TIMING OF GOLD MINERALIZATION IN THE VAL-DOR DISTRICT, SOUTHERN ABITIBI BELT - EVIDENCE FOR 2 DISTINCT MINERALIZING EVENTS

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