Geochemical discrimination of individual hornblende shards from crypto-tephra deposits intercalated in MD012422 core at continental slope basin off Shikoku and Mihama tephra at Kiyama Formation in Fukui Prefecture, using their major and trace element compositions

Abstract

The major and trace element compositions of hornblende from the Mihama tephra, sampled near its type locality, were compared with those of tephra erupted from Kyushu volcanoes and preserved in the MD012422 piston core from the continental slope basin, off Shikoku. These comparisons show that the Mihama tephra may be correlated to the GHo-2 cryptotephra in the MD012422 core (sample No. 26.10 from 26.00-26.10 mbsf), because the petrological characteristics of hornblende and the stratigraphic position of the GHo-2 cryptotephra are consistent with those of the Mihama tephra. The Mihama tephra was likely erupted from Kyushu volcanoes during the early stage of MIS5.