Kushigatayama Subgroup

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Kushigatayama Subgroup Kosaka and Tsunoda, 1969

Invalid synonym: Kushigatayama Formation

Coherent formation
Miocene (17 - 15 Ma, Foraminifera)

Sedimentary facies: Marine
Sedimentary facies: Volcanic products
Depth of water: Bathyal (200 - 800 m, Shellfishes)
Lithofacies: Island arc tholeiite
Lithofacies: Basalt - Andesite reworked volcaniclastic rocks (Turbidite, Debrite), Dacite submarine pyroclastic flow deposit
Lithofacies (Minor): Lava, Volcanic conglomerate, Tuffaceous sandstone, Mudstone, Interbedded sandstone and mudstone

Thickness: 5,000 m or thicker
Upper limit: Conformity, partly unconformity (Momonoki Subgroup)

Western part
[ Upper ]
--------------
Arakura Formtion
~~~~~~~~~~~~~~
[ Lower ]

Eastern part
[ Upper ]
~~~~~~~~~~~~~~
Fujimiyama Formation
--------------
Jikkoku Formation
~~~~~~~~~~~~~~
[ Lower ]

Koma Group
[ Upper ]
~~~~~~~~~~~~~~
Momonoki Subgroup
-------~~~~~~~
Kushigatayama Subgroup
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Koma mountains, Yamanashi pref.

Ozaki and Sugiyama (2018) Geology of the Minobu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 169p. (in Japanese with English abstract 7p.)