Case studies of conductivity-depth imaging from TEM data

Since the introduction of a method of imaging the conductivity-depth structure of a quasi-layered earth using TEM data was developed by Macnae and Lamontagne, a number of UTEM surveys have been conducted on three continents. This presentation will show some of the results obtained to date. A number of different applications of the method, called depth image processing, have been tested, particularly in petroleum exploration, unconformity uranium exploration, in base and precious metal exploration, and in structural sounding at depths of interest in deep crustal studies. Based on this relatively limited experience, the correlation of imaged conductivity-depth structure, when laterally uniform, and drill hole geology has been excellent. Work is proceeding on obtaining an understanding of the effects that may be introduced by the depth image processing algorithm when the conductivity structure is non-layered. A number of scale and computer model data sets have been generated for non-layered geometries, and will be processed by the depth image process algorithm in the next few months. It is anticipated that examples from these will help to explain some of the artifacts that have been observed in field data