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Koyasawa Pyroclastic Flow Deposit Yanagisawa and Yamamoto, 1998

• Type locality: Koyasawa, Kawanishi city, Higashiokitama county, Yamagata prefecture
• Tephra
• early Pliocene (4.6 Ma, FT)
• Correlation: Nadegi Pyroclastic Flow Deposit?

• Lithofacies: Pyroclastic flow deposit
• Lithofacies: Non-welded hornblende orthopyroxene clinopyroxene dacite lapilli tuff

• Source: Inawashiro Calderas
• Host: Tenoko Formation
• Thickness: 12 - 26 m

• Distribution: Koyasawa, Kawanishi city, Higashiokitama county, Yamagata pref.

• Yanagisawa and Yamamoto (1998) Geology of the Tamaniwa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 94p. (in Japanese with English abstract 4p.)