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Haruna-Futatsudake-Ikaho Fall Tephra Geshi and Takeuchi, 2012

• Type locality: Sogo park, Shibukawa city, Gunma prefecture
• Tephra
• Holocene (late 6th century - early 7th century; 555 - 615 AD, ¹⁴C)

• Sedimentary facies: Pyroclastic fall deposit
• Lithofacies: Orthopyroxene hornblende andesite pumice

• Source: Haruna volcano
• Thickness: ca. 4 - 15 m or thicker
• Thickness (Upper): ca. 2.5 m
• Thickness (Middle): ca. 6 m
• Thickness (Lower): ca. 2 m
• Volume: ca. 1.3 km³
• Upper limit: Unconformity (Futatsudake Lava)

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

• Distribution: Sogo park, Shibukawa 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.)