Kinematic Evolution of the Southern North Atlantic: Implications for the Formation of Hyperextended Rift Systems

Abstract

We focus on the southern North Atlantic rifted margins to investigate the partitioning and propagation of deformation in hyperextended rift systems using plate kinematic modeling. The kinematic evolution of this area is well determined by oceanic magnetic anomalies after the Cretaceous normal polarity superchron. However, the rift and early seafloor spreading evolution (200–83 Ma) remains highly disputed due to contentious interpretations of the J magnetic anomaly on the Iberia‐Newfoundland conjugate margins. Recent studies highlight that the J anomaly is probably polygenic, related to polyphased magmatic events, and therefore does not correspond to an isochron. We present a new palinspastic restoration without using the J magnetic anomaly as the chron M0. We combine 3‐D gravity inversion results with local structural, stratigraphic, and geochronological constraints on the rift deformation history. The restoration of the southern North Atlantic itself is not the primary aim of the study but rather is used as a method to investigate the spatiotemporal evolution of hyperextended rift systems. We include continental microblocks that enable the partitioning of the deformation between different rift segments, which is of particular importance for the evolution of the Iberia‐Eurasia plate boundary. Our modeling highlights the following: (1) the segmentation of the Iberia‐Newfoundland rift system during continental crust thinning, (2) the northward V‐shape propagation of mantle exhumation and seafloor spreading, (3) the complex partitioning of deformation along the Iberia‐Eurasia plate boundary, and (4) a three‐plate propagation model which implies transtension.

Formation of the Iberian‐European Convergent Plate Boundary Fault and Its Effect on Intraplate Deformation in Central Europe

“…At this time, Africa and Iberia were separated by the Ligurian Tethys that connected the Alpine Tethys to the east and the Atlantic Ocean to the west (Figure ; Handy et al, ; Macchiavelli et al, ). Iberia and Europe were separated by a hyperextended rift system and the Bay of Biscay, a narrow oceanic basin in the west (Clerc et al, ; Nirrengarten et al, ; Roca et al, ; Tugend et al, ). The oceanic domains and the rift system had previously formed in response to oblique divergence between Africa and Europe, mainly in Jurassic to Early Cretaceous times (e.g.…”

The Tell-Rif orogenic system (Morocco, Algeria, Tunisia) and the structural heritage of the southern Tethys margin

“…Anyhow, we can postulate that at the end of the Jurassic rifting the North African basins (Rif, Middle Atlas, Sahara Atlas) and their Iberian counterparts (Algarve, Cadix, Subbetic) were already face-to-face (e.g. for a recent reference, Nirrengarten et al, 2018). The development of an E-W transform zone connecting the Alpine Tethys to the Central Atlantic occurred just after.…”

“…In all the recent kinematic and palaeogeographic restorations (Dercourt et al, 2000;Handy et al, 2010;Schettino and Turco, 2009;Sibuet et al, 2012, Nirrengarten et al, 2018Biari et al, 2017), Iberia was located far east of its present position relatively to Africa at the beginning of the Jurassic (Fig. 5A).…”

Unraveling the Mesozoic and Cenozoic Tectonothermal Evolution of the Eastern Basque‐Cantabrian Zone–Western Pyrenees by Low‐Temperature Thermochronology

“…For that reason, it has attracted the interest of numerous international research groups, with large geological/geophysical projects developed particularly during the last decade (Topo‐Iberia, Topo‐Europe PYRTEC, Pyramid, Pyrope, Orogen, and RGF‐BRGM, among others). The Pyrenean‐Cantabrian mountain belt is also a key region to place constraints on kinematic models for Iberia, a topic that has been strongly discussed recently (e.g., Barnett‐Moore et al, , , ; Nirrengarten et al, ; van Hinsbergen et al, ). Discriminating between the different kinematic models requires good temporal constraints on the different phases of the tectonic evolution of the Pyrenean‐Cantabrian‐Bay of Biscay system.…”