Late quaternary transgressive large dunes on the sediment-starved Adriatic shelf
Correggiari, A.; Field, M.E.; Trincardi, F. (1996). Late quaternary transgressive large dunes on the sediment-starved Adriatic shelf, in: De Batist, M. et al. (Ed.) Geology of siliciclastic shelf seas. pp. 155-169 In: De Batist, M.; Jacobs, P. (Ed.) (1996). Geology of siliciclastic shelf seas. Geological Society Special Publication, 117. The Geological Society (London): London. ISBN 1-897799-67-5. 345 pp., more In: Hartley, A.J. et al. (Ed.) Geological Society Special Publication. Geological Society of London: Oxford; London; Edinburgh; Boston, Mass.; Carlton, Vic.. ISSN 0305-8719; e-ISSN 2041-4927, more |
| Authors | | Top | - Correggiari, A.
- Field, M.E.
- Trincardi, F.
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| Abstract | The Adriatic epicontinental basin is a low-gradient shelf where the late-Quatemary transgressive systems tract (TST) is composed of thin parasequences of backbarrier, shoreface and offshore deposits. The facies and intemal architecture of the late-Quatemary TST in the Adriatic epicontinental basin changed consistently from early transgression to late transgression reflecting: (I) fluctuations in the balance between sediment supply and accommodation increase, and (2) a progressive intensification of the oceanographic regime, driven by the transgressive widening of the basin to as much as seven times its lowstand extent. One of the consequences of this trend is that high-energy marine bedforms such as sand ridges and sand waves characterize only areas that were flooded close to the end of the late-Quatemary sea-level rise, when the wind fetch was maximum and bigger waves and stronger storm currents could form. We studied the morphology, sediment composition and sequence-stratigraphical setting of a field of asymmetric bedforms (typically 3 m high and 600 m in wavelength) in 20-24 m water depth offshore the Venice Lagoon in the sediment-starved North Adriatic shelf. The sand that forms these large dunes derived from a drowned transgressive coastal deposit reworked by marine processes. Early cementation took place over most of the dune crests limiting their activity and preventing their destruction. Both the formation and deactivation of this field of sand dunes occurred over a short time interval close to the turn-around point that separates the late-Quatemary sea-level rise and the following highstand and reflect rapid changes in the oceanographic regime of the basin. |
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