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Mikura Group (Chitani, 1931) Kano and Matsushima, 1988

A member of Mikura Belt

• Type locality: Mikura, Mori city, Shuchi county, Shizuoka prefecture
• Accretionary complex
• Deposition: Cretaceous
• Accretion: Eocene - early Oligocene (Fossils)
• Correlation: Muro Group

• Sedimentary facies: Marine
• Sedimentary facies (Upper): Forearc basin
• Sedimentary facies (Lower): Trench (Foraminifera)
• Sedimentary facies: Turbidite
• Lithofacies (Upper): Tuffaceous shale, Interbedded sandstone and shale
• Lithofacies (Middle): Interbedded sandstone and shale, Sandstone, Shale
• Lithofacies (Lower): Tuffaceous shale
• Paleocurrent: from South

• Thickness: 400 - 2,000 m
• Distribution (Width): 18 km
• Upper limit: Unconformity (Mikasa Group, Amakata Formation, Haramishi Conglomerate, Dainichi Sandstone)

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

• Distribution: Mikura, Mori city, Shuchi county, Shizuoka pref.; Ieyama - Kunadaira, Kawane town, Shimada city, Shizuoka pref.; Kamioka, Shimada city, Shizuoka pref.; Mount Sasayama - Lake Ikawako - Ikawa pass, Aoi ward, Shizuoka city, Shizuoka pref.; Sutama river - Daimon river, Hokuto city, Yamanashi pref.
• Fossils (Shellfishes): Fissidentalium nunomae, Orectospira wadana, Pitar matsuraensis
• Fossils (Upper, Foraminifera): Ammodiscus incertus, Ammoglobigerina sp., Haplophragmoides sp., Trochammina sp.
• Fossils (Lower, Foraminifera): Ammodiscus? sp., Ammomarginulina sp., Ammovertillina sp., Bolivinopsis itchodaensis, Dorothia amakusaensis, Glomospira gordialis, Haplophragmoides dibollensis, Haplophragmoides narivaensis, Haplophragmoides shikiyamaensis, Hormosina sp., Lituotuba sp., Placentammina cf. complanata, Psammosphaera sp., Recurvoides sp., Silicosigmoilina futabaensis, Silicosignoilina sakasegawaensis, Thalmannammina cf. anfracta, Trochammina enouraensis
• Fossils (Radiolarians): Cyrocapcella tetrapera, Stichocorys delmontensis, Theocotyle sp.
• Fossils (Pollen): Alnus sp., Ulmus sp, Zelkova sp.

• 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.)
• Tokiwa et al. (2018) Jour. Geol. Soc. Japan, vol.124, no.7, pp.539-544 DOI
• Sugiyama and Matsuda (2014) Geology of the Nanbu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 134p. (in Japanese with English abstract 5p.)
• Sugiyama and Shimokawa (1990) Geology of the Shimizu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 103p. (in Japanese with English abstract 8p.)
• Kawachi (1977) Geology of the Yatsugatake District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 92p. (in Japanese with English abstract 4p.)
• Saito and Isomi (1954) Akihasan, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 34p. (in Japanese with English abstract 10p.)