Shitazaki Formation

Shitazaki Formation (Chinzei, 1958) Tuzino et al., 2018

Invalid synonym: Shitazaki Siltstone Member

Type locality: Mabechi river, Shitazaki, Ninohe city, Iwate prefecture
Coherent formation
late Miocene (10.5 - 8.5 Ma, Diatoms, Foraminifera)

Sedimentary facies: Shallow marine
Sedimentary facies: Outer continental shelf
Climate: Warm temperate
Climate (Minor): Cold temperate
Lithofacies: Siltstone
Lithofacies (Minor): Sandy siltstone, Tuff

Thickness: ca. 200 m
Upper limit: Bottom of Kamazawa Tuff Member
Upper limit: Conformity (Kubo Formation), Unconformity (Asanai Terrace Deposit)
Upper limit (Main part): Conformity (Kamassawa Siltstone and Sandstone Member)
Lower limit: Conformity (Zyumonzi Formation), Conformity, partly unconformity (Yanagisawa Formation)
Lower limit (Main part): Conformity (Kamimetoki Sandstone Member)

Shitazaki Formation
[ Upper ]
~~~~~~~~~~~~~~
Kamassawa Sandstone and Siltstone Member
--------------
Main part
--------------
Kamimetoki Sandstone Member
--------------
[ Lower ]

Sannohe Group
[ Upper ]
~~~~~~~~~~~~~~
Kubo Formation
--------------
Shitazaki Formation
--------------
Yanagisawa Formation
--------------
Zyumonzi Formation
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Mabechi river, Shitazaki, Ninohe city, Iwate pref.; Shimotomai - Kaisho river, Ninohe city, Iwate pref.
Fossils (Bivalves): Solemya sp., Yoldia sp.
Fossils (Plants): Abies protofirma, Actinodaphne cf. nipponica, Cornus sp., Fagus palazeocrenata, Magnolia sp., Rhododendron sp.
Fossils (Diatoms): Denticulopsis dimorpha, Thalassionemaschraderi
Fossils (Foraminifera): Globorotalia cf. cultrata menardii, Globorotalia cf. dalii
Tephra: Shitazaki Tuff

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.)