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Mukaiyama Tephra

• Tephra
• Holocene (June 29th, AD886)

• Sedimentary facies: Pyroclastic surge deposit
• Lithofacies: Biotite rhyolite pumice
• Sedimentary structures: Cross stratification

• Source: Mukaiyama volcano
• Thickness: ca. 50 - 350 cm
• Lower limit: Unconformity (Tenjosan Tephra)

• Distribution: Mount Mukaiyama Kamemimori - Sashima - Nendoyama - Mount Minejiyama - Akazakinomine - Mount Miyatsukayama Niijima island, Niijima city, Tokyo; Jinaijima island, Niijima city, Tokyo; Kohama - Kanbikiura - Mikawa bay, Shikinejima island, Niijima city, Tokyo

• Isshiki (1987) Geology of the Nii Jima District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 85p. (in Japanese with English abstract 3p.)