Hara Formation

Hara Formation (Matsuda and Mizuno, 1955) Ozaki and Sugiyama, 2018

Invalid synonym: Hara Member, Kajikahara Member

Type locality: Ogoyama, Yokaichiba, Minobu city, Minamikoma county, Yamanashi prefecture
Coherent formation
late Miocene (Foraminifera)
Contemporaneous heterotopic facies (Upper): lower Minobu Formation
Contemporaneous heterotopic facies (Lower): Shimobe Formation
Correlation: Kuonji Formation

Sedimentary facies: Marine
Sedimentary facies: Upper - middle continental shelf
Depth of water: Lower bathyal (1,000 m or deeper)
Lithofacies (Top): Conglomerate, Sandstone, Mudstone
Lithofacies: Mudstone
Lithofacies (Minor): Dacite tuff, Andesite volcaniclastic rocks

Thickness: ca. 230 - 950 m
Upper limit: Conformity (Takatori Volcaniclastic Rocks, Sandstone and Mudstone Member), Unconformity (Teuchizawa Breccia Member)
Lower limit: Unconformity (Nishiyatsushiro Group)

Fujikawa Group (Central zone)
[ Upper ]
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Hamaishidake Formation / Akebono Formation
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Aimata Formation
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Kuonji Formation
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Hara Formation
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[ Lower ]

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

Distribution: Yokaichiba - Iitomi - Inuma - Kiriishi - Teuchizawa, Minobu city, Minamikoma county, Yamanashi pref.
Fossils: Gastropods, Sponges (Makiyama sp.)
Fossils (Foraminifera): Globigerina nepenthes, Globorotalia menardii, Globorotalia miozea, Globorotalia siakensis, Neogloboquadrina acostaensis (<= Globorotalia acostaensis), Sphaeroidinella dehiscens immatura

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.)