Geochemistry and geochronology of the Kiggavik uranium deposit, Nunavut, Canada
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ARTICLE
Geochemistry and geochronology of the Kiggavik uranium deposit, Nunavut, Canada Brandi M. Shabaga 1
&
Mostafa Fayek 1 & David Quirt 1,2 & Charlie W. Jefferson 3 & Patrick Ledru 2
Received: 9 June 2018 / Accepted: 16 June 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract The Thelon Basin, Nunavut, Canada, is similar in age, size, and geology to the U producing Athabasca Basin in Saskatchewan. The Kiggavik project area, located immediately south of the Aberdeen sub-basin of the Thelon Basin, contains U deposits and showings along a ~ 30-km-long NE–SW structural trend. The basement-hosted Kiggavik deposit, comprising three separate mineralized zones (Main, Centre, and East), is located at the northern end of this trend. Multiple styles of U mineralization and alteration were identified at the Kiggavik deposit. Disseminated euhedral uraninite (U1; 1284 ± 53 Ma) has elevated Pb contents up to ~ 14 wt% PbO and is associated with illite and hematite alteration. Vein-style uraninite (U2; 284 ± 19 Ma) forms along fractures, contains lower Pb contents (≤ 3.9 wt% PbO), and is partly altered to Ca–Si-rich (~ 4.5 wt% CaO and ~ 3.3 wt% SiO2) uraninite. Highly altered U2 is associated with galena. Late U minerals (U3) have biogenic textures and are Pb-free, indicating that they formed recently (< 1 Ma). Based on SIMS in situ U–Pb geochronology, the minimum age of uraninite at the Kiggavik deposit is 1284 ± 53 Ma; however, this is likely a reset age associated with the Mackenzie dyke event (~ 1267 Ma). Oxygen and hydrogen stable isotope compositions of illite and muscovite suggest that the Kiggavik deposit has been overprinted by high-latitude surficial fluids derived from snowmelt. Keywords Uranium . Thelon Basin . Geochronology . Kiggavik . Isotopes . Geochemistry
Introduction Canada is an important global producer of U, second only to Kazakhstan. In 2014, Canada produced 16% of the world’s U from Proterozoic unconformity-related U deposits in the Athabasca Basin, Saskatchewan (Organisation for Economic Co-operation and Development, 2016). These deposits are among the highest grade U deposits in the world (e.g., Cigar Lake and McArthur River), and their anomalous grade and tonnage have promoted exploration for these types of deposits in other Proterozoic sedimentary basins across the globe. Editorial handling: J. Mercadier * Brandi M. Shabaga [email protected] 1
Department of Geological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
2
Orano Canada, 817 45th Street W., Saskatoon, SK S7K 3X5, Canada
3
Geological Survey of Canada, 601 Booth Street, Ottawa, ON K1A 0E8, Canada
Sedimentary basins of Proterozoic age such as the Athabasca, Hornby Bay, and Borden (Canada), McArthur (Australia), and Espinhaço (Brazil) are economically important in terms of petroleum and metal (Pb–Zn, Cu, Au, U) production (Kyser 2007). These basins are spatially and temporally related to orogenic events associated with the assemblage of Arctica and Atlantica, the accretion of Nuna, and
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