# Tongeren Formation > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Tongeren_Formation > Markdown URL: https://mediated.wiki/source/Tongeren_Formation.md > Source: https://en.wikipedia.org/wiki/Tongeren_Formation > Source revision: 1255977151 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{no footnotes|date=February 2013}} The '''Tongeren Formation''' ({{langx|nl|Formatie van Tongeren}}; abbreviation: TO) is a [geologic formation](/source/formation_(stratigraphy)) in the [subsurface](/source/Subsurface_(geology)) of the [Netherlands](/source/Netherlands). The formation consists of shallow [marine](/source/marine_(ocean)), [epicontinental](/source/epicontinental) and [continent](/source/continent)al sediments, predominantly [clay](/source/clay) and [sand](/source/sand) from the late [Eocene](/source/Eocene) and early [Oligocene](/source/Oligocene) [epochs](/source/epoch_(geology)) (between 37 and 30 million years old). The Tongeren Formation is part of the [Middle North Sea Group](/source/Middle_North_Sea_Group) and correlates with the [Tongeren Group](/source/Tongeren_Group) from [Belgian](/source/Belgium) [stratigraphy](/source/stratigraphy). The name was introduced by Belgian geologist [André Hubert Dumont](/source/Andr%C3%A9_Hubert_Dumont) in 1849. ==Lithologies and subdivision== The Tongeren Formation is subdivided into three members: *the [Goudsberg Member](/source/Goudsberg_Member), an alternation of clay with [chert](/source/chert) nodules and thin [lignite](/source/lignite) layers; *the [Klimmen Member](/source/Klimmen_Member), [mica](/source/mica)ceous fine sand; and *the [Zelzate Member](/source/Zelzate_Member), shallow marine [glauconiferous](/source/glauconite) sand alternating with clay layers. ==Stratigraphic position== In southern [Limburg](/source/Limburg_(Netherlands)) the Tongeren Formation is lies on top of formations of the [Lower North Sea Group](/source/Lower_North_Sea_Group) (in particular the late [Paleocene](/source/Paleocene) to early Eocene [Dongen Formation](/source/Dongen_Formation) and [Landen Formation](/source/Landen_Formation)) or the Dutch [Chalk Group](/source/Chalk_Group) (represented by the [Late Cretaceous](/source/Late_Cretaceous) to early Paleocene [Vaals Formation](/source/Vaals_Formation), [Gulpen Formation](/source/Gulpen_Formation) and [Houthem Formation](/source/Houthem_Formation)). In most places, the late Oligocene, marine sands and clays of the [Rupel Formation](/source/Rupel_Formation) are found on top of the Tongeren Formation. ==References== {{Reflist}} *{{aut|[Dumont, A.](/source/Andr%C3%A9_Hubert_Dumont)}}; 1849: ''Rapport sur la Carte géologique du Royaume'', Bulletin de l'Académie royale de Belgique 16 (2ième partie), p. 370. ({{in lang|fr}}) *{{aut|Kuyl, O.S.}}; 1975: ''Lithostratigrafie van de Mio-Oligocene afzettingen in Zuid-Limburg'', in: {{aut|Zagwijn, W.H. & Staalduinen, C.J. van}} (''eds.''): ''Toelichting bij geologische overzichtskaarten van Nederland'', [Rijks Geologische Dienst](/source/Rijks_Geologische_Dienst), Haarlem, pp. 56–63. ({{in lang|nl}}) ==External links== *{{aut|Ebbing, J.H.J.; Menkovic, A. & Busschers, F.S.}}; 2003: [http://dinoloket.nitg.tno.nl/nomenclatorShallow/nl/marien/tongeren/index.html Formatie van Tongeren]{{Dead link|date=July 2018 |bot=InternetArchiveBot |fix-attempted=no }}, [TNO](/source/Netherlands_Organisation_for_Applied_Scientific_Research) website ({{in lang|nl}}) Category:Geologic formations of the Netherlands Category:Oligocene Series of Europe Category:Eocene Series of Europe Category:Paleogene Netherlands --- Adapted from the Wikipedia article [Tongeren Formation](https://en.wikipedia.org/wiki/Tongeren_Formation) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Tongeren_Formation?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.