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Tenjosan volcano Isshiki, 1982

Invalid synonym: Shiromama Formation, Tenjosan Lava, Tenjosan Lava Dome

• Type locality: Mount Tenjosan, Kozushima city, Tokyo
• Volcanic rocks
• Monogenetic volcano
• Holocene (July 29th, AD838, 1,560, 1,260, 1,230 yBP, ¹⁴C)

• Sedimentary facies (Upper): Lava dome, Crumble breccia
• Sedimentary facies (Middle): Pyroclastic cone, Pyroclastic fall deposit
• Sedimentary facies (Lower): Pyroclastic flow deposit, Pyroclastic surge deposit
• Lithofacies (Upper): Biotite rhyolite lava
• Lithofacies (Middle): Biotite rhyolite pumiceous pyroclastic depostis
• Lithofacies (Lower): Biotite rhyolite pumiceous - vitreous lapilli, Volcanic ash, Pumiceous volcanic breccia
• Sedimentary structures (Lower): Cross stratification

• Distribution (South - North, Lava dome): ca. 2 km
• Distribution (East - West, Lava dome): ca. 1 km
• Thickness (Upper): ca. 150 - 200 m
• Thickness (Middle): ca. 200 m
• Thickness (Lower): ca. 30 - 50 m
• Lower limit: Unconformity (Nagahama volcano, 262m-yama volcano, Nachisan volcano, Matsuyamabana volcano, Osawa volcano, Takodoyama volcano, Jogoyama volcano, Hanatate volcano, Sanukayama volcano, Menbo volcano)

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

• Distribution: Mount Tenjosan - Takowan bay - Nagahama - Sawajiriwan bay - Maehama, Kozushima city, Tokyo

• Isshiki (1982) Geology of the Kozushima District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 75p. (in Japanese with English abstract 3p.)