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Hayaguchigawa Formation Ozawa, 1961

• Type locality (Upper): Fujikoto river, Hayatobizawa, Fujisato city, Yamamoto county, Akita prefecture
• Type locality (Middle): Hayaguchi river, Nakashida - Obuchi, Hayaguchi, Odate city, Akita prefecture
• Type locality (Middle): Misouchi creek, Okawame river, Odate city, Akita prefecture
• Volcanic rocks
• Miocene
• Correlation: Shiraishizawa Formation, Daijima Formation
• Intruded by: Futatsumori Quartz Diorite, Augite olivine dolerite, Augite olivine basalt

• Sedimentary facies: Marine, partly Terrestrial
• Sedimentary facies (Main part, Dacite, Rhyolite): Lava dome, 0.5 - 1.5 km in diameter
• Lithofacies (Main part): Dacite lava, Rhyolite lava, Acidic tuff, Volcanic lapilli tuff, Tuff breccia
• Lithofacies (Minor): Andesitic pyroclastic rocks, Mudstone, Sandstone, Conglomerate

• Thickness (Overall): 450 - 1,000 m
• Thickness (Main part): 200 - 600 m
• Upper limit: Bottom of Subari Andesite and/or tuffaceous sandstone
• Upper limit: Conformity (Onnagawa Formation, Daira-Komagatake Volcanic Products, Subari Andesite, Ittori Formation), Unconformity (Tatematazawa Formation)
• Lower limit: Bottom of acidic pyroclastic rocks
• Lower limit: Conformity (Kuroishizawa Formation)

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

• Distribution: Fujikoto river, Hayatobizawa, Fujisato city, Yamamoto county, Akita pref.; Hayaguchi river, Nakashida - Obuchi, Hayaguchi, Odate city, Akita pref.; Misouchi creek, Okawame river, Odate city, Akita pref.; Nakanomata creek - Ichinomata creek - Tomari river, Mase river, Hachimori, Happo city, Yamamoto county, Akita pref.; Nagaki creek, Hanawa river, Minehama, Happo city, Yamamoto county, Akita pref.; Sotokawara - Kikoshi, Odate city, Akita pref.; Boyama, Komori, Kitaakita city, Akita pref.
• Fossils: Sponges (Aphrocallistes, Makiyama chitanii)
• ���� (Foraminifera): Ammonia takanodensis, Ammonia sp., Cassidulina? sp., Cibicides sp., Cyclammina spp., Dentarina setanoensis, Epistominella? sp., Globigerina sp., Globigerinoides sp., Haplophragmoides spp., Lagenonodosaria fukushimaensis, Lagenonodosaria sp., Lenticulina lucidus, Lenticulina sp., Martinottiella communis, Martinottiella sp., Melonis? sp., Nodosaria? sp., Spirosigmoilinella compressa
• ���� (Shellfishes): Anadara cf. makiyamai, Anadara sp., Clementia nakamurai, Ctena sp., Dentalium yokoyamai, Dosinia sp., Glycymeris cf. cisshuensis, Glycymeris sp., Modiolus yasuheroi, Monia macrochisma, Palliorum peckami, Patinopecten kimurai, Pitar itoi, Placopecten nomurai, Siratoria siratoriensis, Venericardia siogamensis, Vicaryella sp.
• Fossils (Daijima-type flora): Castanea miomollissima, Comptonia naumanni, Cyclobalanopsis sp., Fagus antipofi, Glyptostrobus europaeus, Liquidamber miosinea, Machilus ugoana, Metasequoia occidentalis, Parrotia fagifolia, Quercus miovariabilis, Ulmus sp., Zelkova ungeri

• Ozawa et al. (1984) Geology of the Noshiro District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 91p. (in Japanese with English abstract 9p.)
• Ozawa et al. (1983) Geology of the Nakahama District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 62p. (in Japanese with English abstract 4p.)
• Hirayama and Sumi (1963) Takanosu, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 90p. (in Japanese with English abstract 7p.)
• Sumi et al. (1962) Dairakozan, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 51p. (in Japanese with English abstract 7p.)