Hongo Formation

[ Top ] [ Japanese ]

Sagashi Formation Minashi et al., 1984

Type locality: Hongo - Oi, Minamiboso city, Chiba prefecture
Coherent formation
Landward slope basin of trench
early - middle Pleistocene
Correlation: Higashinagata Formation

Sedimentary facies: Marine
Lithofacies: Interbedded sandy mudstone and scoriaceous sandstone

Thickness: ca. 250 m
Upper limit: Conformity (Sagashi Formation)
Lower limit: Conformity (Oi Formation), Unconformity (Minamiboso Group)

Toyofusa Group (Western part)
[ Upper ]
~~~~~~~~~~~~~~
Ikenouchi Formation
--------------
Hongo Formation
--------------
Oi Formation
~~~~~~~~~~~~~~
[ Lower ]

Toyofusa Group (Eastern part)
[ Upper ]
~~~~~~~~~~~~~~
Takigawa Formation
'''''''/,,,,,,
Higashinagata Formation
~~~~~~~~~~~~~~
Kamo Formation
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Hongo - Oi, Minamiboso city, Chiba pref.; Takehara - Kamigo, Tateyama city, Chiba pref.

Suzuki et al. (1990) Geology of the Nago District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 48p. (in Japanese with English abstract 3p.)