Constraining South Atlantic Growth With Seafloor Spreading Data

• Main Authors: Pérez-Díaz, Lucía, Eagles, Graeme
• Format: Conference Object
• Language: unknown
• Published: 2015
• Subjects: Mid-Atlantic Ridge; South Atlantic Ocean
• Online Access: https://epic.awi.de/id/eprint/39620/; https://epic.awi.de/id/eprint/39620/1/Abstract_PerezDiaz_Eagles.pdf; http://pesgb.org.uk; https://hdl.handle.net/10013/epic.46792; https://hdl.handle.net/10013/epic.46792.d001

The opening of the South Atlantic Ocean is one of the most extensively researched problems in plate kinematics. Models of it have proliferated since Bullard, Everett and Smith [8] published the first-ever computer-assisted reconstruction in the 60s. In recent years, focus has shifted to understanding the early stages of continental separation. General agreement exists about ocean opening being the result of the northward propagating mid-Atlantic ridge between two main tectonic plates, implying a certain degree of intracontinental deformation. Modern studies assign most of this intracontinental deformation to narrow mobile belts between large plate- like continental blocks in order to achieve best fits of the blocks' extended continental margins [1-6]. The geological record of intracontinental deformation constrains the magnitude, orientation, and timing of block motion at very low resolution only. Similarly, with continent-ocean transition zones in the South Atlantic being up to 150 km wide, the ages and shapes of the extended margins are not unanimously interpretable at high resolution. Therefore, these are not suitable basis on which to lead a reconstruction effort. Aiming to avoid the uncertainties inherent in this approach, plate divergence has been modelled as depicted by seafloor spreading data (fracture zone traces and magnetic anomaly identifications), and this model has then been used as a context within which to interpret intracontinental tectonic motions [9].