Honmagawa Lavas

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Honmagawa Lavas Kawachi, 1974

Abbr.: HO

Type locality: 1,110 m above sea level of Goka, Koumi city, Minamisaku county, Nagano prefecture
Volcanic rocks
early Pleistocene

Lithofacies: Olivine orthopyroxene clinopyroxene basaltic andesite
Lithofacies: Lavas (more than 2 flow units), Pyroclastic rocks

Source: Oishi river
Eruptive volume: 0.3 km³
Thickness: ca. 12 m
Thickness (A unit): 5 - 10 m
Intercalated in Komadeike Volcaniclastics.

Komadeike Volcaniclastics
[ Upper ]
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Honmagawa Lavas
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Oishigawa Lavas
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Chiyosato Lava
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[ Lower ]

Oishigawa Volcanic Rocks
[ Upper ]
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Kengamine-jobu Lavas
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Kengamine Pyroclastics
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Chiyosato-bokujo Lavas
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Kengamine-east Lavas
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Komadeike Volcaniclastics
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Kabutoiwa Lava
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Yachiho-kogen Lavas
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Oishigawa-futamata Lavas
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[ Lower ]

Kengamine volcanic body
[ Upper ]
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Oishigawa Volcanic Rocks
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[ Lower ]

Yabashira volcanoes
[ Upper ]
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Kengamine volcanic body
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Byobuiwa volcanic body
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Yabashirayama volcanic body
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Ryugamine volcanic body
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Tokin-no-iwa volcanic body
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[ Lower ]

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

Distribution: 850 - 1,1100 m above sea level, Honma river - Arakura river - Barasawa river, Chiyosato, Koumi city, Minamisaku county, Nagano pref.

Nishiki and Takahashi (2012) Jour. Geol. Soc. Japan, vol.118, no.8, pp.499-515 DOI
Nishiki et al. (2007) Jour. Geol. Soc. Japan, vol.113, no.5, pp.193-211 DOI
Kawachi (1974) Geology of the Tateshinayama District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 114p. (in Japanese with English abstract 5p.)