Alaska Volcano Observatory
Makushin reported activity
EVENT SPECIFIC INFORMATION
Event Name : Makushin A'a flow
|Start: 40000 (± 6000 Years) || Years BP Ar/Ar || |
|Lava flow: ||
From McConnell and others (1998): "Plagioclase-dominant (up to 27 vol.%), two-pyroxene andesitic a’a flow. The end of the flow extends from above Bishop Point Valley to above Koriga Point. Rubbly surface characteristic of a’a flows is still evident at lower elevations. This flow is overlain by the younger Qmbp flows above Bishop Point Valley and Qag above Koriga Point. The matrix is microcrystalline plagioclase and magnetite and the mineralogy also includes minor (<1 vol.%) olivine. Clinopyroxene overgrowths of orthopyroxene are common as are crystal clots of plagioclase and clinopyroxene. 40Ar/39Ar age determinations place its deposition at 40+/-6 ka (table 2 [in original text])."
Page modified: March 30, 2017 14:36
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