3D Modelling of Banded Iron Formation incorporating demagnetisation – a case study at the Musselwhite Mine, Ontario, Canada ^*

Abstract

Three-dimensional (3D) high-susceptibility tabular models of Banded Iron Formation (BIF) were built for the area of an aeromagnetic survey at the Musselwhite Mine, Ontario. The study used all available drill information to create geologically plausible models built from a central axis of nodes with geometrical and susceptibility attributes assigned to each node. The forward total magnetic intensity was then computed using an algorithm that includes a calculation for the demagnetisation effect. The model-building process greatly enhanced the understanding of the BIF geometry and demonstrated the importance of the interaction of these strongly magnetic units with the Earth’s magnetic field. As BIF is associated with mineralisation at the mine, the interpretation of the observed magnetic anomalies has strong implications for target generation.