Analytical results and outcrop photographs of Tomari volcanic rocks, Shimokita Peninsula, Aomori Prefecture

Fig. S1. Outcrop photographs of the Tomari volcanic rocks. (a) Lamination of volcanic breccias of Stage I (Kanatsuyama Andesite, 41.1316°N, 141.3940°E). (b) Cross-lamination of volcanic breccias of Stage I (Kanatsuyama Andesite, 41.1322°N, 141.3955°E). The scale is 1 m. (c) Volcanic breccias colored black and red in the lower unit of Stage II (Gassan Andesite, 41.1051°N, 141.3729°E). (d) Pillow lava in the upper unit of Stage II (Tomari Basalt, 41.0995°N, 141.3980°E). (e) Massive light-reddish lava of Stage III (Takahoko Andesite, 41.0368°N, 141.3637°E). (f) Reddish volcanic breccia of Stage IV (Fukkoshi Andesite, 41.0361°N, 141.3162°E).

Fig. S2. Modal compositions of the Tomari volcanic rocks (surface and SN-010 core samples). Data are from Takimoto and Shuto (1994) and this study (red shading).

Fig. S3. Histograms of anorthite content (An%) in plagioclase for the Tomari volcanic rocks (surface and SN-010 core samples). An% = 100 × Ca/(Ca + Na + K) (atomic ratio).

Fig. S4. Quadrilateral diagrams of Mg–Ca–Fe in pyroxene for the Tomari volcanic rocks (surface and SN-010 core samples). En: enstatite, Fs: ferrosilite, Di: diopside, Hd: hedenburgite. Division lines are from Suwa and Kuroda (2006).

Fig. S5. Fe2+–Fe3+–Ti ternary diagrams of Fe–Ti oxides for the Tomari volcanic rocks (surface and SN-010 core samples). Mt: magnetite, Usp: urvöspinel, Hem: hematite, Ilm: ilmenite. Calculation of the Fe2+/Fe3+ distribution of Fe–Ti oxides was conducted to ensure cation charge balance in stoichiometry.

Fig. S6. Histogram of forsterite content (Fo%) in olivine for the Tomari Basalt. Fo% = 100 × Mg/(Mg + Fe) (atomic ratio).

Fig. S7. Representative diagrams of the whole-rock chemical compositions of the Tomari volcanic rocks (surface and SN-010 shallow and deep core samples). Large symbols show new data from this study, and small symbols show data from the literature (Takimoto and Shuto, 1994; Hanyu et al., 2006). The division line of tholeiite (TH) and calc-alkaline (CA) rock series on the FeO*/MgO vs. SiO2 diagram is from Miyashiro (1974) and extends linearly to a basaltic composition.

Fig. S8. Bivariate diagrams of Ba and Rb (large-ion lithophile elements) vs. loss on ignition (LOI) and vs. Zr (highfield- strength element) for the Tomari volcanic rocks (surface and SN-010 shallow and deep core samples).

Table S1. Modal compositions of the Tomari volcanic rocks.[Foot Note] Pl : plagioclase, Ol : olivine, Cpx : clinopyroxene, Opx : orthopyroxene, Opq : opaque minerals. 

Table S2. Whole-rock geochemical compositions of the Tomari volcanic rocks.