A preliminary report on the palynological investigation of the Middle Oligocene (Henis Clay and Sands and Marls of Oude Biezen) in the Tongeren-Valkenburg area, Belgium and The Netherlands

A preliminary investigation on the pollencontent of Oligocene deposits of the Tongeren-Valkenburg area (Belgium and The Netherlands) demonstrates that the lower part of the Henis Clay is barren, whereas the Oude Biezen compler and the higher port of the Henis Clay generally contain more or less well-preserved palynological material. The results do not contradict the assumption of Henis Clay and Oude Biezen complex belonging to the same sedimentary cycle.