| Titre | LIPS and Proterozoic uranium (U) deposits of the Canadian Shield |
| Télécharger | Téléchargements |
| Auteur | Jefferson, C W; Peterson, T; Tschirhart, V; Davis, W; Scott, J M J; Reid, K; Raemaekers, P; Gandhi, S S; Bleeker, W; Pehrsson, S; Morris, W A; Fayek, M; Potter, E; Bridge, N; Grunsky, E; Keating, P;
Ansdell, K; Banerjee, N |
| Source | Commission géologique du Canada, Dossier public 7352, 2013, 56 pages, https://doi.org/10.4095/292377 (Accès ouvert) |
| Année | 2013 |
| Éditeur | Ressources naturelles Canada |
| Document | dossier public |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/292377 |
| Media | en ligne; numérique |
| Référence reliée | Cette publication est reliée Jefferson, C W;
Peterson, T; Davis, W; Reid, K; Raemaekers, P; Gandhi, S S; Bleeker, W; Fayek, M; Pehrsson, S; Potter, E; Bridge, N; Scott, J M J; Tschirhart, V; (2013). LIPs and Proterozoic uranium deposits of the Canadian Shield, Prospectors and Developers
Association of Canada Annual Meeting, abstracts |
| Liens | readme
|
| Formats | pdf; ppt; xls; rtf |
| Province | Alberta; Saskatchewan; Nunavut |
| SNRC | 64E/13; 64L/03; 64L/04; 64L/05; 64L/06; 64L/12; 64L/13; 74E/15; 74E/16; 74F/07; 74F/08; 74F/09; 74F/10; 74F/11; 74F/12; 74F/13; 74F/14; 74F/15; 74F/16; 74G; 74H/04; 74H/05; 74H/06; 74H/07; 74H/09; 74H/10;
74H/11; 74H/12; 74H/13; 74H/14; 74H/15; 74H/16; 74I; 74J; 74K; 74L; 74M/01; 74M/02; 74M/08; 74N/01; 74N/02; 74N/03; 74N/04; 74N/05; 74N/06; 74N/07; 74N/08; 74N/11; 74N/12; 74O/01; 74O/02; 74O/03; 74O/04; 74O/05; 74O/06; 74O/07; 74O/08; 74P/01;
74P/02; 74P/03; 74P/04; 74P/05; 74P/06; 74P/07; 56D; 56E; 66A; 66B; 66C; 66F; 66G; 66H; 86L; 86M; 96I; 96P; 85F/09; 85F/10; 85F/15; 85F/16; 85J |
| Lat/Long OENS | -112.0000 -103.0000 59.7500 57.0000 |
| Lat/Long OENS | -102.0000 -94.0000 65.9083 64.0000 |
| Lat/Long OENS | -114.0000 -110.0000 68.0000 66.0000 |
| Lat/Long OENS | -117.0000 -114.0000 63.0000 61.5000 |
| Sujets | magmatisme; roches ignées; gisements minéraux; gîtes minéralogiques; uranium; discordances; caractéristiques structurales; interpretations structurelles; analyses structurales; prospection minière;
gisements d'uranium; minéralisation; Formation de Christopher Island ; Supergroupe de Dubawnt ; Bassin de Baker Lake ; Suite de Nueltin ; Groupe de Wharton ; Bassin d'Athabasca ; Bassin de Thelon ; Bassin d'Hornby Bay ; Groupe d'Athabasca ; Province
de Rae ; Province d'Hearne ; pétrologie ignée et métamorphique; géochronologie; géologie économique; géophysique; Protérozoïque; Précambrien |
| Illustrations | photographs; location maps; tables; plots; photomicrographs; profiles |
| Consultation | |
| Bibliothèque de Ressources naturelles Canada - Ottawa (Sciences de la Terre) |
| |
| Programme | Uranium, GEM : La géocartographie de l'énergie et des minéraux |
| Diffusé | 2013 04 08 |
| Résumé | (disponible en anglais seulement)
Most large igneous provinces (LIPs) are associated with lithospheric extension driven by mantle upwelling. The Dubawnt Supergroup LISP (Large Igneous and
Sedimentary Province) contains two LIPs and a BLIP of mantle-sourced magmatism likely driven by lithosphere plateau collapse and strike-slip deformation rather than plumes. LIP #1, the mafic/ultrapotassic Christopher Island Formation, was
