Sedimentary record of ice divide migration and ice streams in the Keewatin core region of the Laurentide Ice Sheet

Hodder, Tyler; Ross, Martin; Menzies, John

doi:10.1016/j.sedgeo.2016.01.001

Cited by 22 publications

(22 citation statements)

References 49 publications

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“…Ubiquitous glacial lineations include the well-documented Dubawnt Lake ice stream bed in the southern part of the area, which records rapid ice flow roughly from east to west (Stokes & Clark, 2003a, 2003b. A further major flow is recorded along a south-north axis across much of the eastern part of the area, which may have fed the Boothia Ice Stream to the north-east (see also Hodder et al, 2016;Kleman et al, 2007;Margold et al, 2015). In addition to these large flow events, the landform record also reveals several smaller events which, in some locations, are recorded by complex clusters of lineations cross-cutting in up to three different directions.…”

Section: Discussionmentioning

confidence: 96%

“…Some of the large (10s km long) S-N trending lineations in the south of the study area have previously been identified as 'mega-scale transverse bedforms' akin to giant ribbed terrain (Greenwood & Kleman, 2010). These landforms have more recently been interpreted by Hodder et al (2016) as relict MSGL. This interpretation is supported by parallel striations, which would be difficult to explain if the features formed transverse to ice flow.…”

Section: Mapped Landformsmentioning

confidence: 94%

“…First, prior to deglaciation the study area was located in a core region of the Keewatin sector of the Laurentide Ice Sheet, and acted as a centre of ice dispersal (Dyke et al, 2002;McMartin & Henderson, 2004). A series of ice divides developed over the area, which reconfigured over time, having a dramatic influence on ice-flow direction as recorded by cross-cutting glacial lineations and striae (Boulton & Clark, 1990;Hodder, Ross, & Menzies, 2016;McMartin & Henderson, 2004).…”

Section: A Brief Glacial Historymentioning

confidence: 99%

“…It has also been suggested that, prior to deglaciation, another ice stream operated in the northern and central parts of the area, which flowed to the north-east and fed the Gulf of Boothia Ice Stream (Hodder et al, 2016).…”

Section: A Brief Glacial Historymentioning

confidence: 99%

“…This interpretation is supported by parallel striations, which would be difficult to explain if the features formed transverse to ice flow. For this reason we follow Hodder et al (2016) and classify these features as glacial lineations, though we note some uncertainty in this interpretation.…”

Section: Mapped Landformsmentioning

confidence: 99%

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Glacial geomorphology of the northern Kivalliq region, Nunavut, Canada, with an emphasis on meltwater drainage systems

Storrar

Livingstone

2017

Journal of Maps

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This paper presents a glacial geomorphological map of glacial lineations, ribbed terrain, moraines, meltwater channels (subglacial and ice-marginal/proglacial), eskers, glaciofluvial deposits, ice-contact outwash fans and deltas and abandoned shorelines on the bed of the former Laurentide Ice Sheet in northern Canada. Mapping was compiled from satellite imagery and digital elevation data and landforms were digitised directly into a Geographical Information System. The map reveals a complex glacial history characterised by multiple iceflow events, including fast-flowing ice streams. Moraines record a series of pauses or readvances 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 km 2 . It is presented at a scale of 1:500,000 and is designed to be printed at A0 size. ARTICLE HISTORY

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Section: Discussionmentioning

confidence: 96%

Section: Mapped Landformsmentioning

confidence: 94%

Section: A Brief Glacial Historymentioning

confidence: 99%

Section: A Brief Glacial Historymentioning

confidence: 99%

Section: Mapped Landformsmentioning

confidence: 99%

See 3 more Smart Citations

Glacial geomorphology of the northern Kivalliq region, Nunavut, Canada, with an emphasis on meltwater drainage systems

Storrar

Livingstone

2017

Journal of Maps

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A GIS‐based multi‐proxy analysis of the evolution of subglacial dynamics of the Quebec–Labrador ice dome, northeastern Quebec, Canada

