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SAMPLE INFO : 53-B-13
Sample ID:53-B-13
Station ID:53-B-13
Latitude:53.88707
Longitude:-166.93202
Datum:NAD83
Date Sampled:1953-01-01
Sample Type 1:Countryrock
Sample Type 2:Plutonic
Field Lithology:Gabbro
Text Description:
Granogabbro occurring one-third mile from the Beaver pluton contact on the east side of Final Bay. The texture is hypidiomorphic and the groundmass is myrmekitic. Felsic minerals compose 80-85 percent of the rock: 7-10 percent quartz, 15-25 percent alkali feldspar partially altered to kaolin (2-3 percent), and 50-58 percent plagioclase partly altered to sericite (about 5 percent) and epidote-clinozoisite (about 1 percent). The plagioclase composition, by extinction angle, is A62 [mean of 28 crystals, standard deviation is 10 percent An, average amount of zoning per individual plagioclase crystal is 2 percent An per crystal], by index oils, is An54. Mafic minerals compose 15-20 percent: 10-13 percent uralitic hornblende (probably 85 percent of this after pyroxene, 15 percent after biotite) partly altered to penninite (0.5-1.5 percent). 0.5-1.5 percent sphene partly altered to leucoxene (0.1 percent), 4-6 percent magnetite, and <1 percent apatite. The discrepancy in plagioclase composition is probably due to sodium in the alkalic feldspar, and potassium in the plagioclase (?).

References:
Geology of Unalaska Island and adjacent insular shelf, 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
53-B-1353.88707-166.93202Barnett, H. F. J.1953-01-01 MakushinGranodiorite and related rocks from mouth of Final Bay. One-third mile from the Beaver pluton contact on the east side of Final Bay.Granogabbro occurring one-third mile from the Beaver pluton contact on the east side of Final Bay. The texture is hypidiomorphic and the groundmass is myrmekitic. Felsic minerals compose 80-85 percent of the rock: 7-10 percent quartz, 15-25 percent alkali feldspar partially altered to kaolin (2-3 percent), and 50-58 percent plagioclase partly altered to sericite (about 5 percent) and epidote-clinozoisite (about 1 percent). The plagioclase composition, by extinction angle, is A62 [mean of 28 crystals, standard deviation is 10 percent An, average amount of zoning per individual plagioclase crystal is 2 percent An per crystal], by index oils, is An54. Mafic minerals compose 15-20 percent: 10-13 percent uralitic hornblende (probably 85 percent of this after pyroxene, 15 percent after biotite) partly altered to penninite (0.5-1.5 percent). 0.5-1.5 percent sphene partly altered to leucoxene (0.1 percent), 4-6 percent magnetite, and <1 percent apatite. The discrepancy in plagioclase composition is probably due to sodium in the alkalic feldspar, and potassium in the plagioclase (?).53-B-13Whole Rock 57.3 0.82 16.1 8.4 0.08 3.6 8.1 3.2 0.92 0.21Total not given in table. 100.25315RAPIDA2.95.8H2OM=0.06; H2OP=1.1; CO2=0.05RAPIDAB V=0.003, M=NN, R=315;S V=0.01, M=RAPIDA, R=315;Ba V=0.04, M=NN, R=315;Sr V=0.06, M=NN, R=315;Yb V=0, M=NN, R=315;Y V=0, M=NN, R=315;Zr V=0.009, M=NN, R=315;Pb V=0, M=NN, R=315;Co V=0.003, M=NN, R=315;Cr V=0.003, M=NN, R=315;Cu V=0.0008, M=NN, R=315;Ga V=0, M=NN, R=315;Mo V=0, M=NN, R=315;Ni V=0, M=NN, R=315;Sc V=0.005, M=NN, R=315;V V=0.03, M=NN, R=315;

SAMPLE LOCATION

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