Dynamics of submarine sediment mass-transport, from the shelf to the deep sea

Mass-sediment transport processes affect continental margins on all scales, from the microscopic to the lithospheric. I present here the results of four different projects, examining various types of mass-sediment transport processes and products.; Chapter I presents geological evidence that large-scale isostatic rebound has occurred in association with the Storegga submarine landslide, Holocene of offshore Norway. This rebound has resulted in local changes in accommodation space and consequent shifts in depositional systems and sediment pathways, including local unconformities on the shelf-edge, and potentially seismic activity due to rapid curvature of the crust.; Chapter II presents geological data from a late Carboniferous paleofjord fill near San Juan, Argentina. The data demonstrate that (a) the fill of the paleofjord occurred during rapid climate change at the end of the Gondwanan glaciation, (b) the sedimentary succession preserved differs in some key respects from that of another nearby paleofjord, and (c) mass-sediment transport was an important control on sediment pathways in the paleofjord, second in importance only to sea-level change.; Chapter III presents data which suggest that some channelized turbidite processes may be similar to fluvial processes. These data come from a sinuous late Cretaceous channel system that preserves point bar deposits. Paleocurrent data from the deposits indicates that the primary currents ran along the channel thalweg, but strong secondary flows were oriented both up and down the point bars at different times. This suggests that at times the lower part of the turbidity currents behaved similarly to within-bank fluvial flows, with a cross-channel component of flow towards the cut bank, and return flow at the bed sweeping up the point bar. At other times this secondary circulation was reversed.; Chapter IV presents examples of structural deformation within sediment mass-transport deposits (MTDs) that are directly related to the resedimentation process. This deformation therefore provides a framework to interpret the dynamics of mass-transport. The major controls on the distribution of structural development within MTDs are lithofacies distribution, which controls deformation on the small-scale, and position within the MTD, which is the major large-scale control.