Application of RADARSAT-1 in mineral potential evaluation, Lac Grandin area, NWT: identifying geologic features/processes associated with mineralization

The purpose of using RADARSAT-1 for this mineral potential evaluation was to provide a means for acquiring quick and relatively inexpensive information about the study area. The problems faced in carrying out the mineral potential evaluation of this area were two-fold: (1) very limited geologic information exists to base a mineral assessment on and (2) the rocks with the greatest mineral potential are overlain by younger flat-lying sedimentary rocks. The Lac Grandin area has never been flown by regional or industry geophysics, it has only seen very limited reconnaissance geological mapping, no geochemical data exists and no mineral exploration has been carried out over the area. Flat-lying sedimentary rocks of the Phanerozoic Interior Platform underlie the Lac Grandin area. The Great Bear magmatic zone (GBmz) of the Proterozoic Bear Geological province outcrops 30-50 km to the east and underlies the Phanerozoic sedimentary cover rocks of the Lac Grandin area. Depth to Proterozoic crystalline basement (GBmz) rocks in the study area has been determined to be less than 200 m. The GBmz is known to host significant mineral deposits and some past producing mines. An industry aeromagnetic survey exists for the area immediately adjacent to the study area and was flown to fill in a gap in the regional geophysical database. It was hoped that structural patterns recognized from the aeromagnetic data could be extrapolated into the study area using the RADARSAT-1 images. The RADARSAT-1 images acquired were Fine Mode, Beam 1 descending (f1d) and Standard Mode, Beam 4 descending (s4d), which partially overlap the study area and the adjacent area with industry aeromagnetic coverage. The images proved very effective in demonstrating that basement feature lineaments could be recognized through the sedimentary cover rock and continued beyond the aeromagnetic coverage area into the study area. The RADARSAT-1 images proved very effective as an ancillary tool to the aeromag maps by aiding in locating and identifying structures thought to be important to the determination of areas of high mineral potential.