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Yanagisawa Tuff Ishida, 1978 ex Kitamura et al., 1981

Invalid synonym: Naruko-Yanagisawa Tephra

• Type locality: Yanagisawa, Kami city, Kami county, Miyagi prefecture
• Tephra
• Pleistocene (ca. 50 - 40 ka; 50 yBP, ¹⁴C; 63 - 40 ka, FT; 57 - 41 ka, TL)

• Lithofacies (Upper): Pyroclastric fall deposit
• Lithofacies (Middle): Dacite pyroclastic flow deposit
• Lithofacies (Lower): Base-surge deposit
• Lithofacies: Dacite pumice tuff
• Lithofacies (Bottom, Upper): Volcanic ash
• Lithofacies (Bottom, Lower): Pumice
• Sedimentary structures (Base-surge): Sandwave structure, Dune structure, Chute and pool structure

• Source: Naruko volcano
• Thickness: 30 - 80 m
• Distribution: ca. 150 km²
• Eruptive volume: ca. 5 - 10 km³ or more
• Upper limit: Unconformity (Aira-Tn Tephra)
• Lower limit: Unconformity (Iketsuki Tuff, Shimoyamasato Tuff, Nizaka Tuff, Onoda Formation, Aso-4 Tephra)

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

• Distribution: Yanagisawa - Nakashinden - Karasu river, Kami city, Kami county, Miyagi pref.; Iwadeyama - Kanbara, Osaki city, Miyagi pref.; Kaneta - Shimizu - Katakozawa, Ichihasama, Kurihara city, Miyagi pref.; Hanayama - Takashimizu, Kurihara city, Miyagi pref.; Kiyotaki, Furukawa, Osaki city, Miyagi pref.

• Tsuchiya et al. (1997) Geology of the Iwagasaki District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 96p. (in Japanese with English abstract 4p.)
• Kitamura et al. (1981) Geology of the Furukawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 32p. (in Japanese with English abstract 4p.)