Role of Upper-Flow-Regime Bedforms Emplaced by Sediment Gravity Flows in the Evolution of Deltas

authored by: Svetlana Kostic, Daniele Casalbore, Francesco Chiocci, Jörg Lang, Jutta Winsemann
Abstract: Upper-flow-regime bedforms and their role in the evolution of marine and lacustrine deltas are not well understood. Wave-like undulations on delta foresets are by far the most commonly reported bedforms on deltas and it will take time before many of these features get identified as upper-flow-regime bedforms. This study aims at: (1) Providing a summary of our knowledge to date on deltaic bedforms emplaced by sediment gravity flows; (2) illustrating that these features are most likely transitional upper-flow-regime bedforms; and (3) using field case studies of two markedly different deltas in order to examine their role in the evolution of deltas. The study combines numerical analysis with digital elevation models, outcrop, borehole, and high-resolution seismic data. The Mazzarrà river delta in the Gulf of Patti, Italy, is selected to show that upper-flow-regime bedforms in gullies can be linked to the onset, growth, and evolution of marine deltas via processes of gully initiation, filling, and maintenance. Ice-marginal lacustrine deltas in Germany are selected as they illustrate the importance of unconfined upper-flow-regime bedforms in the onset and evolution of distinct delta morphologies under different lake-level trends.
Organisation(s): Institute of Geology
External Organisation(s): San Diego State University
Sapienza Università di Roma
Type: Review article
Journal: Journal of Marine Science and Engineering
Volume: 7
Pages: 476–496
Publication date: 01.2019
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Civil and Structural Engineering, Water Science and Technology, Ocean Engineering
Sustainable Development Goals: SDG 14 - Life Below Water
Electronic version(s): https://doi.org/10.3390/jmse7010005 (Access: Open)
https://doi.org/10.15488/1267 (Access: Open)