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Kojinyama Welded Tuff

• Volcanic rocks
• Cretaceous (59.8 Ma, K-Ar)

• Sedimentary facies: Pyroclastic flow deposit
• Lithofacies: Rhyolite welded tuff
• Lithofacies (Basal): Tuff breccia, Sandstone, Mudstone

• Thickness: ca. 200 m
• Thickness (Basal): 5 - a few dozen m

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

• Distribution: Mount Kojinyama - Lake Sonenuma - Nishikiyosaki - Katayama town - Takeshima island, Hikone city, Shiga pref.; Okinoshiraishi, Adogawa town, Takashima city, Shiga pref.

• Ishida et al. (1984) Geology of the Hikone-Seibu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 121p. (in Japanese with English abstract 6p.)