Sousa Lemos Pereira, Ricardo Nuno and Alves, Tiago Marcos ![]() |
Abstract
Using a dense grid of high-quality 2D seismic profiles, dredge and outcrop data, the offshore prolongation of a first-order transfer zone, the Messejana–Plasencia Fault Zone (MPFZ), is explained within the context of oblique rifting between Southwest Iberia, Newfoundland, and West Tethys. The offshore MPFZ is shown to comprise a 5–10 km wide region of deformation, oblique to the continental margin, reactivated in the Mesozoic as part of a wider transcurrent domain, the São Vicente sub-basin. Here, the geometry of faults and strata denotes the generation of a pull-apart basin during the Jurassic-Early Cretaceous. In contrast, its Late Cretaceous to Cenozoic evolution favours left-lateral transpression during the counter-clockwise rotation and eastward migration of Iberia towards its present position. Erosion was subsequently enhanced in the São Vicente sub-basin due to the reactivation of syn-rift structures. By documenting the evolution of the São Vicente sub-basin, and adjacent MPFZ, this work demonstrates: 1) the temporal and spatial scales in which first-order transfer zones accommodate crustal movements during continental rifting and subsequent inversion episodes; 2) the generation of an extensive region of strain accommodation in the vicinity of the MPFZ, an observation with profound implications to future palaeogeographic reconstructions of the North Atlantic Ocean; and 3) that the São Vicente Canyon, the physiographic expression of the MPFZ, incised the margin as early as the latest Cretaceous-Paleocene, synchronously with the onset of tectonic uplift in Southwest Iberia. In such a setting, the São Vicente sub-basin and MPFZ formed important by-pass corridors for sediment sourced from proximal areas of the margin. At present, the MPFZ comprises a complex releasing-restraining bend accommodating important vertical and horizontal movements in Southwest Iberia. Based on earthquake data from similar transfer zones, the MPFZ should be able to generate large-magnitude earthquakes and potentially destructive tsunamis.
Item Type: | Article |
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Date Type: | Publication |
Status: | Published |
Schools: | Earth and Environmental Sciences |
Subjects: | G Geography. Anthropology. Recreation > GC Oceanography |
Uncontrolled Keywords: | Divergent margins; Transfer zones; Tectonic inversion; Submarine canyon incision; North Atlantic; Geohazards |
Publisher: | Elsevier |
ISSN: | 0040-1951 |
Funders: | Partex Oil and Gas |
Last Modified: | 24 Oct 2022 11:37 |
URI: | https://orca.cardiff.ac.uk/id/eprint/48751 |
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