CGRG Bibliography of Canadian Geomorphology
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Author : Gilbert, G.R.; and Barrie, J.V.
Date : 1983
Title : Provenance and sedimentary processes of ice scoured surficial sediments, Labrador Shelf
Publication : Program with abstracts - Geological Association of Canada
Issue : 8:
Page(s) : A75.
Abstract
Iceberg scour marks are evident over much of the Labrador Continental Shelf. The preservation/degradation potential of these features depends on the nature of surrounding sediments and the intensity of the hydrodynamic forces they are exposed to. Mineralogical and textural analysis of grab samples from southern Saglek and Makkovik Bank reveal information concerning sediment provenance and post-glacial sedimentary processes affecting these ice scoured surficial sediments. Heavy mineral and lithic fragment analysis indicate sediment origin from Precambrian terrains of Labrador, evidenced by igneous and high grade metamorphic rock assemblages. Clastic sedimentary and low grade metamorphic rocks are notably absent. Fossiliferous carbonate fragments identify a secondary sediment derivation from northern Greenland and/or the Canadian Arctic Islands through iceberg rafting. The sedimentary environments of Saglek and Makkovik Bank differ based onhydraulic equivalence relationships, texture, acoustic geophysical data and submersible observations. Southern Saglek represents a low energy environment with little evidence of sediment reworking except towards the seaward Bank margin. The well defined dense distribution of linear and curvilinear iceberg scours are well preserved. Conversely, the areally smaller and shallower Makkovik Bank is intensely disturbed by short linear and pit scours. Degradation of the scour marks by hydrodynamic reworking is evident and can be predicted from hydraulic equivalence relationship of the surficial fine sand sediment.
Bibliography of Canadian Geomorphology