Jurassic Fernie group in the Canadian Rocky mountains and foothills

Abstract

The Fernie group comprises most of the Jurassic strata in the Canadian Rocky Mountains and Foothills. Only the uppermost part of the Jurassic is not included in the Fernie group, but forms the lowermost part of the Kootenay formation and its equivalent, the Nikanassin formation, which normally overlie the Fernie group. The Fernie group extends from the International Boundary in the south to the Peace River country in the north in a band about 700 miles (1,120 kilometres) long and about 60 miles (about 100 kilometres) wide. The outcrops are mainly in the valleys and on the slopes of the mountains and most are comparatively easily accessible by motor car or horses. Complete sections are rarely seen mainly owing to vegetation cover. The name "Fernie shales" was first used by McEvoy and Leach (1902) 1 on the gedlogical and topographical map of Crowsnest coalfields, East Kootenay District, and their age was determined as "Lower Cretaceous or Jurassic". However, as shown in Telfer's (1933) sections and further proved by the writer's investigation in this area, the strata mapped by McEvoy and Leach as "Fernie shales" include beds of Triassic age. Furthermore no continuous section is exposed in the area that gave its name to the group. The name "Fernie shales" was used again on the map of the Blairmore-Frank coalfields (Leach, 1903) for a 700-foot series of shales, which were regarded as Lower Cretaceous. Later Leach (1912, pp. 193, 194) placed the "Fernie shales" in the Jurassic and separated them from the overlying Kootenay beds. Since then the "Fernie shales", "Fernie formation", and "Fernie group" have been regarded as belonging to the Jurassic system. Many palaeontological and stratigraphical contributions have been made to the knowledge of the Fernie group in the course of the years, particularly by McLearn and Warren who proved the presence of beds belonging to the Lower, Middle, and Upper Jurassic. These earlier studies have shown the necessity for a systematic stratigraphical and palaeogeographical investigation of the Fernie on a palaeontological basis. Such a study was commenced by the writer in 1950 between the International Boundary and Snake Indian Valley and in the Pine Pass region in the north. It was not possible during the time available to study all the outcrops within this large area and many details may be added by future investigations. Information on the area between Snake Indian Vallej' and Pine Pass region was obtained by several Geological Survey field parties. It will be shown in the present report that the sequence of the Jurassic Fernie group in the Canadian Rocky Mountains and Foothills is very 'Names and date9 in parentheses are those of references listed at the end of this report. the Triassic is missing in those places where the Toarcian is the oldest Fernie sediment (see Figure 3). The most important index fossils of the Fernie group are ammonites. In the lower Fernie appear Arnioceras, Harpoceras, Dactylioceras, and Peronoceras. In the middle Fernie Sonninia, Teloceras, Stephanoceras, S...

A new ammonite and coccolith fauna from the lowermost Fernie Formation (Hettangian) in northwestern Alberta, Canada

“…D. silberlingi, provides the oldest date so far for the basinal shales of the lower Fernie Formation in the subsurface of Alberta, confirming that these beds are older than both the typical Nordegg Member of the outcrop belt (questionably Sinemurian; Frebold 1957Frebold , 1969Poulton et al 1990) and its supposed basinal subsurface equivalents called the "Nordegg Member" (Pliensbachian) by some recent authors.…”

“…It rests with apparent conformity on Triassic or Paleozoic units. Frebold (1957Frebold ( , 1969 dated these outcrops as early Sinemurian, based on the occurrence of poorly preserved arietitid ammonites; recently, this age assignment has been questioned (Poulton et al 1990). …”

Shale gas potential of the Lower Jurassic Gordondale Member, northeastern British Columbia, Canada

“…The Gordondale Member was deposited during transgression/regression cycles in a partially silled basin, created by terrane obduction onto the North American craton (Riediger et al, 1990;Riediger and Bloch, 1995). In NE BC and west-central Alberta, the Gordondale Member is the basinal equivalent of the lithologically and faunally different Nordegg Member in southwestern Alberta (see Frebold, 1957). The lithological and paleontological variability of the Gordondale/Nordegg members lead to a revision of the lower Fernie Formation nomenclature by AsgarDeen et al (2004) who proposed the Gordondale Member for the highly radioactive, Hettangian to upper Toarcian organicrich strata in west-central Alberta and NE BC.…”

The ammonite genusHarpoceras(Early Jurassic) in New Zealand

“…It also became distributed throughout the circum-Pacific region, with occurrences recorded from Western Canada and Alaska (Imlay 1955;Frebold 1957;Jakobs 1997), Japan (Hirano 1971), southern South America (Möricke 1894 ;Burckhardt 1903;Hillebrandt & Schmidt-Effing 1981;Hillebrandt 1987), and New Caledonia (Avias 1985) (see Howarth 1992b, pp. 108-109).…”