1st stage products

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1st 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

Sedimentary facies: Pyroclastic flow deposit, Mudflow deposit
Lithofacies: Pyroxene andesite tuff breccia, Volcanic breccia
Lithofacies (Minor): Sandy tuff, Lapilli tuff
Lithofacies (Lower, Minor): Dacite tuff

Thickness: 200 m
Upper limit: Unconformity (3rd stage products)
Lower limit: Unconformity (Uenohara Welded Tuff, Ketto Formation)

Naeba volcano
[ Upper ]
+__+__+__+__+_
4th stage products
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3rd stage products
~~~~~~~~~~~~~~
2nd stage products
~~~~~~~~~~~~~~
1st stage products
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Older Naeba volcanic products
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Oakazawa creek - Shimizugawara, Tsunan city, Nakauonuma county, Niigata 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.)