Alaska Volcano Observatory

Sample from 300 ft elevation from package of flows exposed along ridge east of straight glacier and extending into the lowlands. Porphyritic andesite with about 35% phenocrysts of millimeter-sized plagioclase, sub-millimeter-sized ortho- and clinopyroxene, and opaque oxides in a groundmass of brown glass, microlites, and microphenocrysts.

Sample Location:

Great Sitkin

Spurr

+−

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Legend

	Red (Warning)
	Orange (Watch)
	Yellow (Advisory)
	Green (Normal)
	Uninstrumented

200 km

100 mi

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References Cited

[1] Geochemistry of some Quaternary lavas from the Aleutian Arc and Mt. Wrangell, 2018

Nye, C.J., Beget, J.E., Layer, P.W., Mangan, M.T., McConnell, V.S., McGimsey, R.G., Miller, T.P., Moore, R.B., and Stelling, P.L., 2018, Geochemistry of some quaternary lavas from the Aleutian Arc and Mt. Wrangell: Alaska Division of Geological & Geophysical Surveys Raw Data File 2018-1, 29 p. http://doi.org/10.14509/29843

publication on DGGS website.

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