Re-Os dating of molybdenite from the Pueblo Viejo Au-Ag-Cu and Douvray Cu-Au Districts, Hispaniola

Re-Os dating of three samples of hydrothermal molybdenite collected from the Pueblo Viejo Au-Ag-Cu district (5.5 Moz gold, past production, 16.2 Moz proven plus probable gold ore reserves) yields ages of 112.1 + or - 0.4, 112.0 + or - 0.4, and 111.5 + or - 0.4 Ma. These Re-Os dates confirm an Early Cretaceous age for mineralization, coeval with tholeiitic, intraoceanic island arc volcanism and, in particular, with an episode of felsic magmatism and extension across the Early Cretaceous arc (110-118 Ma). Re-Os dating of a sample of hydrothermal molybdenite collected from the Douvray porphyry Cu-Mo deposit (with inferred resources of 1,257 Mlb Cu, 0.276 Moz Au, 6.84 Moz Ag, and 4,367 tons Mo) yields an age of 93.3 + or - 0.3 Ma, coeval with calc-alkaline magmatism along the Greater Antilles island arc.