The information on this page is a summary description.
The full formal description is available here: La Roche à 7 Heures Formation
| Abbreviation | RSH |
| Parent unit | Revin Group |
| Child units | |
| Lithological description | Formation subdivided into two members. The unnamed lower member (old: Rv2a) has at the base thick quartzite beds; the thickness of the basal quartzite beds diminishes laterally to the east. The unit contains more quartzite than slate and becomes gradually more slaty than quartzitic upward; characterised by grey quartzite in 1 to 4 m thick beds; slumps and convolute laminations are often present; locally conglomeratic bands occur, mostly in the lowermost part of the unit; the less frequent slate is black, fine-grained with a mat appearance and is exploitable as roofing slate (Beugnies, 1960; Belanger, 1998 ms). The La Folie Member (LFO, old: Rv2b), is a black slate vein, composed of an alternation of grey quartzite beds a few decimetres or more thick and of slate layers up to several meters thick. |
| Age | Most of the formation contains acritarchs of the Zone 2, dated as the upper part of the Middle Cambrian (Vanguestaine, 1992). |
| Thickness | 170 to 400 m, with 10 to 30 m for the La Folie Mbr (Beugnies, 1960). |
| Area of occurrence | Rocroi Massif. |
| Type locality | Outcrops in the crags “La Roche à 7 Heures”, north-east of Monthermé, Meuse valley. The La Folie Mbr has its stratotype in the abandoned roofing slate quarry, south of Fumay, left bank of the Meuse. |
| Alternative names | Rv2 |
| Authors | Verniers, J., Herbosch, A., Vanguestaine, M., Geukes, F., Delcambre, B., Pingot, J.-L., Belanger, I., Hennebert, M., Debacker, T., Sintubin, M. & De Vos, W. |
| Date | 01/01/2001 |
| Cite as | Verniers, J., Herbosch, A., Vanguestaine, M., Geukes, F., Delcambre, B., Pingot, J.-L., Belanger, I., Hennebert, M., Debacker, T., Sintubin, M. & De Vos, W., 2001. The La Roche à 7 Heures Formation, 01/01/2001. National Commission for Stratigraphy Belgium. https://ncs.naturalsciences.be/lithostratigraphy/La-Roche-a-7-Heures-Formation |
| Additional information |
