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Shirakawa Pyroclastic Flow Deposit Arai, 1962

Invalid synonym: Muroda Pyroclastic Flow Deposit

• Type locality: Kojin, Kaminakai town, Takasaki city, Gunma prefecture
• Tephra
• Haruna caldera-forming eruption
• Pleistocene (ca. 50 ka; 40.5 ka, ¹⁴C; 45,030 - 44,740 yBP, ¹⁴C)
• Contemporaneous heterotopic facies: Hassaki Fall Tephra

• Lithofacies: Orthopyroxene hornblende andesite
• Lithofacies: Pyroclastic flow deposit
• Lithofacies: Pumiceous volcanic sands and grevels, Volcanic breccia

• Source: Harun caldera of Haruna volcano
• Thickness: 5 - 30 m or thicker
• Upper limit: Unconformity (Jinba Debris Avalanche Deposit, Harunafuji Lava)
• Lower limit: Unconformity (Older Haruna Volcanic Products, Older Haruna Volcanic Fan Deposits)

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

• Distribution: Kojin, Kaminakai town, Takasaki city, Gunma pref.; Haruna river - Harunashirakawa river - Haruna pass - Tenjin pass - Suzuriiwa - Mount Jagatake - Mitsugosawa - Nakasatomi - Shimosatomi, Takasaki city, Gunma pref.; Nishiakiya, Misato town, Takasaki city, Gunma pref.; Itahana, Annaka city, Gunma pref.

• Geshi and Takeuchi (2012) Geology of the Haruna San District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 79p. (in Japanese with English abstract 3p.)