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Maki Siltstone Member (Ida, 1944) Yamasaki et al., 2020

Invalid synonym: Maki Member, Maki Formation

• Type locality: Hachiyato, Agi, Nakatsugawa city, Gifu prefecture
• Coherent formation
• First Seto Inland Sea
• Sedimentary basin in island arc
• early Miocene, Burdigalian (ca. 18 Ma; 16.9, 16.3 Ma, FT, 18.3 - 17.0 Ma, Diatoms)
• Contemporaneous heterotopic facies (Marginal facies): Kubohara Sandstone Facies
• Correlation (Upper): Hazama Member
• Correlation (Middle): Yamanouchi Member
• Correlation (Lower): Togari Member

• Sedimentary facies: Marine
• Climate: Deciduous broad-leaved forest associating with conifers and evergreen broad-leaved trees
• Depth of water (Upper): 100 - 200 m (Shellfishes)
• Depth of water (Lower): A few dozen m (Shellfishes)
• Lithofacies: Sandy siltstone
• Lithofacies (Minor): Sandstone, Interbedded mudstone and sandstone
• Sedimentary structures (Minor): Parallel stratification

• Thickness: 65 m or thicker
• Distribution (East - West): 1.3 km
• Distribution (South - North): 500 m
• Upper limit: Unconformity (Higashibara Formation, Mashizume Formation)
• Lower limit: Conformity (Midorigaoka Member)

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

• Distribution: Hachiyato, Agi, Nakatsugawa city, Gifu pref.; Kamaya - Hara, Yamaoka town, Ena city, Gifu pref.; Hazama, Kamitoge, Yamaoka town, Ena city, Gifu pref.
• Fossils (Shellfishes): Lucinoma acutilineatum, Macoma izurensis, Macoma optiva, Malletia inermis, Megayoldia thraciaeformis, Nipponomarcia nakamurai, Portlandia watasei, Saccella miensis
• Fossils (Plants): Castanopsis miocuspidata, Keteleeria ezoana, Pinus miocenica, Pseudotsuga ezoana, Quercus miovariabilis, Quercus nathorstii, Quercus praegilva, Zelkova ungeri
• Fossils (Pollen): Fagus sp., Juglans sp., Pinus sp., Pterocarya sp., Quercus sp., Ulmus sp., Zelkova sp.
• Fossils (Diatoms): Crucidenticula ikebei, Crucidenticula sawamurae
• Tephra: Ty-6 (16.9 Ma, FT), Ty-8 (16.3 Ma, FT), Ty-12

• Yamasaki et al. (2020) Geology of the Akechi District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 120p. (in Japanese with English abstract 5p.)
• Sasao et al. (2018) Jour. Geol. Soc. Japan, vol.124, no.2, pp.141-150 DOI
• Sasao et al. (2011) Jour. Geol. Soc. Japan, vol.117, no.8, pp.476-481 DOI