Maehotakadake Welded Tuff

[ Top ] [ Japanese ]

Maehotakadake Welded Tuff Harayama, 1990

Type locality: Mount Maehotakadake - Mount Okuhotakadake - Daikiretto, Matsumoto city, Nagano prefecture
Volcanic rocks
early Pleistocene (2.8 Ma, FT)
Intruded by: Diorite porphyry

Lithofacies: Augite hypersthene andesite - Dacite welded tuff (A cooling unit)
Sedimentary structures: Eutaxitic structures

Thickness: 1,000 m or thicker
Upper limit: Conformity (Minamidake Tuff Breccia)
Lower limit: Unconformity (Yarigatake Metamorphic Rocks, Yarisawa Breccia, Okumatashiro Granite, Byobunoatama Granophyre, Mino Belt)

Hotaka Andesites
[ Upper ]
~~~~~~~~~~~~~~
Minamidake Tuff Breccia
--------------
Maehotakadake Welded Tuff
~~~~~~~~~~~~~~
Yaemonzawa Lava
~~~~~~~~~~~~~~
Senjosawa Breccia
~~~~~~~~~~~~~~
Yarisawa Breccia
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Mount Maehotakadake - Mount Okuhotakadake - Daikiretto - Hidanokkoshi - Mount Yarigatake - Mount Roppyakuyama, Matsumoto city, Nagano pref.; Suiendani valley, Okuhidaonsengo, Takayama city, Gifu pref.

Harayama et al. (1991) Geology of the Yarigatake District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 190p. (in Japanese with English abstract 8p.)
Harayama (1990) Geology of the Kamikochi District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 175p. (in Japanese with English abstract 11p.)