Geology of Buldir Island Aleutian Islands Alaska & ROBERT R. OOATS MINERAL RESOURCES OF ALASKA, 1951 GEOLOGICAL SURVEY BULLETIN 989-A The geagrafihy and geologic history of the islmd, with its flora, lzwd the getrogruphic a~dchemical chlaracter of its aolcanic racks UNITED STATES GOVERPJMENT PRlNTINQ OFFICE. WASHINGTON : 1953 UNlTED STATES DEPARTMEMT OF TB& INTERIOR Dongllls McKm Seerefm GEOLOGICAL SrnvEY w. R* Wmtber* mrector CONTENTS ~~*,-,-,,*-*--"*-----*~~--------c----*--------*-*----------- XntroduFtI~~~,,,-------------~--------~~---------*----~--------- Hiatorg---,,,,,---,----,-~-------*-----*-----*------"-----r-----" Geagraphy---,-,-,,,----------,,-------------------------- LDcstionandaim-----+-------.-----.-----.-----------r-------- Topo~phy,,,,-,,,,,,,,,-,,.-,*,.--,,--,,,----,---..-------- ClimatB---,--------,----,---------.----,------------,--,-------- Animl EiEe,------------------------------------------------.- Vegetation,--,,,,,,------------------------,-,,-,,,,,,,,,,---, wogs---------------*--*----------r-------------1"----.---I---r Buldir voleanic rock6,,,,--, ,,,-------.----- ------ -" --- --- --- East Cepe volcanic rocka ...................................... Wimenta~rook~----------------------------------,,--------- AUuvi~rn,-,-,-,--*--------------------------.--~--------,- kchdepoeita,,,-,---,.,,--,,,--,-,-,-,--,----,-.-,,,-,,- Structural geol~gy-,,,,,,,,--,--,---------------,-----~-------- Geologichi~Co~,,,,-,-,--,.---.-~-,----.----------~----------- Petr~grephy-------~~--------------------------------,--,----- Buldir volaanic rocka,,,---,----,------.---------------.--.- East ape volcanic rwb,,,,,,,,, --,,-,,----------.- .-----. Cbemiatry,-,,,,, .,--- -------- - -----------------.----.-------- DiEerentfation of the analyard rwb,,,.,,,,,,,,,, - - - - - - - - - - The rmr oo&Ituenta ,,,,, - -- - - - - - - - - -- - -- - --- --.--. -- - -. Nickel, oobelt, chromium, and vanadium ,,,,,,,,. , ,- ----, Rake- olhd,-,--,-==-.--.,,--------.--.-------------- ----------- Index,, ,- -, - - ,-- ,,- , , , ,, , ,, ,, , , , , , - - ,,- , - - ,,- , ,, , -. - - - - - - - - - - - - - - m Plate 1. VeMd sedal photograph of Buldir Ialsnd, Aleutian bbda, ALBIlka-,-,-,*-----ka-----ka---ka--kaka-kaka"kaka----------4---- 2. North ~ideof East Cape Volaano, Buldir Inhnd, Abka------, Figure 1. Index map of Alaska, ahowing Wtion of Buldit Islsnd--- - --- 2. Geologic map af Buldir Island, Aleutim Inlands, Alaaka 3. Relation of magnesia, iron, and alkaliea in volcanic rocb from Buldir Island-- - ..---,--------------,-,,----. -,,-, ----- 4. Relation of al.. alk,. and c-I-fm in volcanic rooks fmm Buldir I~iend-,*,,---,---,,--,--~-------------------.~---,---, b. Reistion of the atmntium-barium ratio to ailIea in volaanie rocks from Buldir, Adak, and Kanaga 1skwh-k- - -,- - ,- ,, .-, 8. Relation of barium oontent to tbb of pub8iurn in wlcania rocka from Buldir, Adak, and Ka-a Islsnda-,-----,-,.,-, 7. A, Reletion of cobalt and of vanadium to magnesia in volamia rocka from Buldir Island; B, Rclation of nlckel to mameaia in volcania rocks from Buldir, Adak, and Kanq bhds,-, 8. Relation of chromium to magnesia in volcanic rocks from Buldir, Adak, and Ken- Idand8 -,-,,,,,,,,,,-,,,--+------,,- TABLES Table 1. Flora of Buldir Iulsnd,, -,-- - -- --- - - - - - - - - - - - - - ..