Addressing geometrical attributes and seismic imaging capability of fault systems in a world-class metal endowed region: Abitibi Greenstone Belt, Canada

Abstract

With an excess of 75 Moz of gold produced, the Timmins-Porcupine mining camp in the Abitibi green stone belt is the largest gold producing camp in Canada. Most of the endowment is associated with two major, east-west striking, crustal fault zones, the Porcupine Destor fault and the Pipestone fault. The seismic survey presented in this study crosses these prolific fault systems in the Matheson area, which represents the eastern extension of the Timmins-Porcupine mining camp. The survey includes two receiver lines, the east and west profiles, with unequal receiver spacing among them and seismic shots only acquired along the east profile. After careful considerations, we treated the survey as a parallel geometry and designated the east and the west processing profiles to potentially image subsurface architecture in crystalline rock environment. We considered three scenarios to process the data: the entire survey, the east, and the west profiles individually considered. A full pseudo pre-stack time migrated 3D cube of the Archean crust documents the usefulness in imaging the extent of the geological features. By integrating the 2D and 3D seismic images with the local magnetic susceptibility isosurface model, we interpreted the Porcupine Destor fault to dip shallowly to the south and the Pipestone fault as steeply-dipping/subvertical. The techniques used here can be further applied to other areas with similar dense infrastructure requiring imperfect acquisition survey geometry, including crooked lines, to produce fully 3D or pseudo seismic cubes in such areas of great exploration interest.