The information on this page is a summary description.
The full formal description is available here: La Chapelle Formation
Abbreviation
LCH
Parent unit
Child units
Lithological description
Formation subdivided into two members. The unnamed lower member (old: Rv2a), is an alternation of black quartzite in 1 to 4 m thick beds and thin bedded black roofing slate. The Olly Member (OLL, old: Rv2b) is a vein of black roofing. The lower boundary of the formation is not observed (Beugnies, 1960).
Age
The acritarchs in the Olly Mbr and the upper part of the lower member belong to the Zone 4b, dated as Mid to Late Cambrian. The acritarchs in the lower part of the lower member belong to the Zone 3 dated as probable Middle Cambrian (Vanguestaine, 1992); see also discussion on the ages at the Illy Fm.
Thickness
At least 100 m, with the Olly Mbr only a few meters thick (Beugnies, 1960).
Area of occurrence
Givonne Massif.
Type locality
Not yet defined; type area in the outcrops north of the village La Chapelle and close to Illy; the Olly Member has its type area in the outcrops along the Ruisseau de la Hatrelle, east of Illy.
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 Chapelle Formation, 01/01/2001. National Commission for Stratigraphy Belgium. https://ncs.naturalsciences.be/lithostratigraphy/La-Chapelle-Formation
