Geology and origin of the Mowat creek breccia zone, Parkin Township, Sudbury, Ontario, Canada

Abstract

The geology of the Mowat Creek area, Parkin Township, Sudbury, Ontario, Canada, comprises Archean greenstones, Huronian metasedimentary rocks, and diabase intrusive rock. The mineralogy and strong northwest-southeast trending foliation, especially within the greenstones, represent regional compression and metamorphism in the greenschist to amphibolite facies. The breccia zone of Mowat Creek is approximately 300m wide, trends northeast-southwest, and occurs between the greenstones and the diabase. It consists primarily of rounded quartzite clasts within a microcrystalline matrix of similar mineralogy. A reverse thrust fault, assuming a 45° dip-slip, is proposed as a model for the origin of the breccia zone, with an approximate overthrow of 425 m. This large scale faulting is parallel to other concentric faults in the Sudbury Basin, and therefore, might suggest a relation to the Sudbury impact event.