Nakatsukyo Tuff Member

[ Top ] [ Japanese ]

Nakatsukyo Tuff Member

Type locality: Koayukawa river, Funazawa - Odai, Kiyokawa city, Aiko county, Kanagawa prefecture
Volcanic rocks
Trough-fill deposit at the collision boundary between Oceanic arc of Paleo-Izu-Bonin arc (Ocean crust) and Honshu arc (Island arc)
late Miocene
Interfingered: Junreitoge Conglomerate and Sandstone Member

Sedimentary facies: Marine
Lithofacies: Andesite lapilli tuff, Tuff breccia
Lithofacies (Minor): Dacite tuff, Lapilli tuff, Tuffaceous mudstone, Sandstone

Thickness: 550 m or thicker
Lower limit: Conformity (Funazawa Formation)

Nakatsukyo Formation
[ Upper ]
--------------
Nakatsukyo Tuff Member
--------------
Ichido Mudstone and Sandstone Member
--------------
Junreitoge Conglomerate and Sandstone Member
--------------
Nakatsukyo Volcanic Breccia Member
--------------
[ Lower ]

Aikawa Group
[ Upper ]
--------------
Sekirozan Formation
--------------
Nakatsukyo Formation
--------------
Funazawa Formation
--------------
Miyagase Formation
--------------
[ Lower ]

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

Distribution: Koayukawa river - Mount Takatori, Kiyokawa city, Aiko county, Kanagawa pref.; Shimofurusawa - Okatsukoku, Atsugi city, Kanagawa pref.
Fossils: Chlamys kaneharai

Oka et al. (1979) Geology of the Fujisawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 111p. (in Japanese with English abstract 5p.)