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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:Gabbroic
 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 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
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-13CountryrockEnclave/InclusionWhole-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=0.05RAPIDA units are percent 0.04units are percent 0.06 units are percent 0 units are percent 0units are percent 0.009 units are units are percent 0 units are percent 0.005 0.03units are percent 0.003 0.003units are percent 0units are percent 0.0008 units are percent 0units are percent 0 315NN

SAMPLE LOCATION

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