Topography of the Top Chalk surface on- and offshore Denmark

A time-structure map of the top of the Upper Cretaceous-Danian Chalk Group (the Top Chalk surface) in the entire Danish sector is presented. The prese nt topogaphy of the Top Chalk surface is a result of various erosional and tectonic events taking place during the Cenozoic. The analysis shows that t he Cenozoic is characterised by significant reactivation of the Mesozoic st ructural elements of which the Central Graben, the Ringk phi bing-Fyn High and the Sorgenfrei-Tornquist Zone are the most important. A tectonically co ntrolled relief caused the generation of widespread sheet like erosion on t he Ringk phi bing-Fyn High and incisions along the margins of Ringk phi bin g-Fyn High during the mid Paleocene. Incisions in the northern part of the Danish sector formed valleys, which probably transported sediment towards t he west. The present topography of Top Chalk in the eastern part of the Dan ish Sector is highly influenced by the late Cenozoic erosion of the uplifte d eastern margin of the North Sea Basin. The topography of Top Chalk also r eflects the distribution of mobile Zechstein salt as collapse structures fo llow the pitch-out line of mobile salt onto the Ringk phi bing-Fyn High, an d numerous salt structures deformed the Top Chalk surface. (C) 1999 Elsevie r Science Ltd. All rights reserved.