Gipp, M.R., 1996, Glacially-influenced marine sedimentation on continental margins; examples from areas of contrasting tectonic setting: Toronto, Ontario, Canada, University of Toronto, Ph.D. dissertation, 198 p.
The pre-Pleistocene glacial record is dominated by glacially-influenced marine sediments that accumulated on continental shelves and slopes. Terrestrial and inner shelf sediments are seldom preserved. The stratigraphy and overall geometry of shelf and slope strata are strongly influenced by tectonic setting, but the nature of controls and resulting deposits are poorly understood. This thesis establishes descriptive stratigraphic models that show the development of glaciated continental margins in two contrasting tectonic settings. Depositional processes are similar in both settings but tectonic setting controls accommodation space and, therefore, the relative preservation and stratigraphic importance of shelf and slope facies. These models are developed from study of extensive outcrops of Late Cenozoic (6 Ma to present) glacially-influenced strata exposed around the Gulf of Alaska, an active plate margin setting where regional glaciation was initiated by uplift resulting from collision between the Pacific and North American plates, and the Scotian shelf and slope of eastern Canada - a passive margin episodically invaded by the continental Laurentide Ice Sheet. The database from the Scotian margin consists of offshore sediment cores and seismic reflection data collected from Late Pleistocene (less than 25 ka) strata during several cruises. An important part of this thesis is the development of objective, quantitative criteria for the description and interpretation of seismic facies based on their geometry, grain size, and geotechnical properties. This methodology could be more widely employed for the description of seismic facies regardless of depositional setting.
Theses and Dissertations