hagen

most of NW Europe is composed mainly of chalk and asso-ciated shallower water carbonates deposited in a wide epeiric sea during an overall global sea-level highstand (e.g. Surlyk 1997). The Maastrichtian–Danian chalk has been intensely studied over the last 20 years, since it forms the most impor-tant reservoir rock for hydrocarbons in the North Sea Central Graben (e.g. Surlyk et al. 2003; Klinkby et al. 2005). In Den-mark, thousands of water wells have been drilled through the succession as about 35 % of the water consumption is from Maastrichtian chalk and Danian bryozoan limestone