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Fig. 3 | Geoenvironmental Disasters

Fig. 3

From: “Volcanism in the Chugoku region: a review for the first UNESCO field school on Geoenvironmental disaster reduction”

Fig. 3

Magmatic evolution of the SW Japan arc segment (detailed description of individual stages in the text) a: Continental arc stage, formed by a large number of granitic intrusions and associated extrusive rocks, of mainly Cretaceous age. b: Paleogene continental arc stage (second igneous flare up) which precedes the subsequent rift initiation. Many of the volcanic successions of this stage are preserved in relation with collapse caldera structures. c: Back-arc rift initiation starting with continental volcanism – subsequently changing to sub lacustrine / marine stages. d: Ongoing (mainly submarine volcanism in the back-arc basin with contemporary onset of diverse igneous activity in the fore-arc, marking the beginning subduction of the PSP. e: Evolution of several monogenetic volcanic fields, mainly alkali basalt volcanism. f: Ongoing monogenetic alkali basalt volcanism and coeval evolved adakitic magmatism (Nakajima 1996; Kimura et al. 2005a; Imaoka et al. 2011; Sato et al. 2016)

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