The Frenchman Formation is a stratigraphic unit of Late Cretaceous (late Maastrichtian) age in the Western Canada Sedimentary Basin. It is present in southern Saskatchewan and the Cypress Hills of southeastern Alberta. The formation was defined by G.M. Furnival in 1942^[2] from observations of outcrops along the Frenchman River, between Ravenscrag and Highway 37. It contains the youngest of dinosaur genera, much like the Hell Creek Formation in the United States.

Lithology

The Frenchman Formation consists of olive-green to brown, fine- to coarse-grained, cross-bedded sandstone with interbedded claystone bands and minor beds and lenses of intraformational clay-clast conglomerate.^[1] A conglomerate layer with well-rounded quartzite pebbles is present above the basal unconformity in some areas.^[3]

Thickness and distribution

The Frenchman Formation is present in southwestern Saskatchewan and the Cypress Hills area of southeastern Alberta. Its maximum reported thickness is about 113 m.^[3]

Age

The Frenchman Formation is of latest Maastrichtian age, and the top of the formation coincides with the Cretaceous-Paleogene boundary, as evidenced by biostratigraphic changes and, in some areas, the presence of the terminal Cretaceous iridium anomaly.^[4]

Relationship to other units

Although some early workers included the Frenchman Formation in the overlying Ravenscrag Formation, the two are separated by the Cretaceous-Paleogene boundary and are now treated separately. The contact is abrupt but conformable, and occurs at the base of the No. 1 or Ferris coal seam of the Ravenscrag Formation.^[3]

The Frenchman is separated from the underlying formations by an erosional unconformity, and depending on the depth of the erosion, the Frenchman rests on the Whitemud Formation, the Battle Formation, the Eastend Formation, or the Bearpaw Formation.^[3] It is equivalent in age to the lower part of the Scollard Formation, the lower part of the Willow Creek Formation, the lower part of the Coalspur Formation in Alberta, and the Hell Creek Formation in Montana and North Dakota.

Paleontology

Dinosaurs

Dinosaurs reported from the Frenchman Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Ankylosaurus	A. magniventris				An ankylosaurine ankylosaurid
cf. Anzu[7]	cf. A. sp.			Two manual unguals	Claws from a large caenagnathid, tentatively referred to Anzu based on size
?Dromaeosaurus[8]	?D. sp.	Scotty site		Three teeth	Some teeth are up to 3 cm in length.
Edmontosaurus	E. annectens			"Complete skull, [three or four] partial skulls."[9]	A hadrosaurid[10]
	E. saskatchewanensis				Junior synonym of E. annectens[10]
Leptorhynchos[11]	L. sp.			A partial skeleton	A caenagnathid theropod
Ornithomimus[12]	Ornithomimus sp.
Sphaerotholus[13]	cf. S. buchholtzae			"nearly complete left postorbital"	The first pachycephalosaurid reported from the Frenchman Formation
Thescelosaurus	T. assiniboiensis			Nearly complete skeleton
Torosaurus	T. sp.			Frill	A large chasmosaurine ceratopsian distinct from Triceratops. Fossils have also been unearthed in the Scollard Formation.[14][15]
Triceratops[14]	T. prorsus	Redpath, Saskatchewan		Nearly Complete Skull, one other partial skull	Being one of the most popular Dinosaurs, they are widely known.
Tyrannosaurus	T. rex			Nearly complete skeleton	"Scotty", possibly the largest T. rex ever discovered, is from the Frenchman Formation

See also

• List of dinosaur-bearing rock formations

References