As part of the Geological Survey of Canada’s GEM2 Program, Quaternary geology and mineralogical studies of till and stream sediments were undertaken in the southwestern region of Great Slave Lake from 2017-2019. Multi-faceted research activities in the study area addressed the broad research question: “Is there potential for additional carbonate-hosted sulphide deposits under the thick glacial overburden between Hay River to Kakisa Lake and Fort Providence?”
Fieldwork involved surficial mapping of NTS sheets 85C, 85F and 85G and included till and stream sediment heavy mineral sampling; no previous surficial mapping or surficial heavy mineral data existed for these areas. The project benefited from additional samples donated by the Northwest Territories Geological Survey collected as part of former Protected Area Strategy surveys. Heavy minerals were subjected to trace element geochemical and isotopic analyses to elucidate potential mineralization source types, and eliminate known sources (i.e., Pine Point). Our data and results indicate a strong potential for undiscovered Zn, Pb, and Cu mineralization occurring in bedrock concealed beneath Quaternary sediments in the region.
A better understanding of the surficial sediments and glacial history of the study area is achieved through several avenues of research. Stratigraphic sections of Quaternary sediments were mapped and studied in the upper Mackenzie River and Cameron Hills, and surface till samples were analyzed geochemically and for clast lithology content. Detailed stratigraphic and till micromorphological studies were undertaken at the abandoned M-52 pit at the Pine Point mine site, and in the Cameron Hills (which host impressive streamlined landforms for fast basal ice flow). Finally, a compilation of drillhole data and field data were used to construct isopach maps of the Quaternary sediment cover across the entire study and extended beyond to include the Pine Point mining district. The collected field data and results from this project bring considerable new insights including three main ice-flow phases, new age constraints on deglaciation and drainage of glacial Lake McConnell, and several new areas defined by till and stream sediment heavy mineral results, which indicate a high potential for buried mineralization.