Deformations and Manifestations of Degassing in the Sedimentary Cover of the Equatorial Segment of the West Atlantic: Implications for Lithospheric Geodynamics

Tracking the Serpentinite Feet of the Mediterranean Salt Giant

“…Polonia et al [159] related such features to a tectonic inversion of crustal blocks along inherited Mesozoic normal faults, highlighting that this is an example of intraplate shortening, since this area was far from the plate boundary when tectonic inversion took place. As previously mentioned, such an intraplate compressive deformation is not exclusive of the continental crust, occurring in several places of the central Indian Ocean [23] and in south Atlantic Ocean [24,25]. Most intriguingly, Sokolov [25] ascribed such compressive deformations to stress field associated with the upwelling of large serpentinite diapirs.…”

“…As previously mentioned, such an intraplate compressive deformation is not exclusive of the continental crust, occurring in several places of the central Indian Ocean [23] and in south Atlantic Ocean [24,25]. Most intriguingly, Sokolov [25] ascribed such compressive deformations to stress field associated with the upwelling of large serpentinite diapirs.…”

“…Similarly, seismic lines from the Transatlantic Angola-Brazil Geotraverse, performed by the Geological Institute of the Russian Academy of Sciences (GIN-RAS) in a tract 500-1000 km wide and~4400 km in extent from the Brazilian Basin to the Angola Basin [24], evidenced plicative deformations of the sedimentary cover related to vertical motions of basement blocks, even far away from the spreading ridge. In fact, Sokolov [24,25] reports imbricate thrust structures in the eastern part of the Brazilian Basin, 600-1000 km away from the MAR, and hence in the Angola Basin. The author attributed these deformation to the stress field owing to volume increasing during serpentinization of the basement rocks and serpentinite diapirs upwelling throughout the sedimentary cover.…”