Lithofacies and origin of late Quaternary mass transport deposits in submarine canyons, central Scotian Slope, Canada

摘要: Mass transport deposits, up to 3·9 m thick, have been identified from piston cores collected canyon floors and inter-canyon ridges on the central Scotian Slope. These deposits are characterized by four distinct mass-transport facies – folded mud, dipping stratified various types of mud-clast conglomerate, diamicton. Commonly, mud overlain followed diamicton then turbidity current well-sorted sand. Stratified were sourced walls. Overconsolidation in clasts some conglomerates indicates that source sediment was buried 12–33 m, much deeper than present cored depth, implying a heads The known stratigraphic framework for region new radiocarbon dating suggests there or five episodes failure within past 17 ka, most which found more one system. likely mechanism triggering occasional, synchronous failures separate canyons is seismic ground shaking. sequence interpreted as resulting local slides being conglomerate derived farther upslope finally coarser-grained retrogressive re-mobilizing upper slope sediments form debrisflows currents.