F84 - Silverado Formation, Santa Ana Mountains: Thanetian, California
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
|
Gastropoda
- Turritellidae
|
|||||||
|
Turritella cf. pachecoensis
Stanton 1896
|
|||||||
| see common names | |||||||
Geography
| Country: | United States | State/province: | California | County: | Orange |
| Coordinates: | 33.9° North, 117.8° West (view map) | ||||
| Paleocoordinates: | 37.5° North, 98.3° West | ||||
| Basis of coordinate: | based on nearby landmark | ||||
| Altitude: | 130 meters | ||||
| Geographic resolution: | outcrop |
Time
| Period: | Paleogene | Epoch: | Paleocene |
| Stage: | Thanetian | 10 m.y. bin: | Cenozoic 1 |
| Key time interval: | Thanetian | ||
| Age range of interval: | 59.20000 - 56.00000 m.y. ago |
Stratigraphy
| Formation: | Silverado | ||||
| Local section: | Santa Ana Canyon Road | ||||
| Regional section: | Los Angeles | ||||
| Stratigraphic resolution: | bed | ||||
| Stratigraphy comments: The type section suggests a thickness of around 350 m for the Silverado Formation, which lies unconformably upon the Late Cretaceous Williams Formation and Ladd Formation, and is overlain unconformably by the Santiago Formaton. The Silverado Formation is given a Paleocene age on the basis of macrofauna (sparse index taxa), but more finely assigned by McCulloh et al. (2000) to the Martinez stage = Thanetian. Calcareous nannoplankton zone CP7-CP; Planktonic foraminifera zone P4-P5; Ynezian foram zone. The Silverado Formation is correlative to the lower-middle Santa Susana Formation. From upper sandstone beds. | |||||
Lithology and environment
| Primary lithology: | fine,medium sandstone |
| Includes fossils? | Y |
| Lithology description: Fine-medium grained sandstone | |
| Environment: | marine indet. |
| Glacial or sequence phase: | transgressive |
| Geology comments: The contact below the Silverado Formation represents an episode of deformation and extensive erosion and deep weathering between the deposition of the late Cretaceous rocks and the Paleocene strata. | |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
Collection methods and comments
| Collection methods: | selective quarrying,field collection,survey of museum collection |
| Reason for describing collection: | biostratigraphic analysis |
| Museum repositories: | USGS |
| Collection method comments: Collected by J.E. Schoelhamer. Material likely to be reposited in USGS Menlo Park collections or USNM. | |
| Taxonomic list comments:Fossils identified by Stewart (1954, 1955) and Moore (1959). Relatively good nomenclature | |
Metadata
| Also known as: | USGS #18981; Field #S26 | ||
| Database number: | 52594 | ||
| Authorizer: | A. Hendy | Enterer: | A. Hendy |
| Modifier: | A. Hendy | Research group: | marine invertebrate |
| Created: | 2005-08-11 20:57:04 | Last modified: | 2013-11-25 13:37:23 |
| Access level: | the public | Released: | 2005-08-11 20:57:03 |
| Creative Commons license: | CC BY | ||
Reference information
Primary reference:
| 3060. | J. E. Schoellhamer, J. G. Vedder, R. F. Yerkes and D. M. Kinney. 1981. Geology of the Northern Santa Ana Mountains, California. United States Geological Survey Professional Paper 420(D):1-109 [J. Alroy/J. Alroy/R. McClees-Funinan] |