Middle Pumice is 10-115cm thick layer of moderately well-sorted, ungraded vitric lapilli and fine blocks. The most abundant clast-type is brown-beige pumice, which occurs as lapilli and bombs as large as 15cm in the long dimension. PM also has sparse, smaller lithic fragments (5 wt% of layer) that are both vitric (60% of lithics) and vairably altered volcanic lithologies (40% of lithics)
Stratigraphy, distribution, and evidence for mafic triggering of the ca. 8.5 ka Driftwood Pumice eruption, Makushin Volcano, Alaska, U.S.A.
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