| Titre : | Origin of the pegmatites and associated uranium mineralization from the CAGE province (North Québec) |
| Auteurs : | J. Bonhoure ; F. Castorina ; M. Cuney ; Réunion des Sciences de la Terre (2014-10-27 / 2014-10-31; Pau, France) |
| Type de document : | Publication scientifique |
| Année de publication : | 2014-10-27 00:00:00,000 |
| Résumé : | In the western part of the Torngat Mountains (north Quebec), uranium mineralizations are observed in metasediments, mainly localized in the Lake Harbour group. This group consists of calcitic and dolomitic marbles, paragneisses, quartzites, calc-silicate rocks and metabasalts injected by pegmatites [1]. The pegmatites of the Cage area (north Québec) share similar characteristics as the Rössing alaskite from Namibia, of anatectic origin [2]. The heterogeneity of the geochemical characteristics for these first pegmatites favour a syn-metamorphic model (partial melting) where U enrichment has a magmatic origin (melts and fluids injected in metasediments to form the pegmatites). The Sr data suggest that the pegmatites were derived from a continental crust partial melting, and a more enriched source for the pT pegmatite than the others. The carbonate rocks have played the role of chemical barrier, for the crystallization of the pegmatites and trapping of uranium. Among the studied pegmatites, only pT has a within-plate granites signature [3] and it is particularly enriched in U [4]. It clearly comes from a different source (extremely rich in plagioclase) as the other pegmatites with possibly a lower continental crust signature. |
Documents numériques (1)
 ged00001068.pdf Adobe Acrobat PDF |
