Sample: 52-W-38
| Sample ID: | 52-W-38 [1] | ||||||||||||
| Station ID: | 52-W-38 | ||||||||||||
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| Volcano: | Kanaga | ||||||||||||
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| Eruption: | |||||||||||||
| Collector: | Wilcox, R. E. | ||||||||||||
| Date sampled: | 1952-01-01 | ||||||||||||
| Sample type 1: | Lava | ||||||||||||
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| Text Description: | Specimen 52-W-38 (Rittmann: labradorite dacite) is from a light-gray columnar sill 2.5 miles northwest of Cape Tusik on southern Kanaga. This sill is finer grained and megascopically less porphyritic than the sills on southwest Kanaga. Phenocrysts, mostly less than 1 millimeter in diameter, make up 25 percent of the rock as follows: abundant zoned labradorite-bytownite with thin rims of oligoclase-andesine and, commonly, oscillatory zoning; less abundant oligoclase-andesine crystals surrounded by a zone crowded with dark inclusions, then a rim of labradorite-oligoclase with strong oscillatory zoning (included here are many phenocrysts of labradorite with center parts showing patchy extinction); clinopyroxene and orthopyroxene, both rare (<0.5 mm); abundant subhedral opaque oxides (<0.2 mm); rare sphene; ghost hornblende (<2 mm) now composed of fine pyroxene, opaque oxide, and feldspar; rounded quartz relics (<0.6 mm) surrounded by rims of granular clinopyroxene in a brown, weakly anisotropic matrix. The strongly fluidal groundmass is composed of: abundant lath- and blocky-shaped crystals of zoned oligoclase-andesine (<0.2 mm); many stubby crystals of clinopyroxene (<0.15 mm); many blocky crystals and grains of opaque oxide (<0.07 mm); irregular grains and masses of carbonate, some within pyroxene crystals and some within plagioclase crystals; abundant interstitial isotropic, material having a low index of refraction and a fracture pattern suggestive of cristobalite or opal. | ||||||||||||
| Sample Location: |
      7 80 133 25 120  Akutan Aniakchak Atka volcanic complex Augustine Cleveland Dutton Edgecumbe Fisher Gareloi Great Sitkin Griggs Iliamna Isanotski Kanaga Katmai Little Sitkin Mageik Makushin Martin Novarupta Pavlof Redoubt Semisopochnoi Shishaldin Snowy Spurr 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 the Delarof and westernmost Andreanof Islands, Aleutian Islands, Alaska, 1959
Fraser, G. D., and Barnett, H. F., 1959, Geology of the Delarof and westernmost Andreanof Islands, Aleutian Islands, Alaska: in Investigations of Alaskan volcanoes, U.S. Geological Survey Bulletin 1028-I, p. 211-248, 4 sheets, scale 3 at 1:25,000, and 1 at 1:250,000.
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