The late Quaternary stratigraphic record northwest of Montréal: regional ice-sheet dynamics, ice-stream activity, and early deglacial events

2006 ◽  
Vol 43 (4) ◽  
pp. 461-485 ◽  
Author(s):  
Martin Ross ◽  
Michel Parent ◽  
Beatriz Benjumea ◽  
James Hunter
Keyword(s):  
Late Quaternary ◽  
Late Glacial ◽  
Ice Flow ◽  
Glacial Sediments ◽  
Ice Stream ◽  
Digital Elevation ◽  
Flow Features ◽  
Ice Sheet Dynamics ◽  
Late Wisconsinan ◽  
Elevation Model

The Quaternary sediments of previously unstudied buried valleys and sections near Montréal are analyzed and other sites are revisited to further develop the stratigraphic framework of the St. Lawrence Lowland and to establish regional glacial and deglacial models. The southwest-trending buried valleys were investigated by stratigraphic drilling and high-resolution seismic profiling. The Quaternary succession consists, from base to top, of proximal glaciolacustrine sediments, two superposed till sheets (Argenteuil and Oka tills) of inferred Late Wisconsinan age, and Champlain Sea sediments. The glacial sediments of this sequence record an ice advance toward south (Argenteuil Till) followed by an abrupt ice-flow shift toward the southwest (Oka Till). Compositional and geomorphic data indicate that Oka Till is ubiquitous and is associated with a regional set of glacial landforms. The analysis of a regional digital elevation model in combination with published ice-flow indicators shows convergent flow patterns from the Ottawa–Montréal–Adirondack regions toward the Lake Ontario basin. Landforms produced by the inferred ice stream are locally crosscut by southward-trending ice-flow features. Hence southward flow in the upper St. Lawrence Valley seemingly took place in two distinct contexts: (1) during full glacial conditions, as ice margins stood at or near the late glacial maximum limits, and (2) during late deglaciation, as a post-ice stream reequilibration mechanism. Early deglacial events in the study area were also characterized by subglacial meltwater channelling and erosion along the valleys, subaquatic outwash deposition in glacial Lake Candona, and rapid infill of the valleys during the early stages of the ensuing Champlain Sea.

scholarly journals Glacial Stratigraphy of the Bulkley River Region: A Depositional Framework for the Late Pleistocene in Central British Columbia*

2006 ◽  
Vol 58 (2-3) ◽  
pp. 217-228 ◽  
Author(s):  
Andrew J. Stumpf ◽  
Bruce E. Broster ◽  
Victor M. Levson
Keyword(s):  
British Columbia ◽  
Late Pleistocene ◽  
Late Glacial ◽  
Ice Flow ◽  
Glacial Sediments ◽  
Fine Grained ◽  
Local Erosion ◽  
River Region ◽  
Flow Directions ◽  
Late Wisconsinan

Abstract A depositional framework for late Pleistocene sediments in central British Columbia was developed from the composite stratigraphy of glacial sediments found in the Bulkley River region. Nonglacial deposits correlated to the Olympia Nonglacial Interval, are overlain in succession by sub-till, ice-advance sediments, Late Wisconsinan (Fraser Glaciation) till, and late-glacial sediments. Due to local erosion and depositional variability, some of the units are not continuous throughout the region and differ locally in their thickness and complexity. At the onset of the Fraser Glaciation, ice advance was marked by rising base levels in rivers, lake ponding, and ice marginal subaqueous deposition. Physiography and glacier dynamics influenced the position of drainage outlets, direction of water flow, and ponding. The region was completely ice covered during this glaciation and ice-flow directions were variable, being dominantly influenced by the migrating position of ice divides. Deglaciation was marked by the widespread deposition of fine-grained sediments in proglacial lakes and glaciofluvial sands and gravels at locations with unrestricted drainage.

scholarly journals Dynamics of the last Scandinavian Ice Sheet’s southernmost sector revealed by the pattern of ice streams 

2021 ◽  
Author(s):  
Izabela Szuman ◽  
Jakub Z. Kalita ◽  
Marek W. Ewertowski ◽  
Chris D. Clark ◽  
Stephen J. Livingstone
Keyword(s):  
Ice Sheet ◽  
Ice Streams ◽  
Climatic Forcing ◽  
Ice Dynamics ◽  
Geomorphological Mapping ◽  
Ice Stream ◽  
Digital Elevation ◽  
Scandinavian Ice Sheet ◽  
Ice Sheet Dynamics ◽  
Elevation Model

