Title: The Nature of Glacitectonic Structures and Sediments at Sub-Polar Glacier Margins, Northwest Ellesmere Island, Canada
Abstract:Observations at four glacier snouts on northwest Ellesmere Island are used to determine the nature of glacially thrusted masses and their role in glacial debris entrainment processes in a high latitud...Observations at four glacier snouts on northwest Ellesmere Island are used to determine the nature of glacially thrusted masses and their role in glacial debris entrainment processes in a high latitude environment. Glacial landform sediment associations are reported and the implications for glacigenic depositional sequences are discussed for areas that have experienced proglacial thrusting. Thrusting occurs when a suitable expanse of deformable sediment is available and where ice impinges on a topographic high.Thrust block moraines, composed of glacimarine sediments and coarse outwash, concentrate sediment reworking by meltwater streams, in ponds and on ice aprons at the ice margin. Proglacial thrusting has been followed by some overriding and subglacial shearing and penetrative deformation. The degree of internal disturbance of thrusted blocks is dependent on sediment characteristics and the magnitude of overriding. Pre-syn-and post-tectonic sediment reworking at the ice margin combined with thrusting and overriding creates complex debris entrainment patterns. In this area of the high Arctic, proglacial thrusting is important to debris entrainment and is critical to moraine formation. Hummocky moraine is seen to be the product of primary proglacial/subglacial construction rather than supraglacial redistribution processes.Read More
Publication Year: 1989
Publication Date: 1989-10-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 36
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