Integration of High and Very High-resolution Seismic Reflection Profiles to Study Upper Quaternary Deposits of a Coastal
- PDF / 878,649 Bytes
- 14 Pages / 595.276 x 841.89 pts (A4) Page_size
- 106 Downloads / 162 Views
Marine Geophysical Researches (2005) 26:109–122 DOI 10.1007/s11001-005-3711-z
Integration of high and very high-resolution seismic reflection profiles to study Upper Quaternary deposits of a coastal area in the western Gulf of Lions, SW France Caroline Labaune*, Michel Tesson and Bernard Gensous Laboratoire de Biophysique et Dynamique des Syste`mes Inte´gre´s, BDSI Perpignan University, 52 Avenue Paul Alduy, 66860 Perpignan cedex, France *Corresponding Author (Phone: +33-4-6866-2112; E-mail: [email protected]) Received 30 January 2004; accepted 5 June 2005
Key words: borehole, coastal plain, Gulf of Lions, lagoon, late Quaternary deposits, near-shore, seismic stratigraphy
Abstract High resolution (HR – sparker) and very high resolution (VHR – boomer) seismic reflection data acquired in shallow water environments of the Roussillon coastal area are integrated to provide an accurate image of the stratigraphic architecture of the Quaternary deposits. The complementary use of the two systems is shown to be of benefit for studies of shallow water environments.The HR sparker data improved the landward part of a general model of Quaternary stratigraphy previously established offshore. They document an incised valley complex interpreted as the record of successive late Quaternary relative sea-level cycles. The complex is capped by a polygenetic erosional surface developed during the last glacial period (>18 ky) and variably reworked by wave ravinement during the subsequent post-glacial transgression. The overlying transgressive systems tract is partly preserved and presents a varying configuration along the Roussillon coastal plain.The VHR boomer data provide information on the architecture of the uppermost deposits, both in the near-shore area and in the lagoon. These deposits overlie a maximum flooding surface at the top of the transgressive systems tract and constitute a highstand systems tract composed of two different architectural elements. In the near-shore area, a sandy coastal wedge is subdivided into a lower unit and an upper unit in equilibrium with present day dynamics. In the SalsesLeucate lagoon area, the sedimentary architecture is highly complex due to the closure of a former embayment and the formation of the present beach barrier.
Introduction Most studies of near-shore areas have focused on the hydrodynamic regime and its impact on recent sedimentation (Nielsen et al., 2001; Ste´panian and Levoy, 2003). Integration over longer timescales has usually been applied either to deposits onshore in the coastal plain or offshore across the continental shelf. In particular, many studies have addressed the late Quaternary architecture of continental shelves (Suter et al., 1987; Hernandez-Molina et al., 1994; Tesson et al., 2000; Ridente and Trincardi, 2002). However, few studies have really dealt with the architecture of deposits across the coastal zone, i.e. the transition between the continental and marine domains spanning the coastal plain to the inner continental shelf. One of
the first was proposed by Penland et
Data Loading...
