Event Name : Makushin 150 yBP
|Stop: 150 (± 60 Years) || Years BP C-14 (raw) || |
|Maar, tuff cone, tuff ring: ||
From Bean (1999): "Evidence of past glaciation on the flanks of several monogenetic satellite vents surrounding Makushin indicates these are late Pleistocene in age (Drewes and others 1961, Nye and others 1986, McConnell and others 1997). The exception is a series of morphologically young tuff cones and maars, located along a linear fracture stretching northwest of the summit towards Pt. Kadin, which appear to have formed during the late Holocene (Drewes and others 1961, Nye and others 1986, McConnell and others1997)."
"A linear series of at least 10 morphologically young tuff cones and maars stretches from the sea along a fracture zone towards the summit of Makushin Volcano. The explosion craters span a significant amount of time as the most seaward crater has been all but eroded away and forms part of a high beach cliff and the most landward has been partially eroded by glaciation. Some of the craters exhibit overlapping relationships indicating that magma has utilized the fracture system repeatedly to get to the surface. In fact the youngest crater is perhaps as young as a few hundred years. A peat sample dated at 80+/-60 14C yr B.P. was taken from the edge of a shallow pond at the bottom of the youngest maar. In addition, only two tephras totaling a thickness of 22 cm were preserved here. Since Makushin is known to have been fairly active during the past few millennium it seems reasonable that such a crater would have collected more than two tephra units if it were of significant age. At the very least, the date provides a maximum age for the most recent significant tephra eruption of Makushin."