Sylvain Calassou¹
(1) Elf Exploration Production, Pau, France

Abstract: Evidences of deformational control of tertiary turbidites deposits in an extensional domain. Congo basin-West Africa

Using high quality 3D seismic and advanced 3D imagery, we propose a new geological approach especially applicable to West Africa. We demonstrate the interaction between deformation and the depositional stacking of sinuous channels through an approach linked to interpretation of deformational mechanisms. During channels' erosional and depositional phases, we observe the influence of regional normal faults (1° & 2° order) on topography. Flattening mechanisms (3° order) accommodate the synsedimentary extension using newly interpreted fault systems (normal kink bands, boudinage, & shear zones along sedimentary interfaces). In this context, all the main normal faults (2° order) are segmented with overlapped segments (clay smearing). We present this new deformational concept at different scales and discuss the sedimentary/structural interrelationships. The implications of this concept have been integrated into reservoir modelling.

AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana