GLACIAL FEATURES OF THE QUETICO-NIPIGON AREA, ONTARIO

1965 ◽  
Vol 2 (4) ◽  
pp. 247-269 ◽  
Author(s):  
S. C. Zoltai
Keyword(s):  
Field Studies ◽  
Aerial Photographs ◽  
Glacial Lake ◽  
Glacial Lakes ◽  
Lake Agassiz ◽  
Northwestern Ontario ◽  
Sequence Of Events ◽  
Drainage Channels ◽  
Surficial Deposits ◽  
Lake Minong

The surficial deposits, ice movements, and glacial lakes are described within an area of 25 000 square miles in northwestern Ontario. Field studies and subsequent interpretation of aerial photographs suggest the existence of two major and one minor ice mass during late Wisconsin glaciation. Movements by the various ice masses are shown and correlated. The extent of several glacial lakes and their drainage channels are described. A reconstruction of the sequence of events, based on morphological features, allows a tentative correlation of Glacial Lake Agassiz in the west with Glacial Lake Minong stages in the Superior basin. A radiocarbon date of 9 380 ± 150 years B.P. (GSC No. 287) was obtained from wood buried in a post-Minong beach.

GLACIAL HISTORY OF NORTHEASTERN ONTARIO: I. THE COCHRANE–HEARST AREA

1966 ◽  
Vol 3 (5) ◽  
pp. 559-578 ◽  
Author(s):  
A. N. Boissonneau
Keyword(s):  
Field Studies ◽  
Glacial Lakes ◽  
Sequence Of Events ◽  
Maximum Elevation ◽  
History Of ◽  
Maximum Water ◽  
Differential Uplift ◽  
Two Phases ◽  
A Minor ◽  
Surficial Deposits

Surficial deposits, ice movements, and glacial lakes are described for an area of 42 000 square miles in northeastern Ontario. Field studies and air photograph interpretation suggest the following sequence of events. A major fan-shaped advance of an ice mass over the study area. This was followed by the withdrawal of the ice mass from the area and the formation of proglacial lakes. This ablation phase was followed by a minor readvance. Two phases are postulated for this 'Cochrane' readvance. Within the study area, the extent of the glacial lakes and the limits of extension of the Cochrane readvance are postulated. A maximum water plane, location, and maximum elevation of outlet and amount of differential uplift of sediments are postulated for glacial Lake Barlow–Ojibway.

A reconstruction of Moorhead and Emerson Phase environments along the eastern margin of glacial Lake Agassiz, Rainy River basin, northwestern Ontario

2000 ◽  
Vol 37 (10) ◽  
pp. 1335-1353 ◽  
Author(s):  
A F Bajc ◽  
D P Schwert ◽  
B G Warner ◽  
N E Williams
Keyword(s):  
Wide Spectrum ◽  
Open Water ◽  
Glacial Lake ◽  
Lake Agassiz ◽  
Long Distance ◽  
Distinct Component ◽  
Study Region ◽  
Nearshore Processes ◽  
Northwestern Ontario ◽  
Glacial Lake Agassiz

Mapping of Quaternary geology in the Rainy River lowland, northwestern Ontario resulted in discovery of several fossil-bearing localities. Organic remains are associated with both the Moorhead and Emerson phases of glacial Lake Agassiz. Wood samples recovered from Moorhead Phase deposits have radiocarbon ages ranging between 10.8 and 9.9 ka BP. The wood is detrital and cannot be used to date the beginning of the low-water phase. Nearshore, deltaic, alluvial, peatland, open-water wetland, and upland soil environments are represented in the Moorhead Phase sediment records. Emerson Phase transgressive deposits overlie Moorhead Phase sediments and erosional surfaces. Wood samples recovered from flotsam layers in Emerson Phase nearshore deposits have yielded radiocarbon ages ranging between 10.5 and 9.5 ka BP. Stratigraphic and sedimentologic evidence suggests that the transgression began approximately 9.9 ka BP. Pollen, plant macrofossil, insect, and mollusc assemblages have been affected by long-distance transport, sorting, and reworking by fluvial and nearshore processes. They represent a wide spectrum of terrestrial and aquatic habitats indiscriminantly brought together during high-water periods. The Moorhead and Emerson phase assemblages indicate conditions similar to those in the region today, but there is a distinct component whose modern range is much farther north and west of the study region. In this respect, the assemblages are similar to the mixed communities described from other late-glacial sites of the mid-continent.

