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SAMPLE INFO : Snyder_1959_5
Sample ID:Snyder_1959_5
Station ID:Snyder_1959_5
Latitude:51.9531
Longitude:178.5356
Datum:NAD83
Sample Type 1:Lava
Field Lithology:Dacite
 Text Description:
Oxidized low-silica dacite of Little Sitkin dacite. Color: pale red (5R 5/2). Texture: porphyritic with plagioclase phenocrysts as much as 4 mm long. Plagioclase, 25-30 percent, ranges in separate and individually zoned crystals from An29(?) to An55 with an average composition of about An50; many of the larger feldspars form a graphic "intergrowth" with dusty glass; some have a rim of clear feldspar in optical continuity with the fritted cores; two-fluid inclusions and small needles (0.002 mm by 0.04 mm) of apatite(?) or pyroxene(?) occur in feldspar. Orthopyroxene, 6 percent, occasionally cores clinopyroxene, 9 percent, crystals. Accessory minerals: magnetite, 3 percent, and tridymite, 1 percent. Fluidal groundmass highly charged with hematite dust.

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_551.9531178.5356Snyder, G. L. Little SitkinLittle Sitkin dacite from thin boudinaged seam at contact of the rhyodacite in the Pratt Point member on coast half a mile north of Pratt PointOxidized low-silica dacite of Little Sitkin dacite. Color: pale red (5R 5/2). Texture: porphyritic with plagioclase phenocrysts as much as 4 mm long. Plagioclase, 25-30 percent, ranges in separate and individually zoned crystals from An29(?) to An55 with an average composition of about An50; many of the larger feldspars form a graphic "intergrowth" with dusty glass; some have a rim of clear feldspar in optical continuity with the fritted cores; two-fluid inclusions and small needles (0.002 mm by 0.04 mm) of apatite(?) or pyroxene(?) occur in feldspar. Orthopyroxene, 6 percent, occasionally cores clinopyroxene, 9 percent, crystals. Accessory minerals: magnetite, 3 percent, and tridymite, 1 percent. Fluidal groundmass highly charged with hematite dust.Snyder_1959_5LavaWhole-rock 58.83 0.77 17.01 7.07 0.15 3.39 7.36 3.4 1.24 0.19 99.96424NN5.711.89H2OM=0.17; H2OP=0.37; CO2=0.01NN 27.8 321 7.6 units are percent 1.02745XRF: Rb, Sr, Ni; NN: K;

SAMPLE LOCATION

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