Alaska Volcano Observatory

Grab sample from summit helicopter landing zone. Porphyritic two-pyroxene andesite. ~35% phenocrysts of plagioclase (1 x 0.4 mm), pyroxene (0.5 x 0.3 mm), and opaque Fe-Ti oxides in a matrix of devitrified glass and subordinate microphenocrysts and microlites. Pl:px ~ 2:1

Sample Location:

Great Sitkin

Spurr

+−

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Legend

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

100 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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