*Eric Roots^1,2、Graham Hill^3,4、Ben Frieman¹、Richard Smith¹、James Craven² (1.Mineral Exploration Research Centre, Laurentian University, Sudbury, Canada、2.Geological Survey of Canada, Ottawa, Canada、3.Institute of Geophysics, Czech Academy of Science, Prague, Czech Republic、4.Gateway Antarctica, University of Canterbury, Christchurch, New Zealand)