Diligencia Formation
Diligencia Formation Stratigraphic range: Late Oligocene-Early Miocene (Arikareean) ~ | |
---|---|
Type | Formation |
Overlies | Proterozoic augen gneiss (basement) (in the north) |
Thickness | 1,500 m (4,900 ft) |
Lithology | |
Primary | Conglomerate, sandstone, siltstone, limestone |
Other | Interbedded basalt and andesite |
Location | |
Coordinates | 33°30′N 115°42′W / 33.5°N 115.7°WCoordinates: 33°30′N 115°42′W / 33.5°N 115.7°W |
Approximate paleocoordinates | 32°12′N 107°30′W / 32.2°N 107.5°W |
Region | California |
Country | United States |
Extent | Orocopia Mountains |
Type section | |
Named by | Crowell |
Year defined | 1975 |
Diligencia Formation (the United States) |
The Diligencia Formation (Td) is a geologic formation cropping out in the Orocopia Mountains in southern California. It preserves mammal fossils dating to the Late Oligocene to Early Miocene (Arikareean in the NALMA classification).[1]
Description[]
The non-marine Diligencia Formation, defined by Crowell in 1975, is composed of alluvial, fluvial, and lacustrine conglomerates, sandstones, siltstones and limestones. It contains interbedded basalt and andesite flows, dated by whole-rock and plagioclase K-Ar methods as ca. 24–21 Ma), and andesitic sills and dikes.[2][3]
Fossil content[]
The formation has provided the following fossils:[1]
- Mammals
- Artiodactyls
- Merycoidodontidae
See also[]
References[]
- ^ a b Diligencia Formation at Fossilworks.org
- ^ Coffey et al., 2019, p.481
- ^ Canyon Spring at Fossilworks.org
- ^ Woodburne & Whistler, 1973
Bibliography[]
- Stratigraphy, provenance, and tectonic significance of the Punchbowl block, San Gabriel Mountains, California, USA. Geosphere 15. 479–501. ; , and . 2019.
- Journal of Paleontology 47. 908–912. , and . 1973. An Early Miocene Oreodont (Merychyinae, Mammalia) from the Orocopia Mountains, Southern California.
Categories:
- Geologic formations of California
- Miocene Series of North America
- Oligocene Series of North America
- Miocene California
- Paleogene California
- Chattian Stage
- Aquitanian (stage)
- Sandstone formations of the United States
- Conglomerate formations
- Shale formations of the United States
- Siltstone formations
- Oligocene volcanism
- Alluvial deposits
- Fluvial deposits
- Lacustrine deposits
- Paleontology in California