| Title | Jurassic and (F) Triassic Rocks of the eastern Slope of Richardson Mountains, northwestern District of Mackenzie 106m and 107b |
| Download | Downloads |
| Author | Jeletzky, J A |
| Source | Geological Survey of Canada, Paper 66-50, 1967, 171 pages, https://doi.org/10.4095/100652 |
| Year | 1967 |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Northwest Territories |
| NTS | 106M; 107D |
| Area | Richardson Mountains |
| Lat/Long WENS | -136.0000 -134.0000 69.0000 67.0000 |
| Subjects | regional geology; paleontology; stratigraphy; correlations; fossil distribution, geographic; fossil lists; type sections; volgian; bajocian; bathonian; berriasian; callovian; kimmeridgian; oxfordian;
pliensbachian; portlandian; sinemurian; toarcian; tithonian; lower cretaceous; lower jurassic; Aklavik Arch; Arctoasteroceras Jeletzkyi Zn; Brat Creek Formation; Buchia Concentrica Zone; Buchia Fischeriana Zone; Buchia Mosquensis Zone; Buchia Okensis
Zone; Buchia Piochii Zone; Buchia Uncitoides Zone; Buchia Volgensis Zone; Bug Creek Formation; Cadoceras Spp Zone; Coaly Shale Division; Cranocephalites Borealis Zone; Craspedites Canadensis Zone; Echinoceras Sp Indet Zone; Husky Formation; North
Branch Formation; Rat River Gorge; White Mountains Dome; Pennsylvanian; Permian; Triassic; Jurassic; Cretaceous; Mesozoic |
| Illustrations | correlation charts; stratigraphic sections |
| |
| Released | 1967 01 01; 2016 03 11 |
| Abstract | The area is characterized by thin and incomplete development of the Jurassic System, which is largely represented by shallow-water, marine to non-marine (?)elastics (sandstones and more or less sandy
siltstones with greater or lesser interbeds of coarser elastics). Within the area the Jurassic shallow-water sandstones and siltstones gradually become replaced laterally by the neritic to(?) non-marine sandstones, grits, and conglomerates toward the
south. Westward the shallow-water facies is replaced by the deep-water, predominantly pure shales and various siltstones. The same probably happens at the northern end of the range. The thicknesses of all Jurassic isochronous units increase markedly
westward and (?)northward . The southern shoreline of the Jurassic sea must have been situated closely south of Vittrekwa River basin because of the observed facies changes and apparently complete absence of marine Jurassic rocks south therefrom. The
predominantly sandy lower part of the Jurassic System north of Vittrekwa River basin is named Bug Creek Formation. The presence of a pronounced disconformity within this formation and the apparently erosionally-caused absence of its lower Jurassic
part in the Rat River area indicate the flexing and uplift of the Aklavik arch at that time. The predominantly silty to shaly upper part of the Jurassic System of the same area is named Husky Formation which also includes basal Cretaceous rocks. The
Bug Creek Formation thins out on Stony Creek and at Teeweechee Mountain and presumably wedges out completely south of these localities. The Husky Formation becomes laterally replaced by the predominantly coarse elastics named North Branch Formation,
between Stony Creek and the North Branch of Vittrekwa River. The North Branch Formation is underlain by the undated, (?)Palaeozoic to ( ?) Jurassic shale unit. The Triassic (? ) rocks were only found in the Rat River Gorge and adjacent parts of
Aklavik Range. Their upper part is referred to as the Coaly shale division. This unit is underlain by pebble -conglomerates and coarse, pebbly sandstones with interbeds of finer-grained elastics, named the Brat Creek Formation which disconformably
overlie early Permian sandstones and siltstones in at least one section. The palynological data suggest Triassic age in preference to the also possible Permian (late Permian only?) age. A number of important sections measured by the writer and others
is appended to the report. |
| GEOSCAN ID | 100652 |
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