Abstract: Salt Tectonics and Gravity Driven Deformation: Structural Guidelines for Exploration in Passive Margin

Thomas Mauduit, Gwenael Guerin, Jean Pierre Brun, Hubert Lecanu

The West African Margin, (Gulf of Guinea) presents spectacular examples of gravity driven deformation above a salt decollement (i.e. growth faulting, rafts, diapirs and contractional structures) which have been documented by numerous Oil and Gas investigations.

Seismic data demonstrate that the variation of deformation styles in space and time appear to be function of:

- regional geometry of the margin (i.e. value of basal slope and presence/absence of residual reliefs below the salt layers) and,

- mode, rate and repartition of sedimentation.

The role and effects of the above parameters were analysed using laboratory modeling investigation based on basic structural patterns identified through seismic data. Models are built with sand and silicone putty, that respectively represent the frictional behavior of upper Cretaceous-Cenozoic cover and the viscous behavior of the upper Aptian salt. They are scaled to fit observed natural configurations.

Results are compared with examples from the Gulf of Guinea on the basis of seismic data.

This approach allowed to better understand the evolution of the margin and therefore the reservoir distributions and traps geometries.

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