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Kasamori Formation Mitsuchi, 1933

• Type locality: Kasamori, Chonan city, Chosei county, Chiba prefecture
• Coherent formation
• Fore-arc basin sediments (Kazusa trough)
• Pleistocene
• Contemporaneous heterotopic facies (Upper): Kongochi Formation
• Correlation: Higashinagata Formation, Takigawa Formation

• Sedimentary facies: Marine
• Sedimentary facies: Open bay
• Sedimentary facies: Inner shelf subjected to storm waves
• Water temperature (Upper): Cold ocean current
• Water temperature (Lower): Warm ocean current
• Lithofacies: Sandy siltstone, Silty sandstone
• Lithofacies (Minor): Interbedded sandstone and mudstone
• Sedimentary structures: Bioturbation, Ripple cross-stratification

• Thickness: ca. 100 - 320 m
• Upper limit: Transitional (Kongochi Formation), Unconformity (Jizodo Formation)
• Lower limit: Top of interbedded sands and mad
• Lower limit: Transitional (Chonan Formation)

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

• Distribution: Kasamori, Chonan city, Chosei county, Chiba pref.; Neriki - Nagashi - Mount Kanozan, Kimitsu city, Chiba pref.
• Fossils (Shellfishes): Acila divaritaca, Callithaca adamsi, Cryptonatica janthostomoides, Dentalium rhabdotum, Ennucula tenuis, Granulifiusus musasiensis, Hindsia magnifica, Limopsis crenata, Limopsis tajimae, Limopsis tokaiensis, Limopsis uwadokoi, Macoma calcarea, Neilonella coix, Nemocardium samarangae, Nuculana yokoyamai, Portlandia lischkei, Raeta yokohamensis, Striodentalium rhabdotum, Turritella nipponica, Venericardia sp., Yoldia naganumana
• Fossils (Foraminifera): Buccella frigida, Buccella inusitata, Cribroelphidium bartletti, Elphidium clavatum, Elphidium parvulum var. elegantissima, Globigerina pochyderma, Globigerina quinqueloba, Globigerinita uvla, Lagenonodosaria scalaris, Nonionella stella, Pseudononion japonicum, Pulleniatina obliquiloculata, Rotalia takanabensis
• Fossils (Chemosynthetic community): Lucinoma aokii
• Fossils (Foraminifera): Buccella frigida, Buccella inusitata, Cribroelphidium bartletti, Elphidium clavatum, Elphidium parvulum var. elegantissima, Globigerina pochyderma, Globigerina quinqueloba, Globigerinita uvla, Globorotalia truncatulinoides, Lagenonodosaria scalaris, Nonionella stella, Pseudononion japonicum, Pulleniatina obliquiloculata, Rotalia takanabensis
• Fossils (Pollen): Abies sp., Larix sp., Menyanthes sp., Picea sp., Tsuga sp.
• Fossils (Trace fossils): Rosselia socialis, Teichichunus isp., Thalassinoides isp.
• Tephra: Ks5, Ks6, Ks6.1, Ks7, Ks7.03, Ks7.3, Ks7.5A, Ks7.5B, Ks7.8, Ks8, Ks8.2, Ks8.4A, Ks8.4B, Ks8.5, Ks8.6, Ks9, Ks9.4, Ks9.6, Ks10, Ks11 (Kb-Ks), Ks11.2, Ks11.5A, Ks11.5B, Ks11.8, Ks12, Ks13, Ks14, Ks15, Ks15.2, Ks16, Ks17, Ks17.5, Ks18, Ks19A, Ks19B, Ks20, Ks20.5, Ks21A, Ks21B, Ks22, Ks23, Ks23.5

• Tamura et al. (2019) Jour. Geol. Soc. Japan, vol.125, no.1, pp.23-39 DOI
• GSSP proposal group (2019) Jour. Geol. Soc. Japan, vol.125, no.1, pp.5-22 DOI
• Nanayama et al. (2016) Geology of the Mobara District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 101p. (in Japanese with English abstract 4p.)
• Suzuki and Murata (2011) Jour. Geol. Soc. Japan, vol.117, no.7, pp.379-397 DOI
• Nakajima and Watanabe (2005) Geology of the Futtsu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 102p. (in Japanese with English abstract 8p.)
• Tokuhashi and Endo (1984) Geology of the Anesaki District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 136p. (in Japanese with English abstract 6p.)