Nonacho Bedrock Mapping Project
Nonacho Bedrock Mapping Project
Description
The Nonacho bedrock mapping project aims to provide better geoscience knowledge for a poorly known area of the southeastern Northwest Territories. The area is underlain by sedimentary rocks that were deposited on old Archean basement rocks. The basement rocks were last mapped by geologists in the 1950s and 1960s, and the sedimentary rocks in the early 1980s. The Northwest Territories Geological Survey is mapping the bedrock geology and collecting samples for analysis. University partners are investigating the timing of sediment deposition and metamorphism. Together we are unravelling the geological history of the area and beginning to assess its mineral potential.
Location
The project area is in the southeastern part of the Northwest Territories between the East Arm of Great Slave Lake and Saskatchewan. The area of interest is around Nonacho Lake - National Topographic System (NTS) 75F, and includes part of the Akaitcho region. The geological area of interest is the Rae Craton, which is part of the Canadian Shield.
Justification
Very little research has been conducted in this remote area, and our current geological knowledge is poor. It is estimated that 80% of the Canadian Shield in the southeastern Northwest Territories is not mapped well enough to support informed land-use decisions. A systematic approach to mapping the land is needed to provide good baseline data on the underlying geology. Such data is necessary to assess the geological history of the area and its economic potential.
Approach
Geological bedrock mapping is being conducted by a team of 5 to 7 geologists, including government staff, summer students, and university professors and graduate students. The geologists work from a small camp that is moved weekly and boats are used to access shoreline outcrops. Samples of fist-sized rocks are collected for laboratory analyses. The field observations are compiled and interpreted after each field season and integrated into a geology map. The results of analyses add to our understanding of the geological processes that form the land we walk on today. The results of our work are published in the form of geological maps and scientific reports that can be downloaded by anyone who is interested.
Schedule
This project began in the summer of 2018 with 3 weeks of preliminary fieldwork in the Nonacho Lake area, National Topographic System (NTS) 75F. Fieldwork from 2019 to 2021 included multiple weeks of targeted mapping and sampling for structural, geochemical, mineralogical, and sedimentological thematic studies. From these studies, several reports and theses were published. The final results of this research will be published as Northwest Territories Geological Survey, Open Reports or Open Files.
Partners and Support
Larry Heaman and Thomas Chacko – University of Alberta
Alessandro Ielpi – University of British Columbia, Okanagan
Dan Gibson – Simon Fraser University
Erin Adlakha and Jacob Hanley – St. Mary’s University
Keywords
Nonacho Group, Nonacho Lake, Rae Craton, Churchill Province, tectonic, bedrock mapping, geology map, sedimentary basin, Proterozoic, Archean, Taltson Orogeny, Trans-Hudson Orogeny, uranium mineralization
Publications
Canam, R., 2019. Age, petrology, and geochemistry of an appinitic lamprophyre, Hjalmar Lake, South Rae Craton, NT. B.Sc. thesis, Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia.
Canam, R., 2023. Paleoproterozoic structural evolution of the southwestern margin of the Rae craton, Northwest Territories. M.Sc. thesis, Department of Earth Sciences, Simon Fraser University, Burnaby, British Columbia.
Ielpi, A., Martel, E., Fischer, B., Pehrsson, S.J., Tullio, M., and Neil, B.J.C., 2021. A reappraisal of the Nonacho Basin (Northwest Territories, Canada): Record of post-orogenic collapse and marine flooding in the Palaeoproterozoic of the Rae Craton; Precambrian Research, volume 358, 106140. https://doi.org/10.1016/j.precamres.2021.106140
Landry, K., 2022. Chemical characterization and timing of uranium occurrences in the Nonacho Basin, Northwest Territories, Canada. M.Sc. thesis, Department of Geology, St. Mary’s University, Halifax, Nove Scotia.
Landry, K., Adlakha, E., Roy-Garand, A., Terekhova, A., Hanley, J., Falck, H., and Martel, E., 2022. Uranium Mineralization in the MacInnis Lake Area, Nonacho Basin, Northwest Territories: Potential Linkages to Metasomatic Iron Alkali-Calcic Systems; Minerals, volume 12, 1609. https://doi.org/10.3390/min12121609
Lockie, J. 2021. Orogenic collapse in the Rae Craton recorded though U-Pb geochronology of the Paleoproterozoic upper Nonacho Group, Northwest Territories. B.Sc. thesis, Harquail School of Earth Science, Laurentian University, Sudbury, ON.
Lockie. J., Fischer, B., and Ielpi, A., 2023. Refinement of the Nonacho group sedimentology and stratigraphy: Results of the 2021 field season; Northwest Territories Geological Survey, NWT Open Report 2023‐001, 21 pages and appendices. https://doi.org/10.46887/2023-001
Neil, B.J.C., Tersmette, D.B., Chacko, T., Heaman, L.M., Kjarsgaard, B.A., Martel, E., Creaser, R.A., Pearson, D.G., Stern, R.A., Dufrane, S.A., and Luo, Y., 2023. Discovery of a giant 3.3–3.1 Ga terrane in the Rae craton, Canada: Implications for the timing and extent of ancient continental growth; Geology, volume 51, pages 597–601. https://doi.org/10.1130/G51110.1
Neil, B.J., 2024. Archean to early Paleoproterozoic tectono-magmatic evolution of the Western Rae Craton. Ph.d. thesis, Department of Earth Sciences, University of Alberta, Edmonton, Alberta.
Ngo, N., 2021. Geochemical and Petrographic Analysis of the Northwest Territories Nonacho Red (Sparrow) Dykes. B.Sc. thesis, Department of Earth Sciences, Carleton University, Ottawa, Ontario.
Regis, D., Canam, R., and Martel, E., 2022. U-Pb geochronological results from the Nonacho Lake area (NTS 75-F), Northwest Territories; Geological Survey of Canada, Open File 8880, 33 pages. https://doi.org/10.4095/329884
Terekhova, A., 2021. Classification and origin of vein-related Cu-Ag-Pb-Zn mineralization at Salkeld Lake, Nonacho Basin, Northwest Territories, Canada. M.Sc. thesis, Department of Geology, St. Mary’s University, Halifax, Nova Scotia.