The information on this page is a summary description.
The full formal description is available here: Maisières Chalk Formation
| Abbreviation | MAI |
| Parent unit | Chalk group |
| Child unit | |
| Lithological description | Glauconitic, granular, calcarenitic green “chalk”, with erosion surfaces and/or perforated hardgrounds at the base. Becomes more chalky towards the west and is the equivalent of lithological units known in France as “Verts”, “Gris des mineurs” and “Bonne Pierre de Valenciennes” (where this chalk was worked in underground quarries as a building stone). Basal beds yield phosphate grains or pebbles. Fossil content: many bivalves. |
| Age | Coniacian on the basis of theplanktonicforaminifers Dicarinella gr. concavata and Globotruncana linneiana (Moorkens, 1969; Godfriaux & Sigal, 1969); numerous oysters Hyotissa semiplana and Gryphaeostrea canaliculata, and the brachiopod “Cretirhynchia” plicatilis. The Late Turonian age given by J. Cornet (1923) was based on the presence of ” Neoptychites peramplus”, but the specimen in the collections of the Faculté Polytechnique de Mons, is indeterminate according to F. Amédro. |
| Thickness | 2 to 7 m, a very good marker level in boreholes. |
| Area of occurrence | Mons Basin, in France corresponding to the “Pierre the Lézennes” near Lille, “Craie grise du Cambrésis”, and ” Bonne Pierre de Valenciennes”. |
| Type locality | Disused quarry “du Cimetière” at Maisières. |
| Alternative names | |
| Authors | Robaszynski, F., Dhondt, A.V. & Jagt, J.W.M. |
| Date | 01/01/2001 |
| Cite as | Robaszynski, F., Dhondt, A.V. & Jagt, J.W.M., 2001. The Maisières Chalk Formation, 01/01/2001. National Commission for Stratigraphy Belgium. http://ncs.naturalsciences.be/lithostratigraphy/Maisieres-Chalk-Formation |
