Sample: 84ARh-42D


Sample ID: 84ARh-42D [1]
Station ID: 84ARh-42D
AT Num:
Volcano:
Possible source:
Eruption:
Collector: Richter, D. H.
Date sampled: 1984-00-00
Sample type 1:
Color:
Final unit:
Text Description: Wrangell Lava. Lavas of Wiki Peak (Tertiary) - Extensive, thin to locally thick (as much as 35 m), lava flows and subordinate interlayered lahars and lapilli tuffs that show an aggregate thickness of more than 1,000 m. Lavas range in composition from basalt to dacite (50.0 - 63.4% SiO2; map nos. 1-15), but are predominately basaltic andesite and andesite. Lavas are characteristically plagioclase-phyric containing 12-40% phenocrysts of plagioclase, clinopyroxene, olivine, and +/- orthopyroxene. A flow high in the intracaldera section [of Sonya Creek] has a whole rock K-Ar age of 20.0+/-0.6 Ma.
Sample Location:

References Cited

[1] Geologic map of the McCarthy D-1 Quadrangle, Alaska, 2000

Richter, D. H., Ratte, J. C., Leeman, W. P., and Menzies, Martin, 2000, Geologic map of the McCarthy D-1 Quadrangle, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I 2695, unpaged, 1 sheet, scale 1:63,360.