Geological Survey of Canada CURRENT RESEARCH 2006-C3 Glacial history and drift prospecting, Conn Lake and Buchan Gulf, northern Baffin Island, Nunavut D.J. Utting, E.C. Little, R.D. Coulthard, O.H. Brown, G.M.D. Hartman, C.A. Huscroft, and J.S. Smith 2006 CURRENT RESEARCH Natural Resources Ressources naturelles Canada Canada ©Her Majesty the Queen in Right of Canada 2006 ISSN 1701-4387 Catalogue No. M44-2006/C3E-PDF ISBN 0-662-43676-8 A copy of this publication is also available for reference by depository libraries across Canada through access to the Depository Services Program's Web site at http://dsp-psd.pwgsc.gc.ca A free digital download of this publication is available from GeoPub: http://geopub.nrcan.gc.ca/index_e.php Toll-free (Canada and U.S.A.): 1-888-252-4301 Critical reviewer D.A. Hodgson Authors’ addresses D.J. Utting ([email protected]) J.S. Smith ([email protected]) E.C. Little ([email protected]) O.H. Brown ([email protected]) Industry and Resources Saskatchewan Geological Survey of Canada G.M.D. Hartman Exploration and Geological Services 3303-33rd Street N.W. C.A. Huscroft Northern Geological Survey Calgary, Alberta T2L 2A7 626 Tumiit Building, P.O. Box 2319 2101 Scarth Street Iqaluit, Nunavut Regina, Saskatchewan S4P 3V7 R.D. Coulthard X0A 0H0 University of Alberta Department of Earth and Atmospheric Sciences Edmonton, Alberta T6G 2E3 Publication approved by Canada–Nunavut Geoscience Office Original manuscript submitted: 2006-03-14 Final version approved for publication: 2006-03-22 Correction date: All requests for permission to reproduce this work, in whole or in part, for purposes of commercial use, resale, or redistribution shall be addressed to: Earth Sciences Sector Information Division, Room 402, 601 Booth Street, Ottawa, Ontario K1A 0E8. Glacial history and drift prospecting, Conn Lake and Buchan Gulf, northern Baffin Island, Nunavut D.J. Utting, E.C. Little, R.D. Coulthard, O.H. Brown, G.M.D. Hartman, C.A. Huscroft, and J.S. Smith Utting, D.J., Little, E.C., Coulthard, R.D., Brown, O.H., Hartman, G.M.D., Huscroft, C.A., and Smith, J.S., 2006: Glacial history and drift prospecting, Conn Lake and Buchan Gulf, northern Baffin Island, Nunavut; Geological Survey of Canada, Current Research 2006-C3, 11 p. Abstract: Northeast Baffin Island, in the region of Conn Lake and Buchan Gulf, is an area having high exploration potential for precious metals, base metals, and diamonds; however, much of the region is exten- sively covered by thick glacial deposits that hinder traditional, bedrock-focused exploration techniques. A better understanding of glacial deposits, transport, and history is essential to reduce exploration risk in the region. This study presents the results of fieldwork in 2005 focused on glacial deposits and complex ice-movement history (four phases are proposed) of northeast Baffin Island. This paper provides a review of previous work; it also includes a summary of field operations and presents a glacial chronology based on geomorphology and ice-movement indicators. Résumé : La région du lac Conn et du golfe de Buchan, dans le nord-est de l’île de Baffin, présente un potentiel élevé pour l’exploration à la recherche de métaux précieux, de métaux communs et de diamants. Cependant, une bonne partie de cette région est recouverte d’épais dépôts glaciaires qui nuisent à l’application des méthodes classiques d’exploration axées sur le substratum rocheux. Une meilleure compréhension de ces dépôts glaciaires, de leur transport et de leur histoire est essentielle pour réduire les risques rattachés à l’exploration dans la région. Cet article présente les résultats de travaux sur le terrain menés en 2005, centrés sur les dépôts glaciaires ainsi que sur la complexe histoire des déplacements de la glace (quatre phases sont ici proposées) dans le nord-est de l’île de Baffin. En plus d’un sommaire des travaux antérieurs, il contient un résumé des activités de la campagne de terrain, ainsi qu’une chronologie glaciaire fondée sur la géomorphologie et les indices d’écoulement glaciaire. Current Research 2006-C3 1 D.J. Utting et al. INTRODUCTION regions: Ravn River–Steensby Inlet, Isortoq River–Steensby Inlet, Buchan Gulf–Scott Inlet, and Milne Inlet (Fig. 1). The western reaches of the Barnes Ice Cap are located in the In 2005, the Canada–Nunavut Geoscience Office, in col- southeast portions of NTS 37 E, and Oliver Glacier occupies a laboration with the Geological Survey of Canada, University northern portion of NTS 37 G. Numerous smaller, unnamed of Alberta, Dalhousie University, and Polar Continental Shelf ice caps are present on the interfiord highlands. Project, expanded the North Baffin Project (Little et al., 2004) from Icebound Lakes (NTS 37 G) southeastward to Conn Lake (NTS 37 E) and eastward to Buchan Gulf Bedrock geology (NTS 37 H) on northeastern Baffin Island (Fig. 1). The pri- mary goal of this study is to reduce mineral exploration risk in The area is primarily underlain