Moraine formation in northwestern Ontario: product of subglacial fluvial and glaciolacustrine sedimentation

1990 ◽  
Vol 27 (11) ◽  
pp. 1478-1486 ◽  
Author(s):  
David R. Sharpe ◽  
W. R. Cowan
Keyword(s):  
Large Scale ◽  
Silty Sand ◽  
Traditional View ◽  
Glacial Lake ◽  
Drainage Network ◽  
Lake Agassiz ◽  
Northwestern Ontario ◽  
Glacial Lake Agassiz ◽  
Transient Instability ◽  
Subglacial Meltwater

Long, arcuate, stratified end moraines in northwestern Ontario may represent major and rapid sedimentation events in glacial Lake Agassiz. Rapid lowering of the lake or lift of a marginal ice dam may have triggered widespread outbursts of subglacial meltwater which deposited these end moraines as coalesced or broad subaqueous lacustrine fans. Moraine cores are of undeformed gravel, sand, and silty sand that fine upward. Coarse beds are massive to weakly stratified. Large-scale cross-stratification may be present. Sandy rhythmic beds are laterally transitional to silt–clay rhythmites (varves). Similar facies occur in adjoining eskers.Moraine sediments have the expected characteristics of rapid deposition on subaqueous fans and, therefore, may not represent either prolonged sedimentation or stable ice margins. Rather, they may reflect rapid sedimentation associated with large discharges that induced transient instability in the drainage network and (or) surging prior to marginal sedimentation. This explanation for moraine formation questions the traditional view that large end moraines represent climatically controlled stillstands.

Relict ice-scour marks and late phases of Lake Agassiz in northernmost Manitoba

1982 ◽  
Vol 19 (5) ◽  
pp. 1079-1087 ◽  
Author(s):  
L. A. Dredge
Keyword(s):  
Marine Sediment ◽  
Glacial Lake ◽  
Hudson Bay ◽  
Glacial Lakes ◽  
Lake Agassiz ◽  
Glacial Ice ◽  
Hudson Bay Lowlands ◽  
Far North

In northern Manitoba, intersecting grooves 300–1800 m long are ice-scour marks created by the dragging of iceberg keels along rises in the bed of a glacial lake whose water plane was at about 305 m asl. The lake was bounded by glacial ice on its northern and eastern margins. The occurrence of scours on topographic divides indicates that a single extensive lake, thought to be a northern extremity of Lake Agassiz, occupied the area as far north as Seal River at the time the ice scours were formed. The lake extended as far west as Sprott Lake and eastwards into the Hudson Bay Lowlands into an area later occupied by Tyrrell Sea. The preservation of the scour marks suggests that the lake drained suddenly.Ice-scour marks are easily recognized on air photographs and provide a means of identifying areas that have been inundated by glacial lakes. Scours in emerged marine sediment are generally obliterated by littoral processes.

scholarly journals Inventory and classification of the post Little Ice Age glacial lakes in Svalbard

2022 ◽  
Author(s):  
Iwo Wieczorek ◽  
Mateusz Czesław Strzelecki ◽  
Łukasz Stachnik ◽  
Jacob Clement Yde ◽  
Jakub Małecki
Keyword(s):  
Little Ice Age ◽  
High Arctic ◽  
Ice Age ◽  
Aerial Photographs ◽  
Glacial Lake ◽  
High Mountain ◽  
Lake Area ◽  
Glacial Lakes ◽  
Mountain Areas ◽  
Outburst Floods

Abstract. Rapid changes of glacial lakes are among the most visible indicators of global warming in glacierized areas around the world. The general trend is that the area and number of glacial lakes increase significantly in high mountain areas and polar latitudes. However, there is a lack of knowledge about the current state of glacial lakes in the High Arctic. This study aims to address this issue by providing the first glacial lake inventory from Svalbard, with focus on the genesis and evolution of glacial lakes since the end of the Little Ice Age. We use aerial photographs and topographic data from 1936 to 2012 and satellite imagery from 2013 to 2020. The inventory includes the development of 566 glacial lakes (total area of 145.91 km2) that were in direct contact with glaciers in 2008–2012. From the 1990s to the end of the 2000s, the total glacial lake area increased by nearly a factor of six. A decrease in the number of lakes between 2012 and 2020 is related to two main processes: the drainage of 197 lakes and the merger of smaller reservoirs into larger ones. The changes of glacial lakes show how climate change in the High Arctic affect proglacial geomorphology by enhanced formation of glacial lakes, leading to higher risks associated with glacier lake outburst floods in Svalbard.

