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Butaijima Basalt Kobayashi et al., 2008

A part of Kamo Lavas and Kuguriiwa Lavas.

• Type locality: Butai island, Oga city, Akita prefecture
• Volcanic rocks
• Submarine volcano complexes, Scoria cone
• Eocene - Oligocene (33.9 - 31.1 Ma, K-Ar)

• Sedimentary facies: Marine
• Lithofacies: Alkali olivine basalt, Basalt, Basaltic andesite
• Lithofacies: Aa lava, Pillow lava
• Lithofacies (Minor): Tuff, Lapilli tuff, Conglomerate (Butaijima Conglomerate), Sandstone (Lahar deposit), Scoria

• Thickness: 220 m or thicker
• Thickness (A unit): several - 20 m
• Upper limit: Conformity (Ryugashima Dacite), Unconformity (Shinzan Rhyolite, Chorakuji Sandstone and Conglomerate)
• Lower limit: Unconformity (Nyudozaki Igneous Rocks)

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

• Distribution: Butai island, Oga city, Akita pref.; Kamo-Aosa, Toga - Monzen, Honzan, Funagawaminato, Oga city, Akita pref.

• Kano et al. (2011) Geology of the Toga and Funakawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 127p. (in Japanese with English abstract 4p.)
• Kobayashi et al. (2010) Jour. Geol. Soc. Japan, vol.116, no.10, pp.552-562 DOI
• Ohguchi et al. (2008) Jour. Geol. Soc. Japan, vol.114, Supplement, pp.17-32 DOI