- - - - - - - - 2. Some phnt ~pecieafrom nearby Aleutian Islanb, not found on BuIdir IWd, ,- - - - - - - -- - - - --- - - - - - -- - - - - - -- - - -- --- - - 8. Chemical aomp&tion and parameters of volcmt~nwkrrpwime~n f~omBuldir Ialand, Aleutian Islands, MB&L-,- -,,,,, ,,,,, I* MINERAL RESOURCES OF ALASKA GEOLOGY OF BULDLR ISLAND, ALEUTIAN ISLANDS ABEJTEUrn Bnldlr Ieland Is a mall volcanfc Island In the western Alentims, aboet eqttl- &tant from Kieka and Shemya Island& It Is the westernmost of the Aleutian volcanoeai that were artlve In lnte Quaternary or Recent time. The rocks of Brzrdir Islrnd are attrihuteri to eruptions from two voiC&nlc Writers. 'fhep differ in agP, are ~eparatdby n considerable period of time dering whtch the island andement marine and subaerial emion, and are mmtd In space by the stwp eea cliff that 18 deveIoped on the older stmctnre. The rocks of the older volcano are cZlIeflr ollvtne hasalts and olivine-hyperstIlene baealte. The rocks of the younger volmno are h.ypersthene-bearing hornblende basalta and basaltic nndeaites. Cbemicnl analyw ef dve of the rocks ahow that the rocks are similar to tho= of other clrmm-PaciAc volcnnoes. Tbey are blghlg mlcIc and mmparatfvely rich in magnesia. Norms and Nigfffi nnmbem have nlm been calculated. Nwmatkelg, the rocks fur ando& and tondose; the Niggli mama- tgpes range from gabbrw3iorltic ta pelbltlc. Spectramaphic analyses show the contents of tbe rarer elements, which, in general, resemble those from other gmchemlc&l disbicta in the Alentlnn Islands, hut the contents of 80- d the elements differ from tho* found in rock frnm Adnk and Kanaga. 'Tbe youth- fulness of Bnldir as a land mass IB sufgested by the fact that the fiamber of qeclewvf flowering plants found there Is mmewbnt leaa than on tbe neighhrlng Islamd~. INTRODUCTION Bddir Idand is geologically interesting becausb it is the westem- most outpost of Quaternary volcanism in the Aleutian Islands. It is geographically and ecologically interesting bemuse it is the most im lated of the Aleutian Islands (fig. 1). In 1947, from July 19 to July 22, a Survey party, cunsisting of Will F. Thompson, JL, field asslatant, and tb writer, worked on the island. The work would not have been possible without the moperatian of Major John Davis, CAC, Port Cloramander, Ad~k,and of Lt. Aaron 'Isaac&, the captain of the FS 238, on which we tmveled from Adak to ,Buldir and back to Kska Island. LL Co1. R E.Ware, CE,Po& Engi- neer, Ad&, and Cmdr. J. M. Oseth, Commander NO33 Adak, worn of great assistance, and their moperation is gratefully ecknowlsdged. Valuable suggestions hare been received from my colleagues in the hlogical Sarvey, particuEarlp R. A. Powm and W. S. Bcnninghoff, I a -as or feet o@ East Capb and Northwest Point are breedink grounds for Shller's sea lions. (Them islanda wem not visited and are not shown on the The distribution of plants in the Aleutian Islands depends to some extent on the geologic history. Apparently no list of the flora of Buldir Island has ever been pu'blishd, and a fuller discussion than nsulrl of the