Tielt Formation


The Tielt Formation is a geologic formation in the subsurface of Belgium. The formation crops out in the north of Hainaut, in the southern and central parts of West- and East-Flanders and in Walloon and Flemish Brabant. It consists of marine very fine sand and silt, deposited in the shallow sea that covered Belgium during the middle and late Ypresian age.
The Tielt Formation is 50 metres thick at most. It is subdivided into three members: the Kortemark Member, the Egemkapel Member and the Egem Member. The formation lies stratigraphically on top of the Kortrijk Formation. In the northwestern part of Belgium, the Gentbrugge Formation covers the Tielt Formation. If the Gentbrugge Formation is absent, the younger Brussel Formation is directly found on top of the Tielt Formation.