Late Proterozoic stratigraphy, U–Pb zircon ages, and rift tectonics, Mackenzie Mountains, northwestern Canada
Stratigraphic evidence suggests sporadic rifting began during deposition of the mainly platformal Mackenzie Mountains Supergroup: minor magnetite iron-formation in shale basins, lead–zinc in karsted and brecciated carbonates, red-bed and evaporite wedges, and basalts at the top. In the unconformably...
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crcansciencepubl:10.1139/e89-151 2024-09-09T19:51:38+00:00 Late Proterozoic stratigraphy, U–Pb zircon ages, and rift tectonics, Mackenzie Mountains, northwestern Canada Jefferson, C. W. Parrish, R. R. 1989 http://dx.doi.org/10.1139/e89-151 http://www.nrcresearchpress.com/doi/pdf/10.1139/e89-151 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 26, issue 9, page 1784-1801 ISSN 0008-4077 1480-3313 journal-article 1989 crcansciencepubl https://doi.org/10.1139/e89-151 2024-08-01T04:10:01Z Stratigraphic evidence suggests sporadic rifting began during deposition of the mainly platformal Mackenzie Mountains Supergroup: minor magnetite iron-formation in shale basins, lead–zinc in karsted and brecciated carbonates, red-bed and evaporite wedges, and basalts at the top. In the unconformably overlying Coates Lake Group similar climates and definite rifting are recorded by thin orthoconglomerates with thick red-bed and evaporite wedges containing stratiform copper deposits in paleovalleys. Unconformably above this, basal Windermere Supergroup records major climatic change and more emphatic rifting, with thick orthoconglomerates next to fault scarps overlain by glaciomarine deposits with volcanics and hydrothermal iron-formation.A quartz diorite plug, here dated by the U–Pb zircon method at [Formula: see text], is bounded by faults but is contained in a thrust panel together with Mackenzie Mountains Supergroup and is chemically similar to diabase sills previously dated at 766–769 ± 27 Ma (Rb–Sr). A diatreme intruding Coates Lake Group contains clasts of granite and gneiss from inferred basement. U–Pb systematics from a granite clast indicate inherited zircons about 1.6 ± 0.25 Ga in age and crystallization between 1100 and 1175 Ma, a maximum age for Mackenzie Mountains Supergroup. Article in Journal/Newspaper Mackenzie mountains Canadian Science Publishing Canada Coates ENVELOPE(162.083,162.083,-77.800,-77.800) Canadian Journal of Earth Sciences 26 9 1784 1801 |
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Canadian Science Publishing |
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crcansciencepubl |
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English |
description |
Stratigraphic evidence suggests sporadic rifting began during deposition of the mainly platformal Mackenzie Mountains Supergroup: minor magnetite iron-formation in shale basins, lead–zinc in karsted and brecciated carbonates, red-bed and evaporite wedges, and basalts at the top. In the unconformably overlying Coates Lake Group similar climates and definite rifting are recorded by thin orthoconglomerates with thick red-bed and evaporite wedges containing stratiform copper deposits in paleovalleys. Unconformably above this, basal Windermere Supergroup records major climatic change and more emphatic rifting, with thick orthoconglomerates next to fault scarps overlain by glaciomarine deposits with volcanics and hydrothermal iron-formation.A quartz diorite plug, here dated by the U–Pb zircon method at [Formula: see text], is bounded by faults but is contained in a thrust panel together with Mackenzie Mountains Supergroup and is chemically similar to diabase sills previously dated at 766–769 ± 27 Ma (Rb–Sr). A diatreme intruding Coates Lake Group contains clasts of granite and gneiss from inferred basement. U–Pb systematics from a granite clast indicate inherited zircons about 1.6 ± 0.25 Ga in age and crystallization between 1100 and 1175 Ma, a maximum age for Mackenzie Mountains Supergroup. |
format |
Article in Journal/Newspaper |
author |
Jefferson, C. W. Parrish, R. R. |
spellingShingle |
Jefferson, C. W. Parrish, R. R. Late Proterozoic stratigraphy, U–Pb zircon ages, and rift tectonics, Mackenzie Mountains, northwestern Canada |
author_facet |
Jefferson, C. W. Parrish, R. R. |
author_sort |
Jefferson, C. W. |
title |
Late Proterozoic stratigraphy, U–Pb zircon ages, and rift tectonics, Mackenzie Mountains, northwestern Canada |
title_short |
Late Proterozoic stratigraphy, U–Pb zircon ages, and rift tectonics, Mackenzie Mountains, northwestern Canada |
title_full |
Late Proterozoic stratigraphy, U–Pb zircon ages, and rift tectonics, Mackenzie Mountains, northwestern Canada |
title_fullStr |
Late Proterozoic stratigraphy, U–Pb zircon ages, and rift tectonics, Mackenzie Mountains, northwestern Canada |
title_full_unstemmed |
Late Proterozoic stratigraphy, U–Pb zircon ages, and rift tectonics, Mackenzie Mountains, northwestern Canada |
title_sort |
late proterozoic stratigraphy, u–pb zircon ages, and rift tectonics, mackenzie mountains, northwestern canada |
publisher |
Canadian Science Publishing |
publishDate |
1989 |
url |
http://dx.doi.org/10.1139/e89-151 http://www.nrcresearchpress.com/doi/pdf/10.1139/e89-151 |
long_lat |
ENVELOPE(162.083,162.083,-77.800,-77.800) |
geographic |
Canada Coates |
geographic_facet |
Canada Coates |
genre |
Mackenzie mountains |
genre_facet |
Mackenzie mountains |
op_source |
Canadian Journal of Earth Sciences volume 26, issue 9, page 1784-1801 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e89-151 |
container_title |
Canadian Journal of Earth Sciences |
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26 |
container_issue |
9 |
container_start_page |
1784 |
op_container_end_page |
1801 |
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1809920927682527232 |