Geochemical Constraints of the Gold Mineralization Sources from the South Mine Complex and the Main/’04 Breaks, Macassa Mine, Kirkland Lake, Ontario
Abstract
Kirkland Lake Gold’s Macassa Mine is a lode gold deposit in the Abitibi Greenstone. It has two systems of mineralization: the Main/’04 Breaks, and the South Mine Complex (SMC). The objective of this work was to constrain mineralization sources between these systems using geochemical signatures. The SMC has different structure, mineralogy, alteration, trace- and major-elements composition, and δ18O values. The Main/’04 is a series of faults with thin alteration dipping south 60-85º. The SMC is a series of structurally controlled zones dipping southeast 25-50° with wide alteration. It is interpreted to be a Riedel Shear between the ’04 and Amalgamated Breaks. Significant findings include δ18O values of quartz mineral separates of 10.1-12.9‰ (SMC) and 11.0-14.0‰ (Main/’04) and paired with chlorite mineral separate calculate temperatures between 134-616°C (SMC) and 128-434°C (Main/’04) within auriferous samples. This suggests higher temperatures and a greater magmatic component present in the mineralizing fluids within the SMC.