Also known as USGS# 18988
Where: Orange County, California (33.9° N, 117.7° W: paleocoordinates 37.5° N, 98.2° W)
• coordinate based on nearby landmark
• outcrop-level geographic resolution
When: Silverado Formation, Thanetian (59.2 - 56.0 Ma)
• 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.
• bed-level stratigraphic resolution
Environment/lithology: marine; fine-grained, medium, shelly/skeletal sandstone
Size class: macrofossils
Reposited in the USGS
Collection methods: quarrying,
• Collected by D.M. Kinney, J.E. Schoellhamer, and W.P. Woodring. Material likely to be reposited in USGS Menlo Park collections or USNM.
Primary reference: 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]more details
Purpose of describing collection: biostratigraphic analysis
PaleoDB collection 52602: authorized by Austin Hendy, entered by Austin Hendy on 11.08.2005
Creative Commons license: CC BY (attribution)
Taxonomic list
Gastropoda | |
Turritella pachecoensis Stanton 1896 turret shell | |
Polinices (? Polinices) cf. hornii Gabb 1864 moon snail | |
Bivalvia | |
| |
Brachidontes sp. Swainson 1840 mussel | |
? Callista (? Costacallista) cf. hornii Gabb 1864 venus clam | |
? Claibornites turneri Stanton 1896 clam | |
Crassatella unioides Stanton 1896 clam | |
Nuculana cf. gabbii Conrad 1866 pointed nut clam |