The information on this page is a summary description.
The full formal description is available here: Kempen Diest Member
| Abbreviation | DiKe |
| Parent unit | Diest Formation |
| Child units | |
| Lithological description | The member is created to accommodate the poorly sorted medium to coarse, very glauconiferous, greyish green Diest sand that is mostly found in subcrop in boreholes in the northern part of the Kempen and in northern Limburg (Houthuys et al., 2020). Glauconite content varies from 25% to 60%. The coarse beds often contain a subpopulation of 0.5 to 2 mm (sub)angular quartz grains. In the vertical direction, grain size is either constant or coarsening upwards. The sand is most often homogenized by bioturbation. In cores, white burrow traces devoid of glauconite can be seen. No clear primary lamination has been reported in this member. The sand of this member has a loose packing. The sand is often non-calcareous. On seismic profiles, this member shows large-scale clinoforms with low slope angles (usually around 2%, locally in north Limburg up to 8%), prograding to NW. In north-Limburg, also stacking of aggrading beds is observed (De Batist & Versteeg, 1998). The clinoforms are interpreted as the slope deposits of a prograding marine delta. |
| Age | Late Miocene: late Tortonian to earliest Messinian, biochron DN9. North of Antwerpen, biochron DN10. |
| Thickness | The thickness is difficult to establish as the lower boundary is not well defined. The thickness is several 10s of metres and reaches more than 100 m in the Roer Valley Graben and near the Dutch border. |
| Area of occurrence | The member occurs in the central and north Kempen region. The western border is a few km east of the city of Antwerpen and the southern border is approximately along a line Lier – Herentals – Olmen – southwest border fault of the Roer Valley Graben. However, awaiting a clear description of the transition to the Hageland Diest and Borsbeek/Deurne members, the borders are at present poorly defined. |
| Type locality | A cored borehole in Mol or Dessel, e.g. from the ‘ON’ series of boreholes drilled by NIRAS such as ON-Dessel-2 or ON-Dessel-5, can be proposed as type section (remains to be done). |
| Alternative names | formerly part of the at the time not yet subdivided Diest Formation sensu De Meuter and Laga (1976) after Dumont (1839) |
| Authors | Houthuys, R., Adriaens, R., Goolaerts, S., Laga, P., Louwye, S., Matthijs, J., Vandenberghe, N. & Verhaegen, J. |
| Date | 01/09/2023 |
| Cite as | Houthuys, R., Adriaens, R., Goolaerts, S., Laga, P., Louwye, S., Matthijs, J., Vandenberghe, N. & Verhaegen, J., 2023. The Kempen Diest Member, 01/09/2023. National Commission for Stratigraphy Belgium. http://ncs.naturalsciences.be/lithostratigraphy/Kempen-Diest-Member |
