Strike-slip related folding within the Malvinas/Falkland Trough (south-western Atlantic ocean). (March 2020)

• Record Type: Journal Article
• Authors: Esteban, Federico D.; Ormazabal, Juan Pablo; Palma, Fermín; Cayo, Lubin Eric; Lodolo, Emanuele; Tassone, Alejandro
• Is Part Of: Journal of South American earth sciences. Volume 98(2020)
• Publication Date: 2020-03
• Subjects: North Scotia ridge -- Morpho-bathymetry -- Slope maps -- Geomorphometry -- Seismic reflection profiles -- Fold arrays -- Strike-slip tectonics; Geology -- Latin America -- Periodicals; Earth sciences -- Latin America -- Periodicals; Geology -- Antarctica -- Periodicals; Earth sciences -- Antarctica -- Periodicals; Geology -- Caribbean Area -- Periodicals; Earth sciences -- Caribbean Area -- Periodicals; Géologie -- Amérique latine -- Périodiques; Sciences de la terre -- Amérique latine -- Périodiques; Géologie -- Antarctique -- Périodiques; Sciences de la terre -- Antarctique -- Périodiques; Géologie -- Caraïbes (Région) -- Périodiques; Sciences de la terre -- Caraïbes (Région) -- Périodiques; Earth sciences; Geology; Antarctica; Caribbean Area; Latin America; Periodicals; 550.5
• DOI: 10.1016/j.jsames.2019.102452
• Languages: English
• ISSNs: 0895-9811

Abstract

Abstract: The Malvinas/Falkland Trough (M/FT) is an E-W trending bathymetric depression along which runs the present-day South American-Scotia plate boundary. To the north of the M/FT lies the southern sector of the South Malvinas/Falkland Basin, and to the south lies the Burdwood Bank, an elongated morphological high constituting part of the South Scotia Ridge. Analysis of bathymetric and slope maps, integrated with seismic reflection profiles, have allowed describing in detail the M/FT in the sector comprised between 60° and 57° W. Data show the presence of an array of folds forming a thin-skinned fold-and-thrust Belt (FTB), previously interpreted as an active compressional field. The thin-skinned FTB is developed in a triangular-shaped area, which extends ca . 100 km in the E-W direction and 16 km in the N-S direction. Four parallel, asymmetric folds that develop to progressively greater water depths (between 1600 and 2600 m depth) towards the north, with orientations ESE-WNW and lengths that vary between 22 and 98 km, have been recognized. These folds are constituted by Late Cenozoic sediments that are undeformed in the Malvinas/Falkland Trough. The development of folds, which began in the late Miocene ( ca . 7 Ma), was associated with the left-lateral strike-slip tectonic regime of the Magallanes-Fagnano-Malvinas lineament, the western segment of the South American-Scotia plate boundary. Graphical abstract: Image 1 Highlights: Morpho-bathymetric description of a thin-skinned Fold-and-Thrust Belt. Evidence of strike-slip folding revealed by bathymetric, slope and 2-D seismic data. The folding is related to the present-day South American-Scotia plate boundary.