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Older Shigayama Volcanic Rocks Akahane et al., 1992

Invalid synonym: Asahiyama Lava

• Type locality: Hotokeiwa - Makuiwa, Yamanouchi city, Shimoakai county, Nagano prefecture
• Volcanic rocks
• middle - late Pleistocene (0.24 Ma, K-Ar; same time as Suzurikawa Volcanic Rocks)

• Lithofacies: Olivine-bearing pyroxene andesite lava
• Lithofacies (Minor): Pyroclastic rocks

• Thickness: 100 - 150 m
• Upper limit: Abut unconformity (Shiga Lake Deposit, Yokoyugawa Lake Deposit), Unconformity (Younger Shigayama Volcanic Rocks)
• Lower limit: Unconformity (Tertiary intrusive rocks, Shiga Green Volcanic Rocks)

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

• Distribution: Yokoyu river - Kakuma river, Yamanouchi city, Shimoakai county, Nagano pref.

• Akahane et al. (1992) Geology of the Nakano District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 106p. (in Japanese with English abstract 4p.)