Numazawako Lahar Deposit

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Numazawako Lahar Deposit

Volcanic rock
Holocene (5.4 ka)
Contemporaneous heterotopic facies: Numazawako Pyroclastic Deposit

Sedimentary facies: Lahar
Lithofacies: Clinopyroxene-bearing orthopyroxene hornblende dacite, Clinopyroxene orthopyroxene hornblende andesite
Lithofacies: Pumice gravels, Sands
Sedimentary structures: Reversed graded bedding, Parallel stratification, Low angle cross-stratification
Sedimentary structures (Minor): Trough cross-stratification

Thickness: 6 - 20 m or thicker
Upper limit: Unconformity (Lowest I Terrace Deposit)
Lower limit: Unconformity

Numazawa volcano
[ Upper ]
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Numazawako Pyroclastic Deposit / Numazawako Lahar Deposit
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Numagozen Pyroclastic Deposit
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Maeyama Lava
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Sozan Lava
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Mizunuma Pyroclastic Deposit
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Mukurezawa Lava
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Shirifukitoge Pyroclastic Deposit / Nm-SB Tephra
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[ Lower ]

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

Distribution: Katakado, Aizubange city, Kawanuma county, Fukushima pref.; Tadami river, Kawaguchi - Mizunuma, Kaneyama city, Fukushima pref.; Miyashita - Hinohara, Mishima city, Onuma county, Fukushima pref.

Yamamoto and Kawanabe (2014) Jour. Geol. Soc. Japan, vol.120, no.7, pp.233-245 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.)