<p>The Polish sector of the last Scandinavian Ice Sheet is a key area for studying ice sheet drainage and decay from its local Last Glacial Maximum (LGM) extent, as it is located at the terrestrial terminus of the large and dynamic Baltic Ice Stream Complex. Geomorphological mapping, based on a 0.4 m LIDAR digital elevation model, revealed about 940 streamlined bedforms, many of which are shown for the first time and consisting of mega-scale glacial lineations and drumlins. The lineation flow-sets together with associated landforms were used to identify seventeen ice streams, occupying 80% of the study area. We demonstrated that subtle topographic variations played an important role in influencing ice sheet dynamics. Variations in ice dynamics were a response to external climatic forcing that controlled deglaciation at the ice sheet scale as well as internal reorganisation due to the influence of topography, subglacial hydrology and glacier thermal regime. During the local LGM, the southern sector of the Scandinavian Ice Sheet in Poland was dominated by four simultaneously operating ice streams, likely active for several millennia, followed by fast active recession interrupted by three main periods of ice stream stagnation. Increased ice flow</p><p>dynamics during the period of the Young Baltic advances is suggested to be caused by variations in subglacial hydrology and the polythermal structure of the ice sheet. </p>

Late Quaternary glacial and interglacial environments of the Nechako River - Cheslatta Lake area, central British Columbia

2001 ◽  
Vol 38 (4) ◽  
pp. 719-731 ◽  
Author(s):  
A Plouffe ◽  
V M Levson
Keyword(s):  
British Columbia ◽  
Late Quaternary ◽  
Late Glacial ◽  
Lake Area ◽  
Glacial Lakes ◽  
Ice Flow ◽  
Coast Mountains ◽  
Quaternary Stratigraphy ◽  
History Of ◽  
Quaternary History

The Quaternary stratigraphy of the Nechako River – Cheslatta Lake area of central British Columbia is described and interpreted to reconstruct the late Quaternary history of the region. Exposures of glacial and nonglacial sediments deposited prior to the last glaciation (Fraser) are limited to three sites. Pollen assemblages from pre-Fraser nonglacial sediments at two of these sites reveal forested conditions around 39 000 BP. During the advance phase of the Fraser Glaciation, glacial lakes were ponded when trunk glaciers blocked some tributary valleys. Early in the glaciation, the drainage was free in easterly draining valleys. Subsequently, the easterly drainage was blocked either locally by sediments and ice or as a result of impoundment of the Fraser River and its tributaries east of the study area. Ice generally moved east and northeast from accumulation zones in the Coast Mountains. Ice flow was influenced by topography. Major late-glacial lakes developed in the Nechako River valley and the Knewstubb Lake region because potential drainage routes were blocked by ice.

scholarly journals Mapping Glacier Forelands Based on UAV BVLOS Operation in Antarctica

2020 ◽  
Vol 12 (4) ◽  
pp. 630
Author(s):  
Maciej Dąbski ◽  
Anna Zmarz ◽  
Mirosław Rodzewicz ◽  
Małgorzata Korczak-Abshire ◽  
Izabela Karsznia ◽  
...  
Keyword(s):  
Ice Age ◽  
South Shetland Islands ◽  
Ground Moraine ◽  
King George Island ◽  
Ice Flow ◽  
Tidewater Glaciers ◽  
Geomorphological Mapping ◽  
Digital Elevation ◽  
Glacial Dynamics ◽  
Elevation Model

The aim of this article is to show geomorphological mapping of remote Antarctic locations using images taken by a fixed-wing unmanned aerial vehicle (UAV) during the Beyond Visual Line of Sight (BVLOS) operations. We mapped landform assemblages developed in forelands of Ecology Glacier (EGF), Sphinx Glacier (SGF) and Baranowski Glacier (BGF) in Antarctic Specially Protected Area No. 128 (ASPA 128) on King George Island (South Shetland Islands) and inferred about glacial dynamics. The orthophoto and digital elevation model allowed for geomorphological mapping of glacial forelands, including (i) glacial depositional landforms, (ii) fluvial and fluvioglacial landforms, (iii) littoral and lacustrine landforms, (iv) bodies of water, and (v) other. The largest area is occupied by ground moraine and glacial lagoons on EGF and BGF. The most profound features of EGF are the large latero-frontal moraine ridges from Little Ice Age and the first half of the 20th century. Large areas of ground moraine, frequently fluted and marked with large recessional moraine ridges, dominate on SGF. A significant percentage of bedrock outcrops and end moraine complexes characterize BGF. The landform assemblages are typical for discontinuous fast ice flow of tidewater glaciers over a deformable bed. It is inferred that ice flow velocity decreased as a result of recession from the sea coast, resulting in a significant decrease in the length of ice cliffs and decrease in calving rate. Image acquisition during the fixed-wing UAV BVLOS operation proved to be a very robust technique in harsh polar conditions of King George Island.

