Kiretto Andesite

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Kiretto Andesite Kawachi, 1977

Type locality: southern part of Mount Yatsugatake, Nagano prefecture
Volcanic rocks
Pleistocene (0.45, 0.22 Ma, K-Ar)
Intruded by: Nakadake Porphyrite

Lithofacies: Basalt - basaltic andesite, Pyroxene andesite
Lithofacies: Lava (more than 10 flow units), Debris flow deposit
Lithofacies (Minor): Scoria, Scoria agglomerate, Agglomerate, Volcanic breccia, Agglutinates

Thickness: 300 m or thicker
Thickness (A flow unit): 1 - 15 m
Distribution (Length): ca. 5.5 km
Distribution (Width): ca. 1 km
Upper limit: Unconformity (Akadake Lava)

Southern Yatsugatake volcanoes
[ Upper ]
+__+__+__+__+_
Nakadake Porphyrite
~~~~~~~~~~~~~~
Kiretto Andesite
~~~~~~~~~~~~~~
[ Lower ]

Yatsugatake volcanoes (South of Natsuzawa pass)
[ Upper ]
+__+__+__+__+_
Southern Yatsugatake volcanoes
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Mount Nakadake - Mount Gongen - Mount Iou - Kiretto - Noroshiba - Toriconi peak - Minotonokkoshi - Jogosawa creek, Mount Yatsugatake, Nagano pref.

Nishiki et al. (2007) Jour. Geol. Soc. Japan, vol.113, no.5, pp.193-211 DOI
Kawachi (1977) Geology of the Yatsugatake District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 92p. (in Japanese with English abstract 4p.)