The information on this page is a summary description.
The full formal description is available here: Maastricht Formation
| Abbreviation | MAA |
| Parent unit | Chalk group |
| Child unit | Valkenburg Member, Gronsveld Member, Schiepersberg Member, Emael Member, Nekum Member, Meerssen Member, Lonzéee Member |
| Lithological description | Six members are distinguished, as follows from the base to the top: – Valkenburg Member (thickness between about 2.5 and 45 m): poorly indurated, white-yellowish to yellowish grey, fine- to coarse-grained “chalk” with greyish brown flint nodules of varying size in the west. In the east, sequence changes into alternation of poorly and more intensely indurated chalk beds, part of so-called ‘Kunrade limestone’. Flints, where occurring, are crumbly, light grey nodules. Base with coarse-grained, phosphatic/glauconitic and pyritic bioclastic sand. – Gronsveld Member (thickness between 4.5 and about 10 m): poorly indurated, white- yellowish to yellowish grey, fine to coarse-grained “chalk”. In its lower portion, small, light to dark greyish brown flint nodules of varying size and shape, in its higher portion arranged in more or less regular beds of nodules. Towards the east the higher portion is missing, where the “chalk” changes into cyclic alternation of more or less indurated chalk beds, part of the so-called ‘Kunrade limestone’. – Schiepersberg Member (thickness 5 to 6 m): poorly indurated, white yellowish, fine- to coarse-grained, homogeneous “chalk” with numerous regular beds and randomly distributed, light-grey to bluish-grey flint nodules. Homogeneous “chalk” changes towards the east into alternation of chalk beds of varying induration, part of the so-called ‘Kunrade limestone’. – Emael Member (thickness between about 5 and 7.5 m): poorly indurated white-yellowish and yellowish-brown, fine- to coarse-grained, homogeneous “chalk”, in its lower portion with numerous light grey flint nodules; typical are large, regular flat and pipe-shaped flint bodies. In the east, this homogeneous “chalk” changes into alternation of more or less indurated chalk beds, which form the highest part of the so-called ‘Kunrade limestone’. – Nekum Member (thickness between about 7 and 15 m): poorly indurated, white yellowish, coarse-grained, homogeneous “chalk”, in its lower part with few randomly distributed greyish brown flint nodules. Locally with coarse-grained fossil hash lenses and beds. – Meerssen Member (thickness between about 15 and 20 m): poorly indurated white yellowish, coarse- to very coarse-grained “chalk” with clearly developed hardgrounds and fossil hash layers and omission surfaces. |
| Age | Early Late to latest Maastrichtian by: coleoid and ammonoid cephalopods: Belemnitella junior, Belemnella (Neobelemnella) kazimiroviensis, Baculites vertebralis, Pachydiscus gollevillensis, