9s J. C. hehm
Associate 3xgin3cr
Territoriel Dq~artmsntof IXrros Juneau, Alaska
Submitted January 23, 1941 Purpose and Scope of Report...... 4
Geogrephy and Geolo~...... 9 -.
S~~C~WD...... ~.~...... *~~~*~***.*~~*~.~ 22
Gold Associated with Intrusives and ~rusives...... 25 -.9
I Formition of Placer Deposits...... m...... 37 i I i Oeologic History...... ~~.~~.~.e~...... *..*.**o:*. 37
Topography since Gald Deposition...... 42 iI Change of Wainye System...... ,..... 42
. Potential Placer &ea~...... ~...... ~. 45
Serpentin3 Springs Area .Arctic Slope...... 45 *.
I XCougarok and Noxapaga Drainage Areas...... 51
'0: -- .I Uppr Xougmlr Area...... 51 ' c* .- -.b i Lower Kougarok and Noxapaga Press...... 62
I !
i Imruk Lske Area...... '...... 83 -_ 1 ------a ------. . lhachuk River Drainage Area...... 89 . Goodhope River Drainage Ares...... Y...... 100 .. - - Upper Kopk Siver bai~aga...... 103 - --- . Kugruk River Drainage hea...... e.....e.. 105 Geological, vrlth Regard to Present Position of . Placer Deposits...... 116 Prospecting and Deval~ping...~...... ~...... ~.....~. 119
Thatdng of Frozen LZtck and 121 . .
Transport~tion...... ~ 128 Taxation ...... ~...... 131 Establishing Validity of Claim...... 134 The Causes of mylfining Failures...... 135 Hydroelectric Power Sites...... 142
Conclusion and S~J...... 145 The north central portion.of Seward Teninsula is aa area
which is geologically favorable for placer gold deposits. It contains
soma mining, but the area is far fron being developed to its full
capacity of production. The area was roughly prospected during the
Nome gold rush end the pears that follovnd; nmiy, 1899 to 1904. Only the most accessible and easily vro~keddeposits ;=re mined bocnuse of '-- the many hardships and difficulties encountered. lhny of the early i mining vanturas vrere failures r\%ich in part vaiare due to lack of knorrledge
in dealing with the various problem, the high costs, md the lack of adaptable mini% machinery.
~h'ewater portion of the area is underlain by interbedded limostone and schist of Ordovician and pre-Ordovician ages. These fom-
tions vrsra subject to intense foldinf: dining the Xesozoic oya. Large
. . s! open folds and elongated anticlinal structures mre fom~d,as a result - c of this dsf omtion, with.a general east-:=st structure. This defomt ioa 3
was accompanied by the major intrusives which formsd the Bendeleben and
Kigluaik muntain ranges. These intntd~esmked thebeginninz of the
gold deposition. In late Crefaceous or eorly Tertiary tims a sscond period of doformtion took place which produced a second series of open
folds and anticlind elongated dones vhich mare superiaposad upon tho
fom9r ones at nemly right =glea or in a north and south direction.
The structural effects of this cross folding is much in evidence today
- rd$h the numerous basins and domes giving the effect of an old age topography decidedly v~omdo~m. These basins and elongated structural I' valleys which contain the basins were ideal for the fornation of placer
gold deposits during the extensirs erosional poriods and minor uplifts
that follovnd. The folded fomtions of limestone and schist, and the coal
beds with the nccompmying faulting and shearing, fomed ideal channel- f I aags, especially on the contacts, for hydro'cheril solutions to poaotrate I, 1 outvmd to:;ard the surfacs from the crystallizing maw.
I I 6, Llany Tertisry chmels ware forxed as a result of tho great 8rosLv0.cycle of the Tertiar~Epochs. These chcnncls r-rare.confined to
the structural vnllsys so that basins contained therein r.2re filled and
emptied many times during the progress of the rivers to the sea. Each
period of subsequent uplift is repressnted by an extensive delta de-
posit which is more or less modified by sea action. The effects of
these uplifts nsde a series of unconsolida$ed bosch dogosits across .the
morthern portion of the area, ranging in elevation fron tho present beach %in0 to 600 feet abovo. :b At the end of the Tertiery period surface lava flo~scovered a
section of! 1,000 square niles the area. These floi~sspread out,
oovering the greater portion of one of the largsr structural basins vdth
portions of the flms continuing along myly of the Tertiary chennels, cawins a disruption of the mjor Tertiary draiwge system. The Tertiary doposited gravels wre left intact under the la~as. Very little The Pleistocene or ~lscialepoch follo~~ndclosely the lava. . emission with the later f10';rs believed to have been during glacial
times. Evidence of anbal ond vegetable life ere still contained in the
frozen unconsolidated deposits. Tho great atmwph'eric disturbmces which ! took place during the glscid. epoc3 are believed to have bv-en the trans- I porting agency of the lighter loose materials, incl;ding tho ramins of the abmdant vegetable growth, fron the higher points of - elsvation into (. the lo~varvallqys and basins. This formd the extensive black muck and
sllt deposits that cover nost of the unconsolidated deposits and -kes the mining of placer dzposits so difficult. - Alpine glaciers vrare formad in the higher Bendeleben mountains. On the north slopes of the- range these glaciers viare small and their movenont rras not so extensive as compared to tha south side vrhich ap- -.. I parently received a greater amount of precipitation. ! I The pyesent day drainage is cospsratively young and has been superimposed on the older drainage and on top of the frozen unconsolidated 1
The gold and sulphldes are believed to have been derived f'rom
ascending hydrothemd solutions anti deposited by praaipit st ion brought
about by a rapid reduction of tomgerature with the oxides forred fron I.4 the other notals as they reached the zone of free oxygen ~ndc~bonaceous
.?.a,. .?.a,...... -> - . . - mtter, all vrithin a zone of near surface couditi~ns...... 4-c...... --_ >"*...... -...... -:. . , >.t?; <,>,A , . . ..-. . . . - . ,...... - ...... _..I ...... -..%,*.r., Z ...... - ... .. ,-:A :.-.--. .... - : ...... ~. . . ..-...... , . .> ...... - ..i ...... - -:... *&: ..-* . -...... , . . . i, , '3. ' ...... ,. . - - ,..- .--.?u+,#. >.".;...... ,- ., . . . \'. ;...
...... -, ...... ,.q. < ..'...:..L.7 . . ~ .. .? ...... - ....+,:,,;= --. ....a .-.: .:.-...... : ...... _ ... .. - . ;':. T, , . <:, ::4 %;'.,;.,z:.;- ;.:>L.::;5j$py, +-!+ ..; :, . . .. - ...... - ...... -2-. .:. - . .- . 4 .;-..:-g;;;;,-::!:?y . ...I ... - .i .....'. .. :;.;-;;'$:., .-.*: .... ,:;. .; < '~ . .- - .-.<:-, -@* ...... 2;-...... , . . . .- -.- V .... .- ..- -3- ... I .: - ,I ...... ' . .---...... -...... ^._ _-. ..^ .-.. L .: ...,- ....- .' .,-i-5- ..... -...... \ . . I . , . .: ...... - .... .- . . . .. 3 - f ...... -. ,: . . . . - .. . "., . -...... >...... j,; ... .. , ;.... !. :;s.:.::.;. 1 ...... a..;...... -. . .-- . . . - ... ,: :. ' . .* .... -......
. . cat ions appear to r.wra.t considerably nore f nvest iga't ion, prospecting and develo?msnt. However, in association xith these activities it is inportant to kaep in mind the various problem, both in ralation to
mining and geology.
INTRomCf10:Lf
( -- 9ose and SCO~of Report: - The yems from 1934 to ad includigg 1960 wka period of teaendous incrsssa in tho number of placer mining activities in Alaska.
Azl a result of this incroase mynex conditions and unsolved problems
have cone before the Terri5orial Dagmtxent of Nnss. The depsrt~ent ...... j- . '.* .. itself needs to expand to keep pace vdth the rapid expznsion of the ... industry in ordai. to direct it in the future and to mintain a steady
production in mtallic output fro2 the Territory. .... A continuous search must be mintailled for r?ow,placor mcas and new lode prospects. The (, prospectors should be onco'uragod, md their propsrt ies exmined and brought- - befora the props~parties for less= or option. Operators and . * pros2ectors alika mst bs' constmtly assured that the value of gold is sound. Along with these activities there has arisen nunerous mining
problems and tendencies such as increased transportation rates, mzscs,
taxes, costs of xmchinery, end the use of credit. TBoss proble,m hsve
tho effect of ret;ardiw the industry rather tkm building it u? and stimulating it into greetsr developnent for the bensfit of every one.
The tyro incenti-res, vihich have fostered and caused the increase in - . aativity, have been the increased price of gold adthe greater a~plica- f .I . tion of mschanical machinery. They have enabled the operator to increase
his potentizt reserves by the mining of lowr pade ores and deposits,
and to inzrcsss his =gin of profit, vihich in Plaska has been mainly
turned hack into the industry by the purcim3s of more proserty and a / - 1 L. tremendous aoWt of ~chinery. This is one tendency v;hich Government ,I agencies should considsr wll before conteqlating fWther taxes on this
young and grorliing indxstry.
It is a comn tendency among myto ?lace too much st;ress i . .. i on one or tvo factors riith rsgard to an industry and to negl2ct some of the major facto~supon r:liich the industry is based. The increase in .. .. . , the price of gold would not have increased the number of ogerations had not the deposits existed and further, had they not been discovered. In other words, the knb~mcsisting discoveries actually account for the
I increased nuuber of activities. To the thousmds of Alaskan prospectors I 1 who spent a pmt of their lives and enorgy in the pest, esd to the very - - - - 7------A- -- - I=--.------. -. few remsinir.g oEes, goes tha @eater portion of the credit and yraise I for mskin~possible our present indus9ry. It is still the duty of the 1 Governmnt, to encourcza, to help, md to stinulzte interest in mining in order to raint~ina steady gzoducfion of minerals rhicL in return means a stearly incom to the &vorament. One of the mydutias of the Territorial Department of liines is to call attention to and to supply * infomation concerning cartain mining areas vihich hare potential reserves
and thosa 11lost ada?ted to proseat day doing xilethods. : =' , " ,>: b Thus, the purpooa of this report is lour-fold, and it 1s -. * . , , . . -.'.l "l*_l ' . 0, ...... I . , hoped that it riill contribute to the graving mining interest in Samd . . Peninsula and vrill bo of diroct help to the Alaskan operator, prospector
and new-comr , 1. It is hoped that It vdll help to craate interest in 1 I minix on Sevmd Paninsula by stblA.ati:ag further prospecting and by ' ... so doing lsz5 to roars mining operations.
2, That this rzpozt :dl1 help to fu3.f ill tho demd for . . potential plncar pound an8 in so doing help the industry to continue - 4- ..-. . . / ._ -.__- . , r . -.. ,. * ..' - to eqmd and to msintain a steady gold production. :-z :-- y - 3. That it fbthzl* €it-es the nxr operator a clear picture of sons of the major ?roblecs and to guide him around the pitfalls which ...... have caused so mny failures in the past...... -* 4. Thst it fills a particdsr need of bringing to the attention -ofAlaskan operators md prospectozs soce of the important geologic facts
-Inrogard to Saxad Peninsula, vinich hav.0 been published in the past and
. L i ,..I. . t 3.. x5b3 vihich at the present tkcs are mainly out of print and nore or less
L. L. 3 ,_,, 5.... - . - - The scope of this report is confined to a ferv of tha ~ndevelo~ed
areas on Se:vard Teninsuln located on tho northern slo~esof the peninsula . .* ......
J, and to such areas where nining has cot advanced to the full capacity of - the potentid, deposits, This area includes apposiraatoly 5,525 square
Miles, A general account is given of the geological conditions which
are more or less fttvorable for placer gold deposits. A relation betimen the present placer deposits as originating near htrusive and extrusive
igneous rocks 6nd deposition from hydrothe&l solutions is shom. The
placer areas 8s visll as individud operations are described in datail.
Furthermore, nzny problem are discussed rrhich apply to tho vrhole of
aid L- Semd Peninsula olld suggestions are made rhich it is hoped rill in their solution. ....
The contents of this report consist of an accumlation of data gathered from two months of field vroz-k within the area concerned, . . This consisted of the examination of most of the operations, ssveral --. . - ., - points of &eo1opic interest, and .iollecting data from oparators, engi-
neers, prospactors, and others. A study of three months duration was made. of the past geological literature v~ttichhas been mitten and which . . consisted minly of U, S. ~aologicalSurvay reports. Prior to this year 3 the miter has spont four years in fiold xork of nearly six months each
-year in exanining both lade and placer properties throu@out mst of the
.-- - - active mining districts in Aleska. &my things in common vere noted - In ragard to place2 occurrencos. Each mining district has its my difficult problems as to mining costs , transportat ion and physical mining conditions. Xuch has bees learned as to the tenor of plscer
de,ooslts mined, mathods ussd, and the best adapted types and mkes of .machinery. It can bo stztad vrith considerable assurance that the
' various aroas on Scsard Pczlinsula'rank hiaer in opportunity at the present timo under the existing conditions for the future developnent
of placer mining thm mst of tho other placar amas in Alaska. It ,.> - -'isnaturally edvantagnous to mite concerning an area vhere tho futuro
.possibilities ma good and offaz the best chmces for develogmnt.
The writer is deely indebted to Lb. B. Do Stecrxrt, Terri-
C' I torial Co=issioner of ?Ims,for the oppoztmity and special privilege
to spertd t:.ro ~o~thsin field work on Sev:ard Peninsula. This privilege also offered tho oppor:unity to be of service to the myoperators of - . Alaska a~dto collect corsidar~blemteridistic data to be leter used
. in su?gort of a nerr theory on the o~iginof certain plecar deoosits.
Acknovlodp3rrt ai?d thdcs &re due I&. &en Shsllit, Associste Bgineer
and Territorial Assaysr at PTona, who materially assisted the miter on
eertain field trigs, and whose general and geological 'morrledge of
Serrard Penilsula has contributed much to the contents of this report.
-3bther, to 11~s~~~.Castles-on a94 .Keenan, - operst ors on the Kougarok,, , _ .. _ * - Rivsr, the vrritor a@'bov;ledgas mch free end helpful infoncation. To
pilots John C~ossand ?. L:U& -7 thanks ax due for the opgo~tuaities
of oboorving 13my points of interest r;hich otheznise it muld hs~ebeen . . . impossibls to see dwi= the the availab19. The rrriter ds5ss biti. .. id '. ... I. . . ..:*.:i..:;,*'3 -.,* - . . - - ., ...... ,, .., .,..^.> . . ...-..,.. . , . 2 ,... ,. .. ,, -,' .: . ,:. ..,.:. ;,:, .;..I:-. . . . . , ...... , ::. > :. . , . . .. .,... ' T*, - . * ..,: . . .,.... ' .:., i.<..- _ L.. . ,. . . .',.- :<,. . : ,.:.., to thank further the & operators, prospectors, miners and numerous other -individuals for their kind hospitality and for informtion which has added mterially to this report. . . .'' A special effort has been made to acknor~ledgothe contributions
,I of others, particul&ly the U. S. Gaological Survey, for the use of the
many reports to v~hichreferences have bean numerous, All such references are listed at the bottom of the page on which they aro used. -
The area under discussion in this raporf consists of a
1s situated in the north ceilCral part of Sevmrd Peninsula. The total -1 ,- - zkiii'contains approx&~cly 5,525 square niles which is slightly mre
tha one fourth the total area of the Peninsula. The position is be-
165010' and 162315' loagitwde and 65020' and 66020' latitude. This section is that portion of Se1'1ard Peninsula which contains the
greetor portion of the oldor draimge system vdth th~'presont drainage in part ~uparirr~posedupon the older, The southern portion is drained
to the west by the Kuzitrin River adto. the east by the Kopk Eiver.
The rrastern section is drziaed by the Kougarok River to the south ad .
the Serpentins River to the north, The central and northern part is
drained by tha Goodhope adIl?llschul: rivers. The oastcrr. section is -. drained by tha Kugruk River and its lergest tributary, :'!ado or Burnt River...... r . % ,a .-, -. The Ifoxapsga River, the l=gest tributery of tho Kuzitrin River, drains
a large ern2 of the ce~t.ral~orfion. salient featmas bounding the
areit is the Bendolebon Range along the southern border, on the north
by the Arctic Ocean and Kotzebue Sound, on the west by the high plateau
mat end Kivnlik zxountains. The highest portion of the crea is the
southern boundwy vhich marks the hi& divide of the Bendeleben LIountains.
This divide consists of serrated and irregulsr mountains ranging between
! *C
parallel north flo;ring cresks rrhich drain off to the KoyJuk River on the
numerous springs which drain fYon around the -gins to the l0ri8r eleva- tions, aid other dreinage. This lava plateau is the important distinguish- ing fertura orhich rrxts the interval bottreen the old drainage systcn,
-. --i=----i-- orhich is intrcTTnder-t3FQaz,--ad-ths new dreinag8 sgstm rihich-is--
. .
------:@ rims are encountered us in the valleys of the Kopk, hchuk and Burnt rivers, note Plato 150. 4, The wee, due to its superimposed drrinege,
is very poorly drained and contains nunerous small lakes and niggerhead marshes. Betr:.een the table-lad and the coastzl province to the north,
m. m. ,* , the section baco~esmare rugged and consists of intermittent structural
ridges of limestone and schist, with 'large structurel valleys in vihich are contained the mjor rivers. Theso vellegs are broad with gentle .- (:= slopas, end represent opsn folds. The rivers, as they approach the coastal plain, leave their entrenchent, build deltas consisting ~f a tremendous
amount of Inaterial, md mender beck and forth across the valleys.
The coastal. plain is a broad flnt plain severd miles wide
whiah exbends up the river valleys, and Ghich is leveled off at 2C0 . - . . ;L, - feet elevetion. Along the cohst line &e occasionel lend points vriiich
butt into the ocem and across which bluffs heve been fomed by mve action.
This plain is mde up mainly of sea orash grzvel deposits that represent <:; in pert the land eroded frcn the higher elevztions to the south, The area is divided into three distinct provinces; the rzountain
province on the south, the intermediate teble-lend, and the coastal c---E--ziE.~-~ - .-.z------ilain. To uudor stand Gdd~btZiZaaaEie& Pihile structtue is t&en up late6, as it is of h~portencein regard to the position of placer deposits, the present relief is effected by . . --a I . s ..,r * .. , , - * b SF:- .- ,t > -...... :',' . .-, ...... , ' , ? , . *. - .~;.'.,.. ;: . - .z ...... ,,?. ~$:*~~~~:;>:.":.:~,;~.~,;;y,>:;~?@y~~v<: ...... *:::.y..., . . .*...... , . ., T.. ;- .:. ; r: :.,-,* pt:;::::7>;k+<,i.,.-a. <, .i...... r - ...... , .'A. ..7;,:I.~p;[':?..-.. . c,. l .-. ..' .~.,' . . .. :. .,,;, .,; : :,L:- .<.. :;!:;&?::<. .*.:,, .,; ,.- ...... , ....;...,,. ..: *.' ...... -,. ,*: . .. , ...... , . . : . , .,;:+:<. ::.<:~, ,. ,:,. 1 ..: .. ...! ;.s; ...... - I _ structural conditions of the past plus considereblo erosion. ~bffit,1' , . . , gives the prevailing structural featurcs of this area as .Consisting I. * I of opon folds, rrhoso axes pitch at lo:r angles eithor to the north or to the south with the intensity of the forces producing folding, in- ,.. -., creasing tolwd the eastern psrt.' &se r.orth and south folds eccount 7". , - I for the prevailing strikes of th* interbedGed schists end limstones which mcke up the greater portion of the axea. Thus the earlier forces which affected the area epparently mre froa different directions and forracd the east-risst folding which rms fol1ov:ed by intrusives. This east-west fo1dir.y fom the eest -rest elevated nsss nor.r*conprising the Bendeleben Range. Thus the intensity of the foldi~gbeing aeatest in the southern erea gradually decreases to the north. Therefore, the * -.,. - -. - mountain or. southern province has an east-vast trend and sho~sthe ...... -...... present east-vest drainege, 'such as the Kuzitrin and Koyuk rivers, I ,* --. I. representing the valley of the underfold. The upland or central province f I '. , consists of a ~odifiednorth-south structure superiqosed upon a I modified east-xest folded structure. This superim~osingof one systea 1 of foldine; on mother system nearly at right angles desa topography of shallorr-d~?r%ssionsand rounded hills. It gives the province en ------r- = ------_-_------. ---- . a - I=-- ap~&oncoof beiq worn dorm to a greater extent than actually oxists. I -Thus; on the coastal province the north-south folding structure I is the strongest feature &ich is still prominent, es noted by the north and south rirers. The east-vest - structure sifccts it only slightly, but .....?.".... . , - .-- -... hffit, 3'. E., "The Feirheren Gold Plasers, Sev.wd Feninsula, Alaska,.,w I U. S. -01. Survey Eull. 247, p. 22. - -:..:.*...-, ... :irS$ ..-. :!,ycp"<+X . - - -. J., I .-",:,-.-'-., . . ..-: ,? r"..-.- ...... i f ...... t 14 ,. -..&".- '- .. . I is in evidence sufficiently to produce a topomaphy which gives the appearance of boing considerebly worn dovm. The only feature ~ihichdoes not confomi to this gradual south to north slops is the south flowing Ibugmok Rirer. This area on the western section of the district, ~vhich is less affected by the north eJrd south... folding, but moderately in- fluonced by the east-west folding, contains the Hot Springs gr~tnite area of local origin rrhich diszupts the gzneral topography. The P;ougarok River drainass viill be taken up later vrith res~ectto structurz and local description of the ares. Gonerally, the area is of lovr relief, poorly drained, covered vdth tundra, fea outcrops, some willow brush along the banks of the larger rivers and streams, a fevr alders, and pernacontly frozen to a depth extending into bedrock, -. 1-2 : . :- :;It is not the purpose of -this paper to present a detailed -...... geolo~icaldiscussion and description of the arm. Tho greater portion I of the area is covered in generd. by 1;Ioffit and other reports. . . * (1. .- Tho follovring sketch m%p, Plate lo. 4 shotring the distribution of formatibns, is a tracing &om a nRecomaissmce Llap of Sewad Penin- sula, Alaska, * scale 1 compiled by the Alaskan Breslch of the 500,000 Geological Survey, with the areal geology taken from the geologic map of -...... Semd Peninsula, Alaska in Bull. 433, Plate 11.~ The percentages of the various fornations are only apgoximnte, being given in the order of greatest extent. The classified :Jone' group, vifiich consists of various . . ...... C --. >.. ll.loffit, F. X. , U. S. Gsologicdl Surceg 3ull. 247. . Z~mith,P. S, ftGoolo~and 1finer;il Resources of the Solczm and Casadepagcl Qucdrul~;les,Se\+xrd Penirssula, Alaska, U. S. Cool. Svep . - ...... Bull. 433, ?lato 11. . :...... * .+ .*.*. .,, . ~ ...... l.',P ...... a .T,, ...... '.'I:. -,.i.?":h ....- . - -..., ;,,=: .= ,$,*; b.. : :..!>.,'>!:;;;7i,;.i.,:..', -. .'..,,';' LA., , .,+- land area. This formtion covers the greater portion of Samd Peninsula and is the formtion on which nearly all of the placer gold is found. , ,.. -- , . * .. I%e most favorable plrcer concantration is a limostone-sshist contact of . t - < steep dip. This percentage of limestone and schist must be considerod rrith limitations. Thus if one disregzds the gravel deposits and accepts the ,, .- bedrock bslox the gravels.then tha percentaga of bedrock geology vrould be almost doubla the mount msntioned above. Also, in accepting the gravels for their full ares, then it mst be considersd that, as the tundra and black silt cover sox9 grmsl, the perce~~tagoof groval t*iould be greator =d the actual linestons md schist less. As t'care appams . - to bo considerable are3 which is i~ doubt as to whether it is barren or ...... 4% - r- , ...... gravil covered, such nreas have been classified lritll tha linaatoxJ and schist as reprassnted on the accoin?an.~i~gskstc'n. Tiere is also tha extensive recent lam area r:hich covers both gravel end li~sstooa- sehist areas. As noted on sketph No. 4, azl area of 35 per cent is nore or less bovm gravels. Included :&thin the grmels ore all mconsolidzted - deposits such as sands, beach mstarials, etc. Considsrin~the isolated -2 ...... -. gravel deposits, both knom and ukno~m,and th9 old drsimge @'avels under tha lavas, this percantage would no doubt be incraased and the limestone-sshist area docreassd. .@ Descriptiocs of the various grcvel deposits will bo t&en up under the dcs2riptions of th9 various areas under consideration. The qusstion arisss hwe rs to ho-;r isolated basills becas fillsd ;vith gravels, if gold is ~0~5aincdin the gravels, adrhether or not it in corrcontrated. These isolatsd grsvel depoaits are foy.dto exist at various elevations froa1,OOO feat t:, coa level, In fact, it is safe to assme that they possibly e~Js2up to adabova 1400 fest elsvation. It is not the pur- pose of this papels to trace all the geolozic history of the arer, as it is ~relldLscuss3d in the various geolczisd repoiits listed ia this regozt. It is coxmily accaptad thet wst of tha graval deposits wro formd durir,~ad since Tertiwjr ags. Thus the psriods. of subsargence . a- ., .. -., &:elevation during end since that tiz3 lome their records of geological - .- /.., "-q*'.:. ,.'...... ,-.I#>,> ....,.... ' history in vmious foras. One bit of evidence is tho isolztted placer or tmcl-a gravel deposit. Each psriod of elav~tioilhad its systea of drai~again eccozclalce vith structwrsl cocditions. At least tr:o cycles I \, of elevation rrit'n intsmediate silbsidence ars in evidonze fro= Tertiary time to the pmsent. It is very possibla that there vsre nor2 within each nnjor cycls as there rvere periods of hssitstion and cont inl~ence, ___-- _ - _ __z------I - Thus, the basin, i*lliich hss$Sns'to bs os&-the water 'sm~acaor rezths - 1 . .- . . (.. ,'- i I .beqch line end asaoclsted with son3 drainaga strem or river rt tkt I I particular tbe, b$co~.,jsfilled. Contincail elsvation lanzthans the I I draincgu, partly cuts arr.37 the foxs~depositioa in the basin, m&es a ...... concentriit ion, fills' up the next basin alox the beach or border -... >. :a,. 2 ,-?; :-.2,,:'.: .-....; <:.. .. ;:.: -...... :...... -...... -...... :.:_.-.;j...... a...... I...... ,:...... ;...... : . - ...;...... : ...... _...... :. .-14nq . $i;.si. in &votion...... - ,,..."...... _ I. ., ._ The deposition of the Tertiary sediments, which are in evidence on the,Kue;ruk and Royuk rivers, range fro~nover 1,000 feet in elevation to ne& sea level. This mmks a period of sub~9rgenceand deposition during Tertiary timo. Faulting of various areas and other various . . I forccs of structural dorageant also effect drainage and help fill basins, concentrating heavy motds in the=. It nust bo talcen into considera"son tht large, nedium and small (- . v sized basins existsd, rrhich affected the deposition of the Tertiary ;;dims&' and the leter lava flmrs. The priod of the recent lava eruption shorn by its very nature; tfiat is, the lack of cinder cones and the usual ash, that it vns enitted fron large opsnings on the s1mface. . .-, 1 , I n: -.:: ;,.$:: $ rlAl.T .st 2.; . .q-1:. ... LC,< ...... ;....:. ,+a., ..These various recent flo-irs are definitely later thq the underlying ...... I" gravel deposits. Rocavnr, tho period a: erosion since has continued -- - -,,. . ' @' b' . 'to hava its effects u2on the gravel deposfts other than those under the -8 A.. , lava. The largest basin, into which the recent lavas flovrsd, extends . . . . t. east-mst alon,o the north' side of the Eendsleben Range, and in which the upp8r valleys of the Kuzitrin and ICopk rivers are situated. \ A. J. collisrl describes the Kuzitrin Basin as follows: 1.. . - '. .: -. ... -.'d?;, "*' . . - .. + . %* . ,. ': "The Kuzitrin 1o;:lmd deposit is the m~stextensive of the .c -..--. basin a8sss. ugper lryars sea2 to be more gavs11y than those - .....- - I. .#. of the Irriuruk daposit. Around its vrastern and northern borders . a - I.!-- ;.:..there: is s terrace fro3 50 f o 100 feet above the general level, . :- - -. . from which it is sspcrated by a n3~kadesc~rp1~3nt. Thsre are also XIWIT isotsted g-zvel b:lt+,es fro12 25 to 50 feet high scattered , , over the lcnsr porkion. T;2o:a festwas a-re ragardad as residual . . . .- parts of an older s'xrfsce lsft bshind in ths erosion that has . ***. ., l . ' . - ..* ...;- ':,-51:"reduced the surrace to the gresant level. Romins of the (. . .$-.. ir...:- ...... --i .- -...... ". , - "" .vth, horse, and other mxnsls, ' together with 'some large logs .'- * . -.- - .- -..,. .*. , .-. and accurr:~lstions of voggtable rnterial, hava beon found in these buttes and terraces. Near the east end of this basin the gravels are overlain by lavas that flotlnd from vents nea ths head of Ku- zitrin Rivsr." This basin, in its present position esst-?lest along the north side of the Be~deleben,Smse, 3ppsrently at one the contained and still con- tains the greater portioa of the gold vihi~hrms associzted with the numerous grwite intrusivas which mI:e up a sent portion of the Eende- lebsr, Ray~a,not3 Plate Ice. 4. It is not assmed here that ell the placer gold r:ithin tho erea originated fron thesa intrusive~,hoviaver, fron evidarce shorm later this mass of c1ostl;r colmected intrusives ware the origins1 source of the greater portioo of it. There has been much mitten as to the ori~irrof the gold along the 1Tons beaches and the Solomn River district. In studyins the various &olo~icslreports and exaainin~tho effects of various agonzies in that district one =rivas at tho conclusion that the greater portion of the gold originated from . the Kiv;alik 1;au.ntsin range, vrhich is an extension of ths Be~delaben Range on the v;ast. The gold found on the beach levels and benches, as vrell as the rivars and strems in the vicinity of Ko~e,is believed to have beea deposited Cluring erosional periods by nmerous agencias, nainly ------, . --. ------. - --a - wave and glacial action, as partly concentrated gold in vhich migrzted along structural valleys collscting nore gold and depositiz it with the go19 fornsd locdly. It has 2l;iaj.s bzea a msoloed proSlen as to the vr:~ersabouts of tha gold that hzs nipstsd to the corth of the . "- Bcndolsben and lii-;ralik nomtain rages. _:- ,, :... c , . - The miter docs not ettcapt to solve this problem, but the intent is to detail t3ose areas in 7:r'nich the gold is most likely to be found. The reader is left to dra:r his ova conclunions as to vrhich of throe po~sibleposit ioas =rent attention, I First, tke lsrga structural basin along the north side of the Bendebben Rar-ge, containing the Kuzitrin adKopk rivers, which is filled with extensiva g~aveldeposits, ray be the solution. In con- sidering this basin (SZO Plate Xo. 4) it should bo note3 that naarly half is covered with the recent lava flo~~s.The Koyuk Rivsr cuts through the lavas in the eastern sec$ioon. Proqec:ozs regort the gravels in the upps?: Ko3- Ezsin as thawed, and that they vi3re uzbls to side holes to bedToc'x. Just what poztion of these gravels ere thsmd and frozen is , . s , . . '- . .' ' '. . I,: ., .,,. ,. , . . not Zlcnovrn. It is possible that hestsd vwfers osy have flovred from the recent hcrt lavos dszifi: the last frecze-tl;, perice adkept them thaxed. Furthzr roports fronthis saction xsre to the effect that the black . muck, v~hiehlies oil top the &.ravels, contains great amounts of old bones ! and horns of anhzls, Tacs~aniris wy hzre cror8;3ed into this section, attrac:ed by the heat arising fron tho w.tells during a period of cold, perishing within tha r~uck. hother theozy for the thazad gravels, is that ?,%tors possibly drained under the southern border ol the lams into ...... the old drainaga wavsls an3 later flo-;:sd out in50 the Koyulx basin and - in so doing, the frozan g~svslsFiSTt3 th~~t:ad. Thus the prospectors vare handicrlgped in the emly dnys by the 2rosan:e of thamd grovels uihich - .. ... :. .---!-. ... :.l.'~.:,.:!.'.'.::--':::.."''.:~'wted. . &. . ::,;. - :.,. '....2 t .;: ~.:.?. .: ,- .: ,L.?,? +;...... pros,,T'3cting bocsusa of the leck of pum,n%ng equipnent. , _ :_..... :.- ' ...... - .... _ _" ... Ia+'; 'C .. ,.. ' r. .. .-I..,)';;.;:,;';,.: _,;:... . : ...... _,,, ...... ^ . . . .-.. -:,...... :. >:.. ..:...... ;; ::.: .. .a.:.. *-,: - ,;. -- . ' The western half of the basin, occupied by the headvrators of 1, the Kuzitrin River, contains extensive ,gzvels. The smll rounded gravel ,~ - \+.. ..L.' buttes, ns mantiolied by collier, show considerabls water act ion which no doubt hzd considerable co;lcentrat ing act ion. Tnis extensive basin has - 'i -, . ., - C not bean proayscted. Information is lacking as to depths to bedrock, ! f exteat of frozen or p~rtlythwsd areas, and gold content, except along --: IS , the outsr oxtrcnities such as the Nox3paga and Lw~rKougarok districts - -*/ - which are described later in this report. . &,*: 7, ----<,,1-.y t:.. The sscond area to be considered is the structural valleys of a. north md soutl~di~ection r~hich contain the larger rivers. Si~cethe early gold rurh dzys, gold has been found b the valleys of the Ilougarok, ..-A _ . . I.. . '. Goodhop-., Iw~ohuk adKug~mk rirors. The east-:=st arcs containing - .. . ,k. . - theso river valleys represents the transitioml section from tho upland . . proviuce to the coes';aJ. glai=1. Hatuxally, this section FYZS the area in vrhich mst of the early pros2ecting uns done due to shallo;? bedrock ...-. . . outcro2s. Ems this saction contain the geater portion of the placer i . .- gold, or does it regresent only a portion of tho gold with the major amount having trsveled on bsing degosited along the coastal plain, or is the gold foimd here only that portion.eroded end mipsted from tho - .- .. .1 Kuzitrin and K9yu!! basins? / - * ,,-: & .,.:.,- ' -:':T-.. --. ; -. .' . .. a .\ . - - The third =sa for conside~ationis the coastal province. . -:-.- ,. ;' Soms gold has bsen fovud along the beaches of the cosstal plain as at Alder Gulch in t3e nozthsast xction of Plate 170. 3. Occasional color$ ...... - . ., . . .. i ..I. , .. . - -,. . : :-, . -.:. ..:"t. . l~ollier, 4. G. st nl., U. S. Geol. Survey Sull. 323, p. 89. - .+, . a*. ' havo been found along the present besches, The expectation of visvo concentration and the formtion of beach line deposits along the south shore of Kotzebue Sou~dis not within the limits of the agencies involved. The occasional rock bluffs bre& up strong tidal currents, md storm that reach the coast line are only fron the north and these are not serore. Duyin?; a portion of the winter the Sohd is frozen. Had the greater portion of the gold migrated to the present beach levels it tlmuld be in delta legosits at the aouths of the present and the older It: .r I. rivers. The present rivers sho~:considerable delta deposits aild the . L<,+, :,: , ,. , . * effects of old chamcling naar their ~ouths. This would rralce for ex- . :tt . . tensizre low grade daposit s . 1. . $The ,next geological formation, represanting the suface areal : , . . f - .. geology in order of e~ent,is the recent lavr flows. Thesa cover 15 -. . .:,- "., . : T , . . ,per can! of the ersa. Tne hiaost ele-ration at vrhich they occur is - .,' . t .,: 1400 feat and they are located to the south~~3stof Iauruk me, which . , I ., region is belie~erlto be tlie vicinity of ejsction. Several dlcraters show frm the air, but vhether theso ere actu.31 vents or sinks is not known. Located near the center of the lava area is Imuruk Me, which agsoars, from the gir, to be very deep in the csnter. It is believed by soxo to be one of the larger craters fron which the greater "~rtion . . of the lava vms emitted. mee, adpossibly four, f leis 83s in evi- t \-:. ,.. dsnca. These are t3iclcest nes the points of eaission and padually thinning, out to the outer extrznities. The u3pc~ZCug~uk Ri-~er, which drains the ldco, has formd a canyon below the lake cutting though the lava bods. Trosp~ctoz-sraport grso::els under ths lava in this locality. Those laves are classified as basalts by collier1 as folloi~~: "At a point on the IJoxapqa Piver 2 miles abo~eI!oxapga these lavas extend across the river, and their relation to the othsr rock vms seen in a bluff above the river. Rere the Pleistocene gavels fillin3 the l!oxzpsga Valley rest on the upturned ed~esof the schists. The basalts lie upon these gravels, and nac the contect the gravels are cemented by - indurnted clay. In the uppsr part of this gravel a few pebbles derived f~oabasalt we Touzld, mixed with quartz pebblss derived fron the schist. This lava flovr r~robablyoccurred in Pleistocene tine, vrhils the upper gravel plain of the Icuzitrin Easin r.xs being formed. In the KO* Valley ?:endenhall found evidence that the basalt is of Pleisto3cns or late Pliocene tine. The evidence obtained in the Kuzitrin Basin indicates a sini1a.r age for the basalt s found thero. Granite of vmious kinds makes up the present surface of a considerab3.e part of the Bendelsbezl Rmge, sho~~min the southern part of the district. LIany contact re-mats of the olde~schists ad linestones renain around the tops of the highest nowtains and ridges, . - but they naroly re2resen-t a.thin hzrdened shell. The area 1s.under--- .. - lain by granite xore exterrsive tha s'no~*,non Plats KO, 4. Several Isolated gs&s and ridges of -mite stick up throu& the laves, the ' I' . latter-. having flo~~:sdaround thm. This shorvs that considerable of the area on the south covered by lat-as is granite ursderusath. The actual granite outcrop coaprisss 7 per cent of tho area...... Tertisry deposits congise only one per cent of ths =ea. E. -. PJhile it is held thdt some of the granites are of Tertimy we, they ar.e not included in this percentage of Tertiary deposits, It is pos- -- _ sible that there reaain, in sona of the basins under the black nuck and * - ?:?st lcollier, A. J., n:70rthern Podion of Saimrd Fenins~la,~U. S. Geol. Survey Prof. Fapec Ilo. 2, p. 31, -, 4. . . . gravel deposits, moro Tert isry sedineats. These sedhents (note Plate No. 4) are distributed along the Kuryuk rive^. Theg are folded ad dis- torted' and contain lignite coal. Smith1 states concernizg these sediments: Vhe paleontologic evidence as to the age of these rocks is not adequate for basin3 a final conclusion but it is believed to indicate that the beds =e Iocene end probably are in gensral correlative with tha beds of sinilsr coq~ositionand relation that are so videly distributed through other perts of Alaska and that have uswlly boen referred to as KenaiOn Eocene beds =e of comon occurrence in the vicinities of soae . -. . . of the rajo? placer fields of Alaska. Some of the richest creek place~s are in close pi-oxinity to these Tertiwjr beds. The relationship that these beds have to placer gold deposits has not been adequately presented ... - - . .. .- in any geological literatrcre on Alaska. They are represented as being - * deposited later than cost Tertiary intrusives, hovraver, there. . is evidence to show that soae of these later intrusivss my have been formed later . . than the Eoceno. At least soae of the ninerelizing solutions of Tertiary intrusives may have ponetrztsd these ssdiments end fomzd high grade . . deposits, now worn amy, leaving gold in placer form. -. - - -. . A - - - - -.-- - - _3_- - -- L__ * -..- - STRUCmTTS - -- .------.- The trvo prevailing structures of north-south adeast-:yest G..- : folding havet been explained under geography and geology. TTeerly all ,. evidence e~counteredin the field ~hichis evident today is Eore or less controlled by these prevailing structures. Each direction of +. .- .. , ...... :.. . . ''Smith, P. A., "Areal Geology of Meska, U. S. Geol. Survey Prof. Pagsr : 192, p. 65. , . . . -t-.=i~i-.J'..z *.-_? ------J.*= :, :>. - - - ,. . ->. *.c <-.A. , . . ,* -.--> , - -.a - - 1 .- --"%, - 22 - . .. folding is accoxpmied by a fault structure in shflar direction. . ' This systein of faulting prevails along the contzcts of the linestones and schists in the north and south structure, and cuts across the beds =. in the east zntl west structure. 'This produces alnost squwe block *& faulting, along vhich my~~talliferous locta veins ake associated, as . .It observed in the southern section of Se~iardPeninsula vhere rock exposures -.% - . .---, - L are nore in evidence. These fault lines, as they occur. 'on the north and south structure, represnnt at least in part the begiming of the ; {lb,. i-: i: .. k . . . early draiwe. They also repressnt the points of greatest ~ieahess 1,,.-:,: :, --'Z:'r - . ' and the lines alonz vfizh ths catallife~oussolutions floxrrd from the - t: j;tb--&c.,: z2:* - ! . intrusives and along vrhich gold de?osition took ?lace. & .L : ::.L: -$:i:.c: .I Aloiig the anticlinsl donoa of both structures--. -\ occur the. ..%.::: , . ,. .. - .,:--.. , : --I r -*--. .-.+ .,. -d,.- intrusives. Thus the prevailing pcnite intrusivas v;ere most numerous . ;I ; .: : -. on the east-xast uplift re~resentedby the Esncleleben and Kigluaik . : lWA>....:,. :-, . ranges. Less, but vrell re?resertsd, me the intrusives of the domed :,,.La;.:, --. 2 .... 1 arass strikins north such as the divides betT::een Goodhope, Immchuk c I .....- -x".- - . and Kugruk, rivers. collier1 gives the dpdc history as follo~~s: T?e have thus four definite peziods of crustal novenentsr-;------with acco~~p~ulyingin,jsctions, in the nor-th;rn proyrince. The first, r.rlrich vias roSzblY regional, occurred in pre-Silurian tines. The secoad rras a pericd of intrusion, and can be provisionally assigned to the closo o-the? Paleozoic, or the beginning of the , . ,* Uejozoic. The tkird 72s a priod of folding, rrhicc'a r;as rather local in its effect. Tne last an e2och of extensive lzvas, ' ~hicZ1,t20ugh rat3ol" :*ricies~ra?d,was no2 gre~tin the aount of 8 .. '-: material v;hich IMS e jslctsd." -, -.\!...... <,.* .,>>..-;.t-.. . ..? . \i t. ... .'I- ....-. ,,:6., .C.-*.= id. :.*:...... **e3;.:;~ .lier, A. J. , U. S. Gool. Survey Prof. Pepar Xo. 2, pi 33. . 2r.,_ _.- -;4;- +; -%.= .... ., ' ;5.?:;;;~%~::&* _. - - * - - .. - . .,- . . - :'.. --;- *---,PCF -- j,+.$&F%!z&:9. 1%. .. ,-9r&,-:,< - - ,> - "2 - . L *":;. - ,.- . "- -d.-~*:-b =_.* * - :;-- . .. - -"-a*- - 23 - . .--i+,.:.%- ..- 2 .. -;,6rnT A. i.-.i . j" .... , . %.. - fur$. > .< - " '. .."...... r .. a .S -9"~6-.--- -- ..* s 7 ,+.-.a '. .x.,.-,.-? >v-uu-?% * ,--A ., , , - YL .z.~... - . .1 .- 7-1 .,.- --.A. --.A. :Fx>:.f%';:< _ /i ..- ,. The dip changes continually in crossing a section of a fold from an anticline to a s~yncline. The dip is rather flat on top of the dome then gradually increases tov1~dthe center at vrhich point it is - nearly vertical, adthence less as the troua or syncline is a?=oached. With the interbedded linestones and schists the lines of greatest weak- ness occur along the contacts, Faulting occurred 'along several contacts and fomed the path for the oineralizing solutions. In,the areas vrhere the dip of the beds is greatest, it confoims with the greatest number of faults and the greatest mineralization, as cozpared to areas of less dip. . ...- ~rooks' gives the line-schist contact as the origin of the gold: has already been pointed out that there appears to be a connection betxaen structure pact the distribution of the . .5<-- -., .-auri$orous gravel. This viev is borne out by the evidence of "the geologic nzps, vihich indicate thet rmst of the v;orkable . *&.-st---... . .placers occur along or close to the contacts of linestone and .. schists, These ccntacts have in may places been exposed to erosion as a result of the do^^ uplifts already nentioneit. b -. This, ho~mver,is not evs~pherethe csse, for some of the limestooe-schist coatzcts are simply the mzrgins of lenses of limestono included in the schist, Be the relction of the linestone \ to the schist what it my, it appears to be established that the bed-rock sotcrce of the gold in most deposits is traceable to a limestono-schist contact, Furthomore, these contacts appear to have been loci of the ce~testaineraliz~tion, either as inpromated zones or as fissure veins." - The structure is the important feature of the entire area, It - - -I is the controlling agency for the granitic intrusives which are the origi- -. '. %'rial-sburce of the minord solutions which cmi~dthe gold, the control- . .. .-. . . . -**.':: . - ,, .:- . . ling agency for the deposition of the gold along certain contacts, and the controlling feature, with some exceptions, of the drainage basins - 5 l&ooks, ,. A. H. st ale, U. S. Geol. Smey Bull. 328, p. 121. into which 'the gold has migrated and exists as potential placor deposits. GOLD ASSOCIAT3D XITH II~X'FtUSIIiKTD F"ZT2USFES Gold in placer f om is v&2elg distributed on the vrhole of --t .,..*. -. ' Sovrard Peninsula. In a study of the various placer arees it will be found that the gre~testmount of gold concentrations ere in the vicinities of and not far distant from intrusive end extrusive rocks. Lark8 tablelend are-' such as the hericcn River drainage north of (.- ~eller,appaar to be lacking in intrusives and also lacking in placer . gold deposits. Areas of hotlm placer deposits, such as the Hot Springs, Xbugarok, Inr;2chu4= and Kugruk, pJ.1 contain =all intrusive and extrusive rocks. The presence of the older channels2 show the migration of the gold as having been derived in very close proxidty to the intrusive and extrusive masses. The f ornztions of many of the higher domd areas, by the presence of qumtz veins, contact ninerels, end foreign minerals introduced by hydrothermal action, show thzt they are uneelblain vrith intrusives which also have contributed to the total go12 suppl~. Ehons3 Contributes and associates gold deposits with igneous rocks as: "The association of auriferous lodes with igneous rocks is -- - -practically universal. In sreas of late metellization the lodes are associated vrith lavas or ~4thintrusives fom-zd near the surface. In areas that have older intrusives which have been subject to greater erosion, the deeper seeted and generally more coarsely gainad irtrusives are likely to crop out. In such areas the gold lodes are al~osti~vmisbly associated vith granitic rocks or with porp~piticp, hases of such rocks. Not only are gold lodes . asaocirted chiefly wit11 ocidic intrusives, but they are found . chiefly in certain 2ositions." l~mith,P. S., U. S. Ceol. Survey Bull. 433 - Geol. mp', page 26. a?ote Eot Springs Ares, p. . . . - % bons, :7. H., wGoll Bposits of the 7oorlC," First xd.', p. 12. mile Zhmons does not use the tern extrusive rocks, it is I apparently understood to be contained in the igneous rocks v.tlen he ' mt3ntions the lodes associated rdth lavas in the lster intrusives. lilore .c important consideration should be given the extrusive rocks in areas where they are horn to be genetically related to thp. granitic: maws 1 .. from which the metals originated. It is not within the scope of this 11 report to theprize all the agencies and conditio ns in the transition of - the gold fron the igneous bodies to and until del~ositionin plzcer forn. fiom all evidence gaired in the field, the origin of the mkjor art of I* the gold on Se*:iad Peninsula has been fron mg~~ssencZ de~ositedby hydrothermal solutioils, vrhich originated under-conditions of rapidly de- -. _--I__-- - .L -2. I- creasing temperature sad as the result of the crystzllization of the raws. These hydrotherml solutions carried their metallic content sT:ray fron the 1o:v~r crystallizing rocks ~henthey were forced by pressure and ac- I :- celsrathd by various gases. %en some of the netzls, such as tin and possibly mercury, were believed to have been in a gaseous state. They I 'omre. carried great distznces and precipitated and deposited under environmental conditions of pressure and tenyeratwe, in accordace rrith -. -- . . - .the reactions of physics1 chenistry. These ascendin5 soYatians, as #. they leave the originsl asp, are believed to be higay ecid, but upon emission at the surface, like tha pressnt hot s?rin&s, they cre bksic ., - and alkaline; horraver, they still retain soas of the non-xstallic and I " A* metallic elcnents of the original magma. These solutions in their course of travel through the pay conplicnted openings, forncd by the con3lex structural conditions1 precfpitzte nortions of their metallic content under favorable conditions. There conditions Kere not favorable for precisitation along the entire course, as in the licestone and schist formations of Sexard Feninsula, they still retain apert or most of their metallic load \:hen they arrive near the surface, where a condition (%. of precipitation takes place regarding vrhich very little is hov.m. Thus, until- condit ions are studied fkcthsr md Kore Eno~rledge is gained regarding this area, the follovring observed conditions in the field appezr to be in harmony with this general hnothesis: Within the area concerned, there occur four kno:*m types of Igneous rocks. Those are diorites, sode granites, nonzonites and lavas. ..i**? ! the oldest. Of the igneous intrusives the diorite is regarded as the oldest follovred by soda granite and monzonite. This is based upon age classification elsevhere in Alaska, of sinrilcr igneous rocks by Llert ie. 2 The soda granites of the Bendeleben Range ere regarded as being older ------1--,-. -- * -:------.. - ----7 ------..==-. - than some of the others, however, there is no definite proof. The i~eous rocks observed in the field in this area hare been classified nega- 3. . , ocopidally. kIost of the knovrn occurrences hme been classified by bffit .3 This classification megasco?ically is subject to change vith lop. cit., p. a. . . %ortie, J. B. Jr., U. S. Gaol. Survey Bull. 872. ?8ffif, J. 2.. TJ. 3. Oeol. SI;--?-- 711. 1.1 . further thin section microscopic determineti0r.s. Diorite vias observed along the left limit of the ICugulr River at and above the mouth of Gold Bug Creek. Here the Ku9u.k River has made sane exceptionally large winding bends and has cut across the contacts forming bluffs 25 to 30 feet high. This diorits is in contact with a graphitic, siliceous and limy schist. The only nlineraliaation noted was pjrite in small quartz veinlets and associated with lime silicate minerals. No visible gold / (... in place was noted, however, it is very possible that the mineralized schist my contain low gold values that have contributed slightly to the placer gold content of the Kuguk River. At least some of the pyrite found in the concentrates originated from these contacts. The main intrusive mssl extends frorn above 1-Ena Creek to nearly the nouth of Independence Creek, and it is classified by fbffit2 as nonzonite. This mnzonitic mass is believed to have contributed the mjor part of the gold found in the auriferous gravels of Kina, Xontana and the lovrer Kugruk River. / ~4 t.o"3 At the mouth of Independence Creek on the point on the right 1r '+ limit of the Kugruk, a 16-inch vein vras found in 1917 by I. V. Furkeypile, Barney Ford and Knapner. Ten tons of galena-gold ore was reported to have been shipped from this prospect. A shaft ms sw: 140 feet and several feet of drifting as done from the shaft. A reported $80,000 - - was spent on the property. The gelena ore occurred in kidneys 10 to 20 : feet 'in length along the vain and the formation msreported as being lop. cit., Plate 4. %offit, 3'. E., U. S. Geol. Survey Bull. 247. black limestcne. This prospect has been abandoned sinco 1919 and due to the inactive condition, it vras not exanined. It is the only lode prospect, I. other than coal prospects, vrithin the ares. This lodo, due to its close I proximity to the morizonite, is held to be genetically associated. I 1 The ~11311smite stocks st the head of Spruce Creek in the I i. I - upper Kugruk section1 were not visited. Reports of associated gold I I i i and cassiterite vrith consider~bleyellovr gmitic sand suggests that 1. c-1 these intrusisa plugs nay be of the soda granite type as found in the Imachuk and 3ot Spings areas. Several of the nunerous granitic outcrops in the ~endeieben Wuntains examined. The greeter part of these are more or less continuous and related granitic nasses ~:hich form the high nountein range. They are covered with a hzrdened metmorphic shell of sediments mlth the grzriite outcrops only as maller independent nasses. The individual masses 2, as they outcrop at the surface, represent more or less the contect phase of the whole crystalline granitic na-. Further erosion of these grcnite msses would reveal their true com2osition. Pegpatization is conqon in these msses and various textures of the granites themselves show the various degrees of temperature under which they crystallized from the parent map. This pegnatization is nore or I , .*. less the trznsitional sta~eof segregation of the minerals from rvhich the hydrother~lsolutions collec%zd and were expelled by pressure as the last exponents of a cooling mga. Considerable hot spring deposition is still in evidence along the upper portion of Fish River. The latter is not shovm on the sketch, but is located due south of Bendeleben L&e across the.divide on the south 'slope of the Bendeleben Rangs. One hot spring is still in evidence near the foot of the rmcc on Fish River. Considerable evidence of hot sgring action she;:-s in the granite areas sou+,h of Bunker Hill, The Pil~inSprinzs aye situated on the ~eotend of the Eendeleben Iirrnge in close connzction nith tho granite nasses. These pressnt hot springs are the result of the doeper seated crystallizing mgm. The amount of R hydrothemal act ion which took place during the crystelliz~$ionof the upper zone of this m~anust have been considerable. The metallic content of these earl-ior solutions oas not deposited mithin this contact and pegaatitic zone. 'The teqera%ures.,aCvhich pegitites forxn is be- trrsen 870° an:l 6000 c.~Tho texparature range for hydro-ihe~ddoposition 3 is hold to ranee frola 6000 C. to smcj point well below 100' COU The present swface of: the. Bendeloben Range is characterized by the Bresence of pewtitic granite outcroppings and contact mets- morphic seclirc8nt s, v.%ich myst allized at tenperatures above the t eqera- ture of aost comon mef;iLs. The greater portion of these metds ?rere deposited at sosa distmce fron this-zone in outer lovrer tea~~arature zones. The fomtions in vrhich they vrera deposited have bean rmrn away and deposited at 1ov:er levels throw> the agencies of erosion. A great portion of the unconsalidated daposits found in the basins, the river drainages, md even the coastal ?lain, sebelievsd to have been derivad ' from this range. q The smites of this range breds dovm into yellov sands, similar to rnonzonite sands, with great rapidity. From their orthoclase ' and plagioclass cont ont with s~m11amounts of f erro~gnesimminerals, they were classified as of the soda granite variaty. It is generally found that the nost comon types of granites found associated within the gold placer areas such as the ~uslioh~rin,~~ditarod, ~ub~,and Innoko, are soda granites and nonzonites. Theso types of granites are (- k. . the prevailing ~anitesfound in the other sections of this area, such as Hot Springs, XugruE: and bchuk. The ~atalliccont eut , vriiich vras originally enit t ed from these # extensive granitic ases of the Bendeleben Range by ths action of hydrothema1 solutions, is to be found in soDe form in the unconsolidatad deposits. These deposits are to be found in the structurzl basins on both sides of the range and the structural valleys which lead froin these basins, These netals are not to be found in any concentrated amounts within the range itself or on its transitory slopss. The ex- tensive areas of granite sands their pinkish color ad content of iron oxides derived fron both the granites and the recent lavas, which are found,at the foot of the north slope3 of the Bendeleben Range, are not favorable in themelves for glacer deposits. They are believed to be auriferous by so~eprospactors rrho have been over the area. These sends are on the transitory zone and are derived from the granite which l~fertie,J. E;. Jr. Zi Harrindon, U. S. $801. Stmvsy EU.1. 754. &kin, H. a!., U. S. Geol. Survey Bull. 578. %faddren, A. G., U. S. Geol. Survey Ejull. 410. w: crystallized at a teaporature above that for most metallic xinerals. These sands we further desc~ibedunder the Kuzitrin lowland1. Srmll fine colors of gold can be panned from these sands in certain localities such as at Bendaleben hke and at some of the north fluxing streai from the Bendeleben ::ountains. The sands are, hovmver, underlain by , numerous talus boulders from the range and mixed with numerous lava rocks f'rom the margins of the surface lava flovrs. The fine gold (I deposition in these sands is the result of later hydrotherml action, - - which ~vasonly ninor in mount as compared to the former action. Glacial action also disrupted my extensive conce:ltration. The Hot Springs granite area, located between the Zougaroli qdthe Serpentine River drainage areas, represents the xost advmced I . . ' stage of erosion of intrusive ilrithin the area.' This greuite araa . .is a large amphitheater, over 5 miles in dimeter, with the outside contacts rising as sharg rims above the central portion. The vrhols .. effect is that of a large volcdc crater which has sunken in the center. Numerous groups of' what collier2 calls wearsware scattered within tfie -contra1 basin. The whole central portion consists of coarse grained pinkish granite consisting of pink end white feldspar with quartz. Some ferromagnesim ninerals are present but not abundant. The outer rim consists of hardened sedLments and greenstones, which have been I .,-. . . hardened through contact netmorghisn so that they have resisted the %ee description of Kuziirin lo~rlmndon follovring pages. 2~ollier,A. J., U. S. Geol. Swvej~Prof. Faper KO. 2, p. 30. .~ - I , - agencics of erosion nora than the crystalline mass itself. The upper portion of this intrusj.ve, vrhich contained t3c hydrotherr~land pegpa- titic zone, has been rrorn away by erosion. As a result the gold and other metallic content has been removed frola the Lmadiate vicinity and has nigrsted distances of froln 5 to 10 miles or more away from the intrusive. .The gold is found on the Kou~aro!~,Sarpentine, adGoofiope river sgst ease ( . The nuarous groups of ears, vrhich are in evidence within the ,,:a'. intrusive mass, r:ith the existence of the present hot s2rings1, on Hot Springs Creoli, all evidence of extensive hydrothenzzl action vrhich accompsied th3 coolizg of this Granite. Xot S2rings Creek in its uppsr portion has cut throagh the hard contact rim surroundin$ t3e Eot Springs kanite. This &??hitheater has been fomzd minly by the erosion of softer granitic sands by this creek, but leavine, groups of needles and pinnacles, or ears which aere saall msses tLat resisted erosion noze than the msin crystalline granitic mass. collier2 attributes the fonmtion of these ems to weathering along a double system of joiots. These ears, to the old tins Usskan placsr ?rospector, hzd aa imsortmt significance. They were the evidence on which he decided the country vias favorable for prospecting. nese vrsre often recognized as granite cad =y pros- a pectozs have often skated that they dt7ais orefe- to haw -these ears in sight when prospecting for placer old. kollier, A. J., U. S. Geol. Survay *of. ?aper 2, pp. 55-56.. , z~ollier,A. J., U. S. Geol. Survey Irof. Pepar 2, p. 30. Geologic ally, these have import ant significance. appesr to be the rasult of weathering along joint systens, as mentioned Collier, normally form depressions rather 'ears. Veathering, as it affects nost granites, is most rapid along f'racturas, faults and joint planes. The intersection of trro or nore lines of vrezhess usually roms a ma11 ~epression. In this Eot Springs granite the opcosite effect regzrding these intersecting joint planes was noted. Jointing in igneous rocks, according to ~illis,~is the result of tension h2osed by cooli~g. A double system of jointing occurred within the intrusive areas ad it vras rmre or less pronounced in areas of localized telzsion. These localized meas were the open channelr~aysfor the ascending hydrothemal solutions, vrhich were forned as the result of- dee~ercrystalliz~tion of the origincl cagms. These ascending solutions v;ere heavily burCZened riith ninerals in solution m8, no doubt sMlul to the present hot springs, contained en abwdmce of silica and soda as najor constituents. As the solutions approeched these joints or channelrrays the tenperetwe mil presswe =ere reduced and precipitation began. Due to the ebun2ence of silica end soda, these were -. I- .------.--.--- intermingled and-believed--to have crystallized out ðer end fomeci --- the plagioclase feldspar, whlch in cornperison with the originel plzgio- clase of the parent rock, appeers to be secondary in nicroscopic thin sections. These solutions also ettacked the original felZspars adcaused l~iillis,B., wGeologic Structures, First Ed., r. 31. a recrystallization which formd zoml grovSrthsof plagioclaso feldspars. These arc particularly in ovideoce zro1md the original orthoclase feld- spars. Thus 1:dthin the zone of attack of these solutions the eddition of this induced silica and the recrystzllizction formed a hcrdcr phase or zone, than ,the originzl rock, s;hich ms .nore resistant to weathering. The importznt fact to be tdcen into considerztion regzrdine these ears is ths fect that these ssne solutions elso contained a (1 metallic content which vns deposited in a higher zone at lovfsr teqerz- ....: ' .-- . . ture and pressure. The cnviromsntal condition in which this gold and other n5tals vrore desosited is rot knor:.~, sicce the upper zoaes are worn avray. Eeczuse this Eiot Syrings granite is of the soda genite ...... - .,yariety ~rithits abundmce of soZa feldspar, snd since soda gznite is ., .. <.;r. .re.-. , ,: ... .. :the prevziling grmite asaocizted nith the origind source of the gold, considerabla gold is believed to have be~nassociatetl with this intrusive. The abundence of the rennants of kydrothemd action, the highly dneralized contacts, the associated placer cold on the Ko~ougerok, Serpentine and Goodhope drainages, dl point to a comon origin rrithin the inflence -of the 3ot Sprinzs granite. -ther evidence is the old placer cfiannels, - yhich point tovrard this intrusive, 2nd the associeted granite beming +-t...-,..--:. . i sands rvith the gold itself in the u?per regions of the chmnels. 1. W.dni&t E.Zoun-tain, due south of the Hot Springs grsnite wee, is a long north znd south elrte~dincdoze consisti% of schists and lime- stones. The fornsticns show evidence of minerzlizing solutions v:hich lsee description of Hot Springs placer crca on follorrln,f. PS~CS. ' originated from an intrusive mass that is believed to underlie this elongated done. Since it does not outcrop, its type and kind is not Several snail extrusive masses occur along the Kougarok River, note Plate 4, but since the of tundra and er,asive material which covers tho be&ock in the entire area is hecvy, no doubt.many more ere hidden. These have not been studied aad there is EO avail~bleinfornation regarding then. Tlhether they ere isolated individual injections of mapas, representing "axall stocks which have reached the surface, or whether they we merely remants of an extnisive flmr with the cajor portion worn avmy, is not knorm. It is possible that they represent amall intrusive stocks which, upon arrivixg at the surface, cooled as individual lava areas. The isolated rim, which occur along the Inmachuk, -. Goodhopo ad Kugruk rivers, ere knorfin to be minly isolzted reranants. Such nay be the condition cn tho Kougarok, however, these occurrences are isoleted and scattered end a2parently do not show indications of relationship to any main mass, Further study of these end the lava surrounding Devil 1.Iountain nay show sone assosiation. It is not necessmy for an intrusive to outcrop as a crystalline rock to be associeted with hydrothed solutions end metallic.precipi- tation. Eydrothernal solutions, fomed by the cooling and crystallizztion at depth in m intrusive, my be emitted from an extrusive. Further, it is horn that crystallization takes place at depth under donse surface crustations. Tnus, whether or not. the small lavas of the Kougzrok area have had acconpanying hydrothermal action and have contributed to the total gold supply found on the drair~ageis not knorm. Tho area, ~6thits interbedded strata of schists and lime- etones, the .lat.tor vrrying in positions fron horizontal to-vertical, has offered conditions very favorable for the flow of hydrothermal solutious, ( The . <.folding of these interbedded strata has produced both north-couth and east-rest feulting md sheuing. The greatest mount of shearing oras confirled to the schist in contrct ~riththe lir;.estone. This shearing zone makes for favorable conditions for the ascending solutions and the precipitation of gold. Furthernore, these zones were most readily attacked by erosional agencies and formed the basins end channel~~ays for the placer' deposits. -Geolo@c History: It is not within the scope of this report to give the geological history of the known earlier fornations uctil the present time. Atton~t ._)-. . :'., to give the geological conditions, which affected the deposit ion of gold and the forzntion of the placer deposits, is made subject to change, as the area is further studied and nore mining has been done. Gold 'is believed to have been deposited in this area starting ...... -.) Nith tho crystallization of the intrusives vrithin the Bendeleben Rage, . ..--... by those intrusive masses vrhich acco~paniedthe fornation of the or - I. I ... east-v:est folding and which 1:offit1 holds viere produced before the deposition of the coal beds or before Cretaceous or lovrer Terti~ry .., 1 ., & times. Hy&othe& action within this range or i'n association with - -.. - $'> LC. thesc intrusives carried on for a considerzble time and it possibly was -. .. repeated by the lator or second eruptive period that is still in evidence : "2% E today. Eowevor, follo.:flng this first period of folding and accoqnnying * c?5:. intrusive action, an erosive period follo-;red adthe Eocene sedineats ..-.&.. . . * . were fomed. These sedhants, as they occur in this area and numerous ,. . other areas in Alaska, appear to have been laid d0r.m in chmels and in .. . isolated basins, and are the result of long erosional periods. These . .,a*. Tertiay sedi~ertsray have contained a portion of the gold in placer fom *on this early period of raineralization, as in the Eagle-Circle ( district mentioned by &rtie2, with the gold being released later by the erosion of the greater gortion of these sediments. Some of the gold was apparently deposited in the east-rsst structural valleys as th.s re- sult of erosion frog the rmge itself. Thence cme the second period of defamation with the north and south folding across the east-vest folded structure. The deformtion of this period, vhich folded the coal beds' and Tertiary sedin~ents,VI~S accoa~anied by @ranitic intrlision of Tertiary hoffit , I?. H., U. S. Geol. Survey Bull. 247, p. 55. ere,J. E., Jr., U. S. Gaol. Sumey Bull. 816, p. 161. age, a9 mentioned by ~loffitl. This resultant coaplicated structure fomed the present undulating topography and the later north and south structural ridges and valleys and associated drainage systems. Xrosion robbed in p& tho former valleys and filled the existing basins and fom5d the isolated tundra placer deposits. The younger intrusives, from this - later def ormtion, also contributed to the gold sGply in the existing basins and chznnels. Continued erosion fomd the existing Tertiary c channels. The gold began its nigration fron basin to basin and dorm channalv~ays. Later erosion and hydrothed action contributed moro gold to the channels vihere the conceatrations were fomed. The vride structual valleys Rqre favorable for the many agencies of erosion and these, along with the sorting action of running v:e,ter, were the con- 'centx'ating agencies that fom'ed the various placer deposits. Since the deposition of the Tertiery sedh9nts, there has been no major period of subicergence. The area,' may have experienced some minor periods of submrgence along the outside coast, vms one of a gradual uplift accompanied by a series of erosive periods during Tertizry times and u2 uati.1 the present. me highest elevation of gravel deposits believed to have been degosited along shore lines is approximately 600 - - - .. feet, as observed in the Rot Springs area2. These are believed to have been delta deposits modified by sea shore action. The next mjor level- ing or period of hesitation following uplift occurs at a 200 foot eleva- tion along tho coastal plcin. During this period there were possibly llfoffit, F. H., U. S. G-eol. Survey Bull. 247, pp. 35-36. gop. cit., ?late 4. minor periods of lessel* elevations. The lost level or period the present coast line. The mount of unconsolideted naterial that has been deposited covers extensive areas1 along tha coastil plain and it has filled na3- structurd basins within the u?lmd province. The effect of the'later peripds of uplift hzs increased the efficiency of the drainage systerns, vrhich hme foraed reconcentrations within the basins, trans- ported the gold further fro2 its source and caused intrenchent of the i rivers, and formed old cher~nelsand bench deposits. This stege of active . > erosional agencies continued to recove ?Arther gold *on the bedrocks, receive, sort, and transport: aclditional gold from recurrent hydrothermal - waters, until it was disrapted by the extensive recent latca flv:is and . . the periods of glaciation during Pleistocene tines. The con2arct ively . - .. , y. ,; .-.- . .,- , .. , . --- -..,*&<*.$:.:i.P..t..,: .- ., ;:.; . . thin lavas, 'v:hich viere enittea fron large open fissmes, flovsed over a broad structwal valley rrhich had been ?artly filled by Tertiary un- consolid~tadZeposits. Due to the extent of the flows, the lavas not . only covered the greeter portion of the basin, but they continued to flo~ dovmrmtheexisting Tertiary cternals which lead avmy from the large basins. In so doing, the lavas covered the gravel deposits and made them more -- or less resistant to later erosional agencies. The lavss dsmsd the ..1: ;* - . . e structual bcsins and caused tho fonmtion of lakes. -A .-. - .-+F!?:.... -r t*, -. , . These lavas were either just prior tc or during the first - ,-., period of glaciation. In regard to this area, only the ~ountninprovince was affected by the destructive ecency of novirg glaciers. The other lop. cit., Plate 4. effect of this glacial period, as a whole, was the freezing of the vegetable and animal ~o:.rthwhich apparently was abundant. It stopped the agency of running vrater and put into effect other agencies such as frost and rrind. The latter is believed to have transported the dead vegetable growth and the abundant loose fine grained mterial, such as silts and sands, from higher elevations into the lower valleys'to form the present deposits of black muck and silts v~hichoverlie nost of the I uncorrsolidated deposits. Such.agencies as hillside creep, freezing and thavring, and gravitational r'orces.nere all active during intedttent . periods. . ..:: :. Aftor the 2leistocsne epoch, running vrater again becme ar active agency, xhich in nasy cases disregarded the old chan~elsan2 began to forn ne:: ones. Lakes :7sre fomsd, vhich in sone instances rrers extensive, ss in the IZuzitrin 3asin1, and also fomcd ne7ir d-ainsge system by their ovsrf1or.1 and in so cloing-reaoved considerable of the fiozsn muck. The era from Pleistocene times to the present is one of con- parativelg short duration, during ~rrhicfia nev cycle of erosion has be,- in which running rrater mde uss- of new draiaage sgstens more or less superinp~pedupon a older drainage that had becona sone~r'hatdisrupted. This nem cycle also contzins ninor fertures which hnva affected the placer deposits, sons of which are imntioned dong with others under the descriations of the individual 2lacer areas. %ee doscription of Xuaitrin LOvJ1md on pages following. TOPOGRwIY SPICE GC)U DEOSITIOIJ Chan~eof Draioaye Systems: _--I_---- The deposition of gold in concentrated placer fom is a steady process, beginrling at the time vhen lode deposition comes in contact with erosional agencies and continuing until a definite stage of con- centration is reached. Any psrticul-ar stage of concentration is not the final position of the gold, since it is subject to the action of f, later and future ageilcies. It may be taken that the present tine may be sons dorxmt stage of the concentration ?;:!lich zccounts for the present position of the gold, It is definitely horm thst the greater portion ' of the place? gold that is found in the various areas contained in this report is aore or less confined to the older drainage chsmels and drainege systeas. These deposits 1:rare conccntrsted =in17 during the great crosiond yeriods which began in the Tertiary and vrhich continued to Pliocene and Pleistocene tine. Thus the period of deposition for i this area extended fron esly Tertiary times up to the Tliocene or to the period of lava f1o::'s follo~sdby the glacial and freeze-up periods. Since thsre is a difference in ages of the lava flows, ths extent of the . -...... - earlier flov~swere small, in conparison to the later recent floss, and are disregarded. The general topography hcs changed very little since the beginning of the recent la~as. Tho chanso of drainage, sinco the Tliocana cgoch, v~hichvxas brought about by the lsvs flov:s, has had the nost pronounced effect upon the topography of the structural valley to the north of the Bendeleben bbuntains. An imture drainage exists on top of tho lavas, under which is a mture drainago system. The older drainage is intact beneath the lavas vrith thq leading channels distinctly. mked by the' outvmd flowage of the lavss. Thus r.;; noa hove a series of vsry innature drainage * system, originating on tog of the lava flo~rs,cutting aeross the outer rims of the lava flo.;:s md floxing on top of older deposits that =e super- imposed upon lzrger 2nd older drainzgs sys%em. This -is tru3 of all the larger rivers v,ithin the ares with the exce,ntion of the Serpentine and Kougarok rivers, which h~vsdevelopsd a nsv drainage systeri upon an older one due to causes which ere explained later. ;.-..I%-.. c. * Glaciztion follo~:od OT accoiqanied the lava flows and it also 'had its effect upon the to~ogrzphyof the Eendelsben Range tsnd the drainage basin of the Ko7p.k and Kuzitrin rivers. %her than at the southern section - . L b. of the area, glsciat ion r:as aliiost ent ire17 absant. The miter does not attenpt to eqlain all. the causes and effects of vazious ecencies vhich hays affected the topogr~hysince and during the gol3-C[r",posit~To~-They hzve been nwrous and ex~lsnztionas -- to their causss and effects can only be interpreted from a fen remaining remnants xhich exist es factud evidenca. It is nore the mmiterts pur- pose to present the ectusl existing conditions with r;hich the present day operator has to contend. Ths greatest mount of changa in topography has been within the lovrer structural basins which contain drainqe _I. . . channels. Evldenco shovrs that the lava f1ol:rs produced the @eatest amount of change. ?Text in exbent, and vrith v~hichmost operators have to contend, is the deposition of the black muck strata on top.of most gravel / deposits. The next effect on topogra2hy r7as the freeze-up period which apparently stopsed the drcimgo altogether. It froze the vegetal and' animal gro~~rbhsrhich was evidently abundant. There is evidence of their existence CUE to the presence of renains such as wood and bones under the lavas. Worn the occurrence of gravels under the lavas, as mentioned by ~ollierlad !.bf fit2, aduilder the lave in the shafts of the Sub-la~a Mining Corlpmy on the Ih~~chuk3iver3, the deposit of muck is lacking. This black muck, or co~abinntio2of ice and silt deposition, is collimon in nzny placer fields of Alaska and is described by J. B. 'brtie, ~r.~.Among -the savttral hypo+heses offered for their origin, the one rhich appears the most logics1 and bac%;d by the greatest mount of evidence, is the wind-borne hyyothesis. Theso deposits are also classified as the earliest Plgistocene deposits. Xth further study, these deposits and the clhtic conditions vA-ich must have been associated vdth an agproach- iw period of this kind, possiblg lies the em-)lenation for the silt deposition. The greatest problem, vrhich concerns these silts, is not as to their origin, but as to the best method of thawing and removing them, and especially in an area ~hichlacks natural hydraulic rater &d steep grsdes. ... ;.hollier, A. J., U. S. Geol. Survey Prof. Paper No. 2, p. 67. &offit, F. X. , U. S. Geol. Survsy Bull. 247, pp. 32-33. Z5.?? d*.~~~~:*~:;<:>: :: : , . +-,:-. :.> .: ..,..-, !... .'.---7.:-.w. .. :.,T-z -...... - ...... -- - >.:.a. -. - ...... - ' , ...... ,,, ., ..-. , . < - "5 . -: -= ..-.-. 'J I... ) c , _ . . - ..*-_.. .- - . .;. . . > --... -- --'- - ....- : : , --'> ,.; . J*'a(; A ;:,r.-?.:, . ' 672, gp. iC,3-133. Another agency which had its greatest effect during the Pleistocene age, and which is still much in effect today, is hillside creep or a mild form of hillside glaciation. This had the effect of lowering bench dc$osits and filling the frozen river valleys and covering the more or le'ss sorted older gravels vrith unsorted and angular material. This caused the strerun, when it began to run again after sufficient thaw- ing, to adopt a nevr course superirn~osedoore or less on to? of the older pre-Plsistocene channals. The rivers which began f loving after the glacial period, were overloaded; som intrenched into the older gravels, and others flovisd on top and beean to cut a preferred bank. This drainage change, causad by the frozen g~oud,is one of the xost comon problem with which the operator is faced. The present tundra or accumulated . , - vegetable grorrth, ~hichvaries from a fea inches to several feet, acts as an insulator to the frozen muck undernect'a and in association with the long cold frozen vrinter periods tends to keep zost of the uncon- .- . solidated deposits permanently frozen. (-.' Serpentine Sprin~sPres - Pxctic Slo~e: The serpentine Springs area is located in the northtmst section of the area contained in this report, note Plats 1Co. 4. The drainage, within this area, com,nrises the Serpentine River and its uppel: tribut-aies, which drain to the Arctic Ocean, and the Pish and ~~~uguu~aluktukrivers, and Hubolt Creek, ~ihichdrain to Kotzebue Sound. A pronounced structural ridge, extending from I.iidui&t 1,:ountain on the south to Devil I:ountain on the north, divides the drainage. This ridge risas in the vicinity of Devil 12ountain and slopas f'rom !;lidnight Lcountain tov~ardthe coast a1 plain on tho north. Along this structGe there are associated intrusives and extrusivss. The Hot Springs granite area has been described in preced- ing paragraphs. The original source of the gold, found within the area, (. is related to the granitic intrusives and the related nagms underlying athe extrusives. The Xot Sprizgs graaite has bean the largest contributor, On the north and west contact of this granite, the sc'nistose greenstone country rock is very heavily nineralized and this zone extends northr=d until covered by the coastal gravals. "ot spring action is in evidence along tha zone in the 1imes"vnes and schists of the east portion of - the area. . 8:- . .. I- --- C r 1 The vicinity of Devil lfountain north of this mineralized zone / \. was not visited. lbffitl classifies the mountain as lava. !'bether or e not these lavas have been subject to hot s~ringaction to the extent of' -- - - .-gold - ; deposition vias not learned. The nountain is isolated in the northern section and is surrounded by gravals of the coastal plain. These extensive * *. gravel deposits zenot bayond the limits of gold deposition adsinca the bedrock geolo,~ is unlmo~m, they are ~iorthyof some investigztion, . . lMoff it, F. H., U. S. Geol. Survey Bull. 247. The creeks which head in the vicinity of tho Hot S,~ringsgranite have been lmorm, since the early days, to carry some gold. Plo exceedingly rich strikes 17ore mde and the gold deposits are nore or less buried. A small anount of hydraulickiag has been done on Humbolt and Dick creeks. Not until this year has there been much actititg within the mea. Recently pay &revels were found on Schlitz, Reindeer and Elella creeks. These creeks are tho rain heed tributaries of the Serpentine aver vrhich flov from the (- slope of i.{idnight Ikuntain. In so doing they cross the fomer drainage syste~7;Aiich e:ctended north aod south elong the structural valley, end tlrhich contained the greater portion of the &ole that originated fro= the influence of the 90t Spring smite on the vrest side. This gold gradually worked its way into the synclinal basin on the west, end was deposited as a delta deposit. Ixtensix~egravel slld grenite sand deposits still exist betr11een elevations of 600 to 600 feet. Granite sand is found in the gravels of 1:lacklin Gulch. This I gives evidence of migration southrmd from the Eot Springs gpnite. 1n i. considering the topography of the viestern magin of the Hot Springs granite, e lovr saddle exists across into %cklin Gulch. Thus the greater portion of the go12 found in the upper iougarok is attributed to this drainqe southvrad f'ron the Hot Springs ~enite. 3xtensive @;ravel benches, forned by the kctic Ocean vr3en the section v.ns partly submerged, were noted between elevations of 200 to 600 feet on both the present Arctic Ocean slope adthe slopes to Kotzebue Sound. Since these gravels are possible delta deposits modified by beach action, they orarrmt prospecting as they are within the limits of deposition fron the grmite intrusives. Trospect ors report that colors have been panned 3.n all the crocks of the Arctic-slope extending from Ssrpentine River west to Ear Lbuntain. c The headvrzter creeks of Serpentine -River drain the viestern . slope of this ridge from l.IiCnight Uountain north, Humbolt Creek and its headwater tribut=ies drain the ezstern slope. The upper tributaries of Hunbolt have be3n pros?ected and soxe hydrzulic minixg has been done in the past. Gold was reported to have been panned from its hezd to its r mouth, a distvlce of 17 miles. Gold grospects vrere reported discovered in the ezrly days on 3alkrat Creek, the largest tributary of I.:umbolt Creek. The upper tributeries of the Pish River vwrant prospecting. ' l?alsh Bros. cf 1:oire have a lecse and option to buy the staked i-, ' ;' i.. , ground on Eiumbolt Creek, end are operating a bulldozer end hydreulic operation on the south brznch. This brznch follo~vsa contact of lime- stone and various phases of schist, the latter fodng the bedrock in the creek. These schists range from chloritic to graphitic, me close- folded, nineralized, a.nd hi&ly contorted. The gravels range fron medim to fine, with an averege depth of five feet on the upger portion of the creek and increcsicg grcdually in depth dov.?lstrecn. They me frozen, but with occzsional th2:::ed spots. The gravels thaw very readily with hydrculic ~vaterdue to ths shallwr depth. 3.c gold is fire in textwe and the finensss is compar~tivelylow. The paystreak mined averages 100 feet in width cnd tho grotind was reported to be runni~g$1.75 per yard. Cassiterite lt:23 observed in the concentrates, but the amount was not of sufficient qu.mtity to save, .I - - .'.'!: , J < '4.' George Bodis has tyro mining operations ir the area, one on Dick 'r. Creek end the other, a new hydraulic elevator end bull6ozer operrtion, on Schlitz Creel: rt the nouth of -9ainborr. At the operation on Schlitz Creek I 1- . . tba paystred vrzs reported ragira fron 110 to 130 feet vdcle. The gravals '. 3. I r. . , . . , rmge frosi 5 to E lect in depth an:? consist of a dxture of creek gravels of medim size and fine becch wish. The elevation at the nouth of Rein- deer Creek is nealy 600 feet. The grcvels are frozen in winter and gredually thaw during the sm-er. The bedrock is even and is mde up of schistosc and metmrphosed volcanic tuffs and laves. The gold is fine and has a shotty naturo, vdth 22-cent pieces the largest size observed. 31x lines of 4-inch holes ::.ere drilled across the paystreak that averaged 65 cents psr yard. , f' - On Diclc C~eel:, Rodis has operated with a hydraulic for several , ? I years. The paystreel: averages 45 feet in width end 6 feet in depth. The bedrock is hard md has a blue cl&y on top, The gavels sho;v a 'mixture of old ?.?elllSrorn channel rocks and aqplzr bedrock with fi~eto medium grattels. This deposit appaars to be a reconcentration fron the delta deposit, v:ilich for~edon the viest side of the Hot Springs granite, wlth scum local hot spring action at the head of the creek. The pay- streal; has been oined over five claim lengths to where it e~tiesinto Bryan Creek, The averege ground nined has produced $1 per ymd. Good ' prospects were reported found on Sryan Creek, which joins the Serpentire River belovr Hot Springs Creek. The bed of Hot Springs Creek, vrhich is conposed of pmite a 6. boulders and great amount of granite sand, shor~svery fine gold, This - - ... creek bed was reported to be thaxed, possibly due to the forrcer hot spring v,aters. Very little prospecting has beon done on it. The gold would no doubt be concentrated on or near bedrock and covered with the granite sands. This creek on its lower extremities r~arrzntsprospzcting, a8 also does the Serpentine River below it, A The area is cot seriously handicapped for trznsportation. Three air fields, one at each mining operetion, take care of the neces- .. - sary supplies during the s-or at the rate of 8 cents per pound f'roa 0.. I t. - Nom. The main transport~tionis done, during ezrly spring months, before the marshes thaw, with caterpillar from the road at Taylor and nmorr railroad fron Weto Bunker Hill. A mch cheapsr route, over which both summer and vdnter transport~tionis possible v,i+,k caterpillsr, - would be fro3 Goodhoge Bay betoreen the Goodhope and Fish rivers. At this point, supplies could ba landed on the beach for the a2proriniate -. sum, of $20 per ton from Saattle, plus caterpillar haul to the operation. .r..> 1' - *.'Itis possible to run caterpillars over the tundra in both smer and winter wit21 the exce~tionof the thaared nsrshes end larger rivers ~hich Kougarok and Xoxapa~aIXaine.ge Areas: The Ko~arokdistrict contains tvro mining districts, conmonly termed upper bugarok and loxer Kougarok-Eoxapaga. Since the mining .conditions in each area are soaevlrhat different, and as they have a distinctly different topogrephy, they are taken up separately. Upper Kougarok Area The uppor Kougarok area coqrises the esea directly south of . . !-*. . .the Arctic slope or. Hot Springs mea fron ?"idnight Lbuntain south to the Kuzitrin Basin. The upper kcugarok drainage basin is situated in a vide open fold that is bounded on the east and west by flat hill tops and dcrtes. i ".rl* .. :. ,,Rrooksl.- on the Kougarok Region gives the fo1lo;:ing descripticn: i . - , - Tothe north the Kuzitrin lorvlmd rises gently to an upland, dole flat sumits stznd et altitudes of 800 to 1,600 feet. Here broad, int erstreex areas, Mith flat hillto~s,diversified by sone higher doxes reachir.~altitudes of 2,500 feet are seperated by - wide valleys. This upland level, as elsevhere in the geninsula, marks a forner stage of erosion, when the entire region rles planzted. Subsequent uplift fomed a plateau which has been c &eetly dissected by. the present vrat er cotrses. The upper 10 miles of the Kougarok River flovrs fron west to east with its head off tho east slopes of Kougarok ?,lountain. It then - .'makes a right angle turn .at- the-muth 06 hclrlin Creek and follo~sa I I '. southerly direction to its mouth. In its southe~lycocurse it fo1lo.i;~a structural ve&ness in the schists. This structural cech5ss represents a ahear or feult zone, along which there has been nlovenent. me east cnc? west tributaries occup#y fault zones in ~ihichthere has been sone east- . - . . orest movement. P-s a result of this east-vest novenent , large oxbo~bends have been formzd alon~the river. These bends ere in evidence at the vicinities of the ~routhsof the ljkcl:lin, Taylor, Esnry, Comse Gold, etc. creeks. These oxbor? bends are of considerzble econczlic irqortance .. ,%sincevarious stages of benching took place on which the glacer Ceposits mere formed. . ~rooksl,on the Kou~arokRegion, describes the benches from - Taylor to thd point rhere the Kougarok River enters the Xuzitrin loi.?land (- . r-7 c c'.... .<..li.pI'-.+;t~,*+4qq.;fo1.3.~'ri9 x : \..A . "Though the general trend of the different ;zrts of tke valley is in one direction, its course in detail is tortuous. Xithin the valley mils the river flopis in a very irre~ulu.chamel, uld many of the r;2e=~ders are separzted by ~'rell-2efi~edbenches 1::hose flat ." . surfaces xrrk foricer steges of rrater level. This is especially evident above Taz~lorCreek, 18:here the river flo?~sthrough a cori- tinuous series ol' oxbo~rcurves, vhich ere seperated by sloging beachs 3. "At the 9olnt rmere the Eour;arok enters the Ku~~itr5.nlmrlrnd both vclley i.ia1l.s shov v;all-mmked benches. Ttro levels are here , notic9able - one 50 fect end one 25 feet above the strazz. These cen be traced for several niles above I':indy Cresk; the vmlls then becone steeper ad the river occugies a cayon-like valley up to Left Fork. Froni this point to Tashin~tonCreek, 20 miles above, sone evidence or' benching czn be observed in ;?.ost ?laces, though the benches are not continuous. ,The individual letals heve not been traced, but in the ?art of tke valley beloa Taylor Creek there are at least tyro high-level gravels end possibly three." ---- Y. ----- .------_- _^ -- \ -. .- . . he Kougaroi: andToxapaga rivers are the drily south fl~iiii~~~I"- rivers within the area described. 30th rivers orra their positions md -. ...k , - .:.. .:*,?.,. * .q -?+ .*<.,-.. A: '.*-, -':directions to having origineted on a nuch oldsr draine~esysten which approeched the stage of planstion as nantioaed by kooks2. Of the t7.v rivers, the drainago of the !'!oxapsga is the younser and its drainage hzs l~~~.~. ' . 2 ;. ..*. . ,...... -. .. - - l~rooks, A. H., U. S. Geol. Survey bll. 328, p. 316. 29roolrs, -2.. Y. , U. S. C'301. S~~.rvs:r3-11. 3?S. . * , S" ..:. .-" *- .. - . -..--- >--c . - - - - ._ . been controlled by the recgnt lava beds of the upper Kuzitrin valley. It is vrithin the bounds of assuniption that subsequent to the north and south folding and the grert mticlinal uplift of the Bandeleben and Kigluaik rmg3s, that the area now occupied by the large structural valley, which is no:Or occu~iedby the Rougarok River, drained to the north as does the GooLhope, Inr,mchtrk =d KUGL& drainage basins. Features that tended to block this drainage at intervals visre the lava (: .. .' florrs of Devil L:ourlfuain vicinity as repr'esented by greenstones and tuffs in the Sarpa~ti~le2iaar1 mes, tho iiOt Spri~igsgsnite area, and the delta deposit on tbe vast side of the Eot S~ririgssmite. As a result of the i~neousectivity, tilting also v;as associated with the drainage chesge. Gradudly, through strem giracy fr~nithe south, tLe Kougarok area developsd a south drzinzpe. The gold, which v;es contained in the delta deposit aric! the forr?r drzinzgs syste2, ~2sreconce~trated and now exists on the various bench levels and river bottom of the Itougzrok ! and Serpentine dreinages at the present tine. The present concentrztion is a particl reconcentration of the former desosits and accounts for the irregularity of valuss ukich range from very high to lorn vrith ir- regular distribution. The prasent posit ion of the placer concentrat ions is variable due to the vs~iousch?r.ses and influances to rhich the drainase area has been sub jsct. Tile de-,osit ion of the great qurzitity of silt on top . 5 .". I., . r & of the various bench gravels, the freezing up period, and the agencies . . of erosion since glacial times, izake3.a very complex problem for the present day miner. It is with this thought in mind that the miter recom~ndedto the Gapartment of Nines thzt detailed topographic mapping, to show the position of the benches of the-drainage system from ikdklin Creek to the Kuzitrin valley, be done. In the present creek beds, to which nost of the past mining has been confined, ereas of exceptional values were en'countered along vrith area of lean pay gravels. The failures of past mining have been partidly due to high costs and the lack of an understanding of these conditioas. The Ilougarok district has been noted in the past as one of erratic pay gravels ane hard dning con- ditions. The higher grade 'gravels of the present river courses ::ere dis- covered in thoss localities where the rivers, since glacis1 times, had worn a portion of the old benches axay end crossed the older channels, usually beloil or in the vicinity of the oxbmr bends. The areas of lean pay rrere usually confined to the straight courses of the river on which little gold was de,nosited frou the .formr levels where most of the pay still renains. The present river channel is the course xhich xas fom2d -. after the freeze-~2period. Tde nev chamel does not follov the old channel which ::.as forwd prior to the freeza-rlp, but it does cut across - ...... I the older chsnnal in m.mg instcnces. On the upper Kougarok above 1.kcklin Creek, the present chaw31 i beg- to cut the north bank with sections of the older channel remining 1 I intact on the south or right limit. Belo~~i'acHinCreek the older channel has been cut uore often by the pressnt river channol. The best pay has been found in the prese~tcreek ckannel ivhere it crosses the i i i placez concentrations of the ox3ot.r CL-ves of the older channel. At the I i curves fomned by the older channol, the pcy is rainly intact and such I I . (.I localities are bsing constantly sought by the present operators. After the freeze-up _~eriodand u2 to the present the, the natural ground creap of the frozen rnqterialhas been in progress on the V banks. I Old holes, vihich vrere drilled durizg the emly eqlorrtion ,days i grid that are now in evidence as solid colwas of ice in the frozen gravels, sho~irthis grouad creep. Soao of these holss are no:? tilted totvard the river as nuch as 45O. This shotlrs a novencmt, slotlr in action, grestast i 6. i . in amount on the surface and the stseper slopes, which coinparas to the # movomnt of ice in an alpine glaciar. Seasoml tharving and refreezing on the surface tends to eliminate the light constituents of the soil . . - orhi:h f10t.r off nrith the tha~*~edrmkr of the sunnor seasons. Refreazing -. - -- heaves and bre~ksU_D the surface, causing a great ragidity of noveiaent. , . -The effect of this ground creep-on the benches is to cover then with surface material ad obscure their presance ~3onview by mkinz the surface seen to conforn with the nztursl sloges of the surrounding .topogrqhy. This is only one of natures agencies ~ihich,in a very slow way, helps concentration, and also desthe se=cl~ for mineral de- . . , . posits xuch more difficult. As ne'arly all of tho unconsolidated materiel on the Peninsula is frozen end the ~musualstructural coadition makes for various slopes, this frozen pound creep hes, along with the heavy silt covering and tundra surrace, covered and bwied nost of the older placer deposits. The upper benches have bsen found minly by p~ospectingand mining. -. .be There &re five known pay levels to consider, each more or less limited and affected by the latter one. The level above the present creek is the 25-f~ot bench. A section of this bench level has been partly mined across the river frou the Taylor roadhouse at Taylor, on the Sather bench clain. This bench has a grade of 6 per cent and tha bedrock con- sists of blocky schist, ~rhichnecessitates nining 1 to 3 feet of bedrock. The gravels have a thickness of 6 feet of regular chsnnel wash, and =e covered with 12 to 18 feet of muck and ground creep angular nziterial. The mzterisl is pernanently frozensand tho upper portion xss removed by hydraulic. Castleton end Kseaan mined the greatest amount on this bench with dragline and boxes sst in bedroclr. This operation bsg& in 1936 end terninated last year with tho above opemtors optioning the &.{ gi/- '&..: # - ground and dredge of the Xougarok Consolidated Placers above Taylor. This season the Gold Bullion Con~any,Inc. is ~,-orl.;ixga bench below Taylor on the left limit of tho Kou~crokRiver. This deposit is . .~pproximatcly50 feet above the present river. This reprosonks the . ., second beach level, rrith the first bench level cut away in this scction. Betvmen this operetion and tho second bench level on the right limit above, tho present rivar cut both older chanaels, and exceptional pay oms mined in the present river channel. Last year two partners of the . , Gold Bullion, Inc. ngerstcd on the third bench level approxhately 100 feet above the present river betman 3dorado andSDreamy gulches just below the Gold Bullion, Inc. operation. This high bench deposit con- sisted of 8 foot of shaanel cash covered ~dth4 feet of frozen muck. / (. - This ground xas raported avur-gins 25 cents psr bedrock foot, with con- &dorabls p8y re-.li-ning in the engu1.m bloc'sy bedrock. There has not been sufficient xining on this second bonch lsvel to datemine the pay. This years opention ?:zs based on the drill results of the beech level. The method of xinin~:is using hydraulic for thz~iingend elininsting the . muck, and using dragline mi? bulldozer. for noving mterisl into low elsvated boxes. .. Elelow this opcr~tionthe :Uaska Teylor Eining Cozqany is minirig on the old chamel level with drsgline, hydraulic and bulldozer. Here the gzavels rmge fron 7 to 15 fee: iu thickness end aecovered .. -.all of-vlhich are frozen, -- - -- . with 7 to 15 feet-of ~uck,. - This bench nininc in the vicinity of Taylor represents only a very mall po~tionof the actual bench ground that exists. This series of benchas exist nore or less on all the ox3c~:r curvas of the river. The values contained on theu adhow xuch con ba nined the prssent costs is uni~novrn. Howvar, with reduced transsortation costs, and more .. . . efficient and chcaser mininc nothods, t3ese bench deaosits offer m ' +I , I 'Riis slsason 1.kurice Kelliher h2s started mining on a bench I -' opposite the mouth of f."acklin Creek on the ri&t lMt of the mugarok. Last winter by sinking a shaft 35 foet to bedrock he obtained good ,oay on a level 25 feet above the present river level. He.re the gravels range froa 6 to 12 feet in thiclmess covered ~5th15 to 18 feet of muck end sedhent and 4 feet of black silt, The pay is confined to the lonsr txo feet of grc?vels. He is oper~tingnith bulldozer and hydraulic I _ with boxes set in bedrock, - c. . , , . . Car1 Laderson is beginni~this season to mine bench ground on i- the left limit of !.hcklin Creek just above the muth. Satisfactory re- turns mre indicated by &ill, with the ground averaging 17 feet in depth consisting of 7 to 8 fest af gravs1.s covered by 8 to 10 feet of frozen muck. Sone excegtionsll~high values :.:are reported in a fey! holes, bkcklin Creek, xhich joins tks Ibxarok River at the ri&t . wle bend above Taylor, has a le2sth of 6 miles and flo~vs~iest and I south-sst froin the south~restslopes of ??idnight :.:ountain. This creek has cut across tlle olck drainage systen on the southern border of the v-___ _ ----- delta deposit forced by .thg erosion- - o the Vot Springs granite. Eoxld_ers - and hea-vy rash rocks are evident in the gr~~els,sone ranging up to 4 feet in di~f'~-3ter,sho~vilgc a forzsr drain253 of lwger size than the presont creek, i.3xed with the heavy grarels is considerable granite sand cousistin~minly of feldspars aid quar'2z and identical, mega- scopicslly, to the sands within the Eot S~ri~zsgranite area. The sands and gravels are poorly sorted and loose with the gold mixed through all S the gravels. The gravels range from 7 to 10 feet in thickness and are covered vdth 5 feet of black muck and tundra. Theso poorly sorted gra~els, with the gold'nixed fron top to bottom, show the creek has beon overloaded with this tyype of material. Half of the gold recovered consists of lerge nuggets, with the remining half ransing fron coarse to very fine, vrith a fineness of 917. The deposit is frozen and. the bedrock consistk of various schists, The ground is increasing in value upstrean and the present ground averages $2.50 per yerd from surface to bedrock. rz.ini~-g !!L!-./+' has been in progress by the Lnurin Bros. since 1912, who me operating a drag scraper, bulldozer and hydraulic. This creek has been consistently the richest creek of the area, however, much richer ground has b- found T on the Kougarok River in small concentrated aress. - This season Castleton and &enan expect to mine one of these v4', highly co~centratedaress. This area is located on the Kougarok River, one and a half miles a5ove the xouth of thcklin Creek. This exceptionally rich area is small in extent ad consists of a short section of the old channel on one of the numerous bends on the right limit diractly opposite a -11 tributary &ch from the north side. This gulch tributary ex- tends to the north and reached into the older delta dsposit and older drainage sisnilm to hklin Creek, Since fkeeza-u_o the gold has been held intact and the Koufarok River had continued to cut its north bank and left this old c'aannol segment intact, The gold occurs mainly on bedrock and xas reported ranging froa fine to very corrse. A common drill log consists of 4 to 6 feet of ~uck,2 feet fine rash gravel, 1 to 2 feet of rmck and ice md 6 to 8 feet of nedium to fine gravel. . The gravels and muck are all frozen. Einicg consists of hydraulicking and bulldozing the upper muck and gravel doxn to the lover strata. Thence the lower gravels are thamd with hydraulic water and a dragline is used to move the lower gravels into elevated boxes. . ., , . .. - Between this operation and the izouth of lhcklin Creek on the right limit and on the same old charnel, the Trinity Xinine Coiapany is ' operating a hydraulic ad drag scraper, the latter used as a tailing stacker. A bulldozer is used in the pit with hydraulic nozzle to move material into boxes set in bedrock. 'Ajhile the pay here is not as rich as at tho.Castleton-Keenan operation above, it vms, hourever, reported ss - very satisfactory. i \, 1 3, blow the mouth of Lkcklin Gulch, Castleton and Keenan are \&L\+ 1 f ad operating a 2-&cubic foot dredge, formerly operated by the Kouprok .. Consolidated Placers, Inc. A large oxbow cave has developed in this locality on the Kougarok. Eere sections of the old channel wore found in the curves with good say and on the first level of benches cutting across the curves, good pay ma discove~edby drilling. 30th the old channel segnents and portions of the prcse=lt rive? are to be dredgsd. The bench pay vrill grobably be worked witin dragline. The dredging ;:a grox.d %~?rn,ges20 f??t in ?.9_3tl)n. !L-- -.r-c-*;--."a'l.- --- . .. Y- .? t*?C,t -, h.illJ.9~~5off, The ground is tha~lrodvrith points. The gold is distributed nlsinly on bedrock and varies from medium to coarse in size. The bedrock is blocky schist vrith an occasional bard reef. me cost of drecigirg is reported at 40 conts per yzrd. This high'cost is in part 6ue to the high cost of transportation. Co~?,pletionof the road from Bunker !iill to Taylor will give cheaper transpo~tationto this section and loy?e~*costs. On the other hand, hsld a road been built from Goodhope Bay the reilroad haulage f -- and hi& lighterrgo costs v:ould have been eliminated. This orould have . ' - .. - cut tho preeent cost of $70 psr ton f'rom Seattle to less tila half, This factor alone aould accout for increased dredging reserves and greater prof it , .. . . :>y.-. . + The Fox Bar Dredging Company, located 10 niles below Taylor on i- the Kouprok iiiver, is tha;.;ing siuil= pound arid dredging vrith a 2-3/4- pubic foot 6recl~efor less than 30 cents per yard, exclusivo of taxes, The gravels contziu considorzble sand and the channel g~velsare nediw to fir.6, however, e. fevr lerge boulders ere encountered. The depth varies from 7 to 13 feet. These sha.llovrer gravels, finer material ad a shorter - - -. ..haul Icight possibly account .for , the difqerence in dredging costs, These nine mining operations comprise the total mining elom . .. , - a known lenzth of ne~xlyLO miles of auriferous gravels on the Kougarok River alone, and equally as msny niles along the tributaries in this uppar hugarok sectio~l. Note Plate KO. 3 shoyving Imov.n auriferous &ravels. . -.- . . b - .,.-',--. > . - . The vmiter does not wish to conley the i~pressionthat this =aunt of nlleage of auriferous gravels is all minable at a profit under tho # existing costs. However, with lower trensportation costs, better mthods of ogsration and recovery, a nuch greeter portion of these gravels could be mincd. Cheaper por41zr is a factor vmrthy of investi- . gation vrithin this region. . hvrer ICougarok and ITompaga Areas The lovrzy Kougaroi: section consists of that ?ortion of the ('- lotver Kougticok River fron the point shere it ernsrges from the northern tablela~d,into tho Kuzitrin lo~rlad,to its mouth. As the topogrcqhy and other physiographic features of this section are sonmhat different than the northern section, it has been considered sepirately. This loxer area and the adjoining drainage basin of the Rora?aga to the east offers one of the most interesting potential placer areas of Sevrard Peninsula, with its complex and unsolved, problem. A short study of Plates Nos. 3 and 4 will give son3 concaption of the main valley lovrland. Then the ! various feeder streams fion the north, with the gold which was derived fronthe nuerous granitic intrusives of the Bendeleben Range to the south, and the gold r~hichorisinatad in local vicinities vrithin the lomr drainage system my be considered. The problen confronting the prospector, operztor, geologist, end engineer is as to the type of deposit which this gold occurs in at the present t ine--r:hether agencies have rmoved the gold or buried it underneath the extensive eraval and -. -... . I ,- lava deposits contained within the basin, and vrhether or not the deposits will be of economic im?o~tmce. .. .. E;Iany of th3 agencies, which have been discussed previo~r&~in . . this report, have left their nmks within this area. These nany feetures ..- . are only mentioned not to arrive at a solution of the conclex problem, but to foster interest vrithin the area v~hic1.rmy in the future lead to their . solution, with accox;a:,znying econoaic returns. I ..- i: . \-- . . . Brooks1 recognized the possibilities and the corqlexitiss of , - I . . .\,., :; :. '. . the area and classified the deposits as follo::?~: r. . "The auriferous gravels forming a broken fringe along the f+ii. southern nnrgin of the highlands thst bound the Kuzitrin basin on the north and ?:;sst heve certzin features in co-rz-on, vkich ... . justify describing the2 as a unit. This belt inclitdes the glecers . .-' of Quartz and Garfield creeks, as well zs those of ths Coxapaga ,,:. basin. The bed-rock geology of tha belt is obscured both by the extensive alluvial dsposits and by the products of deep rock - . ,. ;, .rreatherinz. Eov:aver, a belt of graphitic hyllites znd schists, including sons calcaeous beds, apgears to stretch across the up- ., land betmen Ilavirul~ad Kuzitrin rivers. IIeny of these rocks - - camy quartz veins, locally stained vrith iron. Schists occur - - north of these gaphitic rocks, end farther north are succeeded (. by limestone. Thoufh these f omat ions cannot be exactly delinszted, I -..-, because of the deeply vrsathered character of the rocks and the absence of outcross, yet ~ostof the gold-besing creeks a?pecir to 2 cross the contact of the linestone and schist. "The unconsolidzted formtions eabrace (1) the present strem ------i------Iiz-- : gravels, f 2)-the deposits flooring. the E:uzitriK lorrla~d,and (3)-- - . ; '-.-'..;I: ' the bench gavels. * * * * * Little csn ba added to the description ofthe second group already given. The bench grcvels nerit closer -. - =.. . considerat ion. - : ..*' The present creek deposits found xithin the =ea are impo~tant, -. -, > '4: ;'. , - I - as 'some have been steady producars since 1899. Creeks vhich co~3ain - +. .. economic placer deposits include Coffee, Wl, Too and Quartz of the -.--. .r- L-.:<.* ...... : . ., .. l&ooks, A. H., U. S. Geol. Survey. 3ull. 328, p. 809. . . . . lovrar Kougarok drainago, and Garfield, muldor, Buzzard, Goose and Black Gulch, of the IToxapa~adrainage, Thesa creeks are of considerable importance gaologically since they contain both residual and creek placer deposits of local origin. This fact becomes very evident from a close field inspoction of the bedrock as shown in'the cuts of the various operations. The placer gold deposits of Coffee and Dahl creeks are mainly residuzl and alluvial dsposits, and small creek concentrations, all of vlhich are covered with considerable blzck muck. The gold, con- tained in the deposits, ori~instedin the hsdiate vicinity fron ir- regularly distributed locllities vrhich shovr hydrothemal action of hot ascending vatex in the ps2hitic slates and schists. The most pro- nounced evident.:! of this ty-1)e of deposition was noted in tha bedrock at the site of the Sovan ?lacer ooaration on Yonder Girl Gulch, a tributary of upper Coffee Crsel:. Here, under 15 to 20 feet of black frozen muck, anguler broken bedrock is being mined. Gravel, except a fevr rounded i quwtz and quartzite rocks, is lacking in the gulch. Cinnzbar in amorphous form with considerable yellow horphous povder is found in the fractures of the bedrock. Associated with and in the yellow povrder Is considerable row fino gold. Several of these occurrances in the vicinity have produced the gold which fomsd the creek deposits, Due to the highly disseJ5nated nature of these deposits, and the appwent lack of favorable stru~tu~a,it is very hprobable that minable lode deposits v:are fon1.3d. A short description of the various operations mill furt3er su?,~ortthis cviZer?ce. ---. Andrew !'liurm and assqciat es are drift mining below Yionder Girl Gulch on the left limit of Coffee Creek belm the Hoven operation. They .I are mining from 2 to 5 feet of gravels overlain by frozen nuck. The gravels consist of pmtly rounded and an&ar creek gravels mixed with # sons nuck, but laclcing foreign constituents. The gold is all fine and mainly found nezr to end in the soft schist bedrock. r .' , !A'-' The Coffee Creek Cining Co~sany,located on Coffee Creek below F--L.I1 (::. the T'liurm operations, is a hydraulic o~erationwith a bulldozer and a power scraper for stacking tailings. gravels have a thichess of 5 feet under 20 feet of frozen black muck. They are of medim size and contain considerable angular mineralized quartz pieces. The gold, which Is fine and rough to coarse, as well as nuggets vdth considerable quartz attached, are found. ~rooksldescribes some of the operating properties of the early days on Coffee Creek and coments as to the source of the gold: nConsidersble prosgecting had been done t,houghout Coffeo Creek besin ada little gold has been mined in its upcer part. The lower part of th3 creek is incised in the gravel terrece, and here also a little gold has been found. ijrospacting on the ugger part of the creek is exoensive bec~usethe gravels are evewhere -'-z-- -'-z-- --- buried undsrlO to 25-Tee: of xdcli: -This is true cot on.~of-the- --=-- floor of the valley, but also of the slopes and the tributerg gulches. This overburden is too heavy to pe,-t o2en-out nining, and the cost of fusl has so far been too great to encourage drift mining or even prosgecting. As a result much of the grosqacting on Coff;c Creek has bean confined to cuts mde by ground sluicing at favorable lccnlities during floods, and feu cereful tests of olaims have been made. IBrooks,. A. He,U. S. Geol. Survey Bull. 328, p. 313. ,. "In the winter of 1906 some rich placer ground ms found in the talus of the valley slope near tha head of Coffee Creek. This peculiar auriferous de~ositappeared to be almost in place. The gold occurs in 4 to 7 feet of angular schist and quartz debris and vreathcrcd schist bedrock cove~edby 18 to 20 feet of m~tck. The quartz is iron stained, but dogs not apgear tc be auriferous, and the gold proSably cane fro11 the associated schist. The gold is angular, spongy, and bright colored. All these facts point to the conclusion that the mterial nined is a tveathersd part of a mineralizad zone. The deposit has been traced about 1,000 feet, but is bUied so deeply that its boundaries are not vie11 knovm. It is indicetive of the source of the gold and suggests the possibility of finding lode deposits that may carry value^.^ f" . \. - t !#P'l The DDbl Creek Liining Con?any, novr on claim l?o. 8 above the . - *-$*'+ mouth of Dal Creek, started minizg in 1900. This operation consists of a power drag-scraper and hydraulic. The total depth here is 27 feet, all of wlnich is frozen and consists of 21 feet of muck and 5-5 feet of medium gravels. Consicierable of the gold is found in bedrock. The fine- @ ness at the present price ranges from 26 to 28 dollars per ounce. I +~!\q,,k 1 Louis 2Tcshen~:reng vms operat irig a hydraulic a~dbullfioeer on - .. Dahl Creek on 170. 2 claim above the mouth. Re has 5 feet of fine to ,- (9 L- medium grevel covered by 10 feet of frozen muck on top of a clay bedrock. Lea Steavens is miring with a ccterpillm and a one-yard tumble- $+. L\ b\ ,I L.\ bug scraper on Quartz Creek above Carey Gulch. The deposit consists of -- . -. fine creek mterial 5 to 8 feet in thickness covered by 4 to 6 feet of muck on top of a blue cley bedrock. The gold is fine end distributed through the gravels. deposit, like the others, is all frozen. ) Carl Yagger on Joe Creek, a tributery to ~uartzCreel:, is \- hydraulicking and shovaling-in a deposit consisting of 1 foot of fine light gravel end 2 to 3 feet of anzular slide rock. The gold is fine, rouch and 2 feet into bedrock. Mining has mainly been done in the past .on Gmf ield, Soulder, Goose and Turner creeks in the Noxapaga drainage system. Lack of water, low grades, considerzble black muck, znd lack of suiteble n~achineryr:ere (i tho major problers. These were creek deposits very similm to those of the Quartz Creek &~zinagedeposits. The only present oze~ationis that of the Rainbov? >!inas on so~drecent discoveries on Black Gulch abo~e Bouleer Creek. !his deposit corlsists of 3 feet of gravel and 9 feet of muck. The grevel is fine and rounded Nith most of the gold in bedrock. The gold is fine and its averege content was reported to be $4 per 4'2sd. The compny is operating a hydraulic and.bulldozer. -. . Most of the nining on these creoks is confined to near their (1' heads or to the point above where they flow onto the Kuzitrin lovrlend. At these places the creeks flow over extensive &ravel deposits. The little mining, vmich has been done on these lower creek sections, has been confined to a fevr feet of gravel on top of a cley felse bedrock. This shovis a run of the creek gold over and since the clzy bebock vms deposited. -4t the mouth of Quartz Creek these gravels r1mre reported to . be over 200 feet deep as shovm by a drill hole log. A smll mount of fine gold vras also reported throughout the ~avels,but not in sufficient quantities to mine. There appear to be several levels of those gravels that occur as bench deposits and which are unassociated with any large river, ex- cepting the ex-liensive benches along the loxer Kougarok. The high bench gravels are found frort. the right limit of the Noxapnga, mound the fringe of the Kuzitrin valley, to Bunker Sill. other then the few attempts at mining in these grzvels on the producing creeks, they have not been prospscted or tested sufficiently to make any statement regard- !, - ing their econoxic possibilities. There is still the unsolved problen as to how they originated as bench deposits and as to their content. Brooks1 gives many interesting fects adpossibilities as to their origin: - n7ihile the drainage channels were being incised sedhent was deposited in the Ikzitrin basin, then an am1 of the sea. It has been shorn that the charscter of this ssdinent is but im- perfectly knovm. Underneeth Quartz Creek valley thsre ese nearly 200 feet of v:hite quartz grrvels, v~bichvrould &spear to be the result of the denudetion of the old planated lend surface, Such quartz gravels, may of vjhich are not gre~tlq-rounded, are xzost likely to have cone from en area rrhich hzd been long subjected to subaerizl deccy. Their accunulation vras probably brought .about by rapid erosion end sedirsntztion, which fliould ir-dicate rapid u_ulift. It has been stated that both rounded gavels and sands occur on the lo:~srpzrt of Quartz Creek and in a terrece along the v:est brnk of ;Cougaroh- River, a.xd that these are believed to be of about the sane age as the white ravels described above. They probably represent a sozievil~at leter period of deposition, when tha nateriels had becone nore vratervmrn by strer~action and more or less sorting had taken place. "The cxplmstion of the occurrence of the clay c?e?osit under- neath the Kuzitrin lo~landpro?er is still nore difficult. Perhzp an atter!>t to exgdain this deposit is useless Khen so fen facts re~ardingit are aveilable. If, 9s is probable, this clzy bed is extensive undcrnezth the ICuzitrin lo:rlznd, it is probably a doposit in deeper rvater, laid dovm at the sane tine as the l~rooks,A. I-!., V. S. C-.al. Surlroy 33.21. 92?, y. 705. gravels described above. In other v:ords, it is the result of sedimentation in the centrd pat of the er~ba~pentelong v~hose marein the grcvels and sands of flavial origin ware laid doidin. - 'This clay nay, horre~er,be a glacial mud, derived from the valley glaciers of the 3endeleben l.:otmtcins, vhich :.;ere the locus of an ice accmlation in recent the. Oppossd to this genesis for the clays is the fact thst the glacietion, vhich vms confined to a very small arec, occwred at a sonerrhat later period. One ad- ditional fact desarvi~lg ent ti on is that the f6vq borings nade in these clzys encountered secerbl layers of vegstzble mstter r:hich is " in every YiaY sinilar to the present tundra g??or.rth. This indicates that deposition in tkat part of the basin vrhere the clay hzs bsen found has been intcrrug%e,d by periods v:hen the lecd stood cbove I ,. -. , water long enough to penit a covering of vegetable groivth.lt It is to be remezbered that the rivers and stre=s of the % -I'- ,:. Kuzitrin valley show fine gravels from Bunker Eill up to and under the lavas on the upper Xoxapaga and the north and south forks of the Kuzitrin River. These grzvels gradually beco~efiner as one advvlces upstrean. They nzke up the lowland deposits about which Tery little is ~~OIA,and vrill be discussed in a leter paregrayh. The mmy existing gravel buttes, vhich form the only elevations of the lorlrlads, show the t- presence of considerable water acticn v!hich in turn nust have caused considerable concentretion. On the south slope of Bunker Xi11 medium to cozrse pevels -_I- - -- A------.. _-__- _-.. - _ -- - -- __i are found occurring as isogted terraced benches up to en elevation of 400 feet or 200 feet ebove the 'Xuzitrin ISiver level at that point. These gravels are distinctly rr,ter laid, hoxever, they ere none too well sorted and contain considerable send. Gradually these benches becone 1ov;er as the north1:est frin~aof the drainage crea is follo;.~d -. - * . . to the north from Bunker Hill, occurring mainly betvieen elevations of 200 to 300 feet. Thence the gravels are modified by the lomr Kougarolr River, vrhich is incised in them, and fornod a level of low benches. The main gravel deposit of the Kuzitrin lowland is belo~v200 feet in elevation. There are many proble~zls concerning these &revel deposits and their deposition which renain unsolved; first, how they originated or fron whence they vEre derived; second, how they viere trzns2orted to their present location; third, what accounts for their difference in elevation that rqes fron 400 to less than 200 feet, and their deposition as benches; and fourth, ~~hydo they occur only in a portion of the bash at the higher elevations adnot in the other surrourding portions at the same elevations within the basin. ~rooksldescrib'es them as alternate layers of gravel v~thclay and vegetable matter, and xentions this .as indicative of periods of interruytion when the lend stood above the water, permitting vegetable growth. In considering the origin of these mzvels, it is necessary to look to the gravels thenselves for sone clue. They are classified as medium to fine, containing sznd and clay layers. .Uong the lo~rer ------__F_ L. ------.,, ------_I- - -- valley of quartz Creek they are con~osedmainly of rounced pebbles of quartz, quartzite and other various rocks. Since most of the pebbles contained are rounded, they nust have originated in running water of strem action. Ead they originzted from beach action, they vrould have a more ellipsoidal shape. A~ain,this basin my have been en mi of the sea, as mentioned ,by 3rooks2, one or several tines. As an arm, it must action. Although the contents of the gravel show more evidence of creok origin thm beach origin, it is not rezsonable to assue that . . these extensive gravels originated from the small drainage from the northwest and the Kougzrok River. It is a logical conclusion to as- sume that a considereble pzrt of the Kuzitrin Basin was filled to some by extent the inconing drainage and from the high Bendeleben E.:ountains* or ant iclinal uplift to the south. The uper portion of the basin vms * filled by the recent lava flow which is bovm to cover at least a part of the gravel deposits, as noted by ~ollierl. The pavels found under the lava are cer~antedby clay ad considered as of Pleistocene ase. - The elevation of these grzvels under the lava is about 400 feet, cor- responding to some of the benches north of Bunker 'xi11 in the Quzrtz Creek drainage. Above this point between the Korth Fork of the Kuzitrin end the Ezst Fork of the Xoxapaga gavels, ranging up to. ' 600 feet in elevation, are shovm by 1&ffit2 to correspond to those of \..- like elevation on the kctic slope in the vicinity of the Serpentine River. The basin of the ICuzitrin from its origin3 to the period of -=------. -.--=- i-_------.> ------r--- - - planation, as mentioned by ~rooks4,vr~s in the process of being filled ' by many agencies. The lower =avels would be considered the oldest in deposition. If the hi&er bench grcvels are remnants of this de?osition, kollier, A. J., U. S. Geol. Survcy Prof. Paper ?To. 2. %offit, 3'. H. , U. S. Gsol. Survey mil. 247. Sop. cit., Plate ItTo. 3. . . 4~ooks,A. E., U. S. Geol. Survey Eull. 328. they are in order of deposition the youngest. On the other hand, there is the possible emlanation that these northern bench gravels have been pushed out by glaciation and deposited zs out?*:zsh plain. 3vidence of extensive glacirtion shov~sin the Lauruk Basin west of l3unker Eill and within the valley of the Kruzgmepa River. Glaciess formd in and alozlg the outer fringe of the high Zendeleben Rangs nore extensively on the south side than the north siriel. Tneso glaciers my have pushed ecross the Kuitrin valley or formed within the basin a solid ice sheet which moved tonard the north.:!est. Ir so noving the ice nag have ;ushed a mll of the basin gravels ahezd of it and deposited them as the various bench levels on the north~13s-t;fringe of the basin. A rapid rzelting of the ice ~muldaccount for these gravel ridges partly sorted and left as isolated deposits.at elevations above the valley floor. The post ?leistocone drainage nzy have removed most of the glacial evidence vrithin the valley. There is definite evidence that the huruk Bash and the valley of the I(l'uzgmspa 2iver contained a consider~blemunt of ice part of which forwd on the south sides of the i3endeleben and Kigluaik nountains, ...... P-W-- ...... - .. --- moved north an&.. . arour,d.th_o_-east - .. .-- -. .. end.. of the Kigluaik 2.10-t airs, an_d_ that an ice cz? of consider~bleextent 'fomed aroun6 the hi&er eleva- tions of the Bendcleben Rage. ;;'eathsr conditions and ?rerailing south- southeast viinils deposited tho greater arromt on the south slopes. Glaciation of a more modified extent formsd on the north slopes. These north slopes were more or less riodified by erosion and instead of lar~e moving alpine glaciers a modified sheet of little cr slo~imovement cas formed in tho valley. In moving slo~rlyover these medim gravels of the existing basin little erosive action occuri*ed. The slop~sof the basin were lovr and the glacial force was reduced to a ninimum, which caused little destructive action and left only slight evidence. This glacial i copdition v~ouldaccount for xiany of the problem mentioned previorisly, . I.. such as the existence oi' the high bench de?osits, the clzy strzta con- tained in the gravels, their trmsnortation to their present pasitions, and their existence on the north fringe of the valley at high elevations and not on the south. Sor~ever, there is considerable evidsnce lackiog ... regarding the glacial origin for the high gravel bench deposits. In the future, if such a coniition gro~ssto be the origin of thesa bench deposits, one would not expect to find concentrcted ?later (\ deposits vritllin the gravals. 5old concentration n2y have occurred prior to the de2osition of these gravels on bedrock froin local conditians md mould still be iatact. The ice sheet would have acted much like a modsrn ------.------_-- -_ ------_- _=- --._ bulldoze^^ in pushing ghead only the to? gavels of the bnsin and degosit- 1% then in their present gositions. mesa top gravels c.ould.not have contained the gold concsntrations. me relnovel of these surface gravel deposits vrould in reality ~ckefor higher grade deposits of t3e gold deposited belov~near bedrock of the lor.rlmd gravsl plein. I.. ' . The most logical origin of the bench deposits and the present condition found within the Kuzitrin lovrlands is that of the action of erosion of one structural basin draining into another as mentioned in the I sect ion on This basin was mre or less bounded by structural ! basins of lovr north and south anticlines on the east and ?:lest. The north I .. and south structures bet-men the Kougarok and America rivers bound it on the west and the structural ridge betvieen fhe iZugruE= and Kiurali4 rivers !I 6 -. I on the east. GradualljT this basin becme filled with lacustrine de- posits fron Tertiary time up to and until the basin v:as filled to a level of 400 feet or riloro zbove the present sea level. The source of the material was mainly frorn the high Bendeleben Ranee. on the south. Glaciation during tho latter stages of this deposition may have been a contrfbutiag factor to a nore or less extent. The extensive lava flovs acted as an additional filling of this basin and Ellso the existiag I - drainage channels a:my fron the basin on the eastern md central portions. A large lake formsd on the v~esternportion of the basin v~hichgradually cut a new outlet in the vicinity of Buaker Hill. This nen outlet lovrered the basin with meat rapidity to and apjroaching the lover level ~ of the Imurulc i3asin to the west. This is the in~ressiongained by ob- serving the basin at a high altitude. Aerial photography, vrhich is reconmended for the area sithin this report, r~ouldconvey these impres- sions and aid greatly in the solution of these geological problem. lop. cit., pp. 16-17, This sudden outlet of the existing lake, possibly accelerated by an abundance of ueltix glacial ice, removed the greater portion of the deposits within the valley basin vrith the bench degosits along ths northsrn fringe bainz left intsct as remants due to their positions around the edges. In conclusion, it may be said that the bench gravel deposits found on the north and nortbxst fringe of the Icuzitrin Bzsia =e not (:- considered as promising deposits for gold placers, with the exception of small delta desosits formsd zt or new the nouths of the ?resent producing creeks. The greater portion of the gold, o,kich originated off the main BendeleSen Raxge, is confined eithsr to the bedrock basin of the Kuzitrin lo:vland, the central upland grovince within the structural valleys, or deposited on the coastal ?lain. -Kuzitrin Lovland: i The Kuxitrin lovrland com>rises an arec approxhstoly 20 miles 4.-. . • by 10 miles, which extends fron the lava beds on the east to Bunker Hill on the vrest, in the central southsrn section of the area, (see Plate ITo, 4). ------. ---.-. ------. -- - - ..-- _- -. 4 --2 - __a Its north udsouth boundaries cowrise the tabl9land between the Kougarok and IToxapaga rivers on the north, and the northern slopes of the Bende- leben ZIountsins on the south. area on Plrte 270. 3 falls nithin tfiose sections of the entire area that is marked as ~ro~thyof investisation for placer deposits. Since vory littls is ho7;m regarding this lowland basin, and only a few of the surrounding creeks hsve been _oros,~ected, on3 has' to look back over its geologic history and surrounding environ- ment to forn an opinion regarding its possibilities. Furthor study, vdth actual prospecting end considerable more field evidence, is necessary before any definite recornendations can be made with rogmd to a favorable or unfavorable placer aroa. It is, as pointed out'under the section .,on geology, one of those structural valleys fomed by folding that has since been the basin ~~hichhas received the greater sortion of the t -- eroded rnatesiel fron the north slopes of'the Bendeleben I.Iountains, as lndicsted mder thz ssction entit1.d "Gold x~sscciatkdvdtd Grenitic intrusive^.^^ There is sufficiant evidence to assume that considerabls . gold mst have o~iginatedfrom the influence of these intrusives vrith their acconpsnying mstalliferous solutions. It is ~dtbinthe logical bounds of assumption that the greater mount of this gold my still be - retained within the confines of this basin. The presence of the extensive lava flovrs, which disrupted the northern and eastern draizrage fron the basin, leaves ons in doubt as to whether or not this older drainage systen has removed ths greater portion of the gold fron the valley. If ------the greater orti~n. - _ =_---- of. the--gold------was -- not repoved, it is still confi~d. -&a. -- to the valley floor in the older gravels, of ohich more than helf must be,intact under the lava flo;!~. Too little is knorrn regaiiding the gravels , . and deposition under the lavas to consider their in~estigstionat the present time. -. Portions of placer areas in other parts of the r:orld have been covered nith lavas and in mining hzve poduced considerable wealth in gold. In ~all~aratl,';!est Australia, the auriferous series is covsred with about 400 feet of basalt, clcy and drift. The four flows of basalt aggresate 330 foet and aro separated by clay and detritus. Between ths folded beds and the lol:,zr basalt is a blanket of %ash dirt vdth rich gold pavelseft Tnesa flons are gi~enas of Pliocene age. In ~aliforniszsone placer savels vare covered with lavas in Tertiary tine =d the poduction of these lava buried gravels mounts to about $300,000,003. Further investigation of the Kuzitrin Sasin and the areas sur- rouading the lava field my reveal sufficient data to Cetemine further recoxmendat ions. The gravel plain desosits h3ve been described by Srooks3 under -. /-. the- - headiw geology. C 0ollier4 descrLbss this loldmv3 as follo.;:~: nThis is an m*ea of lovrlend coverizg z2proxhtely 200 square xiles on the nort5 side of the Bendelsben t'ounteins and drained bxthe Icuzitrln-- -- River. ?he loaland is t1mba covered, -----_------;__ and underlaill by silts-, sad, znd gr&.;els, p~obabl~of no ~eat ---- depth. It is dotted over aith ~my-11 lzlces, pro55\51y forrned . by oxboirs of the ns.mdering creeks and rivers. &ound the lo~?lmd area on the :;sst, north, ad east sides there is s hi~hergrace1 plain, fron 50 to 150 feet abovs tho lo:.rland. 4- ~~;ell-rm.rkad escarpmnt usuellg sepzrates this up;jer plein from the lov~lnnd. On the lovrlmd squCace, a7;l.zg froa the meins, thsra are occasional gravel buttes, 50 feet or Eore in height, rkich at a distance re- . - semblo haystacks. These are rez'lsded ss reinnants of the ugpar plain cihich hsvs been left by erosion. At the edge of the upper plain tr,ulsitio:l ;hoses betvnen the plateau and the isolated buttes vere noted in a fer7 instances." . .. - - - -. l;...... - . ..)- .- . -.-.> . -.-3:1s, .. :La '2 ..-- --'-. a.. - ., -- . - . . . , - .. ,I .. 2 11 If 11 t,, . --... rgG-"'2 B., S, G;ol. 3ur-:l.:v 2~11.323, >:I. r l. .'. 3arookn, A. v. ' -.' 4colliar, A. J., V. 5. Geol. Surwy Prof. ?a901' ::a. 2, p. 26. 77 . . . - ..--.. ...----. . .. ._ . . ._ - - The occurrence of these isolated gravel buttes aro remnents which indicates that the basin had been fillsd to a much higher elevation with ~rsvelsand the11 rras eroded ra~idly. Tvm fsctors, vhich are both undeteruined and on which mch depends regarding future mining, are: First, rhat is the present depth of the gravels coverins the Kuzitrin lowland and the depth to v~hichthey are frozen? Second, what is the gold content, and its position with respect to bedrock? In order that dredzes mag operate in a valley of this size, the gravels will have to be :vithin the range of dradging depths and contzin sufficisnt values to produce a profit. Should the gold content be near bedrock and beloa the ranse of dredging and in frozen material bu* in sufficient mounts, then mining by shafts and drifts could easily be carried on under proper nining conditions. In the formation of comnercial placers, most deposits have been formed by one or several agencies of concentretion. 'i'rv types are residual and alluvial deposits. Other deposits may be concentrated by the many agenciks over a long period of tine. his the question arises regarding the concentration agencies and the extent to vrhizh they - . . acted within the Kuzitrin Basin. Etrooksl has shovm the gossibility of considerable gold having originsted from the contscts md favorable slate nineralizat ion v,.hich extend east-aest along this structural valley. This bedrock mineraliza- tion may have contributed sotne to the gold content rhrit'ain the basin. The ...... I~rooks,A. H., U. S, Geol. Smvey Eull. 328. -, ." contribution @&the small strems and rivers, rrhich are known to contain gold on the northorn and northvestern side, has added to this a~ount. The writer1 further suggests the _oossibility of the gold content of the great mount of material worn from the Bendeleben l.!ountains as having been more or less concentrated and possibly still retained within the basin. The question then arises as to the amount of concentration. During the very first steps of erosion fron higher to lovrer . (. .-. elsvations, as the different particles brezk fron their original con- solidated positions, the process of gravitation acts, gradually settling the heivy pmticles below the I.i&tar. In novsnent dorm the slopes, the lighter materials on top move with. greater speeds than the hea~ier particlas benoath. Other agencies of erosion, such as rater, snovr, ice, etc,, join in moving the ,~=ticlesfurther on their coursss. As the particles come to rest within a basin the lighter mterizl is above with the heavier belolv. The basin gradually fills and overllo~s,starting - wlth the lighter materials on top, As the drainage systen lowers within the valley or basin =d the water supply becones more abundagt, the deposits of the valley begin to. move into the next loner basin; tho rate . . - -. . - . . and amount of mterial removed degending upon the aaount of vrater, height of fall, and tailing roon for the material belorr. Under some conditions the ontire amount of mtsrial nay be removed to the basin below. These conditions.usually are steep grzdi~ntsand a considezabls mount of action from the agencies. lop. cft., p. 30 on tlGold -bsociated with 1ntrusks and Ectru~ives.~ In considering this Kuzitrin Basin prior to lava flovrs and glaciation in the ~icinitiesof the Bendeleben Range, the drainage fron the area to the north and east vms developed to a considerabla extent. The amount of the gold content thzt vras reno~reddong with the gravels can- not be estimated. Undoubtsdly, the valley must have still contained extensive gravels fron considerable stream concentration at the time the lava flo.;r occ-mzed. Thus, if the gold had concen%rated in the lowar \ - gravels, it vrould ba beyond doubt intact under the lavas, and 'it slmuld be in tho 1o~:rer portion of the gravels of tha Kuzitrin Bssln. In considering the present creeks vrhich flovr from the Bendele- - ben Ilrountains into the Icuzitrin Basin, one would not expect to find gold concsntrstions of ayexbent along then except vdthin the delta de2osits on the valley floor. collier1 arrives at this conclusion, but he also msntions some sluicing on Birch Creek: "Southern tributxies of the Kuzitrin - The creeks floraring into tha Kuzitrin from the south side have not producad gold in comercial quantities; hovmver, the rrriter rws infomed by a prosgector thzt on Birch Creek some sluicing has been done. The pay gravel consisted raainly of deco~l~osedgmite, and the bed rock rims also granite. The gold is probably derived froatfie rocks of the Kigluaik series. The nountains of the Ejendeleben grou~am less rl-~~zedt5an the I'igluaik LIountains, ead there has - bee11 little, if any, glecial erosion in them. If gold occurs in thesa rocks it is nore likely to be concentrated in the gravels of the Bendeleben 3ange thsn in those of the ICiglvaik I:o~teins.~ The trmsitionsl. zone befaeen the high elevations of tho ranEe and the lm:lands, as represer-ted in the past by an area of steep slopes, is novr reduced by erosion to gentle slopes. As shorm in paragraphs on nGold Associated vdth Granitic ~ntrusiws, som gold was deposited at medium lorn te~pernturcssurrounding the intrusives and also a:ith some deposit ion from let or spring action within the grenite along joints, etc. The present surface of the granite of the Bendelebcn 2enge represents the . pegmatite or a higher teol>erature ninordization stege, givirg evi2ence ... - - of considerable caterial as having been v:orn away to expose this high tempereture phase. ?lost of the gold vras eroded. from tho lo~:er ter~p~ra- / \L ture deposits and migrated dovm the slopes. One v~ouldnot ordiilerily ' expect to find cold within the confines of the high teq~er~turegrcnites. The only deposit.ion rrhich does occur riithin the hi& teqerature portions of intrusives of this type is from the later hydrothemif. solutions from graater depths belor4rwhich flowed through the upper zone of crgstzllizo- tion and deposited saxe gold. 'Phis my explein the presence of the gold on ~ranitebedrock and in grwlits sands. Such spriq action is still in -. . evidence along the outer frioge of this range--consider~ble evidence of 6 prior existing springs may be noted in the Fish ~ivgr'mlley on the . . south slopes. Thus, the loYiar gravels of the Kuzitrin valley ?:nuld no doubt co_m_parewith the lower gr~velsunder the lava covered era&. Since - -. - -. they are all contkined within the same bhsin in the sue position xith regard to the mountain range on the south, end subject to the sane agencies, the gold. conce~trztionunder eech sh0uJ.d be slnilm. lop. oit., p. 25 at seq. on "Gold hsoci~tedwith Intrusives 2nd Btrusive~.~~ %p. cit., p. 9 et seq. on nGeopaphy and Geology.tt If, as the miter believes it to be, this history of the bench . gravels on the north fringe of the basin as existing rcrnants of a xuch . . deeper gravel deposition than now exists is the correct interpretation, I a natural concentration of the valley floor gravels should have taken place. The total dapth of the gravels, rvhich existed zbove the present bedrock, vrould be the vertical distance betrveen the present elevztion points of 400 feet to the present gravel surface level at 200 feet plus . I' the total depth from the present surfece to bedrock. The conlmon belief I in regzrd to these gravels is that they are not deep. If the present I gravels should avercge 50 feet, the total depth would hove been 250 feet. Tith the 200 feet of gravel rernovsd from the top a natural con- . centration into 50 feet has talken plece providing the gold had been . deposited originclly on or near bedrock. There mst have been considerable concentration during the deposition of the gravels and the filling of ,. the basin prior to this last renoval of the upper gravels. I I b Sinco this ICuzitrin Basin con2ares to the lava covered arez rdth respect to the lorver gravels, it is considered as the most logiccl for prospscting ~indinvestigetion, since the grzvels are not czpped with . . - lavas. should this sect ion contein economic deposits, then they will 1- i-- lead to discoveries under the lava covered areas. The Inuruk Lake area is that section about 30 miles squzre that surro~mdsIrx.~~: Lake, the greater portion of v:hich hzs been covered vrith recent lzva flow, and mith em3 of lava extending fro= tho main mass and occupying tile older drzinaga channels. These older lava 1. . . filled channels represent the older hainage system fron possibly Tertiary to Pliocene or Pleistocene tines1. This drainage vras developed from a L, . basin v~hichis cor-sidered geologicalljj fzvorsble for the concentration of gold placer doposits2. The lems definitely cover the lorer portions of the gravels ar~dover one-half the total area of this long structhral basin, Since the lavas we clessed zs Pliocere cr Pleistocene, the underlying gzvels are Tliocene or older in age. Thus it is cithin the bounds of asswqtion thct the lo:.rer strata of grzvels of the rrestero , half of the sans structurzl bash, v.hich is not covered mith lavas, is of the sme zge. P. S. Smith3 gives a short description of the lava area and suggests their possible economic value: nThrou&out Sevmd Penir-sulz are say smll areas in hich Terti=y to Recent volcanic rocks have been reported, end in the vicinity of InuruIi Lake, in the north-centrsl pat of the penin- sula, on area of considerrb1:r nora thm 1,000 square dies is covered by these rocks. So rzcent are some of these lavas that the ropy s~wfzceof ths origincl floa is still preserved, and in plsces thay hzve florrsd out over grzvel of late Tertiary or Pleistocene ege. * * * * * "In those glaces the 1273s are old, though from such evidence as is available they are not so cld that they antedate the Tertiary. lliloffit, F. EI., U. S. Geol. Survey ?dl. 247, p. 94. 9t ST!. 02 "2on. cit., p. 9 7f?r?~rlr~nh-r- -"PZC! rr3c!.O?:-." ,-.-...... - . . -.- . - - .. -., -- . 31, r .. -- ?bthormore, sorne of the gravel deposits over vrhich the younger lavas flosr2d contain pebbles derived fion ealier levas. These flows riiust have had very si&nificmt effects on the drainage lines of the region by filling up scze of the strem chennels and c2usir.g the strems to take up new courses elserrhere. 1s many of the old strca coursss else~~herevrere the sites of placer concentrat ion, the det er-nination of the locat ion of those that have been'buried uzc?er the lava might hzve considercble economic value and well repay a search to discover tLemen --: The miter had the privilege of flying over this lava area several times and to exzqine on foot the outer edges in sever21 places. '. L It is not within the confines of this section to describe these laves in detail. They have been described by both collier1 and 1bffit2, as vrell as in the section on ~eolo~.~They represent an area of recent emission \ into the structural basin, apparently froa lmge fissures. They are described as minlg blocky and ropy types emitted cn the surface and covering a large area. They are believed to cover the greater portion of the structural valley which previously vzs partly filled with gravels .. - believed to be aurifarous. The thickness of the levas over the gravels I. Is believed to be comparatively thin. 1ddings4 gives the follmring on leva emissions of this nature: wLiquid- n3,aas rl:hen soured out fron lmge fissures flood - -- A --= -.- .--- -- thesGr0unlir.g countiby with a broad-sheet of lave, like the A- I waters of a lake, often very vdde end coay.zrztively thin. A section 20 miles lorg r.as examined on foot along the southern , border of this lava field. Here unconsolidated soda and biotite smite sands eroded frcn the nunerous granites of the Bendeleben Eange occuyy l~ollier,A. J., U. S. Geol. Suvey Prof. ?qer KO. 2, pp. 30-31 %offit, F. E., U. S. Gcol. Survey Bull. 247, gp. 31-32 cit., p. 9 et seq. or lll~arn.nii.y ~n4~~~~ny-, ------a &---.&*:.'f.~.-,gz, 4. --.-.:,j-- ..-....-..I I -. - - - nost of a long nsrrovl belt along the outer border of the laves. This long narrow belt, due to the pinkish color of the grenite sands them- I selves plus coneiderzble red iron oxide derived fron the recent levas, 8 a2pears es a highly nineralizsd belt, Ehy pilots and prospectozs who have observed this zone fron the air are very desirous of leernine as to xvhether or not it is favorable area in ~hichto pospect for gold. Fronthe air this zone looks very inviting to the averzge Alaskan placor prospector, due to the fact that severzl productive placer ereas 1 I are in vicinities which show these same kinds of grmite ser,ds, howsver, geological evidence in this instance sho~sth~t tho sand belt itself is unfavorable, I - The largest accccnulztion of granite sends is in the vicinity i of Bendeleben This lake is at the head of the south Pork of the , Kuzitrin River near the lorr divide betmen tke ICuzitrin and KO-yuk. river drainage systems. The shores of this 1&e are made us ,of granitic ( $, sands and large rounded pmitic boulders. Due east of the lake a large flat area consisting of granite sands, severzl hundred acres in extent, fills the basin bet.:i-een the lava contact on the north znd the --- -. - . . .-*-.-. -.~ . :-- =, - ~ . -_-.- . ... - -=-.I. . -. -.: . .--- .. ---. . - -. .. -- -. .-:.-.-. - - - -... -. . -. northern slopes of the Bendeleben Range. 1,Iost of the creeks which drzin I=-I from the slopes of this rage carry gmite sads, grulitic rocks, end hardened sedirn~nt~grocks. The hardening of the. sedbentaries was ccused by contoct metzoryhisn in close proxbity to the graite. The sands were parined in vorious localities in the vicinities of Sendeleben - * . . Jake, and upper tributaries of the South Fork of the Kuzitrin end Kopk rivers; In a fevr localities fine colors of &old were obtained, but the amount did nc.t v;arrznt further investigation. Eov~ever,there my be smll buried remnants of delta deposits new bedrock thet nay vmrrat further testing. Geologically, the sand belt is not favorable for tvro reasons : First, the smd belt marks the zone of transition of the ( -- matirials worn from tha high Bcndeleben 1,~ount~insto the low structural valley noa ccbvered s;ith levcs. Gold v:orn fron the disintegrated bed- rock v:ould have migrated dovm into the valley and possibly further along the older drzincge. Second, the erosion of tho Sendeleben Range hes 2rocscded belwr the zone of ninerclization and gold g~ecipitationand the recent eroded sands and rocks are devoid of gold content to any commercial Bxt ent . The grznite s&ds are eroded fron*the nassiva granite with great rapidity in regard to geologic time. Grznife of this tne2 disintepztes into szild more readily than other kinds. In various . -. . . places the sands have covered the leva contact and rest on top of and are niixed with the upper surface blocks of the recently broken lavas. In tho investigation of a lava covered area of this type it will be nedassary to follon pay grzvels dom the old d~zinagechsnnels and then lop. cit., p. 25 ct seq. on ??Gold Pssoci~tedwith Intrusives and 3ctrusi~as.~ 20p. cit., p. 25 et, seq. n n n n w n under the lava. The conditions, vrhich exist at the present time in re- gard to mining and the existence of knovm pay, are such thet considerzble explorztion is needed in the fields around the lava beds and near the borders of the lava to determine the buried channels and their econordc possibilities. The nearest a?proech to mining under the lavas has besn a lea attem2ts with t-mnels and shafts under the high lava rims along the . L Inaachuk Xirer. The Imchul: sub-i"ava Inning Company has in the past ,I , v, L!. I# spent over $150,000 in sinking ten shafts with considerzblc drifting in I ' search of an old high channel. The operation has not been successful. The best values, found in the various shafts, were nearest the rim and they represent a small portion of a hi@ bench concentration vrhich is com?arztiveb low in values as compared to the gresent river bed below, where niniug has been carried on for many years. This creek mining has been mostly successful and nevr developments have good promise for the ! ~turel. The unsuccessful attempt of this one company does not condemn the entire lava section. 111fact it vfould be the lovmr channels and lower benches vihich lead up under the lavas which are zest apt to con- tain the best pay. The guiding factor when follovring the gold to the lava rims will be its black coating on the outside, vrhich it obtained from the highly acid arid black solutions from the hot lava2. kee description of Inteechuk area on follovring pages. 2 w tt w n o w w w The lavns have not been accurately mapped along the Finnell Rivor bf the upper Im.schuk. There appears from the air to be more lava in this section than shovm on plate 4. This section offers one approach tormd the lava area. The Goodhope River ares contains con- siderable lara at its head and repressfits one of the drain323 cliannels along which the lava streas flowed. Upper ;'lade Creek and the Kugruk River ofrer other channels that a?proach the mas. The (-1 Ko;~.~River frm \ Big Bar Creek up to md under the lavas offers one of the best areas for investi~ation, This secl;ion is the most isolated and it leeks trans- portation. The prosgscts znd geologicsl conditions of this upper Koyulc have been nont iowd under geologl. Ths Kuzitrin basin has been discussed izl precedinz par~grcphs. Shodd the under grzvels prow of econoraic ixportsnce and zctivs :lining takes place, it is ass= -.ad thct this section vrill lead the ?.fay for mining under the lava, as this section is the most logicd. one from vrhich to (,- - attack the =ea. At the present tins one my consider this area as beinl; very reraote in ragard to possibilities. Hovisvar, aith the increassd use of machinery and the increasing de-d for placer fields, this area my be investigated soonar than present conditions indicate. 3:ucD depends usou the progress of the industry itself in the face of world conditions. lop. cit., p. 9 et seq. on nGeoga2hy and Ge~logy.~~ * .c . ' This area contains one of tha largest pote2tial hydroelectric deve10'~mmtsites on Seriar? F'eniosula. Inuruk Lake at an elevation of 980 feat m&!?s it a potential source of hydraulic- ?:later for pmr and mining operations, The undeveloped rratsr resources arc described in the section of this report desczibing hydroolactric povrsr sites. -Inmchuk River----LJL-- bainaa~Area: fL The Inrrachuk River is locatzd in the central northern part of the area and drains an wea of approxPitaly 600 sa_usre l~les(see ?late No. 4). It has a length of nearly 30 niles end heads to the west on the slopes of an anticliral structure of' lhlestonss and schists ;(,%ich fom the drainage divido with the Goodnope and Cripcle river drain-,"@es. %e lovter 20 niles and its longest tributwy, Pinnell Xiver, Follo~rthe structural valley betl~eenthe anticlinal structure on the v:est and, the divide with the Kugrui: River on the east. The upper drcinzze has been ', disrugted with lava florrs.unon which nev local drainage has develoced that is so?zlerrhat different than the older pre-lava drains~e, The lo7:rsr section of the new drainage has vrorn through the lava nasses and it no:r - .. conform with the older drainage system bnd with high rim of lava. The old drai-nage systen also contained the formsr lava c)l&mels. It is in these older chvlnels occugied by the new drain& that nost of the mining has been done, The most valuzbla section of the Inr~cl~u!~River to date is that section from the mouth of ?innell Eiiver to the ?oint where it fans out on the lorr extensive coastal plain. An old chmnel near tho present creek channel has been traced over this distance on the left limit of the Imachuk. Othsr creeks of note in past operations have besrl Hanntm, Old Glory and lnericm. It is held by nany of the old miners and grospectors of this section that sll old channel exists above tho junctioa of the. Inmchuk and Pinnell rivers. If such a channel exists, and there is sufficient evidence to suspact that it does, mining or exploration hcs not to dste discovered its exact location. It is possible that this channel is within the struct~l-a1valley end contixues south up to and the lava field and som of the gold found on the lo~lrsrImch;& my have had its source froia the brsin, now occupied by the lava flovs, but orisinally from the Ecndelsben intrusives. There is also considera3le evidence to show that the origin OF portions of the gold of the 1machu.k rlrzs derivsd from tho anticlinsl structura to the v:ast, which is underlain aith older granitic intrusivos lus the younger intrusives, of which ti-ro are repre- i sented by the Xssas Zars and the granite between A~sricmad Old Glory crecksl. It is in vievr of the evidence of the mineralization xhich sho:rs in quartz stringers hyeLnothervjl associztion minerals that the smites . ------A ------.