A constrained potential field data interpretation of the deep geometry of the Sudbury structure
Two coincident high-resolution airborne gravity and magnetic profiles of the Sudbury structure were forward modelled to better understand the geology of the structure at depth. A north–south profile was used to further investigate the deep geological setting of the Sudbury Igneous Complex (SIC) along Lithoprobe seismic transect, while an east–west profile was selected to examine a discontinuity in the magnetic and gravity fields near the centre of the SIC in the North Range. Constraints imposed on the best-fit model were the location of surface magnetic contacts, interpreted seismic and geological sections, and petrophysical data acquired from surface and borehole data. The constrained model computed for the north–south profile, elements of which are consistent with known Lithoprobe seismic reflectors, defines a north-verging fold in the deeper portion of the SIC. It may have developed during the modification of the initial geometry of the SIC by either a post-SIC thick-skinned basement shortening event, ...