Haraoka Formation

[ Top ] [ Japanese ]

Haraoka Formation Kawakami and Shishikura, 2006

Type locality: Toyooka seashore, Tomiura town, Minamiboso city, Chiba prefecture
Coherent formation
middle - late Miocene
Correlation: Nishizaki Formation

Sedimentary facies: Marine
Lithofacies: Interbedded sandstone and siltstone
Lithofacies (Minor): Scoria
Sedimentary structures: Slump structures

Thickness: 200 m
Lower limit: Conformity (Hota Group)

Minamiboso Group
[ Upper ]
~~~~~~~~~~~~~~
Kagamigaura Formation
--------------
Hedate Formation
--------------
Koura Formation
--------------
Kohama Formation
--------------
Haraoka Formation
--------------
Ishido Formation
--------------
Azuma Formation
--------------
Iwaibukuro Formation
--------------
[ Lower ]

Mineoka Belt (Boso peninsula)
[ Upper ]
~~~~~~~~~~~~~~
Awa Group / Minamiboso Group
~~~~~~~~~~~~~~
Hota Group
::::::::::::::
Mineoka Group
?--?--?--?--?-
[ Lower ]

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

Distribution: Toyooka - Oshima island, Tomiura town, Minamiboso city, Chiba pref.
Fossils: Radiolarians

Takahashi et al. (2016) Jour. Geol. Soc. Japan, vol.122, no.8, pp.375-395, DOI
Kawakami and Shishikura (2006) Geology of the Tateyama District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 82p. (in Japanese with English abstract 5p.)