Rice

Ross

Paulen

et al. 2020

Earth Surf Processes Landf

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The glacial records of the inner-core regions of the Laurentide Ice Sheet (LIS) document complex yet coherent patterns reflecting ice-sheet change (e.g. ice-divide migration), providing unique insights into past glacial conditions. This study develops a conceptual model of subglacial dynamics evolution within a major ice-dispersal centre of the LIS in northeastern Quebec, Canada using a GIS-based analysis of the surficial geologic record. Multiple proxies of subglacial conditions (subglacial streamlined landforms, lake density and lake area over thin drift/bedrock) were analysed through grid-overlay techniques and then classified based on different proxy variables ranging from highly mobile warm-based to immobile cold-based conditions. An additional proxy (till blanket) was used to identify areas of thick till deposition, but with few proxies (few lake or landform metrics). Based on local ice-flow reconstructions, the most 'relict' glacial terrain zone (GTZ1) has warm-based conditions over 66% of its area and is remarkably well preserved, suggesting laterally extensive warm-based conditions during the oldest identified ice-flow phase. This relict glacial terrain is partially overprinted by two subsequent ice-flow phases in spatially restricted zones in the northeast (73% warmbased), east-central (41% warm-based), and northwest (33% warm-based) of the study area. A zone of more sluggish conditions (only 3% warm-based) was identified in the highlands at the centre of the study area, characterized by thin till cover, few landforms, yet with large patches of relatively abundant small lakes, indicative of areal scouring. No clear evidence of sustained cold-based conditions (i.e. high chemical index of alteration values or high 10 Be abundances) was found in the study area. These results suggest that warm-based conditions (active erosion and/or deposition) were uniformly widespread during the earliest ice-flow phase, later becoming more spatially restricted with broader sluggish ice conditions. These spatially restricted regions of warm-based subglacial regimes were likely controlled by surrounding and down-flow ice streaming.

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Middle Wisconsinan marine shells near Repulse Bay, Nunavut, Canada: implications for Marine Isotope Stage 3 ice‐free conditions and Laurentide Ice Sheet dynamics in north‐west Hudson Bay

McMartin

Campbell

Dredge

2019

J Quaternary Science

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Evidence suggesting a reduction of the Laurentide Ice Sheet (LIS) during Marine Isotope Stage 3 (MIS 3) is widespread but the boundaries of the ice sheet and the timing of minimum ice extent are still poorly constrained. Radiocarbon dating of glacially transported marine mollusks in Rae Isthmus ice stream till south of Repulse Bay, Nunavut, Canada, provides new evidence for MIS 3 deglaciation in the north‐west part of Hudson Bay. Middle Wisconsinan finite 14C ages varying between 31.7 and 39.2k 14C a BP (∼35.0 and 43.7k cal a) indicate a marine event(s) for a minimum of ∼8.7k cal years. Our findings suggest ice‐free conditions in the ice stream source area in proto‐Roes Welcome Sound, and therefore significant glacial recession of the LIS margin during the Middle Wisconsinan, much farther in the interior of the ice sheet than previously known. The marine incursion possibly occurred because of a calving bay developed from the north in the Gulf of Boothia − Committee Bay area following the recession and collapse of the ice stream. After the MIS 3 marine episode(s), the topographically controlled ice stream stemming from the eastern end of the Keewatin Ice Divide was re‐activated, and maintained until deglaciation.

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Sedimentary record of ice divide migration and ice streams in the Keewatin core region of the Laurentide Ice Sheet

Cited by 22 publications

References 49 publications

Glacial geomorphology of the northern Kivalliq region, Nunavut, Canada, with an emphasis on meltwater drainage systems

Glacial geomorphology of the northern Kivalliq region, Nunavut, Canada, with an emphasis on meltwater drainage systems

A GIS‐based multi‐proxy analysis of the evolution of subglacial dynamics of the Quebec–Labrador ice dome, northeastern Quebec, Canada

Middle Wisconsinan marine shells near Repulse Bay, Nunavut, Canada: implications for Marine Isotope Stage 3 ice‐free conditions and Laurentide Ice Sheet dynamics in north‐west Hudson Bay

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