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SAMPLE INFO : 52-Sn-37
Sample ID:52-Sn-37
Station ID:52-Sn-37
Latitude:51.9242
Longitude:-177.1623
Datum:NAD83
Date Sampled:1952-01-01
Sample Type 1:Lava
Sample Type 2:Dike
Field Lithology:Dacite
Text Description:
Specimen 52-Sn-37 (Rittmann: dark rhyodacite) would be classified microscopically as vitrophyric labradorite dacite. This specimen is a dark-gray rock from the chill border of a small dike on northwest Kanaga. Its texture is porphyritic (~35 percent phenocrysts) with a hyalo-felty ground mass and strong flow structure. Phenocrystic plagioclase (<4 mm) is occasionally uniform, but usually shows either progressive or distinct oscillatory zoning. Composition ranges from An72-46, with most of the determinations about An54. A few of the crystals contain dusty zones of glassy inclusions. Augite (often as an overgrowth on hypersthene), hypersthene, opaque oxides, and rare ghost hornblende with a rim of granular pyroxene are also present as phenocrysts; small grains of cristohalite(?) are less conspicuous, and these are all set in a brown glass (n between 1.506 and 1.510) containing numerous plagioclase (An32-43) microlites. Potash, present in the analysis, is not expressed mineralogically and must be contained, along with occult quartz, in the low-index glass.

References:
Geology of the Delarof and westernmost Andreanof Islands, Aleutian Islands, Alaska

GEOCHEM DATA
StationIDLatitudeLongitudeGeologistDateVisitedVolcanoEruptionLocation DescriptionText DescriptionSample IDMaterialSiO2TiO2Al2O3FeOTMnOMgOCaONa2OK2OP2O5Total-majorsREF majorsMETH majorsFe2O3/Fe203T origFeO/FeOT origVolatiles csvMETH volatilesCsRbBaSrLaCePrNdSmEuGdTbDyHoErTmYbLuYZrNbHfTaPbThUScVCrFeCoNiCuZnGaMoAsNaKRef trace1METH trace1RbBaSrLaCeNdSmEuGdDyErYbLuYZrNbPbThUScTiVCrNiCuZnGaRef trace2METH trace2Light csvHalogen csvother major csvother lile csvother ree csvother hfse csvother hpe csvother tm csvother misc csv
52-Sn-3751.9242-177.1623Snyder, G. L.1952-01-01KanagaNW KanagaSpecimen 52-Sn-37 (Rittmann: dark rhyodacite) would be classified microscopically as vitrophyric labradorite dacite. This specimen is a dark-gray rock from the chill border of a small dike on northwest Kanaga. Its texture is porphyritic (~35 percent phenocrysts) with a hyalo-felty ground mass and strong flow structure. Phenocrystic plagioclase (<4 mm) is occasionally uniform, but usually shows either progressive or distinct oscillatory zoning. Composition ranges from An72-46, with most of the determinations about An54. A few of the crystals contain dusty zones of glassy inclusions. Augite (often as an overgrowth on hypersthene), hypersthene, opaque oxides, and rare ghost hornblende with a rim of granular pyroxene are also present as phenocrysts; small grains of cristohalite(?) are less conspicuous, and these are all set in a brown glass (n between 1.506 and 1.510) containing numerous plagioclase (An32-43) microlites. Potash, present in the analysis, is not expressed mineralogically and must be contained, along with occult quartz, in the low-index glass.52-Sn-37Whole Rock 58.14 0.76 17.19 6.44 0.16 3.17 6.96 3.78 2.07 0.3 100.1355NN2.853.87H2OM=0.08; H2OP=0.74; CO2=0.03NN 51.5 444 13.1 745XRFCl V=0.13, M=NN, R=355;F V=0.04, M=NN, R=355;S V=0, M=NN, R=355;K V=1.72, M=NN, R=745;

SAMPLE LOCATION

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