Geodynamic Setting of the Passive Part of the Charlie Gibbs Twin Transform Fault (North Atlantic)

Abstract

The study of the neotectonic deformation features of the sedimentary cover and seismicity of the Charlie Gibbs twin transform fault has shown that its southern trough is developed in a transtensional mode and its northern thrust, in a transpressional mode. Signs of activity in the structure of the upper part of the sedimentary section were noted in the eastern passive parts of the fault at a distance of at least 150 km from the active rift zone of the Mid-Atlantic Ridge. Dislocations of normal fault kinematics and signs of an increased sedimentation rate and occurrence of landslide clastic deposits near the trough slopes are manifested in the sedimentary section of the southern trough. The median ridge with folded structures, overlain by sediments with angular unconformity, is established in the axial part of the northern trough. Faults located south of the ridge are interpreted as reverse faults. At the present stage, the Northern trough is accompanied by the formation of piercements of the median ridge during extrusion of deep matter and accompanying deformations of the sedimentary cover.