Ohyamashimo Formation
| Ohyamashimo Formation | |
|---|---|
| Stratigraphic range: Albian ~ | |
Type locality of the Tambatitanis, currently covered by concrete for protection. | |
| Type | Geological formation |
| Unit of | Sasayama Group |
| Underlies | Sawada Formation |
| Overlies | Basement (Unconformity) |
| Thickness | 1300 metres |
| Lithology | |
| Primary | Conglomerate, Sandstone, Mudstone |
| Other | Tuff |
| Location | |
| Coordinates | 35°06′N 135°06′E / 35.1°N 135.1°E |
| Approximate paleocoordinates | 47°54′N 132°48′E / 47.9°N 132.8°E |
| Region | Hyōgo Prefecture |
| Country | Japan |
| Type section | |
| Named for | Ohyamashimo, Tamba-Sasayama |
| Named by | Hayashi et al., 2017 |
Ohyamashimo Formation (Japan) | |
The Ohyamashimo Formation(大山下層) is an Early Cretaceous (Albian) geologic formation, distributed in Tamba and Tamba-Sasayama, Hyogo Prefecture, Japan. It has been dated to the early-mid Albian, between 112.1 ± 0.4 Ma and 106.4 ± 0.4 Ma. The depositional environment represents a fluvial system with a subhumid to semi-arid climate. The Ohyamashimo Formation was called the 'Lower Formation' of the Sasayama Group before it was named in 2017.