The Aachen Formation consists of glauconite bearing sand. It was deposited during the Santonian and Campanian ages (85.8 to 70.6 million years ago) of the Cretaceous Period.
The formation rests unconformably on top of Carboniferous rocks of the Limburg Group, which are more than three times as old. Overlying the Aachen Formation is the Vaals Formation, equivalent to the upper part of the Chalk Group of England.
Fossil content
Among others, the following fossils have been reported from the formation:[1]
^Smets, G. (1888). "Aachenosaurus multidens". Bulletin de la Société belge de géologie, de paléontologie et d'hydrologie. 12 (2). Bruxelles: The society: 300 – via Biodiversity Heritage Library.
Leloux, J (1999), "Numerical distribution of Santonian to Danian corals (Scleractinia, Octocorallia) of southern Limburg, the Netherlands", Geologie en Mijnbouw, 78: 191–195
Batten, D. J (1988), "Revision of S J Dijkstra's Late Cretaceous megaspore and other plant microfossils from Limburg, the Netherlands. In J. W. J. Van Amerom (ed.)", Mededelingen Rijks Geologische Dienst, 41: 1–55
Dijkstra, S. J (1961), "On megaspores, Charophyta fruits and some other small fossils from the Cretaceous", The Palaeobotanist, 8: 8–18
Dijkstra, S. J (1949), "Megaspores and some other fossils from the Aachenian (Senonian) in South Limburg, Netherlands", Mededelingen Van de Geologische Stichting, Niewe Serie, 3: 19–32