Anglo-Rouyn Copper Mine, Ore Bay, Lac La Ronge, Saskatchewan

The Anglo-Rouyn Copper Mine is located approximately at 105°W. long and 55°17′45″ N. lat, just north of Ore Bay, Lac La Ronge, Saskatchewan. Copper mineralization was first discovered in 1915. Anglo-Rouyn Mines Limited commenced mining operations in 1966, on estimated reserves of 2 million tons averaging 2.4 percent Cu.

The sulfide ore occurs with vein quartz as lenticular veined zones in Archean metamorphosed argillaceous sandstone and arkosite that generally strike northeast and dip northwest. The zones occur about 30 to 45 m south of a wide sill-like granite body (Jepson Lakes granite). The ore zones are subparallel and en echelon and are doubly plunging to the southwest and northeast along strike.

The ore minerals probably were introduced by hydrothermal solutions along a fault zone, mainly as fracture fillings and to a limited degree as partial replacement of the host rock along fractures. Solutions related to the intrusion of the Jepson Lakes granite probably were the vectors of ore deposition with either the granite magma or adjacent sediments supplying iron, copper, and sulfur for the sulfides.

The minerals pyrite, pyrrhotite, and chalcopyrite indicate a low-temperature assemblage of less than 334°C. Chalcopyrite was deposited after pyrite and pyrrhotite, with subsequent metamorphism and deformation affecting the ore deposits.