The information on this page is a summary description.
The full formal description is available here: Bosbeek facies
| Abbreviation | DiBs |
| Parent unit | Diest Formation |
| Child units | |
| Lithological description | The Bosbeek facies is the local expression of the Diest Formation in the northern part of the Kempen Plateau, such as found in outcrop in the flanks of the Bosbeek Valley (Figure 0 1). It consists of fine, poorly sorted, glauconiferous sand. The sand is bioturbated and has a subhorizontal stratification. It contains thin subhorizontal clay layers. It contains no carbonates or fossils. The outcrops are rare. They show a weathered facies. In the present state of understanding, it is assumed that the “facies of Opoeteren” described by Gulinck (1964) between 6 and 22 m in the Neeroeteren borehole ( http://collections.naturalsciences.be/ssh-geology-archives/arch/064w/064w0234.txt, accessed 14/01/2022) as fine, glauconiferous sand with pale burrows, sporadic clay lenses and some coarse quartz is at least in part comparable to the Bosbeek facies identified in outcrops. The uncertainty in the correlation of this borehole interval and the Bosbeek valley outcrops is due to the presence between both of the Rotem and Neeroeteren Faults. |
| Age | Middle to late Tortonian. Biozones DN8 and/or DN9. Remains to be established. |
| Thickness | 15-20 m, to be verified. |
| Area of occurrence | The Bosbeek facies is found in outcrop in North-Limburg, in Opoeteren, Dorne and Opglabbeek in the flanks of the Bosbeek valley; possibly in the Maas Valley left flank near Bergerven and probably in the Neeroeteren subsurface. Mapping the extent and the correlation to the other Diest Formation members requires new observations. |
| Type locality | Outcrops are scarce. The disused sandpit at Opoeteren, Dorperberg, Eggestraat (Lambert72 X 239965, Y 195400) could be refreshed and re-examined. |
| Alternative names | Opoeteren Sand used by Gulinck in borehole description GSB 064W0234/DOV kb26d64w-B242 to refer to the Diest Formation outcrop in the Bosbeek valley a few km south of the borehole. |
| Authors | Houthuys, R., Vandenberghe, N. & Matthijs, J. |
| Date | 01/09/2023 |
| Cite as | Houthuys, R., Vandenberghe, N. & Matthijs, J., 2023. The Bosbeek facies, 01/09/2023. National Commission for Stratigraphy Belgium. http://ncs.naturalsciences.be/lithostratigraphy/Bosbeek-facies |
