73 research outputs found
Geological controls on the geometry of incised-valley fills: Insights from a global dataset of late-Quaternary examples
Incised valleys that develop due to relative sea-level change are common features of continental shelves and coastal plains. Assessment of the factors that control the geometry of incised-valley fills has hitherto largely relied on conceptual, experimental or numerical models, else has been grounded on case studies of individual depositional systems. Here, a database-driven statistical analysis of 151 late-Quaternary incised-valley fills has been performed, the aim being to investigate the geological controls on their geometry.
Results of this analysis have been interpreted with consideration of the role of different processes in determining the geometry of incised-valley fills through their effect on the degree and rate of river incision, and on river size and mobility. The studied incised-valley fills developed along active margins are thicker and wider, on average, than those along passive margins, suggesting that tectonic setting exerts a control on the geometry of incised-valley fills, likely through effects on relative sea-level change and river behaviour, and in relation to distinct characteristics of basin physiography, water discharge and modes of sediment delivery. Valley-fill geometry is positively correlated with the associated drainage-basin size, confirming the dominant role of water discharge. Climate is also inferred to exert a potential control on valley-fill dimensions, possibly through modulations of temperature, peak precipitation, vegetation and permafrost, which would in turn affect water discharge, rates of sediment supply and valley-margin stability. Shelves with slope breaks that are currently deeper than 120 m contain incised-valley fills that are thicker and wider, on average, than those hosted on shelves with breaks shallower than 120 m. No correlation exists between valley-fill thickness and present-day coastal-prism convexity, which is measured as the difference in gradient between lower coastal plains and inner shelves.
These findings challenge some concepts embedded in sequence stratigraphic thinking, and have significant implications for analysis and improved understanding of source-to-sink sediment route-ways, and for attempting predictions of the occurrence and characteristics of hydrocarbon reservoirs
Stratigraphic arrangement and sedimentologic features of the regressive Lower Pleistocene deposits in the central Bradanic Trough area: geodynamic implications
High-frequency sequence stratigraphy in terraced marine deposits in th einterland of Taranto Gulf (Southern Apennines Foredeep)
The Quaternary terraced marine-deposits of the Metaponto area in a sequence-stratigraphic perspective
Geomorphologic- vs stratigraphic- approaches in the study of the terraced marine-deposits of Metaponto (southern Italy)
Stratigraphic constraints for the Early Pleistocene geodynamic evolution of the Bradanic Trough in-fill
Contribute of sequence stratigraphy in the study of depositional marine terraces: the Metaponto area example (southern Italy)
Response of basin-margin depositional systems to the interference between high-frequency sea-level changes and variations in geodynamics: the case of the Bradanic Trough (south Apennines foreland basin, Italy).
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