Regional structural data from the Hay River area, Northwest Territories, with emphasis on the Pine Point mining camp

Abstract

A regional study undertaken south of Great Slave Lake, Northwest Territories, focused on evaluating evidence for structural control on mineralization at Pine Point. Relatively consistent northeastsouthwest (055°) and northwest-southeast (125°, 140°, 150°, and 160-165°) joint sets were observed in the study area. A dominant east-west (085°) joint set was observed in one domain. The orientation of the 055° set is close to that of the Great Slave Lake Shear Zone (045° at Pine Point) and the Hay River Fault (055°; west side of study area). Previous studies conducted on ore-mineral paragenesis at Pine Point proved that hydrothermal dolomite occurred concurrently with the ore-deposition event. This study demonstrates that fracturing at Pine Point pits largely postdated dolomitization, and therefore ore deposition. Furthermore, no structural controls on mineralization were observed in the pits, and are therefore not considered a primary mechanism for ore emplacement in the Pine Point orebodies.