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SAMPLE INFO : Snyder_1959_3
Sample ID:Snyder_1959_3
Station ID:Snyder_1959_3
Latitude:51.9531
Longitude:178.5356
Datum:NAD83
Sample Type 1:Lava
Field Lithology:Andesite
 Text Description:
Andesite of Little Sitkin dacite. Color: medium gray (N 5). Texture: hypocrystalline, porphyritic with feldspar phenocrysts as much as 4 mm in diameter, and pyroxene phenocrysts as much as 3 mm long. Plagioclase megaphenocrysts, 20-30 percent, range from An35 to An56 and average An47; complex zoning and twinning common. Clinopyroxene, 8 percent, contains rare centers of orthopyroxene, 1 percent. Both unreacted olivine, 5 percent, and pyroxene are stained amber along joints. Magnetite, 2 percent, as anhedrons. Average composition of feldspar microlites in trachytic groundmass is An42.

References:
Geology of Little Sitkin Island, Alaska

GEOCHEM DATA
StationIDLatitudeLongitudeGeologistDateVisitedAge InfoVolcanoEruptionLocation DescriptionText DescriptionSample IDSample Type 1Sample Type 2Final UnitMaterialSiO2TiO2Al2O3FeOTMnOMgOCaONa2OK2OP2O5Total-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
Snyder_1959_351.9531178.5356Snyder, G. L. Little SitkinLittle Sitkin dacite from coast at stream mouth 0.8 mile south of terminus of crater flow of West Cove memberAndesite of Little Sitkin dacite. Color: medium gray (N 5). Texture: hypocrystalline, porphyritic with feldspar phenocrysts as much as 4 mm in diameter, and pyroxene phenocrysts as much as 3 mm long. Plagioclase megaphenocrysts, 20-30 percent, range from An35 to An56 and average An47; complex zoning and twinning common. Clinopyroxene, 8 percent, contains rare centers of orthopyroxene, 1 percent. Both unreacted olivine, 5 percent, and pyroxene are stained amber along joints. Magnetite, 2 percent, as anhedrons. Average composition of feldspar microlites in trachytic groundmass is An42.Snyder_1959_3LavaWhole-rock 55.47 0.89 17.76 8.21 0.17 4.04 8.79 3.29 1 0.17 100.09424NN3.045.45H2OM=0.07; H2OP=0.15; CO2=0NN 18.6 366 8.2 units are percent 0.83745XRF: Rb, Sr, Ni; NN: K;
Snyder_1959_351.9531178.5356Snyder, G. L. Little SitkinLittle Sitkin dacite from coast at stream mouth 0.8 mile south of terminus of crater flow of West Cove memberAndesite of Little Sitkin dacite. Color: medium gray (N 5). Texture: hypocrystalline, porphyritic with feldspar phenocrysts as much as 4 mm in diameter, and pyroxene phenocrysts as much as 3 mm long. Plagioclase megaphenocrysts, 20-30 percent, range from An35 to An56 and average An47; complex zoning and twinning common. Clinopyroxene, 8 percent, contains rare centers of orthopyroxene, 1 percent. Both unreacted olivine, 5 percent, and pyroxene are stained amber along joints. Magnetite, 2 percent, as anhedrons. Average composition of feldspar microlites in trachytic groundmass is An42.Snyder_1959_3LavaWhole-rock H2OM=0.07; H2OP=0.15; CO2=0NN units are percent 0.03units are percent 0.07 units are percent 0.0002 units are percent 0.002units are percent 0.008 units are percent 0.002 0.03units are percent 0.002 0.003units are percent 0.001units are percent 0.006 units are percent 0.001units are percent 0.0002 424SPEC

SAMPLE LOCATION

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