Backward modelling of the subsidence evolution of the Colorado Basin, offshore Argentina and its relation to the evolution of the conjugate Orange Basin, offshore SW Africa

Abstract

Originally published as:Dressel, I., Scheck-Wenderoth, M., Cacace, M. (2017): Backward modelling of the subsidence evolution of the Colorado Basin, offshore Argentina and its relation to the evolution of the conjugate Orange Basin, offshore SW Africa. AbstractIn this study we focus on reconstructing the post-rift subsidence evolution of the Colorado Basin, offshore Argentina. We make use of detailed structural information about its present-day configuration of the sedimentary infill and the crystalline crust. This information is used as input in a backward modelling approach which relies on the assumption of local isostasy to reconstruct the amount of subsidence as induced by the sedimentary load through different time stages. We also attempt a quantification of the thermal effects on the subsidence as induced by the rifting, here included by following the uniform stretching model of lithosphere thinning and exponentially cooling through time. Based on the available information about the present-day 2 geological state of the system, our modelling results indicate a rather continuous post-rift subsidence for the Colorado Basin, and give no significant evidence of any noticeable uplift phase.In a second stage, we compare the post-rift evolution of the Colorado Basin with the subsidence evolution as constrained for its conjugate SW African passive margin, the Orange Basin. Despite these two basins formed almost coevally and therefore in a similar large scale geodynamic context, their post-rift subsidence histories differ. Based on this result, we discuss causative tectonic processes likely to provide an explanation to the observed differences. We therefore conclude that it is most probable that additional tectonic components, other than the ridge-push from the spreading of the South Atlantic Ocean, are required to explain the observed differences in the subsidence of the two basins along the conjugate passive margins. Such additional tectonic components might be related to a dynamic mantle component in the form of either plume activity (Africa) or a subducting slab and the presence of an ongoing compressional stress system as revealed for different areas in South America.

Subsidence and exhumation of the Mesozoic Qiangtang Basin: Implications for the growth of the Tibetan plateau

“…Reconstructing the subsidence histories of sedimentary basins provides data to directly interrogate the tectonic evolution of a basin (e.g. Abadi, Wees, Dijk, & Cloetingh, ; Brunet, Korotaev, Ershov, & Nikishin, ; Carrapa & Garcia‐Gastellanos, ; Holt, Allen, Hunen, & Bjørnseth, ; Holt, Allen, & Hunen, ; Kuhn, Echtler, Littke, & Alfaro, ; Sciunnach & Garzanti, ; Abdullayev, Kadirov, & Guliyev, ; Dressel, Scheck‐Wenderoth, & Cacace, ; Silvia et al, ; Tozer, Watts, & Daly, ). The most commonly applied method to recover the 1‐D subsidence history of a sedimentary basin is ‘backstripping’ (Sclater & Christie, ; Watts & Ryan, ), which relies on physical properties of the stratigraphic sequences (thickness and porosity), combined with depositional ages, palaeobathymetry and eustsay at the time of accumulation.…”

Evolution of the Southwestern Angolan Margin: episodic burial and exhumation is more realistic than long-term denudation

“…In this case, the subsidence of the proximal domain could be larger and predicted when the rift-related asthenospheric thermal anomaly migrates towards the future breakup zone. Entering the post-rift stage, the subsidence is marked by lithospheric cooling and consequent sediment overburden (e.g., Rowan 2014; Dressel et al 2017).…”

“…Data worldwide contend that rift to post-rift evolution of the proximal margins might be controlled by vertical crustal movements related with events of erosion, burial, development of regional unconformities, tectonic reactivation, and magmatism (Gallagher and Brown 1999;Raab et al 2002;Lundin and Doré 2002;Japsen et al 2006;Mohriak et al 2008;Tinker et al 2008;Turner et al 2008;Bache et al 2011;Guillocheau et al 2012;Franke 2013;Wu et al 2014;Dressel et al 2015Dressel et al , 2017Bunge and Glasmacher 2018;Colli et al 2018;Friedrich et al 2018;Müller et al 2018;Kukla et al 2018). In this context, two main points of view are highlighted: (1) the evolution of the proximal margins has been driven by long-term denudation since rifting or another tectonic event (e.g., Cockburn et al 2000;Van Der Beek et al 2002;Kounov et al 2009) and (2) the evolution of the proximal margins has been controlled by episodic burial and exhumation events (e.g., Japsen et al 2006;Green et al , 2018.…”

PALEOSTRIPv1.0 – a user-friendly 3D backtracking software to reconstruct paleo-bathymetries

“…The estimated compaction trends can be applied in thickness restoration of stratigraphic units and subsidence analysis data that can be spatially interpolated between input drill sites to reconstruct a temporal basin evolution. Dressel et al (2015Dressel et al ( , 2017 perform 3D backtracking of the southwestern African continental margin while accounting for 1D thermal subsidence and Pratt isostasy, taking into account lateral density variations. PyBacktrack is a 1D backtracking and backstripping open-source code (Müller et al, 2018b) aimed at reconstructing paleo-bathymetries.…”