Late Cretaceous to Cenozoic Reactivation of Central Scotian Slope Salt Bodies and the Impact on Slope Depositional Systems

Abstract

The history of younger (Late Cretaceous to present) salt-related deformation is largely unknown on the Scotian Margin. This study investigates the style and timing of Late Cretaceous to Cenozoic salt tectonic rejuvenation on the upper Scotian Slope and related effects on depositional systems using two 3D seismic surveys. Salt bodies were passively extruded between the Cenomanian/Turonian and Ypresian followed by a period of quiescence and drape between the Ypresian and Rupelian. Compressional rejuvenation began at different times in two structural provinces. In the vertical salt diapir province (west), compression began in the Bartonian (Late Eocene) and in the allochthonous tongue province (east) it began in the Rupelian (Early Oligocene). At some point between Pliocene and today, compression rates waned and a period of slope regrading took place, planing off much slope relief. This was succeeded by a series of mass transport deposits and erosive canyons to yield the modern-day seafloor.