Basin-scale salt tectonic processes of the Laurentian Basin, Eastern Canada: insights from integrated regional 2D seismic interpretation and 4D physical experiments

Abstract

AbstractThis study integrates seismic interpretation and 3D analogue experiments monitored by digital image correlation techniques to investigate the evolution of the salt structures and the related depositional systems in the Laurentian Basin offshore Atlantic Canada. During the late Triassic, a layer of more than 3 km thick salt was deposited locally in a set of interconnected rift half-grabens forming a 50–70 km wide evaporite basin in the northern part of the Scotian Basin salt provinces. High sediment input in the Jurassic and early Cretaceous mobilized the salt into complex salt tectonic features, which suggest four kinematic domains with: (1) salt welds and pillows; (2) extensional diapirs and canopies; (3) contractional diapirs and folds; and (4) allochthonous salt nappe. The landward grabens trapped most of the Early Jurassic sediments by passive downbuilding into the salt with local extension. The expelled salt has been evacuated basinwards into a large contractional salt massif. The rapid advance of the allochthonous nappe was coeval with the Late Jurassic extensional collapse of the inflated salt massif due to seaward sediment progradation. Late Cretaceous and Tertiary progradation over the salt nappe caused extensional deformation with growth faulting and formation of minibasins on the secondary salt detachment level.