@mastersthesis {39909,
	title = {Late Pleistocene stratigraphy and sedimentology of coarse clastic deposits in the central Canadian Rocky Mountains, Jasper},
	volume = {Geology},
	year = {1995},
	pages = {298},
	address = {University of Alberta},
	abstract = {Six informal lithostratigraphic units are recognized from newly mapped exposures of Late Quaternary deposits in the Jasper region. The oldest deposits consist mainly of locally derived, coarse-grained gravelly diamicton interpreted as large volume, episodic, unchannelled, debris flow deposits. The inferred paleo-environment is a cool temperate, alpine to subalpine alluvial fan setting. Radiocarbon dates indicate that fan sedimentation began prior to 48 ka and continued throughout the Middle Wisconsinan. A unit of stratified gravels and sands interpreted as braided stream glaciofluvial deposits gradationally overlie the paleofan sequences and are distinguished from them by better stratification, sorting, clast roundness and relatively high percentages of distally-derived clasts. Wood from this unit near Jasper town site indicates deposition about 29 ka. Glaciolacustrine sediments overlying this unit in several Front Range valleys, reflect the onset of glaciation in the Athabasca River valley and associated ice-damming of tributary valley streams. Both Rocky Mountain and Cordilleran glaciers advanced through the area, depositing a complex sequence of ice-marginal sediments, basal tills and supraglacial deposits. Several lines of evidence suggest that at the Late Wisconsinan maximum, glaciers flowed out of the Athabasca valley into the conjectural {\textquoteright}ice free{\textquoteright} corridor and were deflected southeasterly along the mountain front by the Laurentide ice sheet.

During deglaciation, sedimentation in the Athabasca valley was dominated by ice-marginal deposition of glaciofluvial sands and gravels and by paraglacial debris flows. Large medial moraines and debris septa that formed at the confluence of main valley glaciers, such as occupied the Miette and Athabasca valleys, probably led to stagnant ice in the valley centre and associated kame terrace development along the valley sides. A radiocarbon date on shells from a small ice-marginal lake near Pocahontas indicates that glaciers there were in retreat by about 12 ka and alpine glaciers in the region were at or near their present limits by 10 ka.

Sedimentologic studies of alluvial fan deposits in the area indicate that fast moving, noncohesive debris flows are prevalent and that the bedrock geology of the fan source areas exerts a strong control on sedimentation patterns. The conclusion that high energy, low frequency, debris flow events are prevalent in the Main Ranges, whereas lower energy, higher frequency events are typical of the Front Ranges is of relevance to modern hazard studies and mitigation efforts in the Canadian Rocky Mountains.
},
	url = {http://search.proquest.com/docview/193964565},
	author = {Levson, Victor Mathew}
}
