The evolution, processes, and deposits of high latitude submarine channel systems

• Main Author: Allen, Charlotte Dawn
• Format: Thesis
• Language: English
• Published: 2020
• Subjects: Arctic; Arctic Ocean; Argentina; Greenland; Greenland Basin
• Online Access: https://etheses.whiterose.ac.uk/29004/; https://etheses.whiterose.ac.uk/29004/1/CA_CorrectedThesis_030521_backup.pdf

Models of the flow processes, evolution, and architecture of submarine channel-levee systems are based on observations from low- and mid-latitude systems. The influence of glacial sediment supply or Coriolis forcing present at high latitudes are not taken into account. Here, I analyse multiple bathymetric, seismic reflection, and outcrop, datasets to identify key extrinsic and intrinsic controls, examine formative processes and architecture, and propose new conceptual models for the stratigraphic evolution of high latitude submarine channel systems in a range of settings. Seafloor and subsurface datasets are used to study the morphology and architecture of large aggradational channel-levee systems from the Arctic Ocean and Greenland Basin. Vertical stratigraphic evolution of systems exhibit notable similarities to their low latitude counterparts, such as propagation of channel-levee systems over lobe complexes. However, marked differences in the resultant architecture include: 1) very large, axi-asymmetric external levees; 2) vertical stacking of axial channel-fill; and 3) low sinuosity planforms. Outcrop studies use detailed sedimentological analysis and sampling to demonstrate the interplay of glacial cyclicity and basin physiography upon the evolution and architecture of small aggradational systems in the Carboniferous stratigraphy of the Paganzo Basin, Argentina. Repeated axial cut-and-fill, and progradation of four channel systems demonstrate a glacial influence, from bed- to system-scale. Fjord confinement aided sediment bypass and led to the development of contemporaneous overbank successions between multiple active channels. A second outcrop study demonstrates channelized incision of a thick submarine landslide. Architecture of channel-fill suggests multiple phases of cut-and-fill, the development of terrace deposits, and the blocking of the conduit to form lobe deposits. This thesis demonstrates the variability of submarine channel-levee system evolution and architecture with latitude. A range of ...