Sample: 54-Sn-284B
Sample ID: | 54-Sn-284B [1] | ||||||||||||
Station ID: | 54-Sn-284B | ||||||||||||
AT Num: | |||||||||||||
Volcano: | Makushin | ||||||||||||
Possible source: | |||||||||||||
Eruption: | |||||||||||||
Collector: | Snyder, G. L. | ||||||||||||
Date sampled: | 1954-01-01 | ||||||||||||
Sample type 1: | Countryrock | ||||||||||||
Color: | |||||||||||||
Final unit: | |||||||||||||
Text Description: | Granite, the matrix of a "plum pudding" rock, from a beach boulder near the head of the north arm of Skan Bay. The texture is hypidiomorphic-granular; the original rock contains many inclusions but this analysis is of matrix only. Felsic minerals compose 93-97 percent of the rock: 10-20 percent quartz, 50-70 percent alkalic feldspar heavily altered to kaolin (10-20 percent), and 15-25 percent plagioclase partly altered to epidote (0.1-0.5 percent), sericite (0.1-1 percent), and kaolin (lumped with above). The plagioclase composition, by extinction angle, is A18 [mean of 5 crystals, standard deviation is 9 percent An, average amount of zoning per individual plagioclase crystal is 0 Percent An per crystal]. Mafic minerals compose 3-7 percent: 2-3 percent hornblende and 0.1-0.5 percent is biotite both partly altered to epidote (0.1-1 percent) and penninite (0.1-0.3 percent), 1-1.5 percent is magnetite, 0.1-1 percent is sphene slightly altered to lucoxene, 0.1-0.5 percent is rutile occurring as stubby yellow rods in sphene, and 0.1-0.3 percent is penninite (interstitial). Comparison of the mode and norm for this rock indicates that the alkalic feldspar contains large quantities of both orthoclase and albite. | ||||||||||||
Sample Location: |
![]() ![]() Great Sitkin Spurr Akutan Aniakchak Atka volcanic complex Augustine Cleveland Dutton Edgecumbe Fisher Gareloi Griggs Iliamna Isanotski Kanaga Katmai Little Sitkin Mageik Makushin Martin Novarupta Pavlof Redoubt Semisopochnoi Shishaldin Snowy Takawangha Tanaga Trident Ugashik-Peulik Ukinrek Maars Veniaminof Westdahl Wrangell Adagdak Addington volcanic field Alagogshak Amak Amchixtam Chaxsxii Amukta Andrew Bay volcano Basalt of Gertrude Creek Behm Canal-Rudyerd Bay Black Peak Bobrof Bogoslof Buldir Buzzard Creek Camille Cone Capital Carlisle Chagulak Chiginagak Churchill, Mt Cone 3110 Cone 3601 Dana Davidof Denison Devils Desk Double Glacier Douglas Drum Duncan Canal Emmons Lake Volcanic Center Espenberg Folsoms Bluff Fourpeaked Frosty Gas Rocks, the Gilbert Gordon Gosling Cone Hayes Herbert Imuruk Lake Volc Field Ingakslugwat Hills Ingenstrem Depression Volcanic Field Ingrisarak Mtn Iron Trig cone Iskut-Unuk River cones Jarvis Jumbo Dome Kagamil Kaguyak Kasatochi Kejulik Kialagvik Kiska Klawasi Group Knob 1000 Kochilagok Hill Koniuji Kookooligit Mountains Koyuk-Buckland volcanics Kukak Kupreanof Lone basalt Maclaren River volcanic field Moffett Monogenetic QT vents of WWVF Morzhovoi Nelson Island Nunivak Island Nushkolik Mountain volcanic field Okmok Pavlof Sister Prindle Volcano Rainbow River cone Recheshnoi Roundtop Sanford Seguam Segula Sergief Skookum Creek St. George volcanic field St. Michael St. Paul Island Steller Stepovak Bay 1 Stepovak Bay 2 Stepovak Bay 3 Stepovak Bay 4 Suemez Island Table Top Mtn Tanada Peak Tanax̂ Angunax̂ Tlevak Strait Togiak volcanics Uliaga Ungulungwak Hill-Ingrichuak Hill Unnamed (near Ukinrek Maars) Vsevidof Western Cones Wide Bay cone Yantarni Yunaska Legend ✕
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References Cited
[1] Geology of Unalaska Island and adjacent insular shelf, Aleutian Islands, Alaska, 1961
Drewes, Harald, Fraser, G. D., Snyder, G. L., and Barnett, H. F. Jr., 1961, Geology of Unalaska Island and adjacent insular shelf, Aleutian Islands, Alaska: in Investigations of Alaskan volcanoes, U.S. Geological Survey Bulletin 1028-S, p. 583-676, 3 sheets, scale 2 at 1:250,000 and 1 unknown.



