Structural setting and controls of gold mineralization at the Macassa Mine, Kirkland Lake, Ontario

The Macassa mine is a structurally controlled gold deposit. Structures controlled intrusion of the syenitic stocks, emplacement of the mineralising hydrothermal fluids, and post-ore displacement. Most of the gold mineralization in Kirkland Lake is associated with the Kirkland Lake break (Main break) fault-system, and associated sub-parallel structures. The sub-vertical, to steeply south-dipping, '04 break is the most important ore-related structure during the last two decades of mining at the Macassa Mine. Other significant ore-related structures at Macassa include the '05 break (referred to as the Narrows break in the eastern mines of Kirkland Lake), and the 45–55° south-dipping No. 6 break.; Several exploration targets have been developed for the Macassa mine. These include: specific prospective areas along the '04 break; mineralised structures to the south of the '04 break, including the No. 6 break; zones to the north of the '04 break, including the '05 or Narrows break; and prospective hangingwall and footwall veins. (Abstract shortened by UMI.)...