Mineral assay results for the 2005 and 2007 field seasons, Boothia mainland area, Kitikmeot region, Nunavut

Abstract

This report presents mineral assay analytical results for 68 widely spaced samples collected from gossanous localities during bedrock mapping of the Boothia mainland region, north-central Rae domain, western Churchill Province, during summers 2005 and 2007. A large subset of the samples yielded anomalous polymetallic mineral values, which, while generally modest, demonstrate that the economic mineral potential for base-metals in the region is significantly greater than previously thought. Despite being comprised largely of a multiply deformed amphibolite and granulite facies metagranitoid terrain, the region includes supracrustal belts of three different ages, all hosting gossans that signal base- and precious metal prospectivity. When considering the results presented herein, it is important to bear in mind that no in-depth prospecting was carried-out at these sites, and that these are merely grab samples. Some very prospective looking outcrops yielded poor mineral assay values. Lower amphibolite facies Archean rocks of the Barclay belt, which correlates with the regionally prospective Prince Albert Group, outcrop to a limited extent in the southwest part of the region. They yielded notably anomalous values for zinc, coupled with copper and nickel. Gold values are low despite lower amphibolite facies metamorphism, and the local occurrence of quartz veins. Small inliers of the Paleoproterozoic Chantrey Group in the central part of the region, which we correlate with other Rae Domain sequences of proven prospectivity including the Penrhyn and Piling groups, also exhibit anomalies in gold, copper and zinc. The supracrustal portion of the granulite-grade belt in the northern part of the region has large map extent, and is comprised in part of Barclay belt correlatives at structurally lower levels, and in part of what we informally refer to as the Halkett Inlet belt at structurally higher levels. The Halkett Inlet belt was deposited around ca. 2.5 Ga, and we tentatively interpret it as correlative with the Sherman Group, recently defined in the Queen Maud block of the western Churchill Province. The Halkett Inlet belt hosts the most ubiquitous, the largest, and the most eye-catching polymetallic gossans of the region, and returned some of the best values in copper, zinc and nickel. Based on the better assay results from the granulite-facies belt, and the large number of gossans spotted there from the air during helicopter fly-overs, we consider the granulite-facies belt as being the most prospective ground for base-metal mineralization in the Boothia mainland area. We believe that strong regional deformation under high-grade metamorphic conditions may have enhanced sulphide concentration in structural / metamorphic traps, for which identification will require detailed prospecting and structural analysis.