Opglabbeek Formation
The Opglabbeek Formation is a geologic formation in the subsurface of the eastern part of Belgian Limburg. The heterogeneous formation consists of clay and sand that was deposited lagoonally and fluvially during the early Selandian. The formation is named after the town of Opglabbeek in Limburg.
The Opglabbeek Formation is subdivided into two members: the Opoeteren Member and the Eisden Member.
The Opglabbeek Formation's thickness ranges between and, reaching its greatest thickness as it abuts the Roer Valley Graben. It lies stratigraphically on top of the Houthem Formation. It is the lateral equivalent of the Hainin Formation. On top of it lies the Heers Formation. The Opglabbeek Formation is part of the Hesbaye Group and can be correlated with parts of the Landen Formation of adjacent areas in the southern Netherlands.