-.-_------1-. -- are classified zs to older or younger. In considering the placer possibilities of an area there are t'hree important steps :: , . lop. ,it. p. 25 ot seq., "Gold Associated with Intrusives and &&sives.- - mineralization; second, there aust be a major concentration to produce economic plecer deposits; end third, the agencies rrrhich h~veaf fscted the' deposits after concentrat ion must be knoom--is the gold rrhere .it vras concentrated or have portions been rewved, or reconcentrated, or covered? The Imchuk ares, 172th the zmount of mining that has been done, offers a vrealth of mterisl for a study of the entire district which may lead to the solution of the various problems nsntioned in this rep0rt.l c' c' \.< The gold contained Frithin Irmzchuk basin may be considered to have been derivad from thea sources: Birst, the hydrothe-mael groduct fron the older grmite, r,.hich is by evidence under the anticlinal structure on the west. The as- socistion of cassiterite and galena on %mu and Old Glory creeks points to a minsral sssociation of the older type of granite2. A smdl . anount of gold is beliaved to have been associated with this emlier type of granite, . . (< Second, the greatgr mount of gold is associated vrith the hydrotherml action fron th3 younger granites. This saction contains -. ------. - ttam smll stocks of t-he younger granite represented by the hses- %irs - - - _--. --L-..___ -_- .= _-__ - -- -- ...- - - - .-. -- and the granite betmen America and Old Glory creeks, There nay be others, in which the hydro.the~d.action penetrated sufficiently to con- tribute to th3 mount of gold, ?hich are not e;qosed oa the su~face, %e3 section on m;ining probls~in this report. Qp. cit. p. 25 et seq., ltGold Associated Intrusives md Zxtrusivas. * -. . Third, a possible source of sone of the gold is *om the structural valley vfnich Tecoived its gold from the nunsrous Eendeleben granitic intrusives. The second condition for placer. concentration is in evidence to the extent that tile older drainage in this structural valley vms developsd prior to the lzva flows on a inuch larger scale than the present drainage. The present river channel of the Imchuk belorrt Pinnell River ('- .- is contained vrithin a partly filled lax vallsy vihich vms made by a river of greater size. This older and lerger drainege no doubt hzd its source within the structurzl basin now covered nth lava. The Piwell River is a con~~ativelydl, and froa its very nature coaparatively young river, rhich occupies a bro~dvalley. Since this ,river does not occupy . - a position directly above the older channels, its ovm creek bed is not particulsrly favorable for placer deposits. 1% is one of those rivers . . with all its tributaries on one lipit superi.nposed upon a wide partly ( C \. filled vallsy where, rather than cut a channel, it has flowed over the valley and finally began tci cut its east bank in which position it re- mains today. TIorraver, within the structural valley older drainzge --- _ _ -__=_-- - --. - - -'.-.--2-f------__- - -- -_ channels are hosm to exist and may oontsid old to the extentof co&nercial importance . The lowar Imachuk River belo?v Lvstic Creek has meandered over an extensive delta deposit of gravels which cowrise a gortion of the coastal plain. This extensire dalta dagosit apge=s to have been built up by a river nuch l~rgerthsn the Inmachulr. The origin of the ex- . tensive gravel deposits alonc the coastal plain has not been eqlained. The surface gravels are of creek and river origin, modified dong the shores by vmve action. Drill cores and. pits to sho1~1the depths of these .coastal gravsls -e lacking. The gold content is also unknovm. Snall amounts of gold have been found along the present beach lines, but not in econonic quantities. The lowar portion of these gravels have not ,. -. 1.. . been tested. As shown under &eologyl, heavily concentrated beach de- posits are not to be expected. The gold deposits, if they exist, would occur as very extensive lox uade delta deposits sli&htly modified by beach action. Smll basins near the present coast or under 200 feet in elevation my contain a concentration as found in the valley of the - a 'Tho third fzctor, regarding the agencies since the mjor concantration, has been the extensive lava flos~swhich disrupted the 'drainage. The present river belov; Pinnell River has caused a sli@ reconcentrat ion of the older concentrat ion. khinly, the ugper old drainage is capped with lava with the central ?ortion of the drainage 7-- - -. -- -.------_-=r -- -- - .- mare or less filled with lava end ssdiment.- ~ueto lack of vGter, the new drainzge has not cut dovm into the older drainage chznnels. The Inmzchuk Rivar below Pinnall conform to the older drains~s,and due to the converg~ncaof the mytributzries, it has fomsd the present gold concentrations. lop. cit. , p. 9 et seq. 2~eedescziption of the Kugruk River area in following pages. In considering the gold content of the delta deposit at the mouth, it is safe to assume that since the river for several miles above contains gold, a part or at least some of the li&ter cold must be contained in the delta deposit. Factors, which point to~rarda gold content in the delta deposit, are the rough, coarse and heavy nature of the gold found on the Imchuk above. YIith all rough heavy placer gold there is usually associated a proportion of light rough gold. This I lighter gold could have been depositsd in the lovmr extremities of the river. ~off3.t~gives a description of the gold mined and its associated minerals : "Cold from the Inz!kchuk district is dwk and heavy, assaying about 3182 to the ounca; altnost no black sand is present, but con- ' sidorable gray sand 07 pyrits is seen in the pan the boxes always contain a large qt~mtityof rounded hemtite pebbles vrhicll the miners call "iroizstonas." The gold frequently contains a little quartz and is sometines seen in the fan of fine veinlats in the ironstones. Sdlpiecas of rutile are occasionally found with the heavy concent~atesand have been nistaken for cassiterite. Dr. Cabell :'kitehead, of the Alaska Banking and Safe &posit Company, has infoxned the t;~iterthat about 27 ounces of tin vrere recovered in cleming gold brought to None from Old Glory Creak, so that the tin ore, cassiterite, mst be present on that stre,m. On the upper pmt of Hannm Creek, a small quantity of galena is associated with tho gold and i~onstones. i.&h of the gold from the Imschuk and its tributaries is coarse end rough. Tieces of the value of $2 or $3 are not uncomon, but no large nuggets have been found." There has been a greatar amount of mining on the Innechuk than on any other river or stream in this area. If mining and e~loration follow up the river, it my lead to the discovery of the older channels which my lead under the lavas. As it continues doumstreaii it may lead to the exploration of the delta deposits at its nouth. 1~l~ffit, 2'. II. , The Kotzebue Pliccr-:old Tic13 of Ser~x~dPe?linsula, Plaska, .- - . Gold \:as first disco-rerad in this section on Old Glor;r Creek in the fall of 1900. This led to lovmr disco-~erieson the loaer Inmschuk and tho other tributaries such as IIann~cz, Perry, Timell, Jsericsn and other craeks. Sone nining was done in the c=ly yesrs follo~~in~dis- covery, but due to t3e er~aticgay, 10i7 grades, a~dthe presmce of numerous lava 3oulde1.s esnd blocks, mining vias carzied on under dif- ficulty. l.'!g of the operations on the Irmch~Cchct-e not been succsss- ful, while socle othe~shave continued. The p~escnt o?orations are In a mch better position thm at an'J tine in the past. .l . , . The Dzy Creek Dredging COE~EII~has mder lsase 50 clair-A con- 1'' sisting of 1500 asres along the Innachuk, nostly be3.0-:I Diraell Ei~sr. This yew mmks the first ye- of operztiox on $53 ritcr for this csn>?.ny. A 3&cubic foot Time dredge has been rehilt and p~tinto @?eration - this season vrith encouraging resdts ra_norted. Yce ~eate?porticn of the creek bo5ton has been nined in esrlier O?CZZ~~O~S,but the olCer (, cl~aur~elon the left limit vras discovered by cozsider~bledrilling. %%is old chmnel pro~liseseven grecter returns tha tha creel: mining. This com2enr is one of the few on Se~ardPeninsule ths.t has sufficient . - - proven grottnd ahead and which has.a mncge~enteqarienced in checkir-$ costs against the values in the ground, The 1nz~chul.ri?ivar, tue to its lsrge valley besin uld hi& rials, lack of tributmies, a;id lo?r srde, offex no oppoztunity far a large source of hydraulic renter. 'This is one of the chisf rehsons f@z the eqensivo mining and also the cause of many minirg failures in the early days. Dredging eliminates the need of hydraulic vat er; hor~ever*, for thawing of ths frozen gravels, vrith the black muck strzta on top, hy- draulic vrater could still be used to advantage. As a solution for vrater in the early days the Fairhayen Ditch was built at-an enormous cost. This ditch starts from a dan at the outlet of Imuruk weand consists of three sections with a total length of 366 nilesl. This ditch hzs been used intermittently up to and until three years ago, but it eras not possible to utilize this ditch alone' for hydrzulic water for tha~rirgat the present rate of capacity. The con,cany punps water with diesel potvar for 600 points. The gravels on the Imachuk are mediux to coarse end mair-ly deposited on a fractured liclsstone and schist bedrock. The gra-rels vary from 8 to 12 feet in thickness and are covered urith 5 to 8 feet 09 black muck, most of which is permanently frozen vdth tundra overburden. Thaw- ing costs are estimted 2% 10 cents per yard vrith dredging costs less than 30 cents per yard. The values of the proven pound on the 1nnachul.k are not horm. The mining in the past had uncovered son8 very high values in localized areas. Drift nliuing along the creek in the early days vms very profitable. The production to 1908 with a short description of a section of the Imchuk River is given by F. F. Eensh~vr2. Iu. S. Geol. Survey !'?ater Sup. Faapsr 514, p. 235 and 8x11. 979, pp. 357-361. Z~enshesr,3'. F. , Kinera1 Iiesourcos of. Alaska, 1908, U. S. Geol. Survey Blill. 379, p. 357. nThe 4 miles of Inmachuk River below the mouth of the Pinnell have contributed a large share of tho production ~ILthis basin, tho total amount to dete, zs nearly as cm be loarned, being fro= $400,000 to ?f500,000, oezrly all of v.-hich hes been takon out by winter drifting. Tho gravel flct in this pert of the river is from 600 to 1,200 feet vrlCe md the de~thto bed rock vzries fron 15 to 30 feet outsido of the rivw cl~annel, The greatest depth, 25 to 30 feet, is in the upper portion, on claim nI?o. lbelom Pinnell;lf be1ol.r the mouth of :'!eshingto:i CreeX the ground is shrtllo:~est, being 12 to 15 feet deep. The channel tha~isto bed rock in saner end as the gravel is moetpy fine and loose, being called by niEers "chicken feedn, there i% a large underflox of water vrliich has hindered open-c~twork of any kind. In the rvinter the river is filled with the ice fomed by the overf1o:qr of the prater from the springs, and under thess conditions the gro~uldhas been drifted, the ice being used es e roof. In so_n!e, plzces enough light cale throu* this coTer to rzke ccndles tmneccsse3.y. "The bed rock is schist ~iithints-bedded limestor,e. Ths linestone seem to have served es e natmrl riffle ~ndcarries most of the gold. It lies in lmge, irregular slabs certeni;ed together with clcy, end is very hzrd to hmdle in drifticg or open-cut rl;ork. Gold is soraeth~osfound in the gravel, but only In the lower 2 or 3 feet." The Dredging end has under lease claim on the Imchuk River belosr the Dry Creek Dredging Company; This con2an.J is operating a 2-cubic foot Flume dredge end a dragline. (; . The dreil&e is used along the creek end the dra~lineis vrorkiag ground contained in the old channel on the left limit. The gravels rznga fkom 7 to 9 feet, and a.ro covered with 6 to 8 feet of muck and tundra, This . -. oompany pior to this year operated the old 31ms dredge only. This year they have new ppumping and bulldozir~gequipment. The drcgline vras formerly used to strip grouncl for dredgirg. It is now used to mine by elevating pzvels from the old channel into elevated boxes. YJith a better and more efficient dredce this co~p~ycould eqwd into the lower delta gravels. ?+' Dick IIoogcndorn is opcritin& a hyZrnulic and scraper on the Inmachuk 2 railes ebove tho mouth of Pinnell River. This is a bench deposit in vrliich the gold is mixed with small molults of gravel, lava p~~k~,and boulders. Ths deposit has the appearance of hsving been carried or sloughed from sono other tee or channel deposit. Mining on Old Glory, Batlnum and other upper tributaries has been internittent and confined to mall hy6rculic operations. ('- - The gold and grzvels are spotty and contain slide material. Due to the existing conditions on these creeks, a sewch for old chmnels is t~.rrznted. These creeks were not visited by the viriter, but were seen from the air at a lovr altitude. They contzin narrow canyons v:hich open out into wide meas or srall basins. 11offitl doscribes these creeks: wIrraachuk--- River - Old Gloq-, on which the origin21 discovery of gold in ttis region c.as nnde, is a short creek about 6 niles in length, rising in the limestone-area corth of the Asses 2ars and joining Pinuell River 1i miles above its jurction v:ith the Ir?- chuk. The vzlley of Old Glory is cut in z series of schists with occzsioual interbedded linastones; it is brocder thm that of Hannum Creek, end is covered vrith a sheet of wash &revel, lzrgely quaI.%, r!hich exte~ds:;.ell up on the slopes. lTear the bottom of the volley the gravels have been much disturbed by tke sliding of -- -- - rock, gravel, and tm&a fron the sides. These gravels differ further fro-a those ebove in the much 1-ger aount of schist which they contain and the decrecse in rowrzed qusrtz pebbles. No pay streak is knovm, the creek being nspotted,n as is Eannum Creek. * llbffit, F. II., U. S. Ceol. Survey Bull. 225, p. 77. wImachuk Eikver - Hmr.m Creek, which flovrs into the I~ch~above the ~outhof the Firmell, has produced a mall amount of gold duri11~the last t~oyecrs. This strem flo71s through a narrorir cenyon-lika valley sur:-ounbed by a rim of - lava and sheeted over with gravels, consisting mainly of schist with ,m&Ller mo~mtsof q~artz,limestone, and leva, which I$,r appear in places as broad tundrz-^coverad flats one-fourth to one-hclf mile long. "The gold is irregularly distributed along the bed rock of the channsl, or "spotted, as the prospectors say; mith it is associated soze pyrite &id s very scall ~~ountof galena." The old chvlnels in this Finnell drainage if found nay offer ___- !.. . , the prospector a gotentiel aree ~~erehis efforts may be vnrth unile./----- Very little prospecting hss been done since the errly d~ysmd this is described by F. F. ~enshd: "Some prospscting hzs been carried on for severnl yeus - under the lava rims which are such noticerblo features in the topography of the lorrer Pimell ad1~~schul.r valleys, =d rr:my interestin3 facts have been brought to light. Pro 012 chanr,els @ . have been located on both sides of Perry Creek near its junction ,. with Pinnoll River. The loi:.cr channel is at least 200 feet in elevation above the river, azd the upper chmel is 52 feet ' higher. In the 10';rer channel there is 3 to 9 feet of pave1 covered with about 20 feet of muck, end this is overlain with (-- lava except ~herethe lava has been eroded array. There is no muck overlying the ugper chmael, and the la~aand grz~elare mixed, a fact rlilich seers to sho1l.v that this channel uiss loter than the lovrer one and rrcs occupied by the strom et the tine of the extrusion of the lava sheet. Pieces of F?'OO~v:ere found on top of the gravels of tilo lczer channel. A log 3 feet in diameter is seid to heve been encountered in one hole, but its relation to other deposits YJ~S not learned. The old channel can be traced dosm the Piimsll fo1lo:fin~ the left of its valley to its nouth. It then crosses the I~mchukto its left or north side and exten6s for 3 OT 4 niles to a ~oint;zSo~e ths Xomestake group of clains, v.-hera it crosses again to tho right. It u~s not learned 7,rhlother nors then one cherael had been locrted in this portion of the valley. Pair prospects mre foullcl under the lava at the nouth of Perry Sreek end also just belozr tke u_opsr .. . crossing of the 11m.zchuk and ne-vly opposite the mouth of ?innell River. It nuat be rem.;nbered thet these chsnnals, vrhich were fourd and slightly prospected, did not offer much to the prospector at that time . Lack of rachinery, mainly pumging equipnsnt, and leck of water discoure~edth~ greater nmbsr of prospectors from working deposits of this typc, Another condition, which is of interest to the orospoctor, is that only a very few creek claims are held and the discovery of the12 channels in the past my be of importance in the future. P:ost of the area on this usjer drainege is open ground at the present time. ---Goodhope Siver Drcinsqe Area: The Goodhops Siver hes its source at the junction of Cotton- mod Creek end Siight Fork. These creeks drain the northaest portioc of the lam plain ad in their lovrer sections have cut through the 1%~ . . beds into the 1inestones.and schists belovr. fro^ their junction tha Goodhope River flo~~sv~est, thence 'it is joined by Esperenza end P1zct.r creeks, thence flovs northvrest to it is joined by Hmbolt Creak, and thence florrs for 10 miles in a northeasterly direction into GOC~~CTC Bay. Its tlraincge =aa is contained in the northern centrel part of the area, see Plete 4. This drainage occupies the wide structure1 kaa> ---.--2 _ - - .--.-- . . j--..- - - --. --= ;-_ -. . .-_--__ ~: ----. --- betmen the enticlinal structure to theaeast of the I~oug~~okSiver ~2 the anticlinel done structure to the t11est of the Inmachuk. appears to heve been much l&rger and developed to a geater extent ;I.<-- to the leva flo-:IS thm at the present time. thin lava follo-ired dovn this older drainage besin. Therefore, it is a new drainage superiaposed upon older drainage, similar in aspect to the Inmachuk drainage basin. Sinco... this older drainage is of the same age as the Imachuk and Kugruk rivers, and likewise originated in the structural basins to the north of the Eeudeleben Range, it is considered I * as a possible poteiltial placer zrea. At the present tine there is only one nining oper~tionwithin the basin, and due to the isolation end lack of airplane fields, the ( .. area was not visited. The f olloTdng information is taken from U. S. G. S. bulletins as listed, reports of grospectors, and from a general I view from the air. This basin is described by 3ked F. ~enst?z:rl: "Goodhope River is formed by the junction of Right Fork and Cottofi~ioodCrcek and flovrs in a general northv:esterly course to Goodhope Bay. sight Fork, the true source of the river, rises in the lava nezr Inurulc Lake, the source of Ku~suk- Iiiter. and flows though most of its course in a rather nar=.ovr cayon; in places 600 feet deep. There are springs in the lsva which 8 oontribute a 1axe portion of the lovr-viatar f 103of the river. Cottonmod and 3;gle creeks enter from the east and Tspera.nzqt, Placer, and Hu~boldtcreeks from the ~mstand south. The lmgsr portions of the basins of these tributzries lie outside the area (. of lava. "Esperznza Cr0e.k is the only tributary on which any systenatic mining has Seen done. Gold in paying quzntity tms discovered in 1908 and the creek was worked in 1909 as far as the scanty supply of water pemittedbn :. . ...--.. The area, comprising the central portion of the drzinnge, I I- I appears as a broed elevated tableland that lacks high uplifted dome areas except on its outer flanks. Intrusives are lacking, excegt those under the structwes to the v:sst of the I~~echuk,and the Hot Springs . . granite area. This latter granitic area Hwibolt Creck, the longest I l~enshaw,F. F., U. S. Geol. Survey aull. 443, gp. 399-400. tributary of the Goodhope Sivsr, is dascribcd under Xot Sgrings araal. There my be snail e-xtrusive areas, like that of the ICougaro4, vlthin the drainage, from which there wy have been hydrothermzl deposi51on that has contributsd sone placer gold. The source of the gold in the * drainage would be from the older drainage ~kichled fro3 the structural basin2 north of the Bondeleben 1:ountains. The only mining operation in this erea, about xhich little is (-' . ' \.- . /known, is a drift mine under lavas on Esperanza Creek by the i-Ioogendorn . ,t5 -.) 4 ' I. Bros. This miningmylead to a definite charmel which leads up under p'I - the lava and vJhish my be of considerable cornercial e-bent. The early mining of this section is described by F. F. ~ensfia:.?: 9lioing ~~asconfined to Zsparms Greek, where r.vrkable placers ware first found in ths s9rir-t: of 1908. 3speraza Creek is a smll strem vrhich drains aa eren of about 20 squzre niles. It has a flat grzde, espscially in Chs lover ?ortion, vrhere the fall is only 5 to 7 feet to the claim, or ebout 25 fset to the mile. The stre= hss a narrow channel winding betrlscn muck banks and its general ap?ear=ce is simihr to that of Candle Creek, The pay streak, so far as developed, lias in a n~rc)~:~,shallorr strip in the creek hsd. :'hen the creek vins visited, on June 24, preparsticns had been made to nine on six claims near the lowar end of the crse;;. Ditches had been dug to convey riater for sluicing and diversion dwhad been put in, Thess ditches tiara - for the most art about a claim in length and viere built with very light- ~ada,but;--aven -then they gave hmdl.fir enough head -to - -- . - - raise the v:eter into the sluice boxes. * * * * * nPlacer Creek, a tributzy of Goodnopa Eiver, below Es- pemnza Creek, v.ns ~rosgectedby shafts during the vinter, but no values wera foud. A hole was sunk about 6 milas abore the mouth, thyoua rmck and ansuls~materid, to a deyth of about 45 feot , where heavy lavs bo~zlders?;era encomtered. "Soxa prosp-xting rras done on Xuzboldt Crsek, r:5ich risss near Yne hot springs rorth of Taylor Crsek and enters the Good- hope about 10 riilss fro12 its mouth. Values v:ere feud, but nothing rich enowh to pay to ~liovel.~ lop. cit., p. 45 ot seq. on Sarpentinc springs &ea. . 29:). 7-t + :, 57 ?+ +?? , -2 ?.:.--..-q -..L ...,-+ ---. T: -,- -, ....,..,. *:J-- 7, CT..-.. " - -- -. -...... L. , :*... , --&-.:.--.*,- . -. . , 5. 2::;*. ------.! 2. .A,.,. . ?. " .., . - .. .- 102 - .. --.- .... .-...... I.-.... +- . *. . . 1 Thus, due to the low grades and the abundance of muck covering the gravels aid the lava boulders, the area did not offer very favorable conditions for the early prospectors. It will be the information gained frdm f7.rture activities in the Inachuk and Kugruk which will deternino the possibilities of the Goodhopo drafnage. The area has not been ade- quately prospected, nor has there been sufficieat mining to make any statement as to its possi~ilities. It remains, as does nuch of Se~ard (: - # Peninsula, an area to be proved as rvorthy or unworthy for placer deposition, . . Upper Koj~k&ivcrDrainn,ge: -. The Koyuk River is situated in the southesstern section of the area under discussion and drains to the southeast into I'orton Sound, note Plate 4. It hcads on the southeastern portion of the huruk lava 0 area and drains the eastern section of the larga structwal valieg on I the northern slopss of the Bendeleben Rawe. The upper 12 miles flos~s CI. on top of the lavas and thence cuts through onto a wide and extensive gravel filled valley. me rigbt limit tributaries ere short steep aroeks , loadsd with numrous boulders end extensive gaitic sands, xhich drain the steep slopss of the range. They are within themelves un- -. - - . -. -- favorabla for placer concantrations. The left limit tri'otltaries *om Iinovles Creek- dotam to Big Bar Creek were reported as containing colozs and fair gold prosaects have been found. Thesa tribut~ieshave extensive gr3vd deposits, indicating an old and 1ru.gsr drainage systen, contained in their short 1. .valleys, cnd the presence of old channels is suspected due to the lo:^ I worn topo~nphy. The uppey I;oyu,t; River occu2ies its formr older valley vrhich in its upper extiremities is filled rv-ith lavas. The extensive * gravels, which shovr at the end of the lava, extend dovm this wide flat vtill.3~to its mouth. me gravels balm the end of the lava are reported thavrsd 2nd as a result ?rospectors have ~assedthem u? for frozen ground which is more easily prosgected :dlen pumping equi9men.t is not available. The origin of these thawed gravels is discussed on pege 18. The Kopk valley, as coxpared to the Kuzitrin valley, is more confined to limits and one r:ould expect the pz'~to be nore confined to one pay channel. There is son? evidence of glaciation as shovm in the valleys of the sd1tributuies frola the Bandeleben ,Sage to the south. The small alpine glaciers ray account fo=. considera~leof the extensiva -gravel deposits vrithin the valley as v.~llas mo':ilas and Big 3ar creoka. The e-dent to which glaciatio~lhzs influenced this valley is not knovm and further study is necessary to determine the effect of glaciation upon the gold concentration. Gravels under the lavas are definitely ho~mto exist, as mentioned by ?.!of fit. 1 The existence of the Iocene Tertisz.1~deposits, the close proxinity of the Eendeleben granites, and the outlet of the b~uru! Basin, all saint tol:.wd a favorcble possi5ility for. potential placer deposits in this are2 :~:hich as yet reneins to be groven. ll,foffit, F, E., U. S, Geol. Survay 3~13.. 247, p. 32. Kugruk River Draicsp;e -4rea:- The Kugruk Rivx drainage system is located in the northeast section of the area shovrn on Plate 3. It drains an area of 700 oquara miles. Its length is over 60 miles of which 45 miles is belovr ar, eleva- " tion of 200 febt and appears to be a more developed and older drainage than the Imachuk and Goodhope rivers. Ths upper 10 niles of its head- waters, from Imuk lake and then across the lavas \*ere it has cut a deep canyon, has the most fall. The largest tributary is !':'ade Creek which has a paallel drainage to the v~stand it joins the Eugruk 10 miles abo7c its mouth. The underlying structure of the area is vie11 shotvn by the east end mst and north and south vrate? coursss of this drainag.e sysf en ~r5ichfollo~~ structural ~~sat.=essesresultirlg from the t~vosystexs of foldi~~l. The writer fler:. over the entire tt-ziot?ge =ee. of the Eugz*ul-: and covered a1 me2 of the central gortion on foot. Smer tyrrelin& conditims, due to nigger-head mashes and lack of trails, is very dif- ficult on foot, adas a result the uppr drzinzge of the Yikgruk vas not covered. z &------_------.-- - This area contains three s~&Ll inirusives Gich v;ere reported by 2rospectors to be in close prozisity to the 2oceae2 coal beds and sedbsnts vrhich occur in this drainece arm. Go15 hes bsen found on severzl of these upper tributmies, both in the creeks and on 1017 benches. lop. cit., p. 22 et ssq. on Structwe. 2cP, tit,, y. 9 sf --r+. Cr ~52--~.-.--. --a ~%?:n-,-, - - _"--- -.. - - lloffitl mentions the occurrence of gold beering gravels in the valley of Dixie Creek at the head of Independence Cre6k. Independence Creek has a length of nemly 10 miles ad it joins the Kugruk Piver 6 miles above LIina Creek. Holtz Creek, .r;hich is nearly as leg@, is its largest tribubary. The upper tributzries of Holtz are Spruce and Reach LI creeks v:llich head in the vicinities of the s-mill grenitic intrusives. Prospectors report colo~sin all these creeks, incl~dingthose on the [. right limit of Independence Creek. Eoviever, values sufficient for crork- ing by had methods were found only on Dixie Creek. The lox flat benches- along both Indepsndence and Roltz creeks were reported as containing the best pay in conparison to the river beds. Indepmdonce Creek vias con- - .. sidered during the years 1914-15 as a dredging area and a dredge cms con- tenplat ed, es mentioned by &oo!ts2: e - "In the Fairhaven district four dredges were in operaticn in 1913, and eech hsd a fairly successful serson. One of these' vms on Candle Creek, one on the Ku~uk,and tvm on Imchuk Ziver. The Kugru_k dredge v.as installed in 1913 and operated for nbo~ta a . (.- . . month and a half. Other dredges vrhich are ?lamed for this region rnay be installed in the near future. Representrtives of the Dearborn Investnent Co. extensively yospected the company's ho1dinj.s on Kr.gruk 2iver last season end expect to instzll a dredgs in 1914. It is also reported that bother con~enyviill put a dredge on Independence Creek, a tributary of the Edgr~k.~ . - Thus it will be nated from this short account of mining ac- tivities on the Kugulr prior to the i'iorld 7k.r that three dredging areas must have been estzblished. The extent of these developxents is not knovm.' The increase of prices vhich accoxlpanied the Tar conditions of those yeuz apparently discoctinued plms for the proposed &edges and suspended activities at the operating dredge. Since that time there had beon only srrall attempts at mining until this year. The present operation of the Kugruk P:ines narks the first major attoqt to mine rvithin this- basin since that the. C Due to the inaccessibility of the upper hrainzge oP the Kupk, it has not been prospected to any extent. There has been somnerl&at of a change in dreicage. A very low divide betveon the headrq.raters of Spruce Creek and Dixie Creek with Kno~;les end Big Bar creeks , respectively, the latter beixg tributaries of the Kogylc 9iver to the south, suggests that there nay have been a change of drainage and that a portion of the present flovr was at one tine into the KoW River. This upper drainage, as reported by prospsctors end in the geological reports, contains some very interesting geology. The presence of lignite coal beds, as mentioned by ~zoffitlon ZrencL Cresk and reported on Po14z and other creeks by prospectors, is en associete that is found in many placer districts of AZas1:e. These Tertiary fometions, or Zocene beds2, are also found along the "10~:er Ku&ruk River frcn llontene Creek dovm to Chicago Creek. At both occurrences it has been reported that gold hes -.. ... been found resting upon the coal beds. The coal beds are not con- sidered velucble as a fuel due to their irqwities, frozen condition, and low fixed czrbon content3. Due to the tundra and covered bedrock in this upper drainzge =on, these Tertiay sedirents viere reported only in the 1~offit,F. H., U. S. Geol. Survey 3ull. 247, p. 67. kith, P. S., U. S. Ceol. Surrey Prof. Pqsr 192, Dlate 1. %offit, F. H., U. S. Geol. Survey 2~11. 