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Takayamazawa-Onizawa Pyroclastic Flow Deposit (Shimazu et al., 1983)

Invalid synonym: Onizawa-Takayamazawa Pyroclastic Flow Deposit

• Type locality: Onizawa creek - Kagoro fall, Takayama creek, Zako river, Sakae city, Shimominochi county, Nagano prefecture
• Tephra
• Pleistocene

• Lithofacies: Calc-alkaline
• Lithofacies (Upper): Hypersthene augite andesite volcaniclastic rocks
• Lithofacies (Middle): Biotite hornblende dacite volcaniclastic rocks
• Lithofacies (Lower): Hypersthene augite andesite volcaniclastic rocks

• Thickness: 250 m
• Upper limit: Unconformity (Shirakurayama Lavas, Takizawa Lavas, Uenohara Welded Tuff)
• Lower limit: Unconformity (Maekura Lavas and Pyroclastics, Ketto Formation, Akiyamago Formation, Wayama Tuff Member)

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

• Distribution: Onizawa creek - Takayama creek - Akiyama forest road - Mount Nunoiwa, Sakae city, Shimominochi county, Nagano pref.

• Igarashi et al. (2007) Jour. Geol. Soc. Japan, vol.113, no.11, pp.565-584 DOI
• 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.)