[ Top ] [ Japanese ]

Mukaiyama volcano Isshiki, 1987

Invalid synonym: Mukaiyama Lava

• Type locality: Mount Mukaiyama, Niijima island, Niijima city, Tokyo
• Volcanic rocks
• Monogenetic volcano
• Holocene (June 29th, AD886; 1,120 yBP, ¹⁴C)

• Sedimentary facies (Upper): Pyroclastic cone
• Sedimentary facies (Middle): Pyroclastic surge deposit
• Sedimentary facies (Lower): Lava dome
• Lithofacies (Upper): Biotite rhyolite pumiceous volcanic ash, Lapilli, Volcanic rocks
• Lithofacies (Upper, Minor): Lithic fragments
• Lithofacies (Middle): Biotite rhyolite volcanic ash, Lapilli, Volcanic rocks
• Lithofacies (Middle Minor): Breccia
• Lithofacies (Lower): Biotite rhyolite lava
• Sedimentary structures (Middle): Sand wave, Parallel stratification, Cross stratification
• Paleocurrent: from Northwest to Southeast

• Source (Upper): 5 craters
• Distribution (Long axis): 2.5 km
• Distribution (Height): 200 m
• Thickness (Upper): ca. 200 m
• Thickness (Middle): ca. 100 m
• Lower limit: Unconformity (Marushimamine volcano, Setoyama volcano, Daisanyama Volcaniclastic Deposits, Minejiyama volcano, Akazakinomine volcano, Miyatsukayama volcano)

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

• Distribution: Mount Mukaiyama Kamemimori - Sashima - Nendoyama - Mount Minejiyama - Akazakinomine - Mount Miyatsukayama Niijima island, Niijima city, Tokyo; Jinaijima island - 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.)