Mid-continent tectonic inversions, Northwest Territories, Canada

Four types of tectonic inversion are recorded on reflection seismic data from the area northwest of Great Bear Lake in the Northwest Territories, Canada. The strata involved span about 1.7 Ga of Proterozoic and Phanerozoic history, and have been subjected to at least five tectonic events, two extensional, two compressional and one transpressional. Two types of positive inversion, one type of negative inversion, and one type of double inversion (positive following negative) are documented. One of the positive inversions is atypical in that it involves no reversal in tectonic polarity; it was effected by a renewal of compression. During the entire 1.7 Ga time span the successive tectonic phases occurred in a mid-continental setting far from any known active plate margin(s).