Ordovician Formations and Faunas, Southern Mackenzie Mountains
Ordovician strata of the South Nahanni River area occur as a western fine clastic facies with graptolitic faunas (Road River Formation) and an eastern carbonate facies with shelly faunas (Broken Skull, Sunblood, Esbataottine, and Whittaker Formations). The lithofacies are controlled by major tectoni...
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crcansciencepubl:10.1139/e75-059 2024-05-19T07:43:47+00:00 Ordovician Formations and Faunas, Southern Mackenzie Mountains Ludvigsen, Rolf 1975 http://dx.doi.org/10.1139/e75-059 http://www.nrcresearchpress.com/doi/pdf/10.1139/e75-059 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 12, issue 4, page 663-697 ISSN 0008-4077 1480-3313 journal-article 1975 crcansciencepubl https://doi.org/10.1139/e75-059 2024-05-02T06:51:27Z Ordovician strata of the South Nahanni River area occur as a western fine clastic facies with graptolitic faunas (Road River Formation) and an eastern carbonate facies with shelly faunas (Broken Skull, Sunblood, Esbataottine, and Whittaker Formations). The lithofacies are controlled by major tectonic features. In the early Ordovician the Selwyn Basin received fine clastic sedimentation (Road River) while carbonate sedimentation (Broken Skull, Sunblood, Esbataottine) was confined to the Root Basin and the fringes of the emergent Redstone Arch. Later in the Ordovician a pronounced transgression caused a marked eastwardly shift of facies belts and resulted in the flooding of the Arch and deposition of a widespread carbonate sheet (Whittaker) in the northeastern part of the study area.The carbonate facies of the Root Basin and south of the Redstone Arch contains a complete record of shelly faunas of Canadian to, probably, Maysvillian age. The Broken Skull Formation consists of craggy weathering, variably sandy carbonates and contains, in its highest parts, the Hesperonomia fauna (Canadian). The Sunblood Formation consists of generally resistant, red-orange-buff weathering limestones and minor dolostones and contains two faunas; the Orthidiella-'Goniotelina' fauna (Whiterockian) and the Bathyurus sp. 1 fauna (?Chazyan). The Esbataottine Formation (proposed) comprises moderately recessive, grey-buff weathering limestones and contains two faunas; the Mimella fauna (Chazyan) and the Doleroides fauna (Blackriveran). The lower Whittaker Formation (Trentonian to ?Maysvillian) comprises three lithosomes containing discrete faunas which appear to represent coeval communities: The Strophomena-Ceraurus fauna in thinly bedded, argillaceous limestones; the Bighornia-Thaerodonta fauna in well bedded, nonargillaceous limestones; and the Hesperorthis-Oepikina fauna in well bedded dolostones. A unique fauna of deep water aspect, the Cryptolithus-Anataphrus fauna, occurs in shales and black limestones of the Road River Formation and ... Article in Journal/Newspaper Mackenzie mountains South Nahanni River Canadian Science Publishing Canadian Journal of Earth Sciences 12 4 663 697 |
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Canadian Science Publishing |
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Ordovician strata of the South Nahanni River area occur as a western fine clastic facies with graptolitic faunas (Road River Formation) and an eastern carbonate facies with shelly faunas (Broken Skull, Sunblood, Esbataottine, and Whittaker Formations). The lithofacies are controlled by major tectonic features. In the early Ordovician the Selwyn Basin received fine clastic sedimentation (Road River) while carbonate sedimentation (Broken Skull, Sunblood, Esbataottine) was confined to the Root Basin and the fringes of the emergent Redstone Arch. Later in the Ordovician a pronounced transgression caused a marked eastwardly shift of facies belts and resulted in the flooding of the Arch and deposition of a widespread carbonate sheet (Whittaker) in the northeastern part of the study area.The carbonate facies of the Root Basin and south of the Redstone Arch contains a complete record of shelly faunas of Canadian to, probably, Maysvillian age. The Broken Skull Formation consists of craggy weathering, variably sandy carbonates and contains, in its highest parts, the Hesperonomia fauna (Canadian). The Sunblood Formation consists of generally resistant, red-orange-buff weathering limestones and minor dolostones and contains two faunas; the Orthidiella-'Goniotelina' fauna (Whiterockian) and the Bathyurus sp. 1 fauna (?Chazyan). The Esbataottine Formation (proposed) comprises moderately recessive, grey-buff weathering limestones and contains two faunas; the Mimella fauna (Chazyan) and the Doleroides fauna (Blackriveran). The lower Whittaker Formation (Trentonian to ?Maysvillian) comprises three lithosomes containing discrete faunas which appear to represent coeval communities: The Strophomena-Ceraurus fauna in thinly bedded, argillaceous limestones; the Bighornia-Thaerodonta fauna in well bedded, nonargillaceous limestones; and the Hesperorthis-Oepikina fauna in well bedded dolostones. A unique fauna of deep water aspect, the Cryptolithus-Anataphrus fauna, occurs in shales and black limestones of the Road River Formation and ... |
format |
Article in Journal/Newspaper |
author |
Ludvigsen, Rolf |
spellingShingle |
Ludvigsen, Rolf Ordovician Formations and Faunas, Southern Mackenzie Mountains |
author_facet |
Ludvigsen, Rolf |
author_sort |
Ludvigsen, Rolf |
title |
Ordovician Formations and Faunas, Southern Mackenzie Mountains |
title_short |
Ordovician Formations and Faunas, Southern Mackenzie Mountains |
title_full |
Ordovician Formations and Faunas, Southern Mackenzie Mountains |
title_fullStr |
Ordovician Formations and Faunas, Southern Mackenzie Mountains |
title_full_unstemmed |
Ordovician Formations and Faunas, Southern Mackenzie Mountains |
title_sort |
ordovician formations and faunas, southern mackenzie mountains |
publisher |
Canadian Science Publishing |
publishDate |
1975 |
url |
http://dx.doi.org/10.1139/e75-059 http://www.nrcresearchpress.com/doi/pdf/10.1139/e75-059 |
genre |
Mackenzie mountains South Nahanni River |
genre_facet |
Mackenzie mountains South Nahanni River |
op_source |
Canadian Journal of Earth Sciences volume 12, issue 4, page 663-697 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e75-059 |
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Canadian Journal of Earth Sciences |
container_volume |
12 |
container_issue |
4 |
container_start_page |
663 |
op_container_end_page |
697 |
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1799483534478409728 |