oa Ore Delineation by Crosshole Seismics, Transmission and Reflection Imaging at Voisey’s Bay, Canada

Three pairs of diamond drillholes were surveyed at Voisey’ Bay, Labrador, Canada, in the Eastern Deeps deposit. The surveys were carried out in NQ diameter drillholes, which were approximately 800-850 m in length. The holes were nearly vertical and hole-to-hole distances ranged from 45 m to 80 m. The p-wave velocity tomography surveys were designed to outline the morphology and continuity of the massive sulphide zone. Reflection imaging was also applied; to confirm whether this method could be used in conjunction with transmission tomography to expand the panel images to a volume. Confidence in the continuity of the massive sulphide zone is crucial since the relatively small massive zone contains a large portion of the metal in the Eastern Deeps deposit. Based on the results of these surveys, further sulphide delineation using surface exploration drillholes may be possible before underground exploration and development.