi.tna Nome :Th.Torton Bay Nulato Ophir Ruby St 0 · Lawrence St., Michael Selawik Shi slmiaref" Shungnak; Solomon Teller Unalakleet N,orthern Ala.ska Ambler River Aretie · Barrow Barter IsJ.and :t3eechey Point Broqks· Chandler LaJ::e De Long Mts. · Demarcatiop. Point Flaxman Island Harrison Bay Howard Pass· Ikpikpuk R~ver Killik River Lookout Ridge :Meade River ;Misheguk .Mtn. Mt'. MichelsQn Noatak 'Point Hope Point .Lay Sagavanirktok Survey Pass lfab.le Mtn. · ~eshekpuk OFFICIAL USE ONLY Umiat Utukok River Wain~ight