| Titre | New developments in the hunt for unconformity-related uranium deposits |
| Auteur | Potter, E; Wright, D |
| Source | PDAC 2016; 2016 p. 1 |
| Année | 2016 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20170372 |
| Éditeur | PDAC |
| Réunion | PDAC 2016; Toronto, ON; CA; mars 6-9, 2016 |
| Document | manuscrit non publié |
| Lang. | anglais |
| Media | papier |
| Formats | pdf |
| Province | Saskatchewan; Alberta; Nunavut |
| SNRC | 64E; 64L; 64M; 66A; 66B; 74E; 74F; 74G; 74H; 74I; 74J; 74K; 74L; 74M; 74N; 74O; 74P |
| Lat/Long OENS | -112.0000 -102.0000 60.0000 57.0000 |
| Lat/Long OENS | -99.0000 -97.0000 64.7500 64.2500 |
| Sujets | gisements minéraux; prospection minière; méthodes d'exploration; directives d'exploration; gîte de type discordance; uranium; genèse des minerais; contrôles des minerais; contrôles structuraux;
remobilisation; établissement de modèles; dynamique des fluides; fluage; système hydrothermal; altération; géologie du substratum rocheux; caractéristiques structurales; failles; zones de failles; zones de cisaillement; tendances structurelles;
lithologie; roches sédimentaires; grès; etudes isotopiques; rapports uranium-thorium; dispersion géochimique; analyses géochimiques; métaux; géochimie du fer; géochimie du magnesium; sols; géochimie du sol; géochimie du pétrole sous-terrain; horizons
pédologiques; géochimie du humus; géochimie des eaux souterraines; radon; hélium; argon; Bassin d'Athabasca ; Groupe d'Athabasca ; Dépôt de Mcarthur River ; Bassin de Thelon ; géologie économique; géochimie; géologie structurale; pédologie;
hydrogéologie |
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| Programme | Systèmes d'uranium, Initiative géoscientifique ciblée (IGC-5) |
| Programme | Initiative géoscientifique ciblée (IGC-4) |
| Liens | PDAC 2016 Program (pdf, 5.84 MB)
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| Résumé | (disponible en anglais seulement)
Unconformity-related U remains a prime exploration target in Canada given the potential for large tonnage, high-grade ore deposits. As more diverse geological
settings for these deposits are discovered and exploration shifts to greater depths, new exploration methods are required to allow for efficient target generation and discovery of these buried ore deposits.
Recent studies under the Geological
Survey of Canada's Targeted Geoscience Initiative Program (TGI-4) clearly illustrate that the ore-forming processes and remobilization of key ore elements produce diagnostic mineralogical, geochemical and isotopic signatures that can be identified
and modelled over the entire fluid pathway through fertile fault systems, including post-mineralization dispersal of metals and gases into subsurface sandstones, soils and groundwater. In the eastern Athabasca Basin, basin-scale numerical modelling
suggests that the hydrothermal cells extended only a few kilometres laterally from the faults. However, the morphologies of the ore zones and the extent of geochemical and mineralogical expressions of hydrothermal alteration for several kilometres
along fault zones support long distance focussing of hydrothermal fluids. In the Athabasca Group sandstones, ore-related signatures (elevated U2/Th and Y2/Th values, etc.) are located directly above deposits and surface projections of fault zones
while hydrothermal alteration signatures (e.g. elevated Mg/Li, Cu/Co, Ni, As, etc.) extend along NE-trending structures for several kilometres. Geochemical signatures reflecting remobilization (e.g. elevated U2/Th with low Y2/Th values, elevated base
metals, etc.) are best expressed along late NW-trending fault zones that intersect the NE-trending fault zones. At the McArthur River deposit, delta-56Fe(IRMM-014) values >0.5 per mille record proximal redox reactions, whereas at the basement-hosted
Bong deposit in the Thelon Basin, high delta-56FeIRMM-014 and delta-26Mg(DSM-3) values that delineate fertile structural zones and alteration assemblages suggest proximal fO2-pH changes. Such new data types indicate the fertility of an alteration
system, and can track changes in the alteration along ore-hosting faults.
Metals such as U, Pb, ± Cu, Mo, Ag, Co, Ni and W are concentrated in humus and B-horizon soils directly above deeply-buried ore deposits and the surface projection of
ore-hosting shear zones. Elevated Rn concentrations in groundwater support recent dispersal of metals from shallow alteration whereas increasing He/Ar values at depth suggest vertical and lateral dispersion of He from the deposits. In surficial
media, the geochemical expressions of deeply buried ore are strongly influenced by the local glacio-fluvial history, soil development and hydrological conditions. Such constraints are critical when considering the potential extents of the ore deposit
footprints in exploration. |
| Résumé | (Résumé en langage clair et simple, non publié)
L'Initiative géoscientifique ciblée (IGC-4) était un programme géoscientifique fédéral collaboratif qui fournissait à l'industrie la prochaine
génération de connaissances géoscientifiques et de techniques novatrices pour mieux détecter les gisements minéraux enfouis, réduisant ainsi certains risques d'exploration. Le résumé et la présentation de la conférence présentent les principales
signatures géochimiques et isotopiques à l'échelle régionale liées aux gisements d'uranium liés à la discordance reconnus au cours du projet TGI-4. En reliant les signatures à des modèles de formation de minerai mis à jour et à la remobilisation
subséquente d'éléments clés, les méthodes décrites fournissent un moyen de classer les cibles et de les guider le long des structures de failles potentielles pendant l'exploration. |
| GEOSCAN ID | 306963 |
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