CGRG Bibliography of Canadian Geomorphology
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Author : Atkinson, N.; and Jardine, K.
Date : 1998
Title : The Late Quaternary deglacial history of Baumann Fiord, Southwest Ellesmere Island, Canadian High Arctic
Publication : 28th Arctic Workshop, March 12 - 14, 1998. Institute of Arctic and Alpine Research University of Colorado, Boulder, CO USA
Issue :
Page(s) :
Abstract
The distribution of glacial landforms and radiocarbon dated glacimarine sediments within Baumann Fiord records the evacuation of pervasive Late Quaternary ice from marine to land based margins. Lateral meltwater channels eroded at succesively lower elevations on the side walls of the surrounding highlands indicate that prolonged downwasting preceded marginal retreat. Dated glacimarine landforms indicate that outer Baumann Fiord was deglaciated prior to 8.9 ka BP. Rapid retreat from outer to central Baumann Fiord was facilitated by calving of the main trunk glacier. Retreat was punctuated by a brief stillstand on Hoved Island, at ~9.3 ka BP. This contributed to the deposition of a morainal bank, correspnding to a pinning point between Hoved Island and Svendsen Peninsula. The suggestion that stillstands are rare is supported by bathymetric charts, which reveal no other submarine irregularities within the deep channel (>300 m)of outer Baumann Fiord. The onset of continued retreat in to the shallower (<200 m) inner fiord occurred ~8.8 ka BP, and also proceded rapidly. Glacimarine landforms surveyed at the mouth of Stenkul Fiord indicate that Baumann Fiord was ice-free at ~8.3 ka BP. Following the rapid removal of the marine based trunk glacier, encircling ice masses stabilized on Svendsen Peninsula to the north of the fiord and Bjorne Peninsula to the south. Slow retreat followed, in response to variations in mass balance associated with the switch from a calving to a land based margin. The rapid retreat of marine based ice accounts for paucity of chronologically constrained geological evidence indicative of full glacial conditions. Slower land based retreat accounts for the abundance of ice marginal landforms, but these indicate a phase of local stabilization following regional deglaciation and not ice limits at the last glacial maximum. This study highlights the importance that fiord topography and glacier retreat rates have on palaeoenvironmental reconstructions based on glacial landforms and raised marine sediments.
Bibliography of Canadian Geomorphology