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Glacial Geomorphology of the Northern Kivalliq Region, Nunavut, Canada, with an Emphasis on Meltwater Drainage Systems

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Glacial Geomorphology of the Northern Kivalliq Region, Nunavut, Canada, with an Emphasis on Meltwater Drainage Systems Journal of Maps ISSN: (Print) 1744-5647 (Online) Journal homepage: http://www.tandfonline.com/loi/tjom20 Glacial geomorphology of the northern Kivalliq region, Nunavut, Canada, with an emphasis on meltwater drainage systems Robert D. Storrar & Stephen J. Livingstone To cite this article: Robert D. Storrar & Stephen J. Livingstone (2017) Glacial geomorphology of the northern Kivalliq region, Nunavut, Canada, with an emphasis on meltwater drainage systems, Journal of Maps, 13:2, 153-164 To link to this article: http://dx.doi.org/10.1080/17445647.2017.1279081 © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group View supplementary material Published online: 24 Jan 2017. Submit your article to this journal View related articles View Crossmark data Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=tjom20 Download by: [University of Sheffield] Date: 24 January 2017, At: 05:53 JOURNAL OF MAPS, 2017 VOL. 13, NO. 2, 153–164 http://dx.doi.org/10.1080/17445647.2017.1279081 SCIENCE Glacial geomorphology of the northern Kivalliq region, Nunavut, Canada, with an emphasis on meltwater drainage systems Robert D. Storrar a and Stephen J. Livingstone b aDepartment of the Natural and Built Environment, Sheffield Hallam University, Sheffield, UK; bDepartment of Geography, University of Sheffield, Sheffield, UK ABSTRACT ARTICLE HISTORY This paper presents a glacial geomorphological map of glacial lineations, ribbed terrain, Received 1 April 2016 moraines, meltwater channels (subglacial and ice-marginal/proglacial), eskers, glaciofluvial Revised 24 October 2016 deposits, ice-contact outwash fans and deltas and abandoned shorelines on the bed of the Accepted 23 November 2016 former Laurentide Ice Sheet in northern Canada. Mapping was compiled from satellite KEYWORDS imagery and digital elevation data and landforms were digitised directly into a Geographical Laurentide Ice Sheet; glacial Information System. The map reveals a complex glacial history characterised by multiple ice- geomorphology; meltwater flow events, including fast-flowing ice streams. Moraines record a series of pauses or re- channels; Canada advances during overall SE retreat towards the Keewatin Ice Divide. The distribution of subglacial meltwater landforms indicates that several distinctive scales and modes of drainage system operated beneath the retreating ice sheet. This includes a large (>100 km) integrated network of meltwater channels, eskers, ice-contact outwash fans and deltas and glaciofluvial deposits that originates at the northern edge of Aberdeen Lake. The map comprises zone 66 of the Canadian National Topographic System, which encompasses an area of 160,000 km2. It is presented at a scale of 1:500,000 and is designed to be printed at A0 size. 1. Introduction was abundant during the deglaciation of the Laurentide Ice Sheet (e.g. Carlson et al., 2009; Storrar, Stokes, & The Laurentide Ice Sheet covered a substantial pro- Evans, 2014a) and produced a large geomorphological portion of North America during the Late Wisconsinan imprint (e.g. Brennand, 2000; Brennand & Shaw, 1994; glaciation (Dyke et al., 2002) and its subsequent demise Mullins & Hinchey, 1989; Prest, Grant, & Rampton, was closely coupled to dramatic climatic changes (e.g. 1968; Storrar, Stokes, & Evans, 2013), the geomorpho- Barber et al., 1999; Clark, 1994; Clark, Alley, & Pollard, logical record of meltwater has to date played only a 1999). Understanding the fluctuations of ice sheets and relatively minor role in ice sheet reconstructions. the processes which take place beneath them, and how This is typically limited to providing supplementary they interact with climate, is important for predicting information about ice geometries and flow direction how ice sheets will respond to contemporary climate (Kleman & Borgström, 1996), rather than to recon- change. High resolution climatic records extending struct basal and hydrological processes in space and over the last glacial cycle (and beyond) are widely avail- time (see review by Greenwood, Clason, Helanow, & able (e.g. Shakun et al., 2012), providing a wealth of Margold, 2016). The long-term effect is that the role data which can be compared with the palaeo-ice of meltwater in governing or modulating ice sheet sheet record. Previous reconstructions have focused dynamics is relatively underexplored (although see principally on ice-margin fluctuations (e.g. Dyke & Stokes, Tarasov, & Dyke, 2012; Tarasov & Peltier, Prest, 1987; Dyke, Moore, & Robertson, 2003) and 2004, 2006). This paper aims to provide the geomor- the activity of ice streams (e.g. De Angelis & Kleman, phological mapping basis for a first attempt to incor- 2005; Margold, Stokes, & Clark, 2015; Ó Cofaigh, porate meltwater landforms into a larger ice dynamic Evans, & Smith, 2010; Ross, Campbell, Parent, & reconstruction, using a study area in northern Canada. Adams, 2009; Stokes & Clark, 2001; Stokes, Clark, & Storrar, 2009; Stokes, Margold, Clark, & Tarasov, 2016), which rapidly drain large portions of ice sheets. 