The information on this page is a summary description.
The full formal description is available here: Folx-les-Caves Member
| Abbreviation | FOX |
| Parent unit | Chalk group |
| Child units | |
| Lithological description | From bottom to top, the Cretaceous strata at Folx-les-Caves comprise: – arenaceous facies of the white chalk (craie arénacée); – conglomerate, with pebble bed; pebbles consist of petrified calcarenites but also of older strata; – calcarenites with Thecidea papillata and Bourgueticrinus ellipticus (tufeau jaune of Rutot & Van den Broeck, 1888) – unconformably overlain by Tuffeau de Lincent of Palaeocene age. The Folx-les-Caves Formation is restricted to the craie arénacée in the section above. |
| Age | The belemniteGonioteuthis quadrata indicates an Early Campanian age for the craie arénacée (= Tuffeau de Folx- les-Caves). The coccolith assemblage CC 22 (Lithastrinus grilli, Aspidolithus parcus, Rheinhardtites anthophorus, Eiffelithus eximius, Uniplanarius sissinghii) mentioned by Mulder & Mai (1999) from one sample of the Tuffeau jaune (not jaunâtre as stated by these authors) is probably based on reworked material. Fossils (such as very numerous specimens of the brachiopod Thecidea papillata) in the collections of the IRSNB/KBIN, confirmed by the publications of Rutot & Van den Broeck (1888), from the same tuffeau jaune, indicate an undoubted Late Maastrichtian age for this younger tuffeau, thus confirming the existence of a a hiatus between the Early Campanian Tuffeau de Folx-les-Caves and the overlying Tuffeau de Jauche (see below). |
| Thickness | 3 to 6 m fide Bless et al., 1991 |
| Area of occurrence | Valley of the Petite Gette, eastern Brabant. |
| Type locality | Stratotype: Entrance to the underground quarry Folx-les-Cavesat Jauche (Orp-Jauche, eastern Brabant) (not in the territory of Folx-les-Caves as shown by Groessens, 1998). |
| 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 Folx-les-Caves Member, 01/01/2001. National Commission for Stratigraphy Belgium. https://ncs.naturalsciences.be/lithostratigraphy/Folx-les-Caves-Member |
| Additional information | Remarks: Previously also known as Tuffeau de Folx-les-Caves Rutot & Van den Broeck (1888); historical review by Groessens (1998). Recently studied by Bless et al. (1991), Kennedy (1987), Mulder & Mai (1999) |
