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2nd stage products Chihara et al., 1977

• Type locality: 900 m above sea level of Oakazawa creek, Tsunan city, Nakauonuma county, Niigata prefecture
• Volcanic rocks
• Pleistocene
• Lacustrine: Pleistocene (before ca. 35 ka, ¹⁴C)

• Sedimentary facies (Upper, Minor): Lacustrine
• Sedimentary facies (Lacustrine): Dammed lake
• Lithofacies: Augite hypersthene andesite lava
• Lithofacies (Lacustrine): Silt, Sands, Gravel-bearing tuff, Peat

• Thickness: 50 m or thicker
• Thickness (Lacustrine): 1 - 20 m
• Lower limit: Unconformity (Uonuma Formation, Nishitajiri Formation, Ketto Formation)
• Lower limit (Lacustrine): Abut unconformity (Quartz porphyry)

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

• Distribution: Oakazawa creek - Mount Kanajiro - Sasabamine - Mount Tenjo - Konoyama, Tsunan city, Nakauonuma county, Niigata pref.; Uenohara, Sakae city, Shimominochi county, Nagano pref.

• Shimazu and Tateishi (1993) Geology of the Naebasan District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 90p. (in Japanese with English abstract 5p.)
• Chihara et al. (1981) Geology of the Echigo-Yuzawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 108p. (in Japanese with English abstract 8p.)