Géochronologie U-Pb par ID-TIMS et SHRIMP des roches volcaniques, sédimentaires et intrusives des régions de Chibougamau, de Val-d’Or, de Malartic, d’Amos et de Rouyn-Noranda, ceinture de roches vertes de l’Abitibi, Québec

The Abitibi greenstone belt is exceptionally well endowed in precious, base, and critical metals. It, however, has a complex geological and metallogenic history. Rocks are generally well preserved but local major deformation complicates the understanding of the belt’s evolution and metallogenesis. Ore deposits were formed at different, and in most cases, specific times in the belt’s evolution, and knowing the age of these deposits is essential in linking ore genesis with key controlling geological factors. Precise geochronology and relative timing relationships are thus key in deciphering the belt’s evolution. This report presents U-Pb geochronological results from isotope dilution-thermal ionization mass spectrometry (ID-TIMS) and sensitive high-resolution ion microprobe (SHRIMP) dating of zircon, titanite, and/or baddeleyite from volcanic, sedimentary, and intrusive rocks from major mining areas (Chibougamau, Val-d’Or, Malartic, Amos, and Rouyn-Noranda) in the Abitibi greenstone belt. The ages (n=17) help better document the evolution of the Abitibi greenstone belt through time and provide further constraints on the timing of ore-forming events at belt scale. In the Chibougamau area, samples from the Blondeau and Stella formations gave ages of