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Hotokezawa Pyroclastic Flow Deposit

Invalid synonym: Iz1 Pyroclastic Flow Deposit

• Tephra
• Caldera-overflow pyroclastic deposit
• late Pliocene (3.0 - 2.8 Ma; 2.94, 2.64 Ma, K-Ar)

• Sedimentary facies: Terrestrial
• Lithofacies: Pyroclastic flow deposit
• Lithofacies: Orthopyroxene clinopyroxene hornblende dacite
• Lithofacies: Pumice tuff breccia, Lapilli tuff

• Source: Hiwada caldera
• Host: Izumi Formation
• Eruptive volume: 150 km³ or more
• Thickness: ca. 1,000 m
• Upper limit: Unconformity (Hakaseyama Volcanic Rocks)
• Lower limit: Unconformity (Iriyamazawa Formation)

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

• Distribution: Fukushima pref.

• Yamamoto et al. (2006) Geology of the Kitakata District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 63p. (in Japanese with English abstract 5p.)
• Yamamoto and Komazawa (2004) Geology of the Miyashita District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 71p. (in Japanese with English abstract 5p.)
• Yamamoto (1999) Geology of the Tajima District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 85p. (in Japanese with English abstract 8p.)
• Yamamoto and Yoshioka (1992) Geology of the Wakamatsu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 73p. (in Japanese with English abstract 5p.)