flora seems appropriate, A -11 collection of plants was made, and the pmnm or abnce of a few of the mnspicnous and easily mpized species, well known from other Aleutian Islands was noM. Theflora of Buldir contrash strikingly with that of Attu and of Zska 1sland. Another mall collection had hen made on Buldir Island by Dr. 0.J. Murie and Mr. J. H. Steenis of the U. S. Biological Survey (now the U. S. Fish and Wildlife Service) and identified by Dr, Eric Hulthn, who kindly furnished the Iist of species (personal communication, 0- Mmle and , 8teanIa GDR. ('I ,=-(I) --- AUyn'um felz-fbmim BU~BP. cycl~l~orurn{Ruppm~ht) Carl ,- ,. - , x - - - -_, Cpnson {+yfefn) .a Lycqd~urnalpamurn Lznnaeue (Alpine elubrnoma) -,,,,---,x ----** ------ Fdillwia camchdceraa ia (Linnacus) Ksr-Glawler (Indian ,a - -,- x - - - +-- riceroat). hatanthero hypwbma (Linnseum) LindIey (Green orchid) - - ,, ,--,x - - ---- SaIix arclico vat. abcordata (Andersson) Rydberg (Arctic ,-,--,r ,,,-,, W~~OW) R (D) - ,,x Claytoma cf. sthm Linnaeus (Spring kautg) ----, -,.. -- - - - -,--, ,--,-- x Ranunculuaap. (Euttetcu ) ,,,---,-------. ,, --,----- - ,,-,, x -----, Ranuncqdus acer frigid- Regel (T~Dbuttercup) --- - - - - - - - - - x ,-- -, _ ,, ,- ,- Cochlearia oficinnli srr hsp. ob?agifolia (A. P. de Candone) =- - - - , x - - - -- FIull&n am. (Scurvy wed). Sazifraga punciala var. inauk* AultQ (Dotted 8axtfrage) - x x ,,,-,, PdPnlillo pncijica Howell (Cinquefoil) - .,, .,- ---- --- -+ -,- x - ,,, -- ,,,,,, Geum cnIthifollum M~nzirs(Cowslip-leaved aven*) --------- x - -,,--,,,,,- Gsum aurcrophyl~umR-iIldsnow (1arp;e-lmvedavene) ----,--,-----I x - ---+- Geranium erianlhum ir. 1'. de Car~dollu(Ij'i'ild geranium)---- ----,-x -,-,,, Empetrum nrgr~tm1,innarua (Crow1)erry)---- - ----- ------- ----- - ---,--x Viola achyroplio~cl.Gr~ane (Viol~t,) ---- -.- ,, --,- - ---- -,--------- x - - --,, Herackurn lannliam M ichau x (Cowp~rani) -----,----------,----x CasniopeEpopodiakaJPallas)U.Don (Ath&i~--------- x ----------c- Primula cune~oliavnr. ~djragij"olia(T~hman) PXuXth x I------ OOI~APTJidenties8 by Dr. &. R. Walker, d the U. 8. NatidMtlseam,empta8notmJ. Idnritifird ky the wrltarlatha Add. Idmllfled by Mr. C.V Morton of then. 8. NatlonalManaam. 4 Idpntlfled by Dr. C. all, orhe U. 8. Natlonel Mnwm. Mr. W. S. Beminghoff of the Geol~gidSurvey has kindly sub mitMthe following commenta on the list : By ebeclring in the 8 volnmes pnbylabed thus far of Hm&nla Flora of aaab nnd Ynkoa, I have compiled the fLlowLng notes on the Sped= mll- from or recogdsd on Buldir IaIand. 1. Tbe following meaham wlde mbnflonn on the fad* Caa* in muthan mka,and the Aleutians : Athmm felds-f emina sub& -* Lycopodfum obiuwm. FHHtTarim meohatmmts. Rdds erraamfulie (7 8. dica in concept of Walkw). AhEmg Sea 8. uroth aa recagnfml by Halt& omrn mly on thc Arctic Comt an8 Bedog Sea &ores and Lahum. Otayfoaia a'-. bochldomndh mbmbnp. oblonglfolta. Potarctau weim &urn mmphyUum. Oerrm mltklfoliasm Qmadma erknthtmr, Empetm *ipmm, Herackurn lanatum. Oasafops lgkopo&olcSes. Srintuto cuMfoIta sarrrflm&SoIi& Tdentalb europama orotim. 2. The following sub~lesdo not ham Mae di&fbatIon orer the gened region : Platantltm k,%perW'm. No prevlons