intercalated from 1845 ± 12 to 1785 ± 3 Ma with siliciclastic rocks of the trans-extensional Baker Lake Basin that partly covers the vein-style, unconformity associated, 1828 ± 29 Ma Lac Cinquante U deposit and correlates temporally with the Martin
Basin of Saskatchewan's Beaverlodge district. LIP #2, granite/gabbro/basalt/rhyolite of the 1.75 Ga Nueltin Suite, was intercalated with siliciclastic rocks of the Wharton Group, invaded pre-Thelon Basin faults, and prepared the ground for basement
hosted, unconformity associated U deposits inferred as <1667 ± 5 Ma (fluorapatite cement within Thelon Basin). Five to 10 km aeromagnetic rings are being investigated as potential, shallow bimodal volcanic centres that powered epithermal precious
metals systems. The two LIPs broadly mobilized U, moving it upward in the crust and available to paleoweathering, basinal fluid alteration and transport, particularly by leaching incompatible element-rich volcanic detritus. The thin, ultrapotassic
mafic Kuungmi lavas cap the Thelon Basin and this BLIP provides a 1540 ± 30 Ma (micro-baddeleyite) upper age for the LISP.
The proposed-plume-related 1.27 Ga Mackenzie event re-set unconformity U deposits in the Athabasca and Thelon basins, and
developed new alteration vectors in the Athabasca Basin such as a third generation of chlorite. U-rich phosphate minerals in the Hornby Bay Basin dated as 1282 ± 11 and 1158 ± 80 Ma suggest the Mackenzie event drove sandstone U mineralization.
New ages of mafic igneous events constrain the tectonic development of siliciclastic basins and hydrothermal fluid events that formed U deposits. Once covered by more than 2 km of Hornby Bay Group strata, Port Radium's classic uraninite veins cut
the 1.74 Ga Cleaver diabase dykes and are, in turn, cut by the 1.59 Ga Western Channel diabase; thus implying U mineralization beneath the Hornby Bay Basin unconformity.
Dating of Mackenzie diabase sills in the largely sub-surface Dessert Lake
basin west of Yellowknife confirms its Paleoproterozoic age and supports correlation with the Hornby Bay and Athabasca basins. An outstanding question is the cause of the regional 1.4 Ga re-setting of U and precious metal deposit ages in the
Athabasca and Thelon regions. |
| Résumé | (Résumé en langage clair et simple, non publié)
La présentation place les résultats du programme GEM sur les gisements d'uranium dans le contexte d'événements volcaniques de grande ampleur,
survenus il y a environ 2,2 à 1,4 milliard d'années (Ga). Le Supergroupe de Dubawnt, qui renferme les gisements d'uranium du bassin d'Athabasca et qui offre des zone prometteuses pour l'exploration au Nunavut, chevauche deux événements ignés, l'un
remontant à 1,83 Ga (volcanisme potassique) et l'autre, à 1,75 Ga (volcanisme rhyolitique-basaltique : événement de Nueltin). Les rhyolites ont pu engendrer des indices d'uranium en altérant leurs roches encaissantes et apporter aux grès producteurs
des minéraux détritiques riches en uranium. Les centres de basalte/rhyolite étaient des sources de chaleur qui ont pu produire des indices d'or-argent et de plomb-cuivre. Le programme GEM a permis de découvrir que plusieurs de ces centres ont une
apparence annulaire sur les cartes des anomalies magnétiques, et la recherche préliminaire de ces anneaux dans l'ensemble du Nunavut fait l'objet d'un résumé. |
| GEOSCAN ID | 292377 |
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