Tongeren Formation
The Tongeren Formation is a geologic formation in the subsurface of the Netherlands. The formation consists of shallow marine, epicontinental and continental sediments, predominantly clay and sand from the late Eocene and early Oligocene epochs. The Tongeren Formation is part of the Middle North Sea Group and correlates with the Tongeren Group from Belgian stratigraphy.
The name was introduced by Belgian geologist André Hubert Dumont in 1849.The Tongeren Formation is subdivided into three members:
In southern Limburg the Tongeren Formation is lies on top of formations of the Lower North Sea Group or the Dutch Chalk Group.
In most places, the late Oligocene, marine sands and clays of the Rupel Formation are found on top of the Tongeren Formation.
