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Gakkogawa Lava

• Stratovolcano
• Old edifice
• Volcanic rocks
• Pleistocene

• Lithofacies: Calc-alkaline
• Lithofacies: Olivine hypersthene augite andesite
• Lithofacies: Lava (4 flow units)

• Thickness (Overall): 50 m or thicker
• Thickness (A unit): 5 - 20 m
• Upper limit: Unconformity (Fujikuragawa Lava, Alluvial fan deposit)
• Lower limit: Unconformity (Tengumori Volcaniclastic Rocks, Horaisan Volcanic Rocks)

------ Conformity, ~~~~~~ Unconformity, ~~~--- Local unconformity, '''/,, Interfingered, :::::: Fault, /--/-- Thrust, +__+__ Ground surface, ?--?-- Unknown

• Distribution: Fujikura river - Gakko river - Mount Horai, Sakata city, Yamagata pref.

• Nakano and Tsuchiya (1992) Geology of the Chokaisan and Fukura District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 138p. (in Japanese with English abstract 7p.)