Coalescence of late Wisconsinan Cordilleran and Laurentide ice sheets east of the Rocky Mountain Foothills in the Dawson Creek region, northeast British Columbia, Canada

2016 ◽  
Vol 85 (3) ◽  
pp. 409-429 ◽  
Author(s):  
Adrian Scott Hickin ◽  
Olav B. Lian ◽  
Victor M. Levson
Keyword(s):  
British Columbia ◽  
Flow Direction ◽  
Ice Sheet ◽  
Rocky Mountain ◽  
Ice Flow ◽  
Oxygen Isotope Stage ◽  
Digital Elevation ◽  
Late Wisconsinan ◽  
Cordilleran Ice Sheet ◽  
River Valleys

Geomorphic, stratigraphic and geochronological evidence from northeast British Columbia (Canada) indicates that, during the late Wisconsinan (approximately equivalent to marine oxygen isotope stage [MIS] 2), a major lobe of western-sourced ice coalesced with the northeastern-sourced Laurentide Ice Sheet (LIS). High-resolution digital elevation models reveal a continuous 75 km-long field of streamlined landforms that indicate the ice flow direction of a major northeast-flowing lobe of the Cordilleran Ice Sheet (CIS) or a montane glacier (>200 km wide) was deflected to a north-northwest trajectory as it coalesced with the retreating LIS. The streamlined landforms are composed of till containing clasts of eastern provenance that imply that the LIS reached its maximum extent before the western-sourced ice flow crossed the area. Since the LIS only reached this region in the late Wisconsinan, the CIS/montane ice responsible for the streamlined landforms must have occupied the area after the LIS withdrew. Stratigraphy from the Murray and Pine river valleys supports a late Wisconsinan age for the surface landforms and records two glacial events separated by a non-glacial interval that was dated to be of middle Wisconsinan (MIS 3) age.

Postglacial emergence of Amund and Ellef Ringnes islands, Nunavut: implications for the northwest sector of the Innuitian Ice Sheet

2004 ◽  
Vol 41 (3) ◽  
pp. 271-283 ◽  
Author(s):  
Nigel Atkinson ◽  
John England
Keyword(s):  
Late Holocene ◽  
Ice Sheet ◽  
The Arctic ◽  
Ice Flow ◽  
Geological Evidence ◽  
Level Curves ◽  
Ice Load ◽  
Holocene Transgression ◽  
Flow Features ◽  
Late Wisconsinan

This paper presents relative sea-level curves from Amund and Ellef Ringnes islands, northwest Queen Elizabeth Islands. These curves are of exponential form and record continuous, ongoing Holocene emergence, although northwest Ellef Ringnes Island is experiencing a late Holocene transgression. Isobases drawn on postglacial shorelines rise southeastward towards an uplift centre in Norwegian Bay. These suggest the Ringnes Islands occupied the northwest radius of the Innuitian uplift, which is congruent with glacial geological evidence suggesting parts of the Ringnes Islands were covered by the Late Wisconsinan Innuitian Ice Sheet. The isobases provide a provisional reconstruction of glacioisostatic recovery within the northwest Innuitian uplift. Their pattern supports earlier reconstructions that maximum Late Wisconsinan ice thickness occurred across Norwegian Bay, marking the position of an ice divide, which is consistent with ice-flow features on Amund Ringnes Island. They record the diminishing thickness of the Innuitian Ice Sheet from Norwegian Bay to the Arctic Ocean. The absence of an isobase embayment across the Ringnes Islands suggests a relatively uniform ice load across both islands and Hassel and Massey sounds. Parallel isobases across Peary Channel indicate this ice load extended beyond Massey Sound, although their northward deflection suggests an increasing influence of the former Axel Heiberg Island ice load.

scholarly journals Paleo ice flow and subglacial meltwater dynamics in Pine Island Bay, West Antarctica

2012 ◽  
Vol 6 (5) ◽  
pp. 4267-4304 ◽  
Author(s):  
F. O. Nitsche ◽  
K. Gohl ◽  
R. Larter ◽  
C.-D. Hillenbrand ◽  
G. Kuhn ◽  
...  
Keyword(s):  
West Antarctica ◽  
Ice Streams ◽  
Channel Network ◽  
Amundsen Sea ◽  
Ice Flow ◽  
Swath Bathymetry ◽  
Ice Stream ◽  
Seabed Topography ◽  
Ice Sheet Dynamics ◽  
Subglacial Meltwater

