Salt Dissolution in Subsurface of British North Sea as Interpreted from Seismograms

Abstract

Salt removal from a certain place in the subsurface can result from either halokinetic salt flow or leaching (= subrosion). Seismograms from the British North Sea show sinkhole diameters of 1.5 km at an approximate depth of 1.5 km, affecting Permian and Triassic salts and their overburden. Sinkholes are sediment collectors and conservators. Further subsidence means good permeability in sink-hole-filling sediments. A regional front of salt leaching, called a "salt slope," is a 2-km wide zone of local dip directed against the (subsaline) regional dip. The age of subrosion seems to be connected to morphologic uplift.