Sample: 87-ARh-7

Sample ID:	87-ARh-7 ^[1]
Station ID:	87-ARh-7
AT Num:
Volcano:	Drum
Possible source:
Eruption:
Collector:	Richter, D. H.
Date sampled:	1987-00-00
Sample type 1:	Lava
Color:
Final unit:
Text Description:	Mount Drum basaltic andesite flows (Pleistocene). Predominantly light-brownish-gray, thick (5-20 m), coarsely porphyritic hypersthene-olivine basaltic andesite flows that contain phenocrysts of plagioclase (5-25%, as large as 1 cm), hypersthene (1-6%, 1-3 mm), and olivine (1-10%, 0.5-3 mm; rounded and locally rimmed by hypersthene), in intergranular to intersertal groundmass. * * * Flows are probably from Mount Drum, but unit may include older lavas from other sources. Maximum thickness about 300 m.
Sample Location:

References Cited

[1] Geologic map of the Gulkana A-1 Quadrangle, south-central Alaska, 1994

Richter, D. H., Duffield, W. A., Sawyer, D. A., Schmoll, H. R., and Ratte, J. C., 1994, Geologic map of the Gulkana A-1 Quadrangle, south-central Alaska: U.S. Geological Survey Geological Quadrangle Map GQ 1728, unpaged, 1 sheet, scale 1:63,360.