The information on this page is a summary description.
The full formal description is available here: informal level 3 clay bed
| Abbreviation | |
| Parent unit | Mol Formation |
| Child units | |
| Lithological description | East of the Mol Rauw Fault zone a high natural gamma-ray signal is observed on top of the Retie Member. A clayey and lignitic horizon is documented at that level in borehole Stevensvennen MHL O3/01 (032W0460/GEO-03/071-B2). It is proposed to provisionally and informally name this geophysically expressed horizon ‘level 3 clay bed ’ as in Vandenberghe et al. (2020). It was observed in boreholes ZEH08/05 and RUS 04/03 that the colour of the drilling mud turned green at the top of the level 3 clay bed. |
| Age | See LIS file Mol Formation for information on the age of the Mol Formation units. |
| Thickness | The thickness, based on the geophycical gamma-ray logs, is 1 to 7 m. |
| Area of occurrence | Only observed in the subsurface in the Poppel-Rauw Fault zone and eastwards of it. |
| Type locality | A reference geophysical expression on the gamma-ray log for the informal ‘level 3 clay bed’ is the Postel SCK 13 borehole (032W0415 / kb17d32w-B385) between 62 and 69 m depth. In borehole Stevensvennen MHL O3/01 (032W0460/GEO-03/071-B2) the gamma ray signal is increased between 51 and 52,5 m depth and sharply increased between 52,5 and 53,5 m. The borehole cores however show only a limited presence of dark stained clay in that interval. |
| Alternative names | |
| Authors | Vandenberghe, N., Berwouts, I. & Vos, K. |
| Date | 01/09/2023 |
| Cite as | Vandenberghe, N., Berwouts, I. & Vos, K., 2023. The informal level 3 clay bed, 01/09/2023. National Commission for Stratigraphy Belgium. http://ncs.naturalsciences.be/lithostratigraphy/informal-level-3-clay-bed |
