Back تكوين هيل كريك Arabic Formació de Hell Creek Catalan Hell Creek Czech Hell-Creek-Formation German Formación Hell Creek Spanish سازند هل کریک Persian Hell Creek Formation Finnish Formation de Hell Creek French תצורת הל קריק HE Hell Creek formáció Hungarian
| Hell Creek Formation | |
|---|---|
| Stratigraphic range: Late Cretaceous to Early Paleogene, Maastrichtian–Danian (Lancian) ~ | |
 Exposure in the badlands near Fort Peck Reservoir | |
| Type | Geological formation |
| Unit of | Montana Group |
| Sub-units | Breien, Little Beaver Creek, Middle Sandstone & Pretty Butte Members |
| Underlies | Fort Union Formation |
| Overlies | Fox Hills Formation |
| Thickness | 50–100 m (160–330 ft) |
| Lithology | |
| Primary | Claystone, mudstone |
| Other | Sandstone, siltstone, conglomerate, amber |
| Location | |
| Coordinates | 46°54′N 101°30′W / 46.9°N 101.5°W |
| Approximate paleocoordinates | 52°36′N 74°24′W / 52.6°N 74.4°W |
| Region | Montana, North Dakota, South Dakota, Wyoming |
| Country | United States |
| Extent | Williston Basin |
| Type section | |
| Named for | Hell Creek, Jordan, Montana |
| Named by | Barnum Brown |
| Year defined | 1907 |
   Hell Creek Formation (the United States)  Hell Creek Formation (Montana) | |
The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of Montana, North Dakota, South Dakota, and Wyoming.[1] In Montana, the Hell Creek Formation overlies the Fox Hills Formation. The site of Pompeys Pillar National Monument is a small isolated section of the Hell Creek Formation. In 1966, the Hell Creek Fossil Area was designated as a National Natural Landmark by the National Park Service.
It is a series of fresh and brackish-water clays, mudstones, and sandstones deposited during the Maastrichtian and Danian (respectively, the end of the Cretaceous period and the beginning of the Paleogene) by fluvial activity in fluctuating river channels and deltas and very occasional peaty swamp deposits along the low-lying eastern continental margin fronting the late Cretaceous Western Interior Seaway.[2] The climate was mild; the presence of crocodilians along with palm trees suggests a subtropical and temperate climate with no prolonged annual cold. The famous iridium-enriched Cretaceous–Paleogene boundary, which separates the Cretaceous from the Cenozoic, occurs as a discontinuous but distinct thin marker bedding above and occasionally within the formation, near its boundary with the overlying Fort Union Formation.
The world's largest collection of Hell Creek fossils is housed and exhibited at the Museum of the Rockies in Bozeman, Montana.[3] The specimens displayed are the result of the museum's Hell Creek Project, a joint effort between the museum; Montana State University; the University of Washington;[4] the University of California, Berkeley; the University of North Dakota; and the University of North Carolina which began in 1998.
- ^ White, Paul D.; Fastovsky, David E.; Sheehan, Peter M. (February 1998). "Taphonomy and Suggested Structure of the Dinosaurian Assemblage of the Hell Creek Formation (Maastrichtian), Eastern Montana and Western North Dakota". PALAIOS. 13 (1). SEPM Society for Sedimentary Geology: 41–51. Bibcode:1998Palai..13...41W. doi:10.2307/3515280. JSTOR 3515280. Retrieved 13 November 2020.
- ^ Fowler, Denver (5 November 2020). "The Hell Creek Formation, Montana: A Stratigraphic Review and Revision Based on a Sequence Stratigraphic Approach". Geosciences. 10 (11): 435. Bibcode:2020Geosc..10..435F. doi:10.3390/geosciences10110435. ISSN 2076-3263.
- ^ Boswell, Evelyn. "Paradise in Hell Creek". Montana State University. Retrieved 2 April 2007.
- ^ Wilson Lab