Extent and Melting History of the Late Weichselian Ice Sheet, the Barents-Kara Continental Margin

1993 ◽  
pp. 1-20 ◽  
Author(s):  
Mikhail G. Grosswald
1987 ◽  
Vol 28 (1) ◽  
pp. 1-37 ◽  
Author(s):  
Svante Björck ◽  
Per Möller

AbstractLate Weichselian litho-, bio-, and chronostratigraphy (14C and varves) in southeastern Sweden provide a detailed picture of the deglaciation pattern and dynamics, shore displacement, late-glacial sedimentation, and history of the landscape, vegetation, and climate. Two plausible glacial models were tested against lithologic, chronologic, and climatic data. Permafrost at and outside the ice margin and topographic conditions beneath the ice apparently caused inward spread of frozen glacier-bed conditions. This led to a buildup of a large zone of debris-rich basal ice. A climatic amelioration about 12,700 yr B.P. changed the temperature profile in the ice sheet. Deposition of basal melt-out till began at the previously frozen glacier bed, and a rapid recession of the clean ice set in; thin exposed debris-rich basal ice which was separated from the active ice margin about 150 yr later. In this zone of stagnant ice there followed a 200– 300-yr period marked by subglacial and supraglacial melt-out and resedimentation, forming a large hummocky/transverse moraine. The mild climate favored rapid plant immigration, and a park-tundra was established. The gradual closing of the landscape was interrupted by a 100- to 150-yr period of tundra vegetation and a cool, dry climate, with local vegetational differences caused by differences in soil moisture. About 12,000 yr B.P. a second climatic amelioration set in, and during the next 1000 yr a birch (and pine) woodland gradually developed. Soils stabilized and Empetrum heaths became abundant as the climate gradually deteriorated at the end of this period. By 11,000 yr B.P. the area had become a tundra again with scattered birch stands, dominated by herbs such as Artemisia, Chenopodiaceae, grasses, and sedges. Some 500 yr later a birch/pine woodland again succeeded, and within about 500 yr the vegetation changed to a rather closed woodland as the climate ameliorated further. However, the time lag between climatic and vegetation change was considerable.


1988 ◽  
Vol 25 (4) ◽  
pp. 547-556 ◽  
Author(s):  
Anders Solheim ◽  
John D. Milliman ◽  
Anders Elverhøi

Acoustical (sparker, 3.5 kHz, and side-scan sonar) and sedimentological data from a local study on Storbanken in the northern Barents Sea support the concept of a late Weichselian ice sheet covering most of the Barents Sea. During a major halt in the retreat of the ice sheet, locally thicker (38 m) accumulations of ice-proximal glaciomarine sediments were deposited, after which rapid retreat took place. Sea-floor morphology indicates that the retreat across Storbanken most likely took place without surging or climatically controlled oscillations.Intense iceberg ploughing characterizes the sea floor down to water depths of 210–220 m. Most of this is relict, but occasional gouges in the shallowest regions may have had a more recent origin. The apparent lower limit of ploughing, interpreted in terms of relative sea level, indicates a rather moderate isostatic depression. This probably resulted from a thin ice sheet, fed from several ice source areas. Depth of the plough marks is largely dependent on thickness of the glaciomarine sediments. A thin and patchy layer of overcompacted till fills local depressions in the sedimentary bedrock surface and forms a flat base for iceberg ploughing.


2010 ◽  
Vol 29 (25-26) ◽  
pp. 3630-3643 ◽  
Author(s):  
Arjen P. Stroeven ◽  
Derek Fabel ◽  
Alexandru T. Codilean ◽  
Johan Kleman ◽  
John J. Clague ◽  
...  

1996 ◽  
Vol 133 (3-4) ◽  
pp. 123-156 ◽  
Author(s):  
Espen S. Andersen ◽  
Trond M. Dokken ◽  
Anders Elverhøi ◽  
Anders Solheim ◽  
Ingrid Fossen

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