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Jizodo Formation (Sakakura, 1935) Tokuhashi and Endo, 1984

Invalid synonym: Higashiyatsu Formation

• Type locality: Jizodo, Kisarazu city, Chiba prefecture
• Coherent formation
• Paleo-Tokyo bay fill deposit
• Pleistocene (MIS 11.3)
• Correlation: Tomobe Formation

• Sedimentary facies (Upper): Marine
• Sedimentary facies (Lower): Terrestrial, Brackish
• Sedimentary facies (Upper): Lower shoreface, Upper shoreface, Fore shore, Back shore
• Sedimentary facies (Middle): Quiet inner bay, Tidal sand ridge, Delta
• Sedimentary facies (Lower): Lagoon, Mudflat, Salt marsh, Estuary
• Sedimentary facies (Lower, Minor): Channel deposit
• Climate (Middle): Deciduous broad-leaved forests with conifers (Pollen)
• Climate (Lower): Cooler (Pollen)
• Water temperature: Cold ocean current (Foraminifera)
• Lithofacies (Upper): Sands
• Lithofacies (Middle): Sandy mud, Muddy sands
• Lithofacies (Lower): Clay, Silt, Sandy silt
• Lithofacies (Lower, Minor): Peat
• Sedimentary structures (Upper): Parallel stratification, Low-angle cross-stratification
• Sedimentary structures (Lower, Minor): Planar cross-stratification, Trough cross-stratification

• Thickness: ca. 1 - 85 m
• Thickness (Upper): ca. 18.2 - 24.6 m
• Thickness (Middle): ca. 7.5 - 13.9 m
• Thickness (Lower): ca. 10 m
• Upper limit: Conformity or Unconformity (Yabu Formation), Unconformity (Joso Formation)
• Lower limit: Conformity or Unconformity (Kongochi Formation), Unconformity (Kasamori Formation, Sanuki Mudstone Member, Sunami Sandstone Member)

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

• Distribution: Jizodo - Nanamagari, Kayano, Kisarazu city, Chiba pref.; Hitomi - Nagashi - Shimonitta - Mount Mifuneyama, Kimitsu city, Chiba pref.; Home - Kongochi, Ichihara city, Chiba pref.; Nagara dam, Nagara city, Chosei county, Chiba pref.; Funabata - Higashiyatsu - Nishiyatsu, Futtsu city, Chiba pref.; Negishi, Kisarazu city, Chiba pref.
• Fossils: Plant fragments
• Fossils (Shellfishes): Croassostrea gigas, Dosinella angulosa, Dosinia japonica, Lucinoma annulata, Macoma nipponica, Macoma tokyoensis, Mactra sulcataria, Modiolus difficilis, Nemocardium samarangae, Panope japonica, Patinopecten kokyoensis, Raetellops pulchellus, Ringiculina doliaris, Scapharca sp., Siphonalia? sp., Solen krusensterni, Spisula sachalinensis, Turritella ikebei
• Fossils (Foraminifera): Buccella nipponica, Cassidulina depressa, Cibicides refulgens, Elphidium advenum, Elphidium clavatum, Elphidium crispum, Globigerina bulloides, Globigerina eggeri, Globigerina pachyderma, Globigerinoides ruber, Globorotalia inflata, Hanzawaia nipponica, Lagenonodosaria scalaris, Pseudononion japonicum, Pulleniatina obliquiloculata, Quinqueloculina spp., Rotalia minuta
• Fossils (Ostracods): Bicornucythere sp., Buntonia hanaii, Loxoconcha optima, Loxoconcha tamakazura, Nipponocythere bicarinata, Pontocythere subjaponica
• Fossils (Diatoms): Achnanthidium spp., Cocconeis scutellum, Cyclotella baltica, Cyclotella cf. littoralis, Cymatosira belgica, Cymbella spp., Thalassiosira spp.
• Fossils (Pollen): Abies sp., Alnus sp., Betula sp., Carpinus sp., Cryptomeria sp., Cyclobalanopsis sp., Distylium sp., Fagus sp., Hemiptelea sp., Lepidobalanus sp., Ostrya sp., Picea sp., Pinus sp., Tsuga sp., Ulmus sp., Zelkova sp.
• Fossils (Trace fossils, Upper): Macaronichnus segregatis
• Fossils (Trace fossils, Middle): Rosselia isp.
• Fossils (Trace fossils, Lower): Plant roots
• Tephra: J1, J2, J3, J4, J5, J6, J7, J8, J9, J10, J11, J12

• 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.)
• Naya and Yasuhara (2014) Geology of the Konosu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 82p. (in Japanese with English abstract 3p.)
• Ooi et al. (2013) Jour. Geol. Soc. Japan, vol.119, no.7, pp.488-505 DOI
• Ooi and Yokoyama (2011) Jour. Geol. Soc. Japan, vol.117, Supplement, pp.103-120 DOI
• Nakazawa and Tanabe (2011) Geology of the Noda District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 72p. (in Japanese with English abstract 3p.)
• Nakazawa et al. (2009) Jour. Geol. Soc. Japan, vol.115, no.2, pp.49-63 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.)
• Komatsubara et al. (2004) Geology of the Kisarazu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 64p. (in Japanese with English abstract 3p.)
• 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.)