Abstract: Stacking Pattern and Stratigraphic Model of Reservoirs from a Modern Analogue to Ancient Deltaic and Siliciclastic Deposits: Golfe du Lion, SE France

Michel Tesson, Bernard Gensous, Georges Allen, Ravenne Christian

The "Golfe du Lion" Pleistocene shelf deposits are used as modern analogues of ancient deltaic and shallow water siliciclastic deposits. At least 6 cyclic surimposed sedimentary packages constituting a seaward thickening wedge are documented, including major progradational clinoforms units bounded by regional unconformities, with their updip terminations. Seismic correlations and geometry models, together with age dating and facies analysis of the uppermost units have been used at regional scale. They allowed to differentiate allocyclic from autocyclic events, to improve our knowledge of the nature of tectonic control on architecture, and to rely the different seismic units, inside the packages, to the environmental changes from interglacial highstand to glacial lowstand n 4 to 5th order cycles. An alternative model of "forced regression" during sea level lowstand was documented and validated. The different illustrated sedimentary units, related to specific parts of the relative sea level curve along a short duration / high amplitude cycle, are: (i) the "forced regression" deposits (ii) the late lowstand massive sands onto the outer shelf (iii) the early transgressive backstepping (?) beach sands, (iii) the late transgressive backstepping parasequences. The sand content inferred from the seismic facies, conforted with the uppermost units facies from data cores, is in agreement with this model.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France