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Integrated Numerical Modeling of the Southern Brazilian Continental Margin
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 74th EAGE Conference and Exhibition incorporating EUROPEC 2012, Jun 2012, cp-293-00095
- ISBN: 978-90-73834-27-9
Abstract
Integrated numerical modeling indicates highly specific rift and sag/post-rift basin developments in the Santos (SB), Campos (CB) and Pelotas Basins (PB) of the southern Brazilian margin. Late Barremian to Late Aptian depth-dependent continental stretching generates sag basins with evaporite deposition in the CB and SB. The PB features volcanic crust, controlled by long-term post-rift thermal contraction and differential accommodation. The subsidence development does not follow a simple trend of progressive thermal relaxation with decreasing subsidence rates. In the CB, total subsidence starts to increase in the Late Cretaceous and reaches a major peak in the Eocene. The PB shows a similar development, but subsidence remains relatively high until today. The SB shows the best match to an exponentially decreasing subsidence trend. Progradation, aggradation and retrogradation differ significantly in the three basins and are controlled by changes in sediment flux. The CB, SB and PB are connected to different continental source areas with individual periods of uplift. Plate-tectonic and structural reconfigurations control accommodation space only during the rift to early drift development. After the Eocene, the flexural subsidence component exceeds the thermo-tectonic component, and therefore primarily controls total subsidence and basin architecture.