Forbes Shale
Geologic formation in the Sacramento Valley, California, USA
| Forbes Shale | |
|---|---|
| Stratigraphic range: Coniacian ~89.8–86.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓ | |
| Type | Formation |
| Unit of | Asuncion Group |
| Underlies | Kione Sands |
| Overlies | Funks Shale |
| Thickness | 1,300 ft (400 m) |
| Lithology | |
| Primary | Shale |
| Location | |
| Coordinates |   Forbes Shale (the United States) Show map of the United States Forbes Shale (California) Show map of California |
The Forbes Shale is a geologic formation in the Sacramento Valley of northern California, United States. It is found in the Sutter Buttes area of Sutter County, California. It preserves fossils dating back to the Coniacian stage of the Late Cretaceous period.[1]
Fossil content
The following fossils were reported from the formation:[1][2]
- Bivalves
- Cladoceramus undulatoplicatus
- Glycymerita veatchii
- Inoceramus subundatus
- I. Inoceramus vancouverensis
- I. aff. chicoensis
- I. aff. klamathensis
- I. aff. whitneyi
- Parallelodon|Parallelodon (Nanonavis) brewerlanus
- Pseudomelania colusaensis
- Gastropods
- Bernaya (Protocypraea) kayei
- Biplica obliqua
- Dentalium (Entalis) whiteavesi
- Pseudomelania colusaensis
- Tessarolax distorta
- Volutoderma californica
- Ammonites
- Baculites chicoensis
- B. inornatus
- Desmophyllites diphylloides
- Eupachydiscus arbucklensis
- E. willgreeni
- Eutrephoceras campbelli
- Lytoceras (Gaudryceras) alamedense
- Nowakites dobbinsi
- N. rumseyensis
- Oxybeloceras petrolense
- Parapachydiscus cortinaensis
- Puzosia (Holcodiscoides) gorrilli
- Puzosia (Parapuzosia) arenaica
- Baculites sp.
- Canadoceras sp.
- Hauericeras sp.
See also
- Cretaceous California
- List of fossiliferous stratigraphic units in California
References
- ^ a b Forbes Shale at Fossilworks.org
- ^ Anderson, 1958
Bibliography
- Anderson, F. M. 1958. Upper Cretaceous of the Pacific Coast. Geological Society of America Memoir 71. 1–378. .
Further reading
- Google Books: The Sutter Buttes of California: A Study of Plio-Pleistocene Volcanism; Howel Williams, Garniss H. Curtis.
