--> Abstract: Stratigraphic Organization of Late Pleistocene Deposits of the Western Part of the Golfe du Lion Shelf, Western Mediterranean Sea, Using High Resolution Seismic and Core Data, by M. Tesson, H. W. Posamentier, and B. Gensous; #90933 (1998).

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Abstract: Stratigraphic Organization of Late Pleistocene Deposits of the Western Part of the Golfe du Lion Shelf, Western Mediterranean Sea, Using High Resolution Seismic and Core Data

Tesson, Michel - University of Perpignan; Henry W. Posamentier* - Atlantic Richfield Indonesia, Inc., and Bernard Gensous - University of Perpignan

Detailed analysis of shallow penetration seismic data, integrated with piston core data, reveals that the stratigraphic architecture on the Rhone shelf of the western Mediterranean Sea is characterized by a complex stratigraphy comprising both the regressive and transgressive parts of Late Pleistocene depositional sequences. Several cycles of deposition are observed and are related to fourth or possibly fifth order cycles of relative sea-level change. The regressive parts of the sequence are inferred to have been deposited either during late highstand or during periods of relative sea level fall. The transgressive parts of the depositional sequences are characterized by backstepping wedges and isolated sand bars. The transgressive deposits seem to be preferentially preserved at both inner and outer shelf locations, and less so in the middle shelf. Key surfaces separating stratigraphic units include ravinement surfaces, downlap surfaces, and subaerially formed erosional surfaces.

Stratigraphic observations made here can have direct applicability to petroleum exploration. Features observed here can serve as analogs for subsurface stratigraphy and can lead to the development of new play types. Such features as outer-shelf isolated sand-prone lowstand/transgressive deposits, zones of sedimentary bypass, compartmentalized lowstand forced regressive units are well documented here. In general the stratigraphic architecture of these deposits is quite complex, especially near the shelf-slope break. Conspicuous by their absence in this study area are incised valleys. Certain features observed here, such as the lowstand/transgressive sand bodies are not common within the Pleistocene record of many continental shelves and may be analogous to significant subsurface petroleum reservoirs.

AAPG Search and Discovery Article #90933©1998 ABGP/AAPG International Conference and Exhibition, Rio de Janeiro, Brazil