| Futaba Group | |
|---|---|
| Stratigraphic range: | |
| Type | Geological group |
| Sub-units | Ashizawa Formation, Kasamatsu Formation, Tamayama Formation |
| Underlies | Unconformity with Paleogene Shiramizu Group |
| Overlies | Early Cretaceous Granite, Permian shale and sandstone |
| Thickness | Over 300 metres |
| Lithology | |
| Primary | Sandstone, siltstone, conglomerate |
| Location | |
| Region | northern Honshu |
| Country | Japan |
The Futaba Group is a Late Cretaceous geologic group in 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] It consists of both fluvial and shallow marine sediments. [2] The plesiosaur Futabasaurus was found in this unit (specifically the Tamayama Formation).