Indicator mineral content and geochemistry of glacial sediments from northwest Alberta (NTS 84L, M): new opportunities for mineral exploration

This report presents the results of heavy mineral and geochemical analyses conducted on glacial sediment samples collected in northwest Alberta. This study was undertaken as part of a collaborative project between the Alberta Geological Survey (Alberta Energy and Utilities Board) and the Geological Survey of Canada (Natural Resources Canada) originally designed to assess the regional occurrence of kimberlite indicator minerals (KIMs) in glacial deposits. Results indicate that KIMs are absent, or rare, and generally consist of trace contents of pyrope and chromite, the composition of which remains to be assessed with electron microprobe analyses. Gold grains are generally absent from all samples with a some exceptions where they are present in only small amounts. Of particular significance, and the focus of this report, is the presence of anomalous concentrations of sphalerite grains with secondary galena (up to 1000 sphalerite grains in the 0.25-0.5 mm size fraction from a bulk till sample) from the south-central sector of the Bistcho Lake (NTS 84M) and north central sector of the Zama Lake (NTS 84L) map sheets. The source of the sphalerite grains in till is unknown. However, given its geographically restricted presence in the regional sample set, it may point to undiscovered sedimentary hosted zinc deposits in this region, and therefore, represents new opportunities for mineral exploration.