Tectonic activity evolution of the Scotia‐Antarctic Plate boundary from mass transport deposit analysis

Abstract

The spatial distribution and temporal occurrence of mass transport deposits (MTDs) in the sedimentary infill of basins and submerged banks near the Scotia‐Antarctic plate boundary allowed us to decode the evolution of the tectonic activity of the relevant structures in the region from the Oligocene to present day. The 1020 MTDs identified in the available data set of multichannel seismic reflection profiles in the region are subdivided according to the geographic and chronological distributions of these features. Their spatial distribution reveals a preferential location along the eastern margins of the eastern basins. This reflects local deformation due to the evolution of the Scotia‐Antarctic transcurrent plate boundary and the impact of oceanic spreading along the East Scotia Ridge (ESR). The vertical distribution of the MTDs in the sedimentary record evidences intensified regional tectonic deformation from the middle Miocene to Quaternary. Intensified deformation started at about 15 Ma, when the ESR progressively replaces the West Scotia Ridge (WSR) as the main oceanic spreading center in the Scotia Sea. Coevally with the WSR demise at about 6.5 Ma, increased spreading rates of the ESR and numerous MTDs were formed. The high frequency of MTDs during the Pliocene, mainly along the western basins, is also related to greater tectonic activity due to uplift of the Shackleton Fracture Zone by tectonic inversion and extinction of the Antarctic‐Phoenix Ridge and involved changes at late Pliocene. The presence of MTDs in the southern Scotia Sea basins is a relevant indicator of the interplay between sedimentary instability and regional tectonics.

Mass‐transport complexes as markers of deep‐water fold‐and‐thrust belt evolution: insights from the southern Magdalena fan, offshore Colombia

“…On tectonically active continental margins, recurrent mass wasting is commonly caused by seabed oversteepening due to structurally induced seabed deformation and/or by seismic activity (e.g. Moore et al ., ; Torelli et al ., ; Goldfinger et al ., ; Frey‐Martinez et al ., , ; Minisini et al ., ; Lamarche et al ., ; Cattaneo et al ., ; Dan et al ., ; Romero‐Otero et al ., ; Geersen et al ., ; Alfaro & Holz, ; Festa et al ., ; Pérez et al ., ). Several studies on active margins have investigated the mechanisms for slope failure and provide detailed descriptions of the deposits resulting from fold degradation (e.g.…”

Tectonic and oceanographic process interactions archived in Late Cretaceous to Present deep‐marine stratigraphy on the Exmouth Plateau, offshore NW Australia

“…Huneke & Mulder, ; Llave et al, ; Pickering, Hiscott, & Hein, ; Stow & Piper, ). One of these processes may dominate, both spatially and temporally, for instance, periods of intense tectonism may be recorded by repeated deposition of mass‐transport complexes (MTCs) spatially associated with specific structures (Bagguley & Prosser, ; Gee, Gawthorpe, & Friedmann, ; Gee, Uy, Warren, Morley, & Lambiase, ; Hampton, Lee, & Locat, ; Masson, Wynn, & Talling, ; Ortiz‐Karpf, Hodgson, Jackson, & McCaffrey, ; Pérez et al, ; Scarselli, McClay, & Elders, ). In contrast, periods dominated by the activity of intense, along‐slope bottom currents may be recorded by deposition of contourite depositional systems, from which oceanographic and/or palaeo‐oceanographic processes can be inferred (Ercilla et al, ; Hernández‐Molina et al, ; Hernández‐Molina, Llave, et al, ; Pérez et al, ; Pickering et al, ; Uenzelmann‐Neben, ; Viana, Faugères, & Stow, ).…”

“…Armandita, Morley, & Rowell, ; Clark et al, ; Gamboa, Alves, Cartwright, & Terrinha, ; Heinio & Davies, ; Scarselli et al, ; Thöle, Kuhlmann, Lutz, & Gaedicke, ), and active margins (e.g. Alfaro & Holz, ; Covault, Romans, Graham, Fildani, & Hilley, ; Normark, Piper, & Sliter, ; Pérez et al, ; Richardson, Davies, Allen, & Grant, ; Romans, Normark, McGann, Covault, & Graham, ; Romero‐Otero, Slatt, & Pirmez, ; Schwenk & Spieß, ; Sømme, Piper, Deptuck, & Helland‐Hansen, ; Vinnels, Butler, McCaffrey, & Paton, ; Völker, Geersen, Behrmann, & Weinrebe, ). In addition, process interactions between these along‐ and downslope processes have also been documented (e.g.…”

Stress Field Evolution of the Southernmost Andean Cordillera From Paleostress Analysis (Argentine Tierra del Fuego)

“…Synchronous with a decrease in the West Scotia Ridge oceanic spreading, the Shackleton Fracture Zone began to uplift 8 Ma ago. This amount of tectonic processes occurring since 8 Ma ago along the Scotia‐Antarctic plates edge has been related to the stratigraphy of mass‐transport deposits in the region by Pérez et al ().…”