Three-Dimensional Electromagnetic Imaging of Porphyry Copper Deposits with MT and ZTEM Data Open Access

[摘要] This thesis investigates the use of the airborne Z-Axis Tipper Electromagnetic (ZTEM) and ground-based magnetotelluric (MT) exploration techniques to image electrical resistivity contrasts associated with porphyry copper deposits. These techniques were individually used to construct three-dimensional (3-D) electrical resistivity models of the Morrison porphyry copper deposit that contain resistivity contrasts caused by hydrothermal alteration, faulting, and possibly sulfide mineralization. The MT resistivity model, which incorporated electric and magnetic field data, correlates very well with the ZTEM resistivity model which only used magnetic field data. 3-D joint ZTEM-MT inversions showed that with appropriate data weighting, the joint resistivity models contained shallow features from the ZTEM data as well as deeper structure required by the MT data. For deposits that require investigation below a depth of about 2 km, there is value in following up a ZTEM survey with a small-scale MT survey to constrain absolute resistivity values and to provide information about deeper structure.

[发布机构] University of Alberta

[效力级别] Mineral Exploration