Hell Creek Formation
Rock formation
>
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... Wikipedia
Age: some 65.5 million years ago
Coordinates: 46°54′N 101°30′W / 46.9°N 101.5°W
Extent: Williston Basin
Named by: Barnum Brown
Named for: Hell Creek, Jordan, Montana
Other: Sandstone, siltstone, conglomerate, amber
Region: Montana, North Dakota, South Dakota, Wyoming