by Archean supracrustal this remote area by improving the existing geoscience knowl- rocks of the Mary River Group, variably metamorphosed and edge base. The project involves mapping the surficial deformed Archean granitoid rocks and related gneiss and geology at 1:100 000 scale; collection of drift, stream, and lesser amounts of Paleoproterozoic intrusive rocks (de Kemp bedrock prospecting samples; and detailed bedrock mapping and Scott, 1998; Jackson, 2000; Young et al., 2004; of key localities. The results of the bedrock mapping will be S.M. Johns and M.D. Young, work in progress, 2006 ). In the reported in a separate paper (S.M. Johns and M.D. Young, northwest part of NTS 37 G is a northwest-trending rift basin work in progress, 2006). A total of 321 till samples and 31 of weakly to unmetamorphosed siliciclastic and carbonate stream-sediment samples have been collected for geochemis- rocks of the Mesoproterozoic Bylot Supergroup (Young try and kimberlite indicator mineral analyses; 123 bedrock et al., 2004). West and south of the study area are unmeta- samples have been collected for assay and 90 for lithogeo- morphosed Paleozoic siliciclastic and carbonate rocks chemical analyses. In addition, the project has yielded (de Kemp and Scott, 1998; Young et al., 2004). 1387 map ground-truthing sites, 336 paleo-ice-movement The area also includes some rare occurrences of a con- measurements, 27 terrestrial cosmogenic nuclide dating sam- glomerate and laminated siltstone which, on the basis of con- ples, and 49 shell samples for radiocarbon geochronology; tact relationships, are inferred to be the youngest bedrock together, these data will allow for advanced research into gla- unit. These were first recognized by Andrews et al. (1972), cial dynamics influencing the surficial geology of north who interpreted a Paleogene age based on the palynology of Baffin Island. the strata. In 2005 these rocks were rediscovered in situ This paper provides a summary of the 2005 field season within fractures and on granodioritic and syenitic gneiss in an and a glacial chronology based on geomorphology, ice- area south of Rimrock Lake (Fig. 1). These rocks are useful movement indicators, and previous work. Four phases of ice because they provide a minimum age for the exhumation of flow were identified and modified from Little et al. (2004). the Baffin Surface (discussed below) following rifting from The earliest, phase 1, the authors relate to the Last Glacial Greenland, as well as the associated uplift and denudation. Maximum. The second phase the authors associate with the formation of the Coburn Moraine system in the midfiord region. The next two phases of ice flow are thought to be Preglacial landscape elements related to the proto-Barnes Ice Cap, when all glacial ice was Baffin Island has two prominent upland surfaces, or pene- grounded on Baffin Island. Several other investigations were plains, having concordant elevations: the Penny Surface at initiated in the 2005 field season, but they rely on data that has 1500 m to 1800 m and the Baffin Surface from 600 m to 730 m not yet been analyzed, and are therefore not discussed in this (Bird, 1967). On southern Baffin Island, high topographic report. A summary of these investigations is included in the relief Precambrian rock with a Baffin Surface elevation is ‘Related studies’ section. exposed in fault contact with flat-lying Ordovician strata, indicating the Precambrian rock has been uplifted since the Ordovician (Sanford and Grant, 2000). It is probable that this PHYSIOGRAPHIC AND peneplain surface existed prior to Ordovician sedimentation (Bird, 1967). The Ordovician rocks also outcrop south of the GEOLOGICAL SETTING field area in Foxe Basin (Sanford and Grant, 2000). Study area Glacial erosional landscape elements The north Baffin Island project’s 2005 field program covered NTS 37 E and 37 H (south), following the 2003 field Dyke et al. (1982) examined major topographic elements season focused on NTS 37 G (Fig. 1). Together, these areas that indicated the extent of glacial erosion on the Cumberland span five of Bostock’s (1970) physiographic regions: Baffin Peninsula of easternmost Baffin Island. Major elements are: Coastal Lowlands, Davis Highlands, Baffin Uplands, ‘plateau’, gently rolling with no distinct summits; ‘dissected Lancaster Plateau, and Foxe Plain (Fig. 2). Four collections plateau’, similar to plateau, but dissected by troughs and/or of drainage basins are superimposed on these physiographic fiords; ‘scalloped-dissected plateau’; and ‘fretted mountains’. Current Research 2006-C3 2 D.J. Utting et al. Study area location, drainage basins, and features discussed in text. Figure 1. Current Research 2006-C3 3 D.J. Utting et al. Figure 2. Glacial erosional landscape elements in the North Baffin Project study area. a) relationship of the extent of alpine glaciation to the type of landscape, from plateau to fretted mountains (modified from Dyke et al.