247, p, 67. .. . . -. creek beds and tho surface extent- is not kno~m. The coal series are folded, and as a result fractured, and in close proximity to the intrusives. The main Tertizry intrusives are believed to be younger than these Eoceae J. B. lifertie, ~r.lhas classified these sediments and intrusives by their mineralogical associations in the Yukon-Tanans Region: "Terrigsn0u.s deposits of Socene age then gredually accuvu- r \ . .. -- lated in such vide valleys, under conditions favorable for the formation of ?eat7 deposits, from ~*ihichthe Eocene coals subsequently derlvzd. The great thickness of these Xocene de- posits, hovrsver, points to a gz-adual subsidence of the region in the lcter statss of their for~!mtion. "Later in the Tartixry period, after these terrigenous de- ' posits \:.ere forraad, the region vns e~alnuplifted, folderl, and intruded by ~zniticrocks. Tnese intrusions gave rise to a second period of gold nineralization in this region and furnished the source of leter gold-quutz veins, tho deposits of cinna.bar, and most of :ha tin deposits of the region, particulmly those in the vicinity of Hot Springs. It is also prob~blethat new highlvld araas were fomned during this Tertiary period of orogenic . disturbmce, and that the stream r:ora rejuvenzted, initiatirrg renevrzd and lons-sont iinaed erosion. "After the Tertiary granitic rocks were intruded, the old and also the ne:!rly q~lictad highland areas vEre propcssively eroded for a long eriod of tins and viere gradually reduced to a mturely dissected lad surface, This aeriod of e~osioncontinued v~ithout interruytion until la$e Pllocene tine, v~henthe country rr,s ~ain regionally uplifted. In the accelerated erosion that follo~:red, the strezvs vrero incisad in their old valleys, the high ter- races desc~ibadelse~trhere in this raport Ticre foned. Considerabla warping of the swfi*sce dso took plzce about this tine, or a iittls later, thus creating anormlies in the drainage systems, some of which heva persisted to the present day. Phile there is no kno7:m evidence in this section to prove the reprsscutative agas of these intrusives in relation to the sediments, there is the mineralogicd evide~ceof the association of tin concentratss and l?d~ertio,J. 5. Jr., U. S. Gm1. S7;rv~:j5!111* $72. 2. 236. the rock types on which I.%rtia basos in part his ego classification. Follovsing the erosiozal pe~ioj.which follo1::ed tho deposition of these sedhents, a considerable =aunt of these 3ocene sedimsnts must have been worn avmy. Either intrusives of this aga vihich my have cone in .-*-_ . , . . , contact with these scdirnents, or the hydrotherr~alsolution; v:hich con- tacted these sedinszts, are held to have precipitatsd considerable of the placer &old found in this md similzr Socene areas in Alaska. In , ,: . 1 .. .--.. .:- 9,- ...... -. 8evezal areas in Alaska1 ::hem both Eocene sediments end younser Tertiary int2usi-~2sare found in clos; associetion there have been later l~va flo~~rson to? of tile scdinents. Xydrothexml solutions from the lava mwas ray also 5ave contributed to the gold su2ply2. The presence of cassi3srite in the gavels of Dixie and Indepcnde~cccreeks is reported by prospecto~s. The presence of yellonish sands in Spruce and Holtz creeks gives some evidence that these grmites in the u?gar drainage are a sods granite tme and possibly of Terti~zyage. A few days of L field work il~ithinthis mcs rrould substantiate this evidence and add to the possibilities of' the area. There is no evidence to bs found shoving ,, ,the direct pracipitation of gold in the Eocene sedinants from the hydrothervlll solutions originatins in the vicinities of thesa panites, although this is z possibility. S%ould this evidence be found in the field in the I'ut~t-c, it will throw coilside,-able light upon the origin of the gold and its as..;ociation within the vicinities of 3ocene deosits . , -- -*.'. .. - ', ...... +.* .. . . :- , -. and Tertiary intrusiveu. .. l.ferti.01 has pointed to the conditions in vrhich these Eocene or Tertiary degosits r:are lsid dovm: "The osrlg Tertiary rocks of Interior Alaska, unlike the marine ssdk.cn:s of the hksozofc and Pelmzoic, tend to haT~c3a line= typs of Cist~ibution,sugsstive of sncient drzinage ch~nels,~cad in sonie aces such line& distribution coincicf.es roughly with mzjor strem valleys of the present dzy." This condition v,as folb-mdby small intrusives that caused gold depositicz and cl3ucted somevrhat the sedinentg in close proximity to ths intrusives ~rhlch,due to their position new drainzge channels, .. . . . accou:lts for tlle3.r r21)i.d erosiou and lack 02 exposures nea the in- Smll basirls, es coted frox the eir, exist in this sea an4 are trzve?sed by the vzriouo tributaries. ?bile inforrztion is lacking regarding this qper &oir.age, its potential ;ossibilities cwot be asccrtoined. conGitjons, as fer as roted adobserved, epped to be sulficientl.~fzvorzble for further prospecting end more detailed exm-inct icns cre r..nrrant eC. The lo~ii!~drai~~age of the ICugrvk offers nore inforxaticn end while minin~hhes not bssn pa-titularly successful, it still repains as one of ths ix?ortznt gotential areas of the district. From the mouth of Independenca Creek to the mouth of the I Al1,the tributaries frora Independence to Chicz~ocreeks on the ri&t limit occupy r.ride valleys and contain euriferous grzvelsl. At Chicago Creek the Ihpuk River makes an abrupt -turn. to the west, leaving a wide valley basin, znd occupies a naro:v nev cut channel across the strike cf the forrutions to tho mouth of :'lads Creel;, its largest tributmy,' The prospectors in the vicinity have expressed their opinion thrt zt one (-& time the river continued in the direction of Chicago Croek 2nd erqtied into the sea in the vicicity of Ca? or Uder creeks. This is based cn holes sunk in the vicinity of Chicago Creek and the gold found in Alder Gulch. ~ensha\rZgiyres an,account of cne hole sunk in this vicinity and a short sum=y of the early mining: The o-nly nine that has produced my considerzbls aount' of gold is on Disco-;erg claim, on the Kugruk, a short dist;errce &ore the mouth of Chicego Creek. At this poi~tthe river velley has a width of zbout a mile md tho chamel, rtnich lies on the ezst (. side of the valley, is about 200 feet vide. The degth to bed rock on Discovezby clein is only 12 to 14 feet, including the over3urciez. The pzy stre& is crescent shapd in outline and necrly a claim length fron end to end. At she aoints of the cresceat the gold is fine; in the =ifidle it is coarse. The ~roductionfrog this claim during the winters of 1903-4 and 1904-5 is said to have mounted to $150,000. Its success led to nuch prospscting in the ' vicinity end o1*01* 100 lioles issre sunk to bed rock vrithout ficdirg any values. One hole, three-fourths of a nile from the river md a short distsnca above Diszovsry clzin, is of interest in showing the great depth of ice and ~ucksonletizes found in this part of Sevmrd Peninsula. The follv:~ing ssction -$,asfurnished b.j the prospector : lkffit, F. H., V. S. Geol. Survey D.11. 247. 2~enshav7, F. B., U. S. Geol. Survey 311. 379, p. 361. Section three-fourths ale from Kwuk River, near Discovery claim. Feet Clear ico...... 26 Uuck...... 60 Reddish gravel ...... 8 Eb~ke.....*...* 3 Bluish gravel. . : . .... 10 Schist bed rock...... 11 Drill records of the Ku~ukI,2ines, Inc. of last yeer show the valuss as continuing from the Kugrub- River just above the ~outhof . Chicago Creek onto a 304oot bsnch and extending in a northezstern direction. "9 crescent shap5 of this gold deuoait iodicntes z developed bar deposit. r Bvo types of granite were fowd in close prox~tgon the left limit of the ICugruk River betviean the fiouth of Independence Creak end Goldbus Creek. The granite noted ct the e~ouihof G~ldbugis interceloted in graphitic end liw schists, containing some quartz and high in.ferro- magnesium minerzls, it is classified cs e diorite. The min mass of granite to the south is classified by ~sffit1 as nomonite. The greater portion of the gold found in l;ina, E'sntane, end dovm to Chicego creeks, is believed to have originated from this nonzonibic intrusive. At the - --- ..-.- -. -. . -. time of the monzonite intrusion, it is within the bounds of probability that it cae in contect with the cod msasures, which ere above cnd below at the present tirre, on a strike vrhich ,aaurellels this intrusive. Since then, through erosion, this zone rras .:ioYil av,~and the gold de- -zz; posited in its present positions. ?ðer or not the Kugruk clrainag5 . 7. -- -f*>r * . .# fit,. . , u. S. Gsol. Survcy ?.l2111. = 57, ?. ??. had an influx of gold from the buruk Lake basin has not been learned. Prospectors report colors and extensive gravels in the upper cmyon of the Kugruk where the river has cut through the lavas, exposing the gravels underneath. Should econonic rilues be found along this cznyon, the location would be favorable for follovring the pay channel under the lavas. On Wade Creek end its drairage a srdl open fold valley exists, f- - . - - dorm 'which considerzble lava flovred. Lava rims ere quite pronounced, as observsd fro3 the ~ir.Frior to the nea chamel cut by the XuguE: River this creek no doubt flovred out to E'btz2bue Sound as e separete stream. Its valley is 1077 snd vide and is extensively covered ~ith ------4 . -- gravels. These gravels have been oriy slightly _~rospected. Colors were reported, but the extensive anount of lavas has Ciscour,,*csd nost prospectors. Its upper tributaries flo~on top of the lav~sand in . places flow under the lavas. During the constyuction of the Bairheven (. . ditch, an underground yasswe into a sink hole on qger 2ade Creek ras utilized. The vrater vras thence diverted fr~a:lade to the Pimell -_--_-_Z-=- - ---...... :-- -. ,,& a . - -- . - dr~in%sel* -- -. ___- ___.. .- . - _ . --:. . . _IA.- -. . . - __ . . .- . __. - .-. ... - .. - - . . .. . - , ., The Kuy~ktunes, Inc. is a neir operation which bagen work this season. The site of this oqeration is 1% miles ebore the mouth of C'nica~oCreek on the right l3mi.t of the Kug-vk 9iver. This ogerztion consists of bulldozing and hydraulicking to e hydrzulic lift;, and bull- dozing tailings. '.'!atex is supplied by diesel povered pups for the hydraulic and the hydraulic lift. This makes a very expensive operation. A coFon 206 of the deposit is one foot of tundra, six feet of black muck, and ten feet of nediun to fine vrell vmrD adrounded gracels. The bedrock is frzctured linestone. 4 The deposit is frozen from top to bottom. It is thovred by removing tur~dra~rith bulldozer stnd thence natural thming by repeated removal of th2::;:rd rcterial with the aid of buJldozer. The gold is mainly I '.- on and in bedrock vrith..a small amunt distributed in the gravels. The various types of gold found suggest a deltz beach deposit. First, the greatest mount of gold is roua with sons wire gold. Second, soma of the worn roundnd gold is oblong in shape, scggesting vmve rolling ection; whereas other rounded gold has e round flattened shape. Third, soae of I the gold is stzined rusty to slightly black, ~u~gesting,that it vres deposited in desd water. The associated concentrates are nkgnetite and considerzble oxidized pyrite. The fineness of the gold vms reported as 900 plus. Fron the drilling operetions within the valley, good pay yes . . reported across a width of 600 to 700 feet. Holes r,:ere placed 25-- feet -..------.., _ _ ------.=-- - -A _i- ___L_ apart in drill lines 500 feet apart. A totel of 235 holes were drilled on the rivor end 70 holes on Coffin Bench abore Chicago Creek. The conpny has 12 niles of pound, gat of vrhich risls stzked 2nd the reminder leased. This basin deposit at its elevation from 100 to 200 feet above sea level is balioved to heve been thb mouth of the Kupuk Rix-er jrior to the last elevation of land. The basin v~sfilled ~11thgravels of stream origin which v~eremodified by beech ac$ion. This same situation is now in progress at the present nouth of the Kuguk River near hering. The elevation of lend and the retreat of the sea to its present level accounts for the Kugruk River's new channel to the west, to vhich Yade Creek with . . 6- . its present mciuth in a similer bcsin is no?! joined. The gold deposit at Chicago Creak and above is in part bench and in part delta deposition. .# The overfl~:r'h.ozl the basin nay be contained in an old buried channel which connects up with Alder Creek, as the prosent drilling and log of' hole, page 114, indicetes. Further mining and drilling considerably enlmge the scope of inforution regarding this c~ndition. The present operation, due to high costs and the mount 'of handling of the material, is a very expensive type of operetion. a- . ( ploratory vmrk, such as d&illing, is recornended until sufficient groud on the river bed is definitely proven for dredging. The bench deposits may be worked by bulldozer and hydraulic, but to operate a hydreulic lif't in an area lecking good grades and natural hydreulic rrater as call as the lack. of tsiling-drainage is a very imprccticable luethod of mining. The extent of auriferous gravels on the Kugruk drainage is verr extensive but before definite limits can be esteblished regerding then, considereble e~loratoryv:ork in the form of drilling has to be done. Along with the development there will have to be nevrer and cheaper . . . . ~~~~03~".c...+-. .- ,--> -,Sniy- .- - + -. .-', . . .-.- .-.- .-.----:+-0 r. .- ... - b .- ._ . . .. _ --...-. . - . - . .--- L .:. . .: .,,- u l .,';a , .. .^-..-. . _ . I .- 8 Past. 1 1. . ~eolo~ical,with Becard to Present Position of Placer Deposits : 1.f i The mycoxplex conditions under which placer deposits are .a formed, such as the various destructiv6 agencies, the renova1 agencies, I and the agencies which tend to cover up and hide these deposits, are numerous within the area. A complete knoviledge and understanding is beyond the scope of hum endeavor. ETovraver, it is withir, the scope of (. ' " ...- - .. . . I most efficient niniw coin_oanies to obtain much information that is i available regarding tho geolo~icalconditions in their particular aree of operetion or contoq~latedarea. The rapid depletion of the known placer ground by machinery and the lack of prospectors places the problem of locating navr ?later deposits directly upon the operct ing official or ,. engineer. He cmot ju~pthe hurdle of exploratory expense from discovery I, to ground proven to be ready to be mined at a profit. The cogst of ~I exploratory work must be assumed to some extent and accomted for in i the later nining costs. ' Thus the logical procedure is to gather all forms of information and to proceed alox definite lines with every sossible aid for the discot-ery of new degosits. ..--,. . The various conclitions so far studied and those contained in this report are by'no mans final as to the exact location of the placer deposits. This problem still exists and will continue to face the operator. . . This report is only m attempt to shovr the possibilities, nunerous problems, and conditions of the area with which the operator nust contend, adto direct efforts in the futurc along lines to procure the best results. Tne miter has shovm thet the deoosits are*contained within th6 structural valleys. The prospector, operator or engineer is still ieced vrith three -. . , probleru, the solution of which vrill neen the expenditure o" ccnsiderzble exploratory funds, as: First, the sections of the slructural besiris ;;hic3 6t.. have retained the greatest mount of gold concentretion; second, the tse and limits of the placar deposits ~ithan estimta es tc their arercg? gold content; and third, the loxest aount of gold that can be contsinad * per cubic yard and still be vorkcd at a p~ofit~rithin the section. As- sociated with this rill be the uie of mining nethods for the reduction 8 of' costs, and a full knovledge of' eccnoeiic conditions :.:hich are likely to increase then. -. Wth the small sxount of doing in this erea as a ?f?ole, 2nd t' '.. the meager anount of infonation available, it is not dlfiriit sly show which proviace is most likely to contain tha peat-r portion df the gold - - -- deposits. There nay be a graatrr a;uunt of gold on ths cocstzl irovi2sa in low grade gravels so extensively sho~.m along the gressnt coast, :p.+?ich . . may, under large capacity o?srations, mke for lmgs _~roduction pad s long-life industry. The greater mount of deposits ray be in the structrwal valleys betvrson the coastal plain urd the struct~zal bash . to the north of the Bondeleben L:ountcins. This section yrould give a higher grade deyosit vrith moro confined channels and less overburden. Discoveries within this section viould be nore easily made and mining would be less e~cilsiveond requira a smaller mount of capitalization. This saction conTzins nost or the nin&ng operations at the present time. Higher grade delosits my be fomd confined to chhnels under the lavas in the large structural basin area north of the Bendeloben Range. Sholild they be discov5red the problem of nining under lavas viauld "'necessitate rwre cost1J mininz nethods. The solution for locating the placer deposits lies in the us3 of all knorm infwiaation ancl all zvailable mthods for obtaining other necessary data. Aerizl photogcphy is one ~ethodby vrhich considerable informtion could be gained rsg~zdi2gthis area. The study of acrid photographs would do nuch to defi~ethe limits of the oldel channels and to give s mxil lwyer p~~?ecti~eor the vihole ares vrhich canndt be gained in other mnner. This is one duty of governlnentsl egenci3s which would detha infcxx&tion available to all concerned. First, it directs the sttentio~of the p~iblicto the 'area; md second, i.t es- tablishas the necessary confidence for the e:~enditureof private capital in exploration which the entire Territory of Alaska is not novr able to do. The average en~ineeror geologist xho is called upon to make an examination in a section of this tyge is usually not inpyessed vith a group of clai~svrllich, rhea vievsd, appazrs as a monotonous expanse of flat and frozon tundra. He has first to vievr the entire section as a whole, to s%udy its possibilities adthen to conpare the particular claim goup with others and to locate its position with regard to the major features, end likely areas. In &der. to do this it is essential that he havz an actual picture of ths v~holesituation. This is possijle through aerizl photopsy5s. Thus ho is enzourzged to mke his ovrn detailed and large scaled mps of proaisin~sections. This vrill reveal detailed . - t inforition as to certain bench deposits, old channels and other physi- cal condi.Lions vlirici when folload by actllal drilling will define the limits of e~istinteconoxic plecer deposits. Further geological study into the solution 02 the various problem mentioned in this report would be a great aid in discover&g and in developing slacer deposits. This is a much bet",? olicy for the Fedaral Govsrruilent to undertake than the present policy of waiting for discoveries to be mzde adnining v~ll advanced before geological work is attex-ted. Prospecting md "uve1onin.t 2roble-.s: ----"- 2 The Izck of interest rz~ithinthe eea, vlfiich has graduslly be- . . . . come 19ss since the ezrly days, accounts for the lack of pros2ectors md the srrall mount of pros2ecting. Climtic and ground conditions, to- gether with insufficient rater and hi& costs, are son3 of tha ressons for the extent of the wgrospectzd zrsa. The older methods of _orospact- 1% were very inadequa-l;e for this t~eof an area. kck of fuel for thawing and cam2 usss, deep frozen pmels, considerable frozea mck, and lava cappings sounded rather difficult for the early prospector. Because of the lack of interest and active prospecting within the area, prospecting and e:c?loration vrill have to be carriad on by' individual groups adequately financed. . The moun't of finance must be such as to ~OUOYIup to the acquisition of staked ground and'for additionel staking follo~vedby extensive drilling to prove areas of my considerable extent. Transportation of sdlparties to the area vrith Waited equip- / k- nsnt may be done by airplane. Ho~rever, surface trmsportstion vritliin the area vrill be limited to overlaad trans~ortationby cztsrpill~. It is necessary to transgort cmg equipn~ntnnd supplies by nechmical means due to the niggeriead tundra which is unfavorable ,for packing and the use of horses'during the sumar season. Furthsr, ths equipmsnt necessary for drilling would require power for o,?eration end a means for transport- ing. The lack of trails, roads aad airfields mkes for independeit transportation. The present airfields could be used as a base for sup- (. plies which betransported bg plane fionP,Torne at costs or 8 to 10 cents per pound for dllots. Once an ares is located, where a more or less - -pemanent camp is to 5e established, airfields czn be easily constructed with the aid of a bulldozer. Geophysical methods of grospacting for bedrock depths, and for the location of the older channels and metalliferous concentrations mi7 be utilized to advatage. '&is msthod, which is more or less in the experimental stage, falls under govermontd. activities until established principles have been vorked out v.hicil will be to the adventage of the With regsrd to the building of roads, trails and airfields, this is one field of activity on Se:lrard 'Peninsula in which the Government is at the presant tine cooporat ing to the mllest. extent. extravagant in one forn and entirely lacking in others, is not the best L policy for the developmnt of nev regions. Thayifi.ng of Frozen--- i,:uck and f~av*: c- The greater portion of the deposits thus far mined, drilled, and kno:*m are pomanently frozen fron the tundrc to and ikcluding the bedrock. This is a burden that, vhen added to the cost of actusl mining, Is the second largest itez of expense. Thavring costs vary fron a few . cents per yard to 15 or 20 cents, depending upon available water, depth of ground and various other physical conditions. This cost, as compared with various costs of mining in the States or operations in tropic331 countries, is even greater than the mining costs alone. The direct cause of many minirg failures on Sevrard Peninsula has been underestimting this (., (., cost, or failure to pre2are or thavr ground in advance of operst ions, . or to depend too much upon nztural tha~ring. -- - - .- There are various methods of tharring norc or less dependent on natural tha~ringor the application of cold water tha&ng. me mathod is usually governed by the de?th of gravels and frozen muck in accordance nifh gredo, the availeble water, end tailing disposal. ' A conbinstion of methods also is governed by conditions. Stream gravels which are not covered v~ithtundra usually thav nomally up to 8 feet in depth, A muck and gravel coubinotion up to 10 feet in depth, or 5 feet of muck on top of 5 feet of gavel is best tha~adby removing the tundra end muck with bulldozsr. A conSination of 15 feet. of muck and gravel, with gravel not over 8 reek, is best tha~redwith bulldozer and hydraulic. Gravels over 10 feet me thawed by points, end an accmulation of muck and gravels of 20 feet in depth nay conbine dl these nethods. The black frozen muck (, [. thaws more rapidly rrith hydraulic and bulldozer methods than with points, For grav6ls ova? 8 feet in depth the use of bulldozer and hgdreulic is slovxer and more e~ensivethm points. Eoi8i~ver,there are instmces where the reverse my be true, The t7;fo most expensive mew of thaw ing are where bulldozers are used in large pits to bulldoze frozen gravels with little or no mter, and vhere hydraulic vister has to be continuslly pumped for hydraulic or for saints. . The developnent of cheap hydroelectric po!l?er within the area t would reduce thmriilg costs. Pumps could be opercted by electric notor for hyilrzulic vmeer and points used in thewing. Electric power would. be cheapar v.;llen co~n_n~-edto diesel govrsr, men its oil hes to be transported, or the ureiat of the ?ovrer equipnsnt it self. A system of thm~ingvdth electricdly charged goints v~ouldbe within the real3 of possibilities for tha~rinsmc!c end gavals if ~bundmtelectric _oo7irer should be available, .qcI-L-' '.. Another systeln of nstural thaxing which may come into comraon -. t?- : , practice is that of thalring by lateral system of ditches. This systen is adaptable vhere the deposit exists as a bench or high channel deposit i r:. covered with considersble black frozen'mck, or where there is sufficient -l:." . - - grade for water to carry a hezvy load. The v:cter is led to the top of the ' . . . . .,>,:,. ; -, deposit by ditch, t3ence the tundra is bulldozed off. -11 parallel ditches are usde vi-ith a bulldozer attachment consisting of a V-shaped c- '.,~4$g~'.,:~ .= ., . - . sharp-pointed point. Ore is attzohsd to each end of tha bull?ozer and /.,.- /.,.- -:- snsll ditches arz constructed pzrallcl to the grzde across the vridth to -a !{- : 2 be thavsd. Thence r:ater fro11 the ditch is controlled and equal volucles :r!:tt: '%. : are proportion21 to each ditch. T'fie rmck, which has a content from . ., . 50 to 75 per cent ice the rarnaininy 2ercentsge in fine sad, vege- " riil, ta5lonC ~nzttterand silt, begins to relt end increases the voluaa of vrater ykifila;; ,: , which givas a directly 2roportional increase to the caount of t3ay!iing. The vmter content of frozen gravels werages 25 psr cent. Too much grade ,<'l~lI. 6,: c,., (< ceusss a quick run-off azld too lo^ a grade does not reaove the material 1 cyt- tl *r block of ground o7er a period of years is the slo'~(;est, but the least expensive netllod of thaxing, an it requires the least amount of labor, A. H. ~rooksl,states the po;sibilities of placsr mining in frozen araos in his summary of dredging activities on Se~rardPeninsula in the yes 1915: "The cause or the decrease in production of dredgs gold is .not clear, as thsre are kno!:n to ba large aress of auriferous gravels on tk~)psninsula ~hicha2yar to be suitcble for Profitable exploitation by dred,i.,es. Ore reason, hor:s~er, is thkt rnost of the successl"u1 dreclges ao_uesr to have work.red on ~lacersof rather high grade, end tksir success h23 besn due to this fact rethe? than to econonicsl nininz by larga operations. Little atteast has been made to aork the gerramsntly frozen ?lsce~s,as has been so suc- cessfully dcne in the Alaska aad Cznzdian Yukon. * * * * * It would sszm that there is in Seviard Peninsula 2 field for strong cora?an?ss that could introduce ecoaonies in the operation of dredgin~ thal:rins. " The frozen tundra, rnuc;,: and gravels offer sono ninor advanfages which are vrorthy of mention and vrhich in some respects offset the costs of thawing as cozgared to ogerating in tropical or heavily ~vooded areas or in clirmtes of heavy rainfall, etc, ha to the frozen condition of the -- - - .- -. tundra, forast ---~r01:Tth is- lacking end ths frozan ground offers. ~ solid . .- . .- -= -I---- - .- - -, ------.. . -- ...- --.: .. . . . I traction for cate~nillarsand e means of overlad transportation vihicb , I~ elidnates the cost of road building. It further offers an adventage in teat pittin es mss ara not ~equiradand c,-iSbing of shafts is un- necessary. Its lugest adv&?tafe is in drilliri, as cssing is not l~rooks,A. H., U. S. Gaol. Sux9vay Bull. 642, p. 70. necessary end the frozen y.al1s offer very accurete volum checks yrhich eliminates riiiiy iinaccuracles. !'lhilo tha~ringcosts ere high, these are somewhat offset by clecric~cnd ejcpensive bulldozirg costs in arees df dense forest go1rt;h. . The actual mining probless x-hich face the operator efter de- posits have been drilled and. tha~redare n2ny. The lewth of the in which operetions cul be cmried on in this region, dve to co16 clivleic conditions, is limited to o period of 100 to 120 deys per year. The mount of uork required ezch year for stutirp en2 closin~operztions causes an iiicreased cost as conpared to erser of year-round operztions. Capacity equi~mentnust be installed to handle sufficient grourd, dur- lag the limited operating season, to carr:r the yerrly overheed end to make o profit. The best and most satisfectory type of operction for tke area is dredgit!g. Eos~ever, the presence of benches and high chmnels and localized deposits mybe suitable for other nining methods. choice of the right tne md mike of smchinery for certain types of deposits is in =any instinces the factor bet~5ensuccess and failwe. Amre stendzrdized method of rnirini: for certain types of cieposits should be developed as conl,=cd to the c;2nlr nore or less experimental tyyes that ere used at the present the. me present practice in the purchase of nachinsry is to purchase it from the conpany that advances ,the most credit, Cheap po?Qrerfor operation is another problsrz thet fcces the operator. The evolution of poT/rer in this area has been fro3 gasoline to diesel oil units, The U. S. Smelting and Refining Company at None bas developed diesel-electric povrer. Electric power for the operat ion of dredges, pumps, and other nethods using sdlpocirer is much more econoni- cal and efficient than any other fora in this mea. Eo~raver, the develop- - -,merit of electric po?vsr by diesel, coal or mter ?over depends upon neny Iconditions. Since the available coal within the area is 'of 2 very low grade, and with rdning conditions and trimsportation costs hi,$.?, diesel oil develogment vrould be cheaper thzn stem. Diesel as conlpzred to hydro- I electric power depends upon the future possibilities and conditions of this area. I-Iydroelectric developzent is possible rrithin the zrerl, and orith a sufficierrt demand established it vnuld becone the cheapest .form ~ of povrer. Thus it is a matter of encouragement to the potential explorc- I < tion conpzny to be assured of an availcble cheap form of power should their developaent s prove v:orthvrhile. - Another problez associated with actuzl mining is the lime- .- .. - - -- -. - . stone bedrock. The underlying bedrocks of .tihe greater portion of the . area are lhestone an8 schist, interbedded and arrenged in a north and south alinerent2. ~rooks3has sho?~~the tendency for bcth the origin and the prc?sent location of slacer deposits to be confi~edto schist ar~d limestone contacts. The schist bedrock is the most favorable for mining -.. -. - - . . - -. l~sesection on Hyeidroalnctric i'omr Sites onfol1o:ring pnrss. . .. L. . 2>->,. .-. 1 ?-L C:.. * .,-:-.:- ---.- .>,. . .- . -. ?it.; .. - -. --.. .-.'.-- .. - -...-. - - . - ---.. .. . -. - -" ... . .--.- ... - - ,-1 - . 5. ;:.:. 2..- J,*~*~:-c.-~.. ..,-,- .. . - - .. -2 r;, >: 5 ) Ci. ;. *.