Sukohata Siliciclastic Rock Member

Sukohata Siliciclastic Rock Member (Chinzei, 1958) Tuzino et al., 1958

Invalid synonym: Sugohata Mudstone, Sandstone and Conglomerate Member

Type locality: Narayama valley, Koida river, Sugohata - Raiden, Ichinohe city, Ninohe county, Iwate prefecture
Coherent formation
early Miocene
Correlation: Nakayama Formation

Sedimentary facies: Fluvial, Lacustrine
Sedimentary facies: Dammed lake
Climate: Warm temperate (Annual averate temperature 12.4 - 15 degree C)
Lithofacies: Interbedded conglomerate, sandstone and mudstone
Sedimentary structures: Imbricate structure, Channel structure

Thickness: A few tens - 160 m
Lower limit: Interfingered (Keiseitoge Volcanic Rock Member)

Yotsuyaku Formation
[ Upper ]
--------------
Sukohata Siliciclastic Rock Member
-------''''/,,,
Keiseitoge Volcanic Rock Member
-------''''/,,,
Koiwai Mudstone Member
-------''''/,,,
Matsukura Siliciclastic Rock Member
~~~~~~~~~~~~~~
[ Lower ]

Shiratorigawa Group
[ Upper ]
~~~~~~~~~~~~~~
Suenomatuyama Formation
--------------
Kadonosawa Formation
--------------
Yotsuyaku Formation
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Sugohata - Raiden - Narayama - Nezori - Nosoki - Mega, Ichinohe city, Ninohe county, Iwate pref.; Numanotai - Sakamoto - Yotsuyaku - Takada - Nisatai - Shinokura - Ohagino, Ninohe city, Iwate pref.
Fossils (Daijima-type flora): Comptoniphyllum sp. Juglans cf. miochinensis, Lindera sp., Liquidambar sp., Machilus cf. ugana, Picea sp. (Cones), Pinus cf. miocenica, Quercus mandraliscae, Quercus cf. protoacuta

Tuzino et al. (2018) Geology of the Ichinohe District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 161p. (in Japanese with English abstract 4p.)