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SAMPLE INFO : 84-ARh-97
Sample ID:84-ARh-97
Station ID:84-ARh-97
Latitude:62.213
Longitude:-144.228
Datum:NAD83
Date Sampled:1984-00-00
Sample Type 1:Lava
Sample Type 2:Flow
Field Lithology:Dacite
Sample Unit:Qsd
Text Description:
Mount Sanford Dacite flows (Pleistocene). Massive, light- to medium-light-gray, conspicuously porphyrtic dacite flows on weset and southeast flanks of Mount Sanford. Flow on west flank contains phenocrysts of plagioclase (4-6%, 1-2 mm), hornblende (2-3%, 1 mm; mostly altered to opaque minerals), and opaque minerals (trace), in trachytic to cryptocrystalline groundmass. Flow fills pronounced topographic low that is possibly along postulated caldera wall; maximum thickness about 500 m. Flow on southeast flank is coarsely porphyrtic, containign phenocrysts of plagioclase (15-20%, as large as 1 cm), clinopyroxene (1-3%, 1-2 mm), opaque minerals (1%), and biotite (trace), in microfelty groundmass that consists chiefly of feldspar. Maximum thickness about 150 m.

References:
Geologic map of the Gulkana A-1 Quadrangle, south-central Alaska

GEOCHEM DATA
StationIDLatitudeLongitudeGeologistDateVisitedVolcanoEruptionLocation 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
84-ARh-9762.213-144.228Richter, D. H.1984-00-00SanfordMount Sanford rocks within Gulkana A-1 quadrangle. Latitude and longitude derived from paper map.Mount Sanford Dacite flows (Pleistocene). Massive, light- to medium-light-gray, conspicuously porphyrtic dacite flows on weset and southeast flanks of Mount Sanford. Flow on west flank contains phenocrysts of plagioclase (4-6%, 1-2 mm), hornblende (2-3%, 1 mm; mostly altered to opaque minerals), and opaque minerals (trace), in trachytic to cryptocrystalline groundmass. Flow fills pronounced topographic low that is possibly along postulated caldera wall; maximum thickness about 500 m. Flow on southeast flank is coarsely porphyrtic, containign phenocrysts of plagioclase (15-20%, as large as 1 cm), clinopyroxene (1-3%, 1-2 mm), opaque minerals (1%), and biotite (trace), in microfelty groundmass that consists chiefly of feldspar. Maximum thickness about 150 m.84-ARh-97Whole Rock 63.3 0.61 16.9 4.6 0.08 2.99 5.81 3.9 1.57 0.18 99.922262NN2.422.41H2OP=0.05; H2OM=0.05; CO2=0.01RAPIDA

SAMPLE LOCATION

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