Borehole Geophysics As An Aid To Kimberlite Exploration In The Canadian Prairie Region

This paper examines various suites of logs from a number of kimberlite fields in the Western<br>Canadian Sedimentary Basin. It is observed that while the physical properties of kimberlite may<br>vary widely, even within a single borehole or pipe, borehole geophysical logs do effectively<br>distinguish kimberlite from the host rock. Ranges of physical properties, including magnetic<br>susceptibility and formation resistivity, can be identified and used in forward magnetic and<br>geoelectrical modeling. Airborne data can thus be modeled with greater confidence, while the<br>effectiveness of various ground based techniques can be predicted in advance of field programs.<br>In addition, logging programs have been useful in identifying kimberlitic material that may have<br>been bypassed in the drilling progam, in locating offhole bodies, and in sterilizing prospects<br>identified from incorrectly modeled surface magnetic data.