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3rd stage products Chihara et al., 1977

• Type locality: Komatsubara forest road, Tokamachi city, Niiagata prefecture
• Volcanic rocks
• Pleistocene

• Sedimentary facies (Lower, Minor): Lacustrine
• Lithofacies (Upper): Augite hypersthene andesite lava (3 - 4 flow units)
• Lithofacies (Lower): Mudflow deposit, Pyroclastic flow deposit
• Lithofacies (Lower, Minor): Gravel-bearing tuffaceous sandstone, Gravel-bearing siltstone, Tuff
• Lithofacies (Bottom): Lava
• Lithofacies (Bottom, Minor): Pyroclastic flow deposit
• Sedimentary structures (Lower, Minor): Parallel stratification, Cross stratification

• Thickness: 500 m or thicker
• Thickness (Upper, A unit): ca. 20 m
• Upper limit: Unconformity (4th stage products)
• Lower limit: Unconformity (1st stage products, Ketto Formation, Tonokawa Formation, Quartz diorite)

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

• Distribution: Komatsubara, Tokamachi city, Niigata pref.; Mount Naeba - Mount Karigamine, Tsunan city, Nakauonuma county, Niigata pref.; Mount Takaishi - Tashiro forest road - Katsusa river, Yuzawa city, Minamiuonuma county, Niigata pref.

• Shimazu and Tateishi (1993) Geology of the Naebasan District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 90p. (in Japanese with English abstract 5p.)
• Chihara et al. (1981) Geology of the Echigo-Yuzawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 108p. (in Japanese with English abstract 8p.)