Ione Formation
| Ione Formation | |
|---|---|
| Stratigraphic range: Eocene | |
A rock from the Ione Formation | |
| Type | Geologic formation |
| Underlies | Chico Formation (regionally) |
| Overlies | Martinez Formation (regionally) |
| Location | |
| Region | California |
| Country | United States |
The Ione Formation is an Eocene Epoch geologic formation in California.[1][2][3]
Geology
The formation regionally overlies the Martinez Formation and regionally underlies the Chico Formation.
History
The auriferous gravels accumulated on slope of Sierra Nevada during the Neocene Period, and at same time there was deposited in the gulf then occupying the Great Valley a sedimentary series consisting of clays and sands.
Description
It is usually overlain by a few feet of reddish Pleistocene gravel and rests on Chico formation. The strata form flat-topped hills, and consists of a succession of light-colored clays and white or yellowish-white sandstones. The largest development occurs south of American River.
See also
- List of fossiliferous stratigraphic units in California
- Paleogene California
- Paleontology in California
References
- ^ "Science". AAAS. doi:10.1126/science.40.1019.67. Retrieved 2026-02-07.
- ^ "Type Region of the Ione Formation (Eocene), Central California: Stratigraphy, Paleogeography, and Relation to Auriferous Gravels". pubs.usgs.gov. Retrieved 2026-02-07.
- ^ "Geolex — Ione publications". ngmdb.usgs.gov. Retrieved 2026-02-07.