The Zemst borehole, first record of the EECO in the North Sea Basin and implications for Belgian Ypresian - Lutetian stratigraphy

1. IntroductionSeveral cored boreholes have recently been drilled in strategic areas in order to generate and update the geological maps of Belgium. Most of these wells were designed to elucidate regional stratigraphic problems. The Zemst borehole (BGD 73E359; x = 155.444, y = 187.591; GPS-coordinates 50°59’54.52”N, 4°26’46.50”E; Fig. 1) was executed in 2001 to evaluate the presence of the P1n clay in the area between Aalst and Mechelen. This...