Development of a freshwater lens in the inverted Broad Fourteens Basin, Netherlands offshore

Abstract

The Mesozoic Broad Fourteens Basin is a northwest-southeast trending structural element, situated in the southern North-Sea,Netherlands offshore. Biodegraded and water-washed oils in the southern Broad Fourteens Basin indicate topography-driven meteoric water flow during Late Cretaceous inversion. Density-driven groundwater flow models support the development of a freshwater lens in the northern Broad Fourteens Basin during Late Cretaceous inversion. Three model scenarios with basin-scale permeabilities and water table heads within the range of most likely values show the possible development of a freshwater lens in the northern Broad Fourteens Basin. The freshwater-saltwater interface is located at a depth of 200-1200 m below mean sea level. Near steady-state flow conditions are reached within 1.5–4 Myr.