Using seismology as a tool for diamond exploration

(From abstract submitted by D. Snyder to the March 2003 meeting of the Prospectors and Developers Association of Canada).

Diamond deposits are typically identified in four stages:

(1) regional targeting in which a region's potential is assessed, often by grid till sampling for indicator minerals or global seismology.

(2) kimberlite detection in which till sampling and high resolution aeromagnetic surveys locate individual deposits.

(3) deposit delineation in which drill hole core sampling determines a specific deposit's volume and lithology

(4) evaluation in which bulk sampling establishes a deposit's worth and its feasibility to be mined.

Results from the past few decades indicate that globally, for every 1000 candidate magnetic anomalies identified, 100 are kimberlites, ten contain gem-quality diamonds and one is economic to mine in Canada's North. The diamond exploration industry needs discriminating tools to reduce risks at all of these stages. Electromagnetic and seismic techniques can provide 3-D maps of key physical properties in the mantle to 700 km depth to help accomplish stage 1. These results can then be used in conjunction with the 'ground truth' of actual rock types provided by rare xenolith samples from kimberlites. To date our efforts are concentrated in the central Slave craton of the NWT, Canada, because of the strong geologic, geophysical and logistical base currently available. Once a physical property model is established in the Slave craton, this innovative, 1st-order exploration tool can be applied throughout Canada and globally.