Fox Hills Formation

Fox Hills Formation Stratigraphic range: Late Cretaceous PreЄ Є O S D C P T J K Pg N
Type	Geological formation
Lithology
Primary	Sandstone
Other	Shale

The Fox Hills Formation is a Cretaceous geologic formation in the northwestern Great Plains of North America. It is present from Alberta on the north to Colorado in the south.

Dinosaur remains including those of the tyrannosaurs as well as those of non-dinosaur mosasaurs are among the fossils that have been recovered from the formation.

Lithology

The Fox Hills Formation consists of marginal marine yellow sandstone with shale interbeds. It was deposited as a regressive sequence during the retreat of the Western Interior Seaway in Late Cretaceous time. It is underlain by the marine Pierre Shale in the US and by the equivalent Bearpaw Formation in Canada. The Fox Hills is overlain by continental sediments, called the Laramie Formation in the US.

See also

• List of dinosaur-bearing rock formations
  • List of stratigraphic units with indeterminate dinosaur fossils