Frenchman Formation

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. A conglomerate layer with well-rounded quartzite pebbles is present above the basal unconformity in some areas.

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.

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.

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.

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. 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

Mammals and birds

J.E. Storer described fossil mammals from the Gryde locality in the Frenchman Formation, including Parectypodus and Alphadon. A bone (the humeral end of the left coracoid) of a bird attributed to the genus Cimolopteryx has also been described from the Gryde locality.

Dinosaurs

Plants

Two megafloral assemblages were collected from Grasslands National Park and the Chambery Coulee site. The differences in floral composition as well as evidence of forest fires indicated these two localities represented an ecological succession in a fire-disturbed environment, with burned mature forests being colonised by pioneer shrubs and then a subsequent reestablishment of coniferous and hardwood forest. Leaf analysis estimated mean annual temperatures of 12-14 C in a largely deciduous mixed forest of temperate climate.

References

References

1. Furnival, G.M., 1942. Preliminary Map, Cypress Lake, Saskatchewan; [[Geological Survey of Canada]], Paper 42-5, contains Preliminary Map 42-5, Cypress Lake, West of Third Meridian, Saskatchewan, Scale: 1 inch to 2 miles.
2. [[Lexicon of Canadian Geological Units]]. "Frenchman Formation".
3. Glass, D.J., editor, 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada. Canadian Society of Petroleum Geologists, Calgary, Alberta, 1423 p. on CD-ROM, {{ISBN. 0-920230-23-7.
4. (1987). "The relationship between the iridium anomaly and palynological floral events at three Cretaceous-Tertiary boundary localities in western Canada". Geological Society of America Bulletin.
5. (30 September 1991). "The mammals of the Gryde Local Fauna, Frenchman Formation (Maastrichtian: Lancian), Saskatchewan". Journal of Vertebrate Paleontology.
6. (December 1989). "Cimolopteryx sp. (Aves, Charadriiformes) from the Frenchman Formation (Maastrichtian), Saskatchewan". Canadian Journal of Earth Sciences.
7. (January 2015). "Large caenagnathids (Dinosauria, Oviraptorosauria) from the uppermost Cretaceous of western Canada". Cretaceous Research.
8. Tokaryk, Tim T.. "The fauna from the ''Tyrannosaurus rex'' excavation, Frenchman Formation (Late Maastrichtian), Saskatchewan". Saskatchewan Geological Survey.
9. "Table 20.1," in Weishampel, et al. (2004). Page 440.
10. Campione, N.E. and Evans, D.C. (2011). "[http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0025186 Cranial Growth and Variation in Edmontosaurs (Dinosauria: Hadrosauridae): Implications for Latest Cretaceous Megaherbivore Diversity in North America.]" ''PLoS ONE'', '''6'''(9): e25186. {{doi. 10.1371/journal.pone.0025186
11. (2015). "New elmisaurine specimens from North America and their relationship to the Mongolian ''Elmisaurus rarus''". Acta Palaeontologica Polonica.
12. "PBDB".
13. (2015-09-01). "First pachycephalosaurid (Dinosauria: Ornithischia) from the Frenchman Formation (upper Maastrichtian) of Saskatchewan, Canada". Cretaceous Research.
14. Tokaryk, T. 1986. Ceratopsian dinosaurs from the Frenchman Formation (Upper Cretaceous) of Saskatchewan. Canadian Field-Naturalist 100:192–196.
15. (2022). "The record of ''Torosaurus'' (Ornithischia: Ceratopsidae) in Canada and its taxonomic implications". Zoological Journal of the Linnean Society.
16. (May 2014). "Paleoclimate estimates and fire ecology immediately prior to the end-Cretaceous mass extinction in the Frenchman Formation (66Ma), Saskatchewan, Canada". Palaeogeography, Palaeoclimatology, Palaeoecology.
17. (February 2002). "The paleoenvironment of Tyrannosaurus rex from southwestern Saskatchewan, Canada". Canadian Journal of Earth Sciences.
18. (May 2007). "Fossil Leaf Species from the Fox Hills Formation (Upper Cretaceous: North Dakota, USA) and Their Paleogeographic Significance". Journal of Paleontology.
19. (December 2020). "Revisiting the Late Cretaceous Parataxodium wigginsii flora from the North Slope of Alaska, a high-latitude temperate forest". Cretaceous Research.