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Kokasan Formation

• Volcanic rocks
• Late Cretaceous
• Correlation (Lower): Yanajimayama Mass

• Lithofacies (Upper): Rhyolite welded tuff
• Lithofacies (Lower): Rhyolite crystalline tuff
• Lithofacies (Lower, Minor): Vitreous tuff, Lapilli tuff, Tuffaceous mudstone
• Lithofacies (Basal): Breccia

• Thickness: 450 - 750 m or thicker
• Thickness (Upper): 250 m or thicker
• Thickness (Lower): 200 - 500 m or thicker
• Upper limit: Unconformity (Abesan Formation, Katajiyama Formation)
• Lower limit: Unconformity (Taragadani Formation)

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

• Distribution: Mount Kokasan, Horado, Seki city, Gifu pref.; Kayano, Otogari, Mino city, Gifu pref.

• Wakita (1984) Geology of the Hachiman District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 89p. (in Japanese with English abstract 6p.)