scholarly journals Simulation and Assessment of Future Glacial Lake Outburst Floods in the Poiqu River Basin, Central Himalayas

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1376
Author(s):  
Taigang Zhang ◽  
Weicai Wang ◽  
Tanguang Gao ◽  
Baosheng An
Keyword(s):  
River Basin ◽  
Hazard Assessment ◽  
Glacial Lake ◽  
High Mountain ◽  
Glacial Lakes ◽  
Central Himalayas ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Social And Economic Development ◽  
Glacial Lake Outburst Flood

A glacial lake outburst flood (GLOF) is a typical glacier-related hazard in high mountain regions. In recent decades, glacial lakes in the Himalayas have expanded rapidly due to climate warming and glacial retreat. Some of these lakes are unstable, and may suddenly burst under different triggering factors, thus draining large amounts of water and impacting downstream social and economic development. Glacial lakes in the Poiqu River basin, Central Himalayas, have attracted great attention since GLOFs originating there could have a transboundary impact on both China and Nepal, as occurred during the Cirenmaco GLOF in 1981 and the Gongbatongshaco GLOF in 2016. Based on previous studies of this basin, we selected seven very high-risk moraine-dammed lakes (Gangxico, Galongco, Jialongco, Cirenmaco, Taraco, Beihu, and Cawuqudenco) to simulate GLOF propagation at different drainage percentage scenarios (i.e., 25%, 50%, 75%, and 100%), and to conduct hazard assessment. The results show that, when any glacial lake is drained completely or partly, most of the floods will enter Nepal after raging in China, and will continue to cause damage. In summary, 57.5 km of roads, 754 buildings, 3.3 km2 of farmland, and 25 bridges are at risk of damage due to GLOFs. The potentially inundated area within the Chinese part of the Poiqu River basin exceeds 45 km2. Due to the destructive impacts of GLOFs on downstream areas, appropriate and effective measures should be implemented to adapt to GLOF risk. We finally present a paradigm for conducting hazard assessment and risk management. It uses only freely available data and thus is easy to apply.

Postglacial Diatom Stratigraphy in Relation to the Recession of Glacial Lake Agassiz

1975 ◽  
Vol 5 (4) ◽  
pp. 529-540 ◽  
Author(s):  
J.C. Ritchie ◽  
L.K. Koivo
Keyword(s):  
Sandy Beach ◽  
Sedimentary Environment ◽  
Glacial Lake ◽  
Lake Agassiz ◽  
Organic Detritus ◽  
Sedimentary Environments ◽  
Grand Rapids ◽  
Glacial Lake Agassiz ◽  
Diatom Stratigraphy ◽  
Beach Sands

The sediment and diatom stratigraphy of a small pond on The Pas moraine, near Grand Rapids, Manitoba, reveals a change in sedimentary environment related directly to the last stages of Glacial Lake Agassiz. Beach sands were replaced by clay 7300 14C y. a., then by organic silt and, at 4000 14C y. a. by coarse organic detritus; the corresponding diatom assemblages were (I) a predominantly planktonic spectrum in beach sands, (II) a rich assemblage of nonplanktonic forms, and (III) a distinctly nonplanktonic acidophilous spectrum. These results confirm Elson's (1967) reconstruction of the extent and chronology of the final (Pipun) stage of Glacial Lake Agassiz. The sedimentary environments change from a sandy beach of a large lake at 7300 BP to a small, shallow eutrophic pond with clay and silt deposition from 7000 to 4000 BP. From 4000 BP to the present, organic detritus was deposited in a shallow pond that tended toward dystrophy.

Micromorphology of iceberg scour in clays: Glacial Lake Agassiz, Manitoba, Canada

2012 ◽  
Vol 55 ◽  
pp. 125-144 ◽  
Author(s):  
Lorna D. Linch ◽  
Jaap J.M. van der Meer ◽  
John Menzies
Keyword(s):  
Glacial Lake ◽  
Lake Agassiz ◽  
Glacial Lake Agassiz ◽  
Iceberg Scour
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