Abstract
Gold-bearing quartz vein deposits in the Val-d'Or area of the southern Abitibi greenstone belt are classified in two categories based on structural and chronologic relationships. Young deposits (<2684 Ma) are characterized by little or no deformation after eraplacement of mineralization and are the only ones to be dated so far, yielding mineralization ages systematically younger than 2.63 Ga. Deposits of this type occur at the Sigma, Lamaque, Camflo, Perron, and Beliveau mines. Older deposits (>2690 Ma) feature commonly deformed orebodies that are cut by dikes of various composition. Such deposits occur at the Siscoe, Kiena, Orion, and Norlartic mines. The Norlartic Main orebody is crosscut by a tonalite dike which has been dated by U-Pb at 2692 + or - 2 Ma, in agreement with structural data. These observations show that gold mineralization in the Val-d'Or area occurs in at least two different settings and was emplaced at different times.
