Magnetic stratigraphy of the lower middle Eocene (type Ulatsian) Vacaville Shale, Solano County, California
Links
- The Publications Warehouse does not have links to digital versions of this publication at this time
- Download citation as: RIS | Dublin Core
Abstract
Mallory (1959) designated exposures of the Vacaville Shale on Ulatis Creek, northwest o Vacaville, California, as the type section of his lower middle Eocene Ulatisian benthic foraminiferal stage. Magnetic samples were taken from the 75 m of exposed section, and yielded a stable remanence held mainly in magnetite which passed a reversal test. The section showed two normal zones and three reversed magnetozones. Based on calcareous nannofossils and planktonic foraminifera, we correlate the type Ulatisian with Chron C20r-C22r (45.0-50.5 Ma), which is latest early Eocene to early middle Eocene on the global time scale. Our data calibrate what has been previously suggested by micropaleontologists: the base of the Ulatisian in the Vacaville Shale is 2 million years older (50.5 Ma) than it is in Media Agua Creek in the Temblor Range (48.5 Ma), and that the top of the Ulatisian is a million years younger (46.5 Ma) in the Vacaville section then it is at Media Agua Creek (47.5 Ma). This is another example of the problems with time-transgressive benthic foraminiferal stages.
Suggested Citation
Prothero, D., Brabb, E.E., 2001, Magnetic stratigraphy of the lower middle Eocene (type Ulatsian) Vacaville Shale, Solano County, California, chap. of Pacific Section, Society of Economic Paleontologists and Mineralogists, v. 91, p. 56-64.
| Publication type | Book chapter |
|---|---|
| Publication Subtype | Book Chapter |
| Title | Magnetic stratigraphy of the lower middle Eocene (type Ulatsian) Vacaville Shale, Solano County, California |
| ISBN | 1-878861-84-0 |
| Volume | 91 |
| Year Published | 2001 |
| Language | English |
| Publisher | Society of Economic Paleontologists and Mineralogists, Pacific Section |
| Description | 9 p. |
| Larger Work Type | Book |
| Larger Work Subtype | Monograph |
| Larger Work Title | Pacific Section, Society of Economic Paleontologists and Mineralogists |
| First page | 56 |
| Last page | 64 |