Projects and

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1 DRIFT PROSPECTING IN THE DISTRICT OF KEEWATIN - URANIUM AND BASE METALS Projects and W. W. Shilts and R. A. Klassen Studies of trace metal distribution in till were continued in the Yandle-Henninga Lake area; sampling at one-mile intervals was extended to the south and west of already completed one-mile grids (Shilts, 1974, 1975). In this area detailed sampling at spacings of less than one quarter mile was undertaken within selected areas that had been previously determined by one-mile sampling to be anomalously rich in copper, nickel, or zinc. Follow-up sampling was designed to determine how representative the anomalies, defined by many widely spaced samples, are of the several square miles of terrain they are supposed to characterize. Anew project was begun to evaluate the effectiveness of drift sampling in uranium exploration. Detailed till sampling was carried out around known uranium mineralization within units of the Dubawnt Group and some Archean-age dykes in the Baker-Pitz Lake area, and at one site within a conglomerate near the base of Hurwitz Group sediments, about 5 miles southwest of Yandle Lake. Till sampling at one-mile intervals was completed over approximately 1200 square miles of terrain underlain by the Dubawnt Group and adjacent Archean-age bedrock. Figure Uranium in till samples from mudboils on Boothia Peninsula, < 21-1 fraction. Samples collected by A. N. Boydell, J. A. Netterville, K. A. Drabinsky, 1974 (project ). ~eol. Surv. Can., Paper 76-1A

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3 In addition to the drift sampling, R. W. Wein directed the collection of large samples of 10 to 15 species of tundra plants, peat, and mineral sediment at each of six sites. Two sites were directly over uranium mineralization, one was over copper-lead-zinc mineralization, one was in a dispersal train 2 miles down-ice from copper-lead-zinc mineralization, and two were background sites. This pilot project is designed to establish which, if any, typical tundra plant species might be useful as a medium in exploration for uranium or base metals. Ashed residue from these samples is presently being analyzed for several trace elements. In preparing for the uranium sampling program over 1500 till samples, previously collected during drift prospecting and terrain mapping programs in the Kaminak Lake and Boothia Peninsula areas, were analyzed for uranium. Figures and illustrate the results of these analyses but are difficult to evaluate at present because of uncertainty about the magnitudes of uranium values to be expected in till from mudboils in close proximity to uranium minerali7ation. In Boothia Peninsula a cluster of high values in widely separated samples occurs near the base of the peninsula in terrain mapped as an Archean-age gneissic complex (Fig ). Consistently high uranium values (5 to 12 ppm) were found in tills of the Simpson Lake- Murchison River area; the highest occurs near an area of modified granitic rocks (Heywood, 1961). The dis tribution of uranium values on this map merely may reflect the varying average background values of the different rock types from which the till was derived and at present should not be construed to represent areas that are favourable for uranium mineralization. In the Kaminak Lake area groups of high uranium values are particularly prominent north and northwest of Carr Lake and north of Kinga Lake. Some of the high values that occur immediately north of Carr Lake are from till resting on or near the Hurwitz Quartzite. Both groups of high values, however, appear to the authors to relate to gneissic terrain mapped north and northwest of the Kaminak- Turquetil igneous complexes and their flanking metavolcanic and metasedimentary units. The clusters of high values may reflect a generally elevated background for uranium throughout the gneissic terrain, which in turn may be reflected by the till on and down- ice (southeast) from the gneissic areas. As with Boothia Peninsula, these clusters of high values should not necessarily be construed to indicate areas that would be favourable for uranium mineralization. References Heywood, W. W. 1961: Geological notes, northern District of Keewatin; Geol. Surv. Can., Paper 61-18, 9 P. Shilts, W. W. 1974: Cu, Zn, and Ni concentrations in till of the Henninga-Kaminak Quartzite Lake area, District of Keewatin; Geol. Surv. Can., Open File : Principles of geochemical exploration for sulphide deposits using shallow samples of glacial drift; Can. Min. Metall. Bull., May 1975.

4 GEOLOGICAL SURVEY PAPER 76-1 A REPORT OF ACTIVITIES PART A

5 Crown Copyrights reserved Available by mail from Information Canada, Ottawa, KIA OS9 from the Geological Survey of Canada 601 Booth St., Ottawa, KIA 0E8 and Information Canada bookshops in HALIFAX Barrington Street MONTREAL St. Catherine Street W. OTTAWA Slater Street TORONTO Yonge Street WINNIPEG Portage Avenue VANCOUVER Granville Street or through your bookseller A deposit copy of this publication is also available for reference in public libraries across Canada Price - Canada: $5. 00 Other Countries: $6. 00 Catalogue No. R'I A Price subject to change without notice Information Canada Ottawa 1976