Inai Gr

Cenozoic

Cretaceous

Jurassic

Triassic

Permian

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Inai Gr

Period:

Triassic

Age Interval:

Early-Middle Triassic (Induan-Ladinian), (8e, 8f, 8g, 8h)

Province:
South Kitakami Belt-Central Sub-belt, South Kitakami Belt-Western Sub-belt

Type Locality and Naming

the Karakuwa-Oshika Sub-belt, the Shizugawa (Shizukawa)-Hashiura Sub-belt; Mizunuma area, the Shizugawa (Shizukawa)-Hashiura Sub-belt; Hashiura area, the Shizugawa (Shizukawa)-Hashiura Sub-belt; Shizugawa area

Synonym:

Lithology and Thickness

The group comprises the Hiraiso, Osawa, Fukkoshi, and lsatomae formations in conformable ascending order (Onukj & Bando 1959).

Lithology Pattern:

Sandy_claystone

Relationships and Distribution

Lower contact

Regionally, the schematic strat column indicates the next older unit as Isatomae Fm

Upper contact

Regionally, the schematic strat column indicates the next younger unit as Kosaba Fm in Central Sub-belt, Uchinohara Fm in Western Sub-belt; Mizunuma area & Hashiura area, Shindate Fm in Western Sub-belt; Shizugawa area

Regional extent

Lower-Middle Triassic rocks are represented by the Inai Gr which crops cut in the Shizugawa-Hashiura Sub-belt and Karakuwa-Oshika Sub-belt of the Southern Kitakami Massif and in the Rifu district to the west of the former.

GeoJSON

null

Fossils

Age

Early-Middle Triassic (Induan-Ladinian)

Age Span:

Beginning stage:

Induan

Fraction up in beginning stage:

0.0

Beginning date (Ma):

251.90

Ending stage:

Pliensbachian

Fraction up in the ending stage:

1.0

Ending date (Ma):

184.20

Depositional setting

Depositional pattern:

Additional Information

Compiler:

Moreno, T., WALLIS, S., Kojima, T. & Gibbons, W. (Eds) 2016. The Geology of Japan. Geological Society. London. 1-24.