SYNOPSIS OF THE POLARIS ZN-P B DISTRICT , C ANADIAN ARCTIC ISLANDS , N UNAVUT KEITH DEWING 1, R OBERT J. S HARP 2 , AND ELIZABETH TURNER 3 1. Geological Survey of Canada, 3303-33rd Street NW, Calgary, Alberta T2L 2A7 2. Trans Polar Geological, 60 Hawkmount Heights NW, Calgar,y Alberta T3G 3S5 3. Department of Earth Science, Laurentian University, Sudbury, Ontario, P3E 2C6 Corresponding author’s email:
[email protected] Abstract The Polaris Mine was a Mississippi Valley-type (MVT) deposit hosted in dolomitized Middle Ordovician lime - stone. Total production was 20.1 Mt at 13.4% Zn and 3.6% Pb. There are about 80 showings in the district, which stretches from Somerset Island to the Grinnell Peninsula. There are two deposit types in the Polaris District: 1) struc - turally controlled, carbonate-hosted Zn-Pb-Fe deposits typical of MVT deposits, and 2) structurally and stratigraphi - cally controlled, carbonate-hosted Cu deposits enriched by later supergene removal of Fe and S. Mineralization is paragenetically simple, with sphalerite and galena as the ore minerals, and with dolomite and mar - casite as the main gangue minerals. The deposits formed from brines at about 90 to 100°C. The age of the mineraliza - tion is constrained to post-Late Devonian folding and may be associated with the last stages of the Ellesmerian Orogeny or the opening of the Sverdrup Basin. Copper-rich mineralization is known from four showings, is associated with zinc- lead mineralization and is confined to a single interval in the Silurian. The metallogenic model for Polaris invokes a source of metal ions within the stratigraphic column since strontium shows no indication of basement involvement.