Imaging Thin Dipping Conductors: The Caber VMS Deposit

Located in the Matagami camp of Quebec’s Abitibi Greenstone belt, the Caber deposit is a zinc- and copper-rich volcanogenic massive sulphide (VMS) target. The deposit presents a significant geophysical challenge: it is characterized by a thin, near-vertical geometry dipping at approximately 80 degrees, buried beneath a layer of conductive overburden. These complex, small-scale features are traditionally difficult to resolve using standard 3D inversion methods due to the massive computational requirements of processing high-resolution airborne electromagnetic (AEM) data.

To overcome these limitations, Computational Geosciences Inc. (CGI) employed a sophisticated multi-mesh partitioning strategy. By using fine mesh cells around specific transmitters while maintaining a full computational domain, CGI’s parallel algorithm significantly reduced the number of cells required for forward modeling. This efficiency allowed for the rapid processing of VTEM-35 field data without sacrificing the detail necessary to image the deposit’s specific dip and orientation.

The resulting 3D inversion provided a clear, high-fidelity image of the Caber anomaly, confirming its steep south-west dip and identifying where the overburden thickens to the north-east. By transforming complex electromagnetic signatures into a precise geological model, CGI’s technology enables explorers to better target thin, dipping conductors that were previously obscured or computationally out of reach.

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