CGRG Bibliography of Canadian Geomorphology
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Author : Gauley, B.L.; and Piper, D.J.W.
Date : 2001.
Title : Lithostratigraphy and sediment failure on the central Scotian Slope.
Publication : St. John's 2001. Geological Association of Canada - Mineralogical Association of Canada 2001 Joint Annual Meeting / l'Association géologique du Canada - l'Association minéralogique du Canada réunion annuelle conjointe. Memorial University, St. John's, Newfoundland, May 27-30 2001.
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Abstract
Shallow, late Quaternary sediment failures are widespread along the Scotian Slope and are a concern for offshore hydrocarbon development. During the Wisconsinan glaciation, slope lithostratigraphy was strongly influenced by outer shelf glacial processes and probably is a factor in the location and style of sediment failures. This study focuses on a central region of the Scotian Slope between 63° 10'W and 61° 10'W, which contains both undisturbed and failed sediment. A seismic stratigraphy has been developed for the region by tracing nine key reflectors throughout Huntec DTS profiles. An associated composite stratigraphic sequence of ~50 meters has been sampled by piston coring specific target areas. A chronology is derived from radiocarbon dating shells and use of ice rafting events (brick red mud and Heinrich layers) of well-documented ages. Within the study area, failed sediment occurs as rotational slumps, bedding plane slides, creep blocks over décollement surfaces, debris flows, and turbidites. Failures begin at water depths of 500 meters and continue downslope beyond 2500 meters. One prominent décollement surface can be traced upslope where it appears to lie directly above one of several till tongues. At least three of the key reflectors within the seismic profile have acted as either failure planes or as depositional surfaces for failed sediment. Large-scale failures have occurred no more recently than 12 ka. The timing of sediment failures and their relationship to lithostratigraphy are important to predict future events.
Bibliography of Canadian Geomorphology