Interpretation of Gravity and Magnetic Measurements across the Continental Margin of British Columbia, Canada

Abstract

Contoured free air and Bouguer gravity and magnetic anomaly maps have been produced for the continental margin off the west coast of Canada from sixteen new profiles and previous data. Models produced from gravity, magnetic, and seismic reflection data indicate a deepening of the oceanic basement towards the continent off Vancouver Island. These results, along with folding and faulting of the large thickness of sediments at the base of the slope, indicate that there is present or very recent subduction in this area. In contrast, off the Queen Charlotte Islands, the basement is nearly horizontal and faulting is predominant, probably representing strike-slip motion along the Queen Charlotte Fault.