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Numazawa-Numazawako Pyroclastic Flow Deposit Takahashi and Sugawara, 1985

Abbr.: Nm-NK

• Type locality: Mukure creek, Okuriyama, Kaneyama city, Onuma city, Fukushima prefecture
• Tephra
• Numazawako caldera-forming eruption
• Holocene (5.3 ka, 3,400 BC)

• Lithofacies: Clinopyroxene-bearing orthopyroxene hornblende dacite, Clinopyroxene orthopyroxene hornblende andesite
• Lithofacies (Upper, UUI): Pyroclastic flow deposit (more than 2 flow units)
• Lithofacies (Lower, LUI): Pyroclastic surge deposit
• Lithofacies: Pumice, Accidental fragments (Rhyolite, Dacite)
• Lithofacies (Minor): Scoria

• Source: Lake Numazawa, Numazawa volcano
• Host: Shirone Formation
• Eruptive volume: ca. 2.0 km³ DRE
• Eruptive volume (Upper, UUI): ca. 4 km³
• Density (Upper, UUI): 1.2 g/cm³
• Thickness: ca. 125 - 200 cm
• Thickness (Upper, UUI, A flow unit): 50 cm - 3 m or thicker
• Thickness (Lower, LUI): A few m
• Distribution (Lower, LUI): 450 km² or wider
• Running distance: 20 km or more

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

• Distribution: Mukure creek, Okuriyama - Lake Numazawa, Kaneyama city, Onuma city, Fukushima pref.; Ozawa, Aizumisato city, Onuma county, Fukushima pref.

• Kamoi et al. (2016) Geology of the Niigata and Uchino District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 90p. (in Japanese with English abstract 2p.)
• Kubo et al. (2015) Geology of the Kawamata District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 86p. (in Japanese with English abstract 4p.)
• Masubuchi and Ishizaki (2011) Jour. Geol. Soc. Japan, vol.117, no.6, pp.357-376 DOI
• Yamamoto et al. (2006) Geology of the Kitakata District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 63p. (in Japanese with English abstract 5p.)
• Yamamoto and Komazawa (2004) Geology of the Miyashita District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 71p. (in Japanese with English abstract 5p.)
• Yamamoto (1999) Geology of the Tajima District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 85p. (in Japanese with English abstract 8p.)