Tongeren Formation
![]() | This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. (February 2013) |
The Tongeren Formation (Dutch: Formatie van Tongeren; abbreviation: TO) 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 (between 37 and 30 million years old). 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.
Lithologies and subdivision[]
The Tongeren Formation is subdivided into three members:
- the , an alternation of clay with chert nodules and thin lignite layers;
- the , micaceous fine sand; and
- the , shallow marine glauconiferous sand alternating with clay layers.
Stratigraphic position[]
In southern Limburg the Tongeren Formation is lies on top of formations of the Lower North Sea Group (in particular the late Paleocene to early Eocene Dongen Formation and Landen Formation) or the Dutch Chalk Group (represented by the Late Cretaceous to early Paleocene , and Houthem Formation).
In most places, the late Oligocene, marine sands and clays of the Rupel Formation are found on top of the Tongeren Formation.
References[]
- Dumont, A.; 1849: Rapport sur la Carte géologique du Royaume, Bulletin de l'Académie royale de Belgique 16 (2ième partie), p. 370. ((in French))
- Kuyl, O.S.; 1975: Lithostratigrafie van de Mio-Oligocene afzettingen in Zuid-Limburg, in: Zagwijn, W.H. & Staalduinen, C.J. van (eds.): Toelichting bij geologische overzichtskaarten van Nederland, , Haarlem, pp. 56–63. ((in Dutch))
External links[]
- Ebbing, J.H.J.; Menkovic, A. & Busschers, F.S.; 2003: Formatie van Tongeren[permanent dead link], TNO website ((in Dutch))
- Geologic formations of the Netherlands
- Oligocene Series of Europe
- Eocene Series of Europe
- Paleogene Netherlands