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Matsukawa Andesite Nakamura and Sumi, 1961

• Type locality: Matsukawa river, Hachimantai city, Iwate prefecture
• Volcanic rocks
• late Pliocene - early Pleistocene (2.3 - 1.3 Ma, K-Ar)

• Lithofacies: Altered lava, Tuff
• Lithofacies (Protolith): Olivine augite hypersthene andesite, Augite hypersthene andesite

• Thickness: ca. 160 m
• Upper limit: Unconformity (Iwate volcanic group)
• Lower limit: Unconformity (Bunamoribokujo Welded Tuff, Kakkondagawa Pyroclastic Rocks)

• Distribution: Matsukawa river, Hachimantai city, Iwate pref.; Kakkonda river - Omatsukura creek, Shizukuishi city, Iwate county, Iwate pref.

• Suto and Ishii (1987) Geology of the Shizukuishi District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 142p. (in Japanese with English abstract 5p.)
• Kawano and Uemura (1964) Hachimantai, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 36p. (in Japanese with English abstract 8p.)