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Eboshiyama Formation (Chihara, 1974) Furukawa and Nagamori, 2018

Invalid synonym: Eboshiyama Volcanic Rocks

• Type locality: Mount Eboshi, Shimamichi, Itoigawa city, Niigata prefecture
• Volcanic rocks
• Pleistocene (1.65 - 0.92 Ma, K-Ar)
• Contemporaneous heterotopic facies: Torigakubi Conglomerate Member
• Intruded in: Nechi Formation

• Sedimentary facies: Subaqueous, Intrusive rocks
• Lithofacies: Andesite - Dacite lava, Volcanic breccia, Tuff breccia
• Lithofacies (Minor): Volcanic mudflow deposit, Andesite tuff, Mudflow deposit, Mudstone, Gravel-bearing mudstone, Conglomerate

• Thickness: ca. 150 - 300 m
• Lower limit: Unconformity (Nadachi Formation, Nakanomata Mudstone Member, Tsutsuishi Alternation of Sandstone and Mudstone Member, Nechi Formation, Sarukura Formation)

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

• Distribution: Mount Eboshi - Mount Sodenoyama - Konouragawa river - Hayakawa valley - Sotoyama - Benteniwa - Mount Fudoyama, Shimamichi, Itoigawa city, Niigata pref.
• Distribution (Intrusive rocks): Mitsumine - Uzurishi, Itoigawa city, Niigata pref.

• Nagamori et al. (2018) Geology of the Itoigawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 75p. (in Japanese with English abstract 3p.)
• Akahane and Kato (1989) Geology of the Takada-Seibu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 89p. (in Japanese with English abstract 3p.)