Search SEDIS
| Data sets | Publications | Expeditions | Thesaurus |
Twin River Formation  | |
|---|---|
| BT | Chronostratigraphic Units |
| .Phanerozoic | |
| ..Cenozoic | |
| ...Tertiary | |
| ....Twin River Formation | |
| RT | Oligocene |
| Miocene | |
| Washington | |
| upper Eocene | |
| SN | Upper Eocene to Miocene. Three mappable sequences recognized: lower member consisting of thin-bedded sandstone and siltstone; middle member of massive siltstone that grades westward into bedded siltstone and sandstone; and upper member composed chiefly of |