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SAMPLE INFO : 87-AWs-5
Sample ID:87-AWs-5
Station ID:87-AWs-5
Latitude:62.0229
Longitude:-144.295
Datum:NAD83
Date Sampled:1987-00-00
Sample Type 1:Lava
Sample Type 2:Flow
Field Lithology:Dacite
Text Description:
Chetaslina eruptive center dacite flow (Pleistocene). Pale-red to medium-gray, massive porphyritic dacite that contains phenocrysts of plagioclase (5-10%, 1-2 mm), aligned oxyhornblende (5-10%, as long as 6 mm), and opaque minerals (trace to 1%, 1 mm) in microtrachytic groundmass of plagioclase microlites and cryptocrystalline material. * * * Hornblende from sample (loc. 36) yielded K-Ar age of 0.84+/-0.14 Ma. Thickness about 300 m, but top not exposed.

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

GEOCHEM DATA