2. Study area and previous mapping Recent work on contemporary ice sheets has drawn attention to the importance of meltwater in controlling The study area corresponds to zone 66 of the Canadian ice dynamics (e.g. Bartholomew et al., 2010; Schoof, National Topographic System (NTS) and extends from 2010; Zwally et al., 2002). However, whilst meltwater the 64th to 68th parallels and from the 96th to 104th CONTACT Robert D. Storrar [email protected] Department of the Natural and Built Environment, Sheffield Hallam University, Sheffield S1 1WB, UK Supplemental data for this article can be accessed http://dx.doi.org/10.1080/17445647.2017.1279081. © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 154 R. D. STORRAR AND S. J. LIVINGSTONE Figure 1. Location and topography of the study area. Locations of the landform examples provided in subsequent figures are indi- cated by boxes and the numbers refer to the associated figure number. Lakes greater than 100 km2 are shown with blue outlines. meridians, encompassing an area of approximately lies on the Precambrian Shield and is composed mainly 160,000 km2 (Figure 1). Despite its large size, the of granitioid rocks, with belts of greenstone and meta- study area is predominantly within the relatively flat morphosed sediments in the north and sedimentary Back Lowland and Thelon Plain (Dyke & Dredge, basins in the south (Wheeler et al., 1996). 1989), with a maximum elevation of 361 m a.s.l. Early mapping of areas like, and including, zone 66 Queen Maud Gulf lies to the north and the area con- (e.g. Craig, 1961, 1964) by the Geological Survey of tains myriad small lakes and several larger lakes, Canada (GSC) resulted in the publication of the Glacial including Aberdeen Lake (1106 km2), Schultz Lake Map of Canada (Prest et al., 1968), which shows the (410 km2) and the Garry Lakes (776 km2). The area generalised glacial geomorphology. Since the 1980s, the GSC have produced several more detailed surficial geology map sheets covering subsets of the area at scales ranging from 1:100,000 to 1:1,000,000, the spatial distribution of which is shown in Figure 2 (Aylsworth, 1990; Aylsworth & Clarke, 1989; Aylsworth & Shilts, 1989a; Aylsworth, Cunningham, & Shilts, 1990; Helie, 1984; McMartin, Dredge, & Aylsworth, 2008; McMar- tin, Dredge, & Robertson, 2005; St-Onge & Kerr, 2013, 2014a, 2014b; 2015; Thomas, 1981a, 1981b). This map- ping is based on the interpretation of aerial photo- graphs and field observations and contains different collections of landforms, depending on the mapper. A summary of the landforms recorded on each map is provided in Table 1. Whilst some landforms, such as eskers, are presented in a high level of detail, others, notably glacial lineations, are necessarily generalised Figure 2. Extent of previous surficial geology maps at various and individual bedforms are often not mapped. More- scales in NTS zone 66. over, Figure 2 shows that several portions of the study Table 1. Features mapped in previous studies. Lineations Crag and tails (including (including Shorelines Ice- Ice- NTS flutings & roches Ribbed De Geer Hummocky Meltwater Marine Lacustrine (including Moraine Lateral contact contact Glaciofluvial zone Reference Scale drumlins moutonnées) Striae moraine moraine moraine Esker channel limit limit beaches) ridge moraine Delta delta face terrace scarp 066A Aylsworth 1:125,000 ✓✓✓✓✓✓✓✓✓ ✓✓ et al. (1990) 066A McMartin 1:250,000 ✓✓✓✓✓✓ ✓ et al. (2005) 066A McMartin 1:100,000 ✓✓✓✓✓ ✓✓ ✓ south et al. (2008) 066B Aylsworth 1:125,000 ✓✓✓✓✓✓✓✓✓✓✓✓ (1990) 066C Aylsworth 1:250,000 ✓✓✓✓✓✓✓✓✓ ✓✓ and Clarke (1989) 066E St-Onge 1:125,000 ✓✓✓ ✓ ✓✓ ✓✓ and Kerr (2013) 066G St-Onge 1:125,000 ✓✓✓ ✓✓ ✓✓ north and Kerr (2015) 066I Thomas 1:250,000 ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓✓✓ ✓ (1981a) 066H Thomas 1:250,000 ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓✓✓ ✓ (1981b) 066J St-Onge 1:125,000 ✓✓✓ ✓✓✓ ✓✓ south and Kerr (2014b) 066L St-Onge 1:125,000 ✓✓✓ ✓✓ ✓✓ ✓✓ and Kerr (2014a) 066C,D, Craig (1964) 1:506,880 ✓✓✓ ✓✓ ✓✓✓ E,F JOURNAL OF MAPS 066O,P Helie (1984) 1:250,000 ✓✓✓✓ ✓ ✓✓✓ 066I,J,K, Craig (1961) 1:1,013,760 ✓✓✓ ✓ ✓ ✓ N,O,P 066 (all) Aylsworth 1:1,000,000 ✓✓ ✓ ✓✓ ✓ and
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