Year: 2024
Type: article
Abstract: Recent recognition of compound delta clinoforms reveals pillars to understanding delta progradation and uncovers a significant misunderstanding in deltaic architecture. Little effort has been dedicated to spatially delineate subaqueous delta 3-D morphologies at and away the sediment sources, and relate these architectures to stratigraphy. Our assessment of over 35 Holocene deltas allowed a robust geospatial qualitative and quantitative analysis where we consistently observe one main gradient break at tens of meters water depth that display varying delineated geometries. The resulting geospatial framework reflects relatively steep shoreline and subaqueous clinoforms, reaching values of over 1 degree, separated by a gently dipping platform of maximum 0.11 degrees. Unique to this study, geometric variability is captured relative to the river sediment source and basinal energies. In most wave-dominated systems, the platform disappears in front of the sediment source and widens laterally away as a relatively smooth surface and in an arcuate fashion, whereas in tide-dominated systems the platform widens in front of active sediment sources and narrows in front of starved sediment sources while hosting erosional features and prominent tidal channel/bar couplets. As a result, platform width can range between few kilometers (Ebro Delta) to 60 kilometers (Fly Delta), and up to an unusual 200 kilometers (Amazon Delta). Consequently, varying basinal energies can modify the subaqueous clinoform where longitudinal swing is often observed even in tide-dominated systems. Quantitative and qualitative results of our study anchor our understanding of sediment transport in deltas and shallow marine systems, support delta numerical models, and facilitate the reinterpretation of ancient deposits’ stratigraphy.
Language: English
Subfield: Earth-Surface Processes
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,290
Funder: Saudi Aramco
OpenAlex ID: W4403156778