DEEP SEISMIC REFLECTIONS IN THE NETHERLANDS, AN OVERVIEW

A project to study deep crustal structures was carried out by the Geol ogical Survey of the Netherlands between 1986 and 1993. In this period deep seismic data were acquired on- and offshore the Netherlands. The data consist of stacked normal-incidence seismic lines with recording times of up to 16 s and wide-angle measurements. Interpretations show that the crust is composed of a transparent upper part and a reflecti ve lower part. The base of the reflective zone coincides with the Moho discontinuity. The seismic lines cross several basins. The Roer Valle y Graben was modelled with a pure-shear McKenzie model. The Mesozoic b asins in the southern North Sea seem to have originated from pure-shea r movements with an additional simple-shear component. The Moho depth map shows that the crust is thinner beneath the basins and thickens be neath the highs.