RE-ASSESSMENT OF THE NEW GEOLOGICAL MAP OF BELGIUM: EARLIEST OLIGOCENE DINOFLAGELLATE CYST-BASED AGES IN THE LEUVEN AREA (SHEET 24 AARSCHOT)
Historical Geology, University of Leuven, Redingenstraat 16, B-3000 Leuven, Belgium
Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, Belgium
Historical Geology, University of Leuven, Redingenstraat 16, B-3000 Leuven, Belgium
Abstract
Abstract. The dinoflagellate cyst (dinocyst) assemblages of two samples from a temporary outcrop in the vicinity of Haacht (Leuven) have been analysed. The co-occurrence of Areosphaeridium diktyoplokum, Cerebrocysta bartonensis, Glaphyrocysta semitecta, Rombodinium perforatum and Thalassiphora reticulata allows correlation with the North Sea Oligocene-1 zone. As a consequence, the considered unit has a latest Eocene to earliest Oligocene age, equivalent to the age of the marine Tongrian. Comparison of the studied area with the recent 1:50 000 geological map (sheet 24 Aarschot) shows that the current lithostratigraphic interpretation of the analysed section, i.e. the Middle Eocene Maldegem Formation, can no longer be uphold.
KEYWORDS: Oligocene, dinoflagellate cysts, biostratigraphy, Tongrian, Belgium