South Africa's offshore Mesozoic basins

Reconstruction of the southwestern African continental margin by backward modeling

“…This implies that the density of the crystalline crust does not change during the post-rift phase, but was established syn-rift. Table 1 Names, lithologies, ages and physical properties of the individual units used in this study for "backstripping" as well as for the calculation of the thermal subsidence (after Broad et al, 2006;Hirsch et al, 2007Hirsch et al, , 2010Holtar and Forsberg, 2000;Maystrenko et al, 2013;Paton et al, 2007 andSclater andChristie, 1980 Throughout the sedimentary succession clastic sediments such as sandstone, siltstones, claystones dominate as well as a few shales and subordinate limestones ( Table 1). The set of properties considered for the different sedimentary units is consistent with previous stratigraphic investigations of Holtar and Forsberg (2000) for the Walvis Basin and with studies by Brown et al (1995), Hirsch et al (2007) and Paton et al (2007) for the southern area, especially the Orange Basin.…”

“…A non-exhaustive list comprises: (1) seismic investigations (e.g. Bauer et al, 2000;Bauer et al, 2003;Fern andez et al, 2010;Gladczenko et al, 1998;Hartwig et al, 2012;Koopmann et al, 2013;Kuhlmann et al, 2010;Weigelt and Uenzelmann-Neben, 2007), (2) potential field modeling (Hirsch et al, 2007(Hirsch et al, , 2009; Maystrenko et al, 2013;Stewart et al, 2000), (3) dating of vertical movements by sequence stratigraphy and geochemical dating methods (Broad et al, 2006;Brown et al, 1995;Holtar and Forsberg, 2000;Kuhlmann et al, 2011;Light et al, 1993;McMillan, 2003;Paton et al, 2007;Trumbull et al, 2007), (4) kinematic analysis or (5) a combination of several techniques (e.g. : Hirsch et al, 2010;Paton et al, 2008).…”

“…The formation and evolution of the margin is structurally related to the opening of the Atlantic ocean, which can be traced back to the continental separation of the Gondwana supercontinent during Late Jurassic-Early Cretaceous times (e.g. Broad et al, 2006;Nürnberg and Müller, 1991). During the last decade, an increasing number of studies have focused on the southwestern African continental margin with the aim of improving the current understanding of the processes responsible for its tectonic evolution and their relevance for the formation and maturation of hydrocarbon resources.…”

Coupled thermo-mechanical 3D subsidence analysis along the SW African passive continental margin

“…Sediments are deposited during a time window of finite duration. At this purpose, we follow the age subdivision after the chronostratigraphy by Broad et al (2006) with a modification of the most recent timescale after Cohen et al (2013). Table 1 illustrates the temporal subdivision adopted to include sedimentation in the forward modelling.…”

“…Bauer et al 2000;Gladczenko et al 1998;Maystrenko et al 2013;Paton et al 2008), post-breakup vertical movements Japsen et al 2012), sedimentation history and tectonic evolution for specific areas (e.g. Hirsch et al 2007Hirsch et al , 2009Hirsch et al , 2010Stewart et al 2000;Broad et al 2006;Uenzelmann-Neben et al 2007;Brown et al 1995). However, apart from some recent efforts Rouby et al 2013), these studies usually neglected to consider thermo-mechanical feedback effects on the subsidence and uplift processes along the continental margin.…”