| Ashizawa Formation | |
|---|---|
| Stratigraphic range: | |
| Type | Geological formation |
| Unit of | Futaba Group |
| Sub-units | Asamigawa Member, Obisagawa Member |
| Underlies | Kasamatsu Formation |
| Overlies | Early Cretaceous Granite, Permian shale and sandstone |
| Location | |
| Region | northern Honshu |
| Country | Japan |
The Ashizawa Formation is a Coniacian geologic formation in northeastern Honshu, Japan. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus. [1] A jawbone belonging to a therian mammal has also been discovered from this unit. [2]