The information on this page is a summary description.
The full formal description is available here: Aachen Formation
Abbreviation | AAC |
Parent unit | Chalk group |
Child unit | Hergenrath Member, Aachen Member, Hauset Member |
Lithological description | A complex unit, in the type area primarily sands with intercalations of clayey and silty sands and sandy and silty clays in the lower part. The Aachen Formation rests on eroded Palaeozoic carbonate and psammitic/pelitic rocks, and comprises three members: – Hergenrath Member (thickness 10-35m): alternation of light to dark grey, sandy and silty clays with silty and clayey, light grey fine to coarse-grained sands, with subordinate fine-grained gravel, silts, minor red clays and ferruginous horizons. Locally, with large quantities of wood debris, marcasite and pyrite concretions. Root horizons are common, and in part they are associated with lignite deposits, especially in the upper part. – Aken and Hauset members (thickness up to about 40 m): well-sorted, yellow-white to clean white, limonite-stained fine sands, locally with irregular gravelly sandstone beds and concretions, with small- and large-scale cross-bedding. Flaser cross-bedding occurs commonly; bioturbation of varying intensity. In the lower part, locally lenticular bodies of silty clays. |
Age | Middle Santonian to earliest ?Campanian on associations of spores, pollen and dinoflagellates (Batten et al., 1987, 1988; Streel et al., 1994). |
Thickness | Varying from less than 1 m to 60 m. |
Area of occurrence | Type area is the wooded area south of Aachen (Aachener Wald), on German/Belgian border. |
Type locality | Hergenrath Member: Schampelheide quarry at Kelmis (La Calamine), Liège province. Aachen Member: Käskorb Quarry (outcrop 62D-74 of W. M. Felder) at Kelmis (La Calamine), Liège province. Hauset Member: Flög Quarry at Hauset, Liège province. |
Alternative names | |
Authors | Robaszynski, F., Dhondt, A.V. & Jagt, J.W.M. |
Date | 01/01/2001 |
Cite as | Robaszynski, F., Dhondt, A.V. & Jagt, J.W.M., 2001. The Aachen Formation, 01/01/2001. National Commission for Stratigraphy Belgium. http://ncs.naturalsciences.be/lithostratigraphy/Aachen-Formation |