Abstract. Increasing evidence for an elaborate subglacial drainage network underneath modern Antarctic ice sheets suggests that basal meltwater has an important influence on ice stream flow. Swath bathymetry surveys from previously glaciated continental margins display morphological features indicative of subglacial meltwater flow in inner shelf areas of some paleo ice stream troughs. Over the last few years several expeditions to the Eastern Amundsen Sea embayment (West Antarctica) have investigated the paleo ice streams that extended from the Pine Island and Thwaites glaciers. A compilation of high-resolution swath bathymetry data from inner Pine Island Bay reveals details of a rough seabed topography including several deep channels that connect a series of basins. This complex basin and channel network is indicative of meltwater flow beneath the paleo-Pine Island and Thwaites ice streams, along with substantial subglacial water inflow from the east. This meltwater could have enhanced ice flow over the rough bedrock topography. Meltwater features diminish with the onset of linear features north of the basins. Similar features have previously been observed in several other areas, including the Dotson-Getz Trough (Western Amundsen Sea embayment) and Marguerite Bay (SW Antarctic Peninsula), suggesting that these features may be widespread around the Antarctic margin and that subglacial meltwater drainage played a major role in past ice-sheet dynamics.

scholarly journals GIS dataset: geomorphological record of terrestrial-terminating ice streams, southern sector of Baltic Ice Stream Complex, last Scandinavian Ice Sheet, Poland

2021 ◽  
Author(s):  
Izabela Szuman ◽  
Jakub Z. Kalita ◽  
Marek W. Ewertowski ◽  
Chris D. Clark ◽  
Stephen J. Livingstone ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Ice Streams ◽  
Southern Sector ◽  
Ice Stream ◽  
Digital Elevation ◽  
Scandinavian Ice Sheet ◽  
Data Source ◽  
Elevation Model ◽  
The Baltic ◽  
The Last Glacial

Abstract. Here we present a comprehensive dataset of glacial geomorphological features covering an area of 65 000 km2 in central west Poland, located along the southern sector of the last Scandinavian Ice Sheet, within the limits of the Baltic Ice Stream Complex. The GIS dataset is based on mapping from a 0.4 m high-resolution Digital Elevation Model derived from airborne Light Detection and Ranging data. Ten landform types have been mapped: Mega-Scale Glacial Lineations, drumlins, marginal features (moraine chains, abrupt margins, edges of ice-contact fans), ribbed moraines, tunnel valleys, eskers, geometrical ridge networks and hill-hole pairs. The map comprises 5461 individual landforms or landform parts, which are available as vector layers in GeoPackage format at http://doi.org/10.5281/zenodo.4570570 (Szuman et al., 2021a). These features constitute a valuable data source for reconstructing and modelling the last Scandinavian Ice Sheet extent and dynamics from the Middle Weichselian Scandinavian Ice Sheet advance, 50–30 ka BP, through the Last Glacial Maximum, 25–21 ka BP and Young Baltic Advances, 18–15 ka BP. The presented data are particularly useful for modellers, geomorphologists and glaciologists.

scholarly journals Lake Onego development in the late glacial assessed with the use of GIS technologies

2019 ◽  
pp. 83-90 ◽  
Author(s):  
D. A. Subetto ◽  
M. S. Potakhin ◽  
M. B. Zobkov ◽  
A. Yu. Tarasov ◽  
T. S. Shelekhova ◽  
...  
Keyword(s):  
Drainage Basin ◽  
Sediment Cores ◽  
Late Glacial ◽  
Lake Basin ◽  
Lake Area ◽  
Digital Maps ◽  
Digital Elevation ◽  
Spatial Parameters ◽  
Elevation Model ◽  
Maximum Development

The GIS-based reconstructions of Lake Onego development in the Late Glacial (14500–12300 yrs ago) were performed. Reconstructions have been based on the deglaciation model of the Lake Onego depression, digital elevation model of the lake depression, SRTM model of its drainage basin and on the data obtained from the palaeolimnological studies of numerous lake sediment cores. This allowed us to distinguish six main stages of the lake development for which a series of detailed schemes were produced. 1. Formation of the ice-dammed lake as a result of the ice sheet retreating (14.5 cal ka BP). 2. Emerging of the southern and central parts of the lake basin from the ice cover (14.0 cal ka BP). 3. The maximum development of the proglacial lake (13.3 cal ka BP). The lake area in this period was around 33 000 km2. 4. The first regression (13.2 ka BP). 5. The second regression (12.4 ka BP). 6. The third regression (12.3 ka BP), when the area of the lake dropped to 18 000 km2. We created detailed digital maps of the main stages of Lake Onego development during the Late Glacial and calculated the spatial parameters of the lake. The quantitative data obtained in this study would be used in estimation of the volumes of the lake and outflow discharges in the past. Maps are available in electronic form.

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