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SAMPLE INFO : 46AC275
Sample ID:46AC275
Station ID:46AC275
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:
Medium light-gray (N5) olivine-hypersthene basalt, with seriate pilotaxitic texture and dense structure. Plagioclase crystals, as much as 3 mm in size, have a median composition of about An75 for the larger crystals and show strong zoning. The salite grains, which reach a maximum size of 1 mm, have nZ 1.73, nX 1.692, and 2V 60 degrees, suggesting a composition of Ca50Mg[?]-[?]Fe15-30. The crystals are visibly zoned, with the higher index material on the outside; the highest and lowest indices obviously do not represent the same material. The highest index measured for hypersthene was 1.699, suggesting a composition of En74Fs26. The olivine, which attains a maximum size of 0.5 mm, has nZ 1.699, corresponding to Fa15. Magnetite in irregular grains up to 0.1 mm, and apatite, in pseudodichroic prisms, are the principal accessories. Orthoclase (?) was apparently the last mineral to crystallize.

References:
Magmatic differentiation in Tertiary and Quaternary volcanic rocks from Adak and Kanaga Islands, Aleutian Islands, Alaska

GEOCHEM DATA
StationIDLatitudeLongitudeGeologistDateVisitedAge InfoVolcanoEruptionLocation 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
46AC27551.937-176.741Unknown, Unknown1946-01-01 MoffettFrom composite cone of Mt. Moffett. Flow 5,000 feet north 23 degrees west of summit of Mt. Moffett.Medium light-gray (N5) olivine-hypersthene basalt, with seriate pilotaxitic texture and dense structure. Plagioclase crystals, as much as 3 mm in size, have a median composition of about An75 for the larger crystals and show strong zoning. The salite grains, which reach a maximum size of 1 mm, have nZ 1.73, nX 1.692, and 2V 60 degrees, suggesting a composition of Ca50Mg[?]-[?]Fe15-30. The crystals are visibly zoned, with the higher index material on the outside; the highest and lowest indices obviously do not represent the same material. The highest index measured for hypersthene was 1.699, suggesting a composition of En74Fs26. The olivine, which attains a maximum size of 0.5 mm, has nZ 1.699, corresponding to Fa15. Magnetite in irregular grains up to 0.1 mm, and apatite, in pseudodichroic prisms, are the principal accessories. Orthoclase (?) was apparently the last mineral to crystallize.46AC275Whole Rock 55.54 0.68 17.76 8.23 0.18 3.81 7.64 3.61 1.67 0.34 100.441085NN3.864.76H2OP=0.25; H2OM=0.3NN

SAMPLE LOCATION

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