Samuraihama Shale Member

Coherent formation
Middle Jurassic, Callovian

Lithofacies: Shale
Lithofacies (Minor): Siltstone, Sandstone

Thickness: ca. 500 - 600 m
Upper limit: Conformity (Kitsunesaki Sandstone and Shale Member)
Lower limit: Bottom of the sands-deficient horizon
Lower limit: Transitional (Tsukinoura Sandstone Member)

Tsukinoura Formation
[ Upper ]
--------------
Samuraihama Shale Member
--------------
Tsukinoura Sandstone Member
~~~~~~~~~~~~~~
[ Lower ]

Ojika Group
[ Upper ]
~~~~~~~~~~~~~~
Ayukawa Formation
--------------
Oginohama Formation
--------------
Tsukinoura Formation
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Urashuku - Izushima island, Onagawa city, Oshika county, Miyagi pref.; Hara, Ogachi town, Ishinomaki city, Miyagi pref.; Oura - Yoriiso - Oharahama, Ishinomaki city, Miyagi pref.
Fossils: Ammonoids, Shellfishes (Aulacomyella sp., Choffatia sp.)

Takizawa et al. (1987) Geology of the Yoriiso District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 74p. (in Japanese with English abstract 5p.)
Takizawa et al. (1984) Geology of the Ishinomaki District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 103p. (in Japanese with English abstract 7p.)
Takizawa et al. (1974) Geology of the Kinkasan District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 62p. (in Japanese with English abstract 5p.)