No abstract

FIGURE 1. Index map showing Hettangian fossil localities southeast of Taseko Lakes. DESCRIPTION OF LOCALITIES The seven sections and fifteen other localities that are described below are indicated on Figure 1 by the same numbers as used in the text. The description of sections 1-5 including the lithology is by H. W. Tipper, that of sections 6 and 7 by E. T. Tozer. The fossil identifications are by the author of this report. Numbers in brackets after GSC locality numbers are collectors' field numbers. Section 1. Approximately H miles northeast of Castle Mountain GSC loc. 62345 (U-107aT D). P art of collections is from talus.

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...

This report describes representatives of the genera A rctocephalites Spath and Cadoceras Fischer, and includes one new A rctocephalites and five new species and varieties of Cadoceras. The A rctoceplwlites species belong to the zone of A. 11m/11s, the Cadoceras species to two stratigraphically different horizons, the lower and the upper Cadoceras beds. These two beds arc best exposed on A xe l H eiberg Tslancl (the sect ion concerned is described in the Appendix by E. T. T ozer) , and contain new species that have some affinities to Russian and English Cacloceraticls but are easily distinguishable. The fauna! Differences may be partly clue to slight differences in age. The two Arctic Cadoceras beds are probably of late earl y Callovian age. The collection from Axel Heiberg Islands shows that the genus Arkelloceras Frebold, whose exact stratigraphic position is still unknown, is older than the beds containing A rctoceplwlites.

The Oxfordian beds of the Jurassic upper Fernie group occur at many places in the Foothills and eastern Rocky Mountains between the International Boundary in the south and the Peace River country in the north. Their lower part (unit a) consists of glauconitic silt or sandstone and shale (Green beds), their upper part of dark shale with rusty weathering bands and concretions (unit bl) or dark shale with sandstone bands (unit cl=lower part of Passage beds). Unit bl is the northern equivalent of unit cl which is characteristic of the south. The Green beds are normally underlain by the lower Callovian Grey beds but locally they lie on the middle Bajocian Rock Creek member. They form an excellent horizon marker, both where they outcrop and in the subsurface. In the southern sections they are 50 to 60 feet thick. In the north (Rocky River sections) they consist of two glauconite beds, separated from each other by 50 to 60 feet of shale with concretions. These beds contain Cardioceratids of early Oxfordian age. Unit bl and the uppermost part of unit a in the south contain Buchia concentrica (Sowerby) which indicates a late Oxfordian or early Kimmeridgian age. In the western interior of the United States and in the southern plains of Canada the equivalent of the Oxfordian part of the Fernie group is the Swift formation. The Oxfordian beds of the Fernie group were deposited in the Logan Sea, which transgressed over parts of Western Canada after the late Callovian period of regression. The Canadian part of the Logan Sea was probably connected with the sea in British Columbia, and through it, with the Pacific Ocean. After the time of the late Oxfordian or early Kimmeridgian the sea began to retreat in the western interior of the United States, where the non-marine beds of the Morrison formation were deposited. During this time marine conditions still prevailed in the Canadian part of the former Logan Sea and there the final regression took place not earlier than in late Portlandian time.