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SAMPLE INFO : 46AC48
Sample ID:46AC48
Station ID:46AC48
Latitude:51.937
Longitude:-176.741
Datum:NAD83
Date Sampled:1946-01-01
Sample Type 1:Lava
Sample Type 2:Flow
Field Lithology:Basalt
 Text Description:
Compact, holocrystalline, pale-red (5R 5/1) olivine basalt with seriate texture. About 60 per cent of crystals of plagioclase are from 2 to 0.2 mm in diameter and range in composition from An84 to An31, with a median of about An72. The augite crystals, which reach a maximum size of 3 mm and make up about 5% of the rock, are olive-black (5Y 2/1) in hand specimen. The maximum index is about 1.72 and the intermediate index about 1.70, suggesting a composition near Ca50Mg30Fe20. The olivine is dark yellowish-orange in hand specimen (10YR 6/6) and the largest grains are about 0.5 mm across. The indices determined are nX 1.688 plus/minus 0.002 and nZ 1.726 plus/minus 0.003, indicating a composition of about Fa28. The principal accessories are magnetite and ilmenite in grains from 0.5 to 0.2 mm; the groundmass consists of blocky plagioclase crystals, augite granules, magnetite, and interstitial orthoclase.

References:
A petrologic re-investigation of the Adak volcanic center, central Aleutian arc, Alaska
Magmatic differentiation in Tertiary and Quaternary volcanic rocks from Adak and Kanaga Islands, Aleutian Islands, 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
46AC4851.937-176.741Unknown, Unknown1946-01-01 MoffettPart of composite cone of Mt. Moffett, from flow exposed on sea cliff, about 5,800 feet north 50 degrees east of summit parasitic cone of Mt. Moffett and about 7,400 feet west-northwest of northwest corner of Andrew Lagoon.Compact, holocrystalline, pale-red (5R 5/1) olivine basalt with seriate texture. About 60 per cent of crystals of plagioclase are from 2 to 0.2 mm in diameter and range in composition from An84 to An31, with a median of about An72. The augite crystals, which reach a maximum size of 3 mm and make up about 5% of the rock, are olive-black (5Y 2/1) in hand specimen. The maximum index is about 1.72 and the intermediate index about 1.70, suggesting a composition near Ca50Mg30Fe20. The olivine is dark yellowish-orange in hand specimen (10YR 6/6) and the largest grains are about 0.5 mm across. The indices determined are nX 1.688 plus/minus 0.002 and nZ 1.726 plus/minus 0.003, indicating a composition of about Fa28. The principal accessories are magnetite and ilmenite in grains from 0.5 to 0.2 mm; the groundmass consists of blocky plagioclase crystals, augite granules, magnetite, and interstitial orthoclase.46AC48LavaWhole-rock 51.24 0.93 18.93 8.5 0.18 4.24 10.76 3.62 1.34 0.24 99.131085NN4.034.76H2OP=0; H2OM=0.02NN 447 660 12.9 27.2 16.6 2.91 1.02 2.95 2.63 1.65 1.63 16.3 90 16 27 265 108 155DCP

SAMPLE LOCATION

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