A study of the P-T-t-fluid evolution of the Glennie domain, Trans-Hudson Orogen

he Glennie domain of the Trans-Hudson Orogen (THO) is characterized by arcuate belts of Paleoproterozoic supracrustal rocks, including island arc volcanogenic assemblages, among variably deformed and metamorphosed granitoid rocks. Four discrete deformation events, termed D1 through D4, have been recorded in the domain. The Santoy Lake area in the central-northern Pine Lake greenstone belt and the Brownell Lake area in the southern Brownell-Wapawekka lakes greenstone belt were chosen as areas in which the P-T-t-fluid histories were ascertained via a myriad of geochemical techniques.;Mineral assemblages associated with D2 metamorphism in the Santoy Lake area suggest equilibrium conditions of ca. 500-650;Oxygen isotope geothermometry yields values approximately 50-100;Five single zircon Pb-evaporation ages of variably deformed granitoid rocks were obtained from the Santoy Lake area. These ages indicate that the D2 event occurred after ca. 1857 Ma, while the D3 and D4 events (and peak metamorphism) occurred after ca. 1815 Ma. The oldest granitoid in the Santoy Lake area provides a minimum age of mafic volcanism in the area and in the Glennie domain of ca. 1886 Ma. ;P-T-t conditions of vein emplacement and gold mineralisation differ between the two field areas. Vein emplacement in the Santoy Lake area is associated with the D2 event. The uplift/cooling path suggests that gold precipitated in its present form after ca. 1715 Ma. Vein emplacement and gold mineralisation at Brownell Lake is essentially contemporaneous. The uplift/cooling path suggests that gold precipitated between ca. 1795-1780 Ma. Gold mineralisation in both field areas post-dates the timing of peak metamorphism and late magmatic events in the Glennie domain. The calculated...