Interactions Between Sedimentation and Deformation During the Structural Evolution of Salt-Bearing Divergent Continental Margins
B. C. Vendeville, M.P.A. Jackson and S. Raillard
Event name: 5th International Congress of the Brazilian Geophysical Society
Session: Geology and Geophysics of Continental Margins
Publication date: 07 November 1997
Info: Abstract, PDF ( 559.43Kb )
Divergent continental margins, like those of the south Atlantic, display a wide variety of salt structures. These include normal faults formed during one or several episodes of moderate to extreme extension, extension-induced reactive diapirs that later grew passively, folds reactivated by younger normal faults or passive diapirs, and passive diapirs subsequently squeezed and rejuvenated by late contraction. We use experimental models and seismic examples to illustrate how this seemingly complex, highly variable structural pattern can be interpreted and explained by relatively simple concepts about the interaction between sedimentation and the two tectonic processes that drive deformation: gravity gliding and spreading. The balance between gliding and spreading is affected by sedimentation and basement tilt.