Fig. 1
From: Oxidation during magma mixing recorded by symplectites at Kusatsu–Shirane Volcano, Central Japan
a Location and simplified tectonic map of Kusatsu–Shirane Volcano, prepared using Generic Mapping Tools (Wessel and Smith 1998). The locations of Quaternary volcanoes (Committee for Catalogue of Quaternary volcanoes in Japan 1999) are shown as triangles. Solid gray and black lines are contours of the depth of the upper surface of the Pacific Plate at 50-km intervals (Nakajima and Hasegawa 2006) and of the Philippine Sea Plate at 10-km intervals (Hirose et al. 2008; Nakajima et al. 2009), respectively (modified after Ueki and Terada 2012). b Geologic map of Kusatsu–Shirane, showing sampling locations, modified by Ueki and Terada (2012) after Uto et al. (1983) and Hayakawa and Yui (1989). The spatial distributions of symplectites and olivine are also shown. The star indicates the location of the bulk sample presented in Table 1. Numbers refer to the samples shown in Figs. 2, 3, 4, 5 and additional files