Structural Anisotropy
and Implications for the Oil and Gas Distribution Along the Campos and Santos Basin, Brazil
The Campos and Santos basins have evolved over a complex basement, controlled by different stretching rates, kinematics and rheology. Both basins show the same geodynamic evolution, beginning with mechanical subsidence in the Neocomian and Barremian, evolving to a sag phase in the Aptian and a further thermal subsidence during the Late Cretaceous and Cenozoic. The opening of the South Atlantic propagated from south to north and was controlled by stress trajectories applied over a NE-striking basement, nucleating new NE and NS faults. Additionally, different strain rates were accommodated in transverse NW and EW faults. The lithospherical attenuation was strongly influenced by imprinting of the Walvis giant-plume. Such processes lead to deformation partitioning, with the Cabo Frio Region working as a supraregional accommodation zone. During the post-rift phase, despite the determinant role of thin-skinned gravitational and overburden post-rift processes, some rearrangement and tenuous modification of the structural geometry of deep crustal blocks are also observed. These processes are evidenced by reactivation of some rift blocks, igneous activities along structural trends during the Paleogene and the uplift of the adjacent Serra do Mar range. The regional


AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil