CGRG Bibliography of Canadian Geomorphology
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Author : Barlow, J.; and Hopkinson, C.
Date : 2004.
Title : Geomorphic evidence for gravitational creep along the Niagara Escarpment.
Publication : 49th Annual Meeting of the Geological Association and the Mineralogical Association of Canada. May 12-14, 2004. Brock University, St. Catharines, Ontario.
Issue :
Page(s) :
Abstract
Cliffed sections of the Niagara Escarpment have often been assumed to be relict features within the research literature. The current morphology being attributed to the periglacial environment that followed the Pleistocene glaciation, unchanged during the Holocene due to the absence of extensive fluvial action along the base of the cliffs. However, there are a number of morphological features, ubiquitous to the cliffed sections of the escarpment between Hamilton and Collingwood, suggestive of an alternate theory for the postglacial development of the cuesta. These include the cambering of the cap rock, evidence of toppling failure, and the presence of deep crevice caves that generally run parallel to the cliff face. Such features indicate that in the absence of exogenetic processes, a slow development due to endogenetic processes has dominated the recent development of the escarpment. Rheological testing of the shale layers that underlie the cap rock has demonstrated that both the Cabot Head Shale and the Queenston Shale possess a compressive stress that is lower than the principal gravitational stresses expected due to overburden. It can therefore be concluded that in the absence of high confining stresses, as would be expected near the cliff face, slow deformation within these formations is occurring. The presentation will review the geomorphic evidence for deformation within the shale layers and (if completed) present the results of a new, high resolution, survey of a section of the escarpment near Milton Ontario utilizing the ILRIS ground based lidar system. This mapping should well illustrate the morphological features described above and provide a base line survey for future comparison. Such technology may be of interest to earth scientists as it offers the potential to accurately plot surfaces at sub-centimetre scales and thereby process rates over manageable time scales through repeat surveys.
Bibliography of Canadian Geomorphology