Geology of the Uvauk complex, Northwest Territories (Kivalliq region, Nunavut)

The Uvauk complex comprises anorthosite, gabbroic anorthosite, diorite, gabbro, and quartzofeldspathic gneiss that have been strongly deformed and metamorphosed at granulite grade, with a subsequent, pervasive, amphibolite-grade overprint. Detailed mapping of the western portion of the complex suggests that the anorthosite represents a synkinematic intrusion into diorite and quartzofeldspathic gneiss wall rocks. Field relations do not unequivocally indicate whether wall rocks had undergone an earlier, Archean, granulite- facies, mylonitization event, or whether all deformation and metamorphism is related to one progressive event. Sinistral shear-sense indicators to the north and dextral shear-sense indicators to the south of the anorthosite indicate eastward transport of the anorthosite body with respect to its wall rocks. The shallow, east-plunging lineation and limited metamorphic contrast across the wall rocks suggest minimal vertical displacement.