-., u--A..-.-' --..a A&*- . .- --.? ..'.... , -..-. as the decomposition is usually greater thm the limestone. For dredging it offers no difficult problen. The limestone offers a condition makes for hard mining by all methods. It is usually fractured in one or more directions ad is rough and has a- degree of hzrdness xhich calls for strongly constructed The fractures in the limestone offer openings for thlv plecer gold which mxke it necessary to nine considerable bedrock to reco-~erthe values. A heavily constructed ladder and bucket .. in.- . - .I : . (- . ', ' line solves tha problem for the li~estonebeilrocli xitfi regard to kedging. The lack of pro-iision for this condition has led to nay mining failures of dredging cor?!:miss on Sec.ard Peninsula. The przctice in past oparz- tions has been ths us9 of small light dredges, oainly of the flume type with light- bucket linos. The actuel light vreigkt of the dredge couptwecl to that of a trc-mel screen, dredge did not allo?r cligging sufficiently deep in the limstone bedrock to recover a11 the values. The reason for the use of these smll dredges vtzs the high cost of transportation md the high cost of porrer developmnt. 'Ems the development of ches? poyrer will pernit the use of heavier machinsry and the tra~sportztionproblen for this whole peninsula cen be re6uced to a rninirmxa figure as conpred to the majority of the other interior placer ereas. Transportation (not a handicap) : One of the lergest proble-m, which has influenced the mining operctions of the past and still exists at the present time in a mis- concepted YU-.,~, is transportation. nir: nisconcoption is tZle result of environmentel conditions during the early gold rush days. Trmsportation in those days rlzs a severe handiczp. The lighterage problem of trans- ferring su2plies and machinery from boet to land vms very difficult;, . c where harbor facilities vrere alxost lacking during all thes of the year, and an opm comt line sas subject to storz~. Land trzllsportetion ~:zs even more difficult. This a7as limited minly to horses znd doe teens. The construction of npnovr gmge railrosds TIES not a materizl hprote- ~ent. The transportztion of hecvy machinery vdth horsas and over nmrcvr gauge rcilrozds v:zs slo~rand difficult, and it rasulteci in exceptionellg hi& rates due both to tha difficulties and the demnd. The rzilrozds'sere 'hastily constructed and considerzble trouble v~sexperienced with track i and bridge conditions. Zo effort for penaanent conditions ~izsexpended-- all more or less for the prssent, and as a result only trzils and tundra roads \rare constructed. The resultant conditions, vrfiich exist today, me . -. . . . . such thzt monopolistic interests hzve control of the trasportction facilities which makes for higher trvlsportation costs than should eriet. The r!zter transportation remains much the sma todcy as in the early days. 'It;n boets a season call at ports in Kotzebue Sound. :'.%ile this sound is not free of ice until the month of 3:hy or early June, it ..-* does offer protection from stoms. It lacks natural habors, but 0 O 2 a, +, t:? p? 4 C C? .+dm Pa 0 23 2 0) U'OV 4 G.0 GCt cJ 3 of+ 4 cr.4 0 0 .'? 0 k 3-T, 2. t3 d 2 lighterage is easy due to the extensive sand and grsvel beaches. For this area the logical means of receivin~supplies vrould be via v;ater transportation to the sound. Spring su~pliesare received the fall be- fore and freight rates are within reason. At hering, vrhich is the largest coast village on the south shore, supplies consisting of general merchandise hzve a $19 freight charge pel. ton from Seattle. A $5 a ton lighterage chsge makes a totel of $24. Yreight on oil is $15 per ton from Sezttle rvith a $4 lighterage chargo per ton. Thus oil delivered to the oper~tionson the Im~chuk River costs 17 cents per gallon froci Seattle, including the original Seattle cost. Freight costs into the Kuplc T5.r-es, Inc. on the Kueruk River are slightly hi@er, due to a catergillar haul over turdre, con- pared to trucks on the Imchu% fiiver. Sugplies are lightered to the C beach at I\Tine id;ile Point. iI31.e cmp buildings vrere constructed on steel skids and hauled by cateryillar to the site of operations. One of the important features in regard to cmp construction for placer minin~;,end especially true on Ser:zrd Peninsula vihere frozen tundra offers a means of trensgorting, is the constrcction of sxsll buildings on suit~bleskids. This enables the operator to heve the camp vrithin a short distance of the operation. Also a3 one deposit is worked out, it enables the cmp to be moved to another site rvithout re- constructing the buildirgs . Another mems of access to this area is via the narrow gauge railroad from I.?one to Bunker Iiill on the Kuzitrin River, 1Tote Plate 2. From Eunker Eill a cable tram ferry operates across the river. Thence a new gravel road is under construction along the 'rlou~arokEiver to Taylor. This road services the lovrer Kougarok operat ions end will, ucon com_~letion,service the upger Kougarok and the Serpentins Springs area. The present mszns af transportation into the Kougarok is via railroad to (I -. Bunker Hill and catersillar to the upper Kou~arckand from Teller via barges to Davidson Landing on the Kuzitrin and thencs via cater:illm. This ncans of trusgortation in the past has been exuensive, totzling in some instances $70 per toa from Seattle to site of operation. This rate will be consider~blylorrered ~iiththe com?letion of the road from Bunker Hill to Taylor. Necessary parts adfresh s~pgliesare niinlg carried duhng the sunrmor months viz airplace from l!o~e. Rates fron six to ten \ cer,ts per pobd for mall lots, dspending upon destination. Zhe present air f ialds are shorm on Plate 2. 3-e co~lstructionof airplane landing fields is an iten of no great exgense due to the esse with ~2nichthey can be built. It has been the policy. for operstcrs to construct their om fields with thsir machinery, and in nuaerous cssss ?rhere fields serve a co~mwlitytho actual. expenses defrayed by the Territory. Sevmrd Peninsuls and its various ~lacerdistricts, with the exception of only one othor sea, hes the 10';:est transportation rates of any large placer area in Alaska. The only nree, :::hi& is only slightly be1017 the ratzs mentioned above, is the Gooilnevs Bay area. Transportation, in Alaska, to the rilining operat ions is 'ons of the greatest probleras and it is with this sroblaa in mind that Sec-ard Teninsuls for ,nlacer minix t is recornended as a place for future eqlorstion and development by this Taxation A Gro~ingFYoble?~: --*------There zre nunerous tzxes, both direct =d indirect, :!:hioh affect the Alaskan rdning industry. This problen in Alaska is not as e serious as in various states ;*Athin the Gnited States =d several foreign countriss. Eo:q~ver, due to the rapid developmnt 2nd the increasing I . financial burdens on both Terri';orial and Federzl Goverm-=ots, this i problem is on the increase and one to be seriously considered in the I. fiture., The txo form of direct tax, the Territorizl 3 per cent gross tax and the Federal I~lcoazTax, are the only tyro ymder discussion within . -. . .A-- ...... - -.. -. . - - - .------, . 3--=. -r- _-..__-- -- . - .. . - - - --.. . -,-.- -. -. - ...... -- . -. this report. Both taxes zre subject to increase. Hence the question arises as to how r~uchthese direct taes can be incrersad before the industry is seriously harued and expansion =d nex developmnt are retarded. It is mt 1:dthin the confinss of this report to discuss this question, only it m~stbe reambered that the aining industry of Alaska is still in its infant stzge of devslopma>t 2nd the future develop~snt . I., 1:- :,>;;:-, ---- - . -. ..- - --.- :-. --.,. :,::.... - - 7- 'C.. ------. -.- ?L!1.3" condit ions ~s~naiaso:is:hzt :he sxa. Of the two form of direct tax, the Territorial gross tax is the best adaptad, and regnrding ;.Aich t3ere has been the lezst objections. Elmy operators hsve ex2ressod their o2inions adtheir reasons for the2 are may. First, it is a Territorial tax vrith the money retained in.* the Territory. They kno~ihoi-,r the Eoney is spent and have some voice, throug3 their reprcsontativas, as to hotr it is to be sgent. It is spent zt least in pat for the peogle or Alaskz. For this one reason alone there are fan objections. Second, the tax is sim~~le easy to understaid, md at the end of the ssasor, the o,uerators cz? eesily figne :.]here they stand. The new and s~l1operstor is given a chmce to survive, under the 920,000 exemption, and to build up ixto a largs o-oerator, the very factor rinich propa~ates the mining industry. The SOTV~COS of tax-ation eqarts are not necess=y and consequsntly there is a substzntizl saving. Third, it is a reasonable tax. Tho Federal IncoLx.Tax is the most ob jestionzble. First, it is a tax difficult to interprat and as a result nurerous operotors do not ------,-. knov ho:* tileg stmd regzdi-nng it- zt the end or the ycsr. Second, dueAo - its yearly basis of incom alone it is unfair to nevr groducing coxpmies because of the seaso~alvorking conditions and the nature of the ind~tstrg. In order to bring a placer property in Alaska into production to the, point &ere thore is an actual incone, a period of from one to ten years is necessary. Exploring of the property and the proving of the ground by drill or other testing mgthods; prepsrinz the deposit to . - mine, such as rexoving overburdeil, thawing, roed building, and ditch building, all coze prior to productioc. This vrork, sll essential and directly applied to mining, is an expenditure ecco~~pmiedby no income (. ,- . ;and which only increases the capitalization rihen gold is produced. Then . comes the first year or years of actual incone, usually a 1crg6 sux corn- pared to the actud e~ezlsesof that year, made possible by the zdvanced I developnant durins gears of no incong. The operator is not allowd'to I carry over from non-poductive years to producinz yaars many of thsse tom-er developeat costs. Concerning these developaent costs, thsre is much controversy at the present tine. There are myother provisions I regarding this tax vrhich the operator does not understand and zs a result pays rather than hire a tech;lical e-xpert to exznine and present additional exemption. This tax does offer a problsn starting a new ooperation. .. .- .-- - .. . .The Territo~ial- tax, under.. its- present rate cnd exemption, need not be increzsed, undsr the existin* conditions, to solde the need for increased govermzntal fuds, providing the growth of Alaska is normal. The norul dsvelop=?nt znd groxth of U~skashould 3%only in I I I proportion to the developmnt and growth of the mining and other taxable i 0 I I industries. Thus the grovth of tha mining i~idustryNil1 provide a osater i . I production of gold and other metels with increased operations r:hich at i the present rate of t~~ctionshould provide for the increased govern- I mental expenses. hy other deve1o.rmen.t of laree proporti~nshould provide its ov,m tax and not be thror:n as an additional burden on the young and developing mining industry. .fi . --.-.. . .-- ~stablishin,.:Validity of Claims: As a result of the .home gold rush, nunerous ol~ccrdiscowries ware made on Se~rardPeninsule and sev2ral thousend claims wre st&-ed. In this area the Kougaro:: and the Innacllulc regions received the most attention. Of the many claims that wre stdccd under legal Ziscoveries, there wre many staked and held xithout discoveries. :by claim xere abandoned nnd a fea of the inoSt proraising ones 7iere retzined. Ykny claims i vere restaked and soae mre restsked several thss in later yesrs. The condition as it exists today is exfremly conplsx and, to the nexcoaer who wishes to acquire ner ground, it offers a vsry difficult problsa. Large clain groups are held by individuals and smell groups of individuals with very little sssessnent r~ork. Lone individuls hold sawrsl xiles of placer claim for long oariods of yeus, and some have no meas of doiag asuessment vmrk other than their om tire. a Due to the lack of timber vrithin the area, most clailns are staked by usixg tha nvailabls vriLlorrs for posts. These are sm11, crooked and actually difcicult to locate. As a result few claims have been leeally staked, hovrsver, this does not-tho-$1 them out as ~alidlocatioos. bTumerous clairils are inaccurstely located on the recorded discovery notice with reference to natural surroundings and monuments. This is due in most instances to the luck of natural xonunents and generally hoxn reference points. heto the lack of roads, trails and survey lines ard rolerence points, the distances ss recorded on discoaery notices Ere very inaccurate. Soxa crseks have two local nm-3s. Sone clah groups are held by tyro or more different pzrties'and the validity of title has never been establisl~ed. ~uchexisting conditions have done xuch to retard active dsvelopxtnt, not only in this maa, but in many plscer areas of Alaska. :'bile this is not a serious ?roblea, it,is one for t3e Attwe exploration comxcsny to keep in mind. There have been in the pzst mny feiluras in glacer riining on Sevmd Peninsula. One has only to trsvel the beach lines at !:one and the trails thzt lead out over the tundra to obsarvs the myre-mznts of early dsy mining activities. 9-esa tellnmy a hard luck story adshsa many of the ganersl causcs of failure. X few of these causes sre mentioned, not to discourage tbe future prospector or exploration comyany, but to warn against aistskes and to help steer the future devalopmsnts aound the pitfalls of the past. These are given in order of their niost fre~uent occurrence. Failures as a rule are not due to one specific cause or one single mistake, but are gsnerally due to mymistakes and czusas, which include a lack of knovrledgs, methods 02 conditions ar,d enviromental agencies with regxrd to the i~dustry,or a voluma of nisconst~uedor C misconceived inforiction regsrding these conditions. One of the n~stcarion csusss of mining failures, -;Liich a-.~ply to this section of Alaska, is the failure to davelo? and accurztely de- ternine the velues within tbe ground to be mined. It is a comon pro- cedwe to assums that a psr'ticulzr creek contains high values o-rar a long distmcc, such assuqtion being based u2on a fer? drill holes, a few prospect pits, or records of eulg mining which nay hz~ebeen in conce~tratedarezs snd not generally true of the vrhole creek. Lzrge .. mounts of machinery are pwchzsad and sometimzs conside;.able mounts 1. of money are s2ent on the results of a fen errsticslly placed drill holss, I-----__-_-- -_y_=-i-TC..yL-iri-- or at other tbJzs-it my-be-from one or two pits vrhi-ch ha2pened to--hit-L--- narrow Fay streak of exceptionally hi@ value. Occasionally, the inaccuracy of detemining values from the drill holss, by not usinz e - --. - 4% ___ .-- lo&xl factor o? by not ~easuringthe actual volume- of the hols, has-- - r resulted in hizhsr values entici,nated than actu&ly exist. In mny instances only the vslues contained in the gravels ma figwed for the deposits, and the frozen block nucb on top is not taken into consideration Thsre are mny other causes of failure ~~rhichenter into this subject, all more or less comon knoyrladge to the experienced placer engineer. Another co~moncause of failure in the esrly day mining ventures on Sey:~erd Peninsula vras the en3lo-pent of men not familisr with mining 6 conditions, costs, and the adverse climatic conditions. It is a coililon occurrsnce today during social, t~lksin the vicinity of Gone to hew related tales of coinpstent men who vrsre sent to Se1;:md Beninsula to xnake exaninations, to operetc end for other Durposes, and vrho turned beck in disaqpointnent . :,by of these men, faced' with adverae climtic conditions, long hard tran~sover nigge-heeb and frozen tundra, high costs, frozen gravels, md general diszppointnent in regerd to their eqectations, carried on and v:on out with finenciel success and established our present indusZry on Ce7;rard Peninsula, and to then considerable credit is due. i' Howaver, many ventures viers stopped upon conclusioils drs~m,not from the known facts of the property, but upon conditions thet &lectsd the -- physical discomforts of the particular individual. I*my of the efforts of the past, vhich led to failures, have been utilized and mde into succesnful operations due to a lcnoriledge of the various conditions end I I eQorience gained by facing, problem. Thus it is a req~isiteof the I ' I . future o~gonizztionto ensloy cen rho me f~.ailierwith conditions within i. the*area. Eourever, these conditions cen readily be lesrned with sufficient reports, a knonled;e of past failures, and a study of tha district as a . The failura to thcuv sufficient ground in advance of mining is another iteru v:hich has led to ray failures. The thavring of ground under the prasent rnsthods of thewing, such es with points, bulldozing, hydraulic, and natural thnvr, requires considerabfe tiroe. A number of operations, vhen stzrting, do not allol;~for this time factor in thawing sufficient ground and as a result the whole operation is held back a~mitingthe tha:~. This nsturzlly cuts dovm the yardage for the season and sometimss to the - .4 extent of naking the entire sezson unprof itabls . Somtiaes the thawing is hastened by the hard use of richinery. This has beell found un$rcctical duo to the wear of frozen gound on machinery, a~dit also accounts fo? sox8 loss in the sluicing, of the gold. At othsr ti~.esin point thawing, the ;oi;:ts are pulled too hzstily. This results in the lower bedrock gravels not becoxing thwied and in mining, these lower gravels c~hich. con- tain the greater portion of the values, are over for bedrock. mis latter condition only occws during dredging. It is found in ~m~y instances that the bedrock itself refreezes after ths surfzce gravel is thY:ed, due to the mout cf frost contained in the lo?:sr bedrock. SOES . bedrock has been found to be frozen to a depth of 80 feet. This rei'reee- ine, that is czused by not d1o:lring sufficient tine to tha~r,&es for harder mining and lo~ra1*recovery. Another cause, which has led to many mining failures, has beer- the puichase of the vrrong tne, or inadequate and unsuitable machinery, This has been very true of the past and it is still true to smle e-bent today. Unless one is ftz~ilicrwith the correct types and makes of machinery vhich are adaptable to minirLg conditions in this section, one . . is a?t to gurchase machinery that r:ould be unsuitzble, solely on a sales presentation, and this vrould lead to financial failure. Dredge machinery (': is more or less of e standmd type and i~volvesniinly the sane principles. Hovsever, there are nmy ,ooints regzrding various rr.&es cf dredges, that ' use variou.~tyyes of povrer end _DUX~S,vrhich are a decided advatage. Serious bre&dor.;ns are costly in an area of this type where the tine factor in replzceaent is exceedingly importat. This factor alone has been hoi;.n to turn an othereise ~rofitsblesoancn into an unprofiteble one. Only the best d;es adtypes of' mchinery should be ymchased. he purchase of new t3.m of po:&;er end ~mchinery,2s agginst proven success- (. . ful types, has bean found to be poor policy. Auxiliary poxer and large repeir supplies on hand have been found to be a great saving in time ad expense , . .- . . Another factor, ~hichcontributes in myinstances to mining. faili.wes, is the use of the too-liberal credit. Commendation is du.e to those agencies that tzve advcnced considerdole credit to the gold mining The .. indusky during the last six or eight years. advancement of this credit has done nucb to increase the nw~berof operations and to maic- tain the production. Ho-t~ever, this has approached the saturation point as numerous new agencies have entered the field. The result is that credit is advanced for nachinery on ground. that is not worthy. On nmerous properties, there has not been sufficient Cevelopnent in advznce to as- rant the mount of machinery gurchased. As a result it is used for prospecting at greet cost which is unnecessaz-y. l'my nex con~ulies that have limited finmcial nems have the additionel burden of interest, - . . . . lu and often %hen they ~eetthe final term of this so-cdled liberal credit, it is found to be mything but liberal. Tbis increzse in the use of credit and the resultant increase of purchased rmchinery, ufless it is checked or avoided by the nevr developins corqanies, threztens to under- .. &ne a most sound industry. This. is a varning, not only to the new developi~~corqsnies, but also ESI equal vrarning to the czedit agsncies as well. -. - - -- This profiteble. gale of advancing credit to golt operators is . h played by vmy agencies in Alaska, includirg the Federal Gsvesrpent. 9 me Reconstruction Finance Corporation, a govermental agency, is the --=------>--. - - %biilyone vihich reducas the-EhZideaFof fGiiure vjhen d loan is zade VO almost nil. The other agencies Ere the banks, the mchinery companies,. through their distributors, and the lcr~ecomerc3.al coaipanies. Should sm2 I these latter cgencies advance credit on the terns end stipulztions I I I and under the sane conditions as the ,9TC then the rrsrni~gto new compnnies . .and to the agencies rrould be unnecessary. There aro nloro particular zdvant ages to those organizations and individual operators who desire a lo~ztc a?ply for an P3C loan rather than to accopt the liberal credit term of other agsacies. TLese advstntzges cone under the terms end stipulations on which the ZCloen is This inclcdes an exanination by an =C engineer. Additional ground is proven if necessary md the loan is not grated unless the property has sufficient roerit to carry the loan. Credit by the. other ... agencies is more or less grnntsd on hemsap regarding the merits of the - property, and the personal reputation of the operator. Yurther, the # IZFC sees that the money is spent along lines tlxt are not out of bounds and in practical y;iiys end for practiczl ekui>~ent,and that the mining is carried on in a logical ad.practical vmy. The interest rzte is usually lo~rerthan the credit agencies, and the elesent of risk is olimineted for the operator. The element of risk is increzsed for the operator '6y the - . . credit agencies and often at the expense of l~bor. It is a comon practice to purchase n~chinergof that agency vrhich offers the greztest mount of credit. This mny tims leads to --the on& kind and tne for. the _~wticulartze of deposit vrhich is to be mined. Over-pronotion falls in with the use of this too-liberal credit and has been Laorsn to be the cause of rm3r failures. 20th activities get out of sroportion for the =aunt of mtal tc be mined, and the resulting condition is blzned on the nining industry. Along rrith credit financo throueh the bs~2cs, the usual stipulaticr? is rdded 'that the gold ' as it is mined is to be turned over to the banks who send it to the I.:int. 1 ' This adds a handling comission of 2i- per cent or more of the value of I the gold groducad. This, plus the credit retes on credit advances, makes a high percentpee of interest and corriission pa3ment. The bnnkts corn- s dssion for hadling gold is nearly as mch es the Territorial gross tax. This, conpmed to the L!int chesge of .25 per ce~tand transportztion costs paid by the operator, crmounts to a difference well v~orthyof con- p +- I. -, i sideration. L Lawsuits over validity of clzh j.3 cnothsr factor yvhich has terminated nining operztions. There me many other factors, which my contribute to failure and :!tnich zro more or less cormon knor~rledgeto experienced operztors. A knovrle2ge of the czuses oi failure is, on the other hand, one of the essentizls or success. The solution of one of the mjor mining problems in this area h Q omuld be the development of a source of cheap abudent povrer. Fiydro- electric gorrzr would be the lo~icalfom of ?over, providing there -. - - -- - should be sufficient de~and. It is also e developnent to be uneertzken either by large corporetions or throu* Govermentel agencies cad finance. To the future exl~lorationcorqmy, arid to those persons interests6 in the developient of nining on Semd Fenir-sula, it is of interest to hoa of possible hydroelectric developnent and to feel at least partly con- . * fident of obtaining o solution to one of the nsjor problem, should the . necessity arise. There is contained within this area, advery centrclly located, a favorable location for the develo?n:ent of an hydroelectric plant. The site is on the IEuti;ruk River :firhsre it is possible to utilize- the vrater of huruk Me. This is described by Eenshal~rand ~mkerlas , f ollov?s: nKup& River rises in Lrcwuk hike. and flovrs in a north- ' easterly 2nd nortkerly direction for about 60 miles, enptying into Kotzebue So~mdnezr Deering. Icu_zuJk Welies on top of the 6' 6' c- lava platezu that occupies a 1mge are2 in the central pzrt of . Serrard Peninsula, at En elsvation, as neer as can be dete~~ained . fi-om barorlater readings, of 960 feet. It hss area of 31 square niles and s drzinzzz bzsin of 102 squsre zilcs. Zslo:*r the lake the river is relatively flzt I'cr S or 4 miles. It then breaks over cLn escmprnent at the edge ol the leva end fl.07:~ through a cvlyon about 2 miles in lengtk ~tnichhcs been cut ir! places 300 feet deep 1,030 feet :.ride. The fell ir- the cm- yon aqounts to nezrly 250 feet to the rxile. At its loaer end the river is probably at about tke level -ii:=ich it occupi2d before the extrusion of the lava flow, nearly 550 feet belo:! the level of the 12ke. The cayon affords a fzvorz'cle location for a slant to develop eloctric poT:ier, for ~:eterfron the lake cstn be diverted through the ugpsr end of the Fairhaven ditch or through a vzter- oray parellel vsith it for about 4-$ niles then through a pipe line to the 1cr:er end of the canyon, where a pressure of about 500 feet can be obtained. I Yater supjly available fron L~urukLake, 1906-1908 - A%. 16, 1906 Cct. 1, 1907 . -. . - -- .- - -. . - to t 0 Aug. 13, 1907 Sent. 25, 1908 Rise of lake surface...... feet 2.17 1.53 Equivalent rater supply .... acre-feet 43,100 30,400 oUtf10i)r ...... do. 0 6,400 - Total mter su2gly...... do. 43,100 36,800 ban amlual discharge .... .second-feet 60 51 Discharge for 100-day secson. . do. 217 186 . Run-off from drainage wez. .. inches 7.9 6.8" .- - l~enshslvr, F. F. & Parker, G. L., !?ater Su?glg Paper 314, p. 229, Another undeveloped vrster power site is located on the Kruzgazepa River in the Iron Creek region v:hich lies on the north slope drainage betmen the I;i~luaikand Ecndelcben renges. This site is des- cribed by ~ens1,ay.v~axd the poi8rer develpped liere could be utilized by many of the nir-ing districts. nSalvon Lake lies at the foot of the Kigluaik 1.Icuntei.n~at an eleration of about 442 feet. It has a v:cter-surfzr-?2 =ee of 1,800 acres and a drninega are2 of 81 sqcce niles. Its princi- pal su2pl;i coxss from Grand Centre1 Siver, rffiich eiiters it at its west end. A nim-ter of s~sllstreas also enter the l&p_ from both the north adthe soilth, but !-rlt5 tks excoytion of FO:C Creek 2nd Jasi~crCresk these a*e of ginor ir::.!yol*tence'. The out- let of the 1zke is throx& Ikuzganepa ;?iv~.z. nThis lake offers zn exooll.ent oy:,o?tu:zity for 2 storage reservoir for no:..-er p.rl:oces znd minin.5 along Yzuzczzzna- - 3iv~r. The use of its v:nter in the vicinity of :kria is ;rectil-llp prohibited, ovring to its 10:~olsvzt ion ar,d the lonz turns1 xhich muld be r.ecessm;r to brinc the v,'il.ter throua ti:e 17~1~~atdivide *****into the !ror~? -5ivor basin. "As it (Kruzge~spa3iver) leaves Sekon LGce tke river flovrs through a narron outl~tha~ing a siidtk of 150 fe-.'i at the botton and 530 feet et the top, offering an excellsnt 227 site and location for a hydro-electric poxer slant. ?lam for the construction of such a glent have been perfected by the Salzon kke Parer Cca?my (l?07), :*:hich intends to develoo 3,000 horse- power to be used on dredges st Koaie and Council =cl on Sclo-m-on River. nSahon Lake at its present level, 442. feet, covers 1,800 -_-=. ._.__--.--- . . acres; it rrised to-q-level . - -.of .. 475 feet, it v;ouLd cover 3, GOO_-, --.:. acres; anc! ~t 500 fee-c, 4,600 acres. ';?le'resarvoir $:?us fo=.ed could bs used for the storage of the oater of the floods czused . by the nslting snol;r in tile spring and the occesionzl hezry- rains in thr! swl$r. Tine viater t1n1.s retained r:ould give a lzrge mini- rrum flovr not only in smzr but also dcrrins tke vrinter rzontks, when the nature1 run-cff becones slirall. nKruzgmepa Xiver seldon freczos over before the first of Januery, and it is proba-bli- that rrith ?ro$dr installntion, r,ovrcr could b5 dsvslopsd t?-roushout the yea-. " ...... 1~enshav1,F. 1. , U. S. Geol. Survey :rater Su?ply Faper 218, 1908, pp. 53-53. That vrhich applies to the such as the Iron Creel: region, Cadlo district, Solozon, Casadepaga and EIom areas. C@I:CLUsIOI: fin m.:.mY In this report the vn?itar hzs attexpted to skov~the cossibili- / \ ties vrhich exist in regard to placer mining in certain u-Ccrsloped aress of Serrard Pe~ir.sl.~l.z.There still rexnin =ees cf cnnsider~bleextent, which are geologiczlly favors!)le for glacer gold Zel~osits,and vrhich have not been thoroughly grospected. A further stter!?t to shorr th,e relation of th9 degcs2.t~^s? i;r?so-~s infrllsiae m-d extrasi-rs rocks has been mads, alonz vrith a gen5ral theo~gof orisin z~ddeosition of the gold. This offers, st least until further ixfor..7~tion is gained, 'a mrking h-ypo5hesis v$?ich n2y fom the bnsis for the solutiorr of many geological grob13=. 229 cl9scri?ti3~sad geologic feztures of the 1 .1 individual meas, it is hopgd, will be found useF~lto the presant o?erntor, the grospactor and the future e:~lorstionconpmy. The list of mining . . : problem and the general causes of failure should be instructive to the nevr o,mrator, v~iloenticiptzs mining in this &-es in the future. The individusl reader is herevit3 git-211 tile oi;portunit~*to dr3i.r his 0x1 con- clusions regmdinr thesc wets and in so doins to ~ciaccordingly. There are numerous nining problem to be overcoioe in a sectioa which lizs just belorr the fringe of the erctic circle. A great nuaber of these problers have been imposed by nature end they can under norm1 circwtunces be solved by mul. In th~seereas as mll as the whole of Seward Feninsuln thera exist myman-mde barriers and problem that are nora or less the result of the early gold rushes and the conpound evolution nixed with tho desire for fortunes, aqd the desire for capi- taiistic control. To eliminate these nnd to furnish aid tp the industry 1 is the duty of Fsderal and Territorisl agoncias, both of ~rllichow their I existence in part to the mining industry in idzska.