This doctoral thesis (this work) is aimed at better understanding ocean bottom current processes and their bedforms in the contexts of 1) ancient outcrops, 2) modern oceans and 3) geophysical bedform processes. First, Miocene Rifian Corridor deposits in Northern Morocco are described, which have been interpreted to have formed under the action of ocean bottom currents. The independent paleontological, sedimentary, and stratigraphic analysis presented in this work shows that these deposits have likely been misinterpreted and actually represent shallow marine tide-dominated delta deposits. The implications of these findings to our understanding of ancient bottom current deposits in an outcrop are discussed and independent interpretations for these sediments are outlined. Second, the abyssal plain geomorphologies are compiled and analyzed to illustrate the bedform types and the diversity of ocean bottom current-controlled landscapes. This work shows that ocean bottom current deposits comprise mostly of migrating dunes and have morphological, sedimentological, and process similarities to aeolian deposits. Compiled abyssal dune data is then used to develop a global map with regions of ocean bottom deposition, erosion, and stasis. A separate chapter of this work discusses the use of ocean floor sediment core to quantify the origin of oceanic sediments, and documents that on average ± 8% of the sediments on the ocean floor are derived from authigenic suspension fallout, as compared to ± 92% that is detrital sediment derived from continental sources. The final two chapters of this work examine active aeolian systems to define physical laws of dune formation and migration, showing that the shapes and migration rates of dunes are controlled by surface-to-volume ratios. These laws are then applied to better understand the role of topography on dune morphology transitions.
Copyright of the original work is retained by the author.
The export option will allow you to export the current search results of the entered query to a file. Different
formats are available for download. To export the items, click on the button corresponding with the preferred download format.
By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.
To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export.
The amount of items that can be exported at once is similarly restricted as the full export.
After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.