Event Name : Pakushin cone 22000 yBP
|Start: 22000 (± 5000 Years) || Years BP Ar/Ar || |
|Lava flow: ||
|Pyroclastic flow, surge, or nuee ardente: ||
From McConnell and others (1998): "The satellite vents [of Makushin Volcano] produced high-volume, individually homogeneous deposits characteristic of monogenetic eruptions. Individual vents and flows are differentiated by location, petrology, and stratigraphy and occur along a zone parallel to the Aleutian Arc trend. None show evidence of activity into historic times and similar erosional features suggest they were all active after the Pleistocene glaciation receded. Samples from all the satellite eruptive centers were analyzed for 40Ar/39Ar ages. Only the dates from Table Top Mountain and Pukushin Cone are statistically different from zero with ages of 68+/-14 ka and 22+/-5 ka respectively (table 2 [in original text])."
"The largest of the satellite vents and is composed of distinctive porphyritic basalt to basaltic-andesite volcanic rocks. The deposit consists of an apron of basaltic pyroclastic flows overlain by a platuea of lava flows. The edificie of Pakushin Volcano is constructed of agglutinates and cinders and contains a single, nested cinder cone. Pakushin Cone displays cirque-like erosion on the south side and flows have been glacially scoured. 40Ar/39Ar age determinations place eruption times at approximately 22+/-5 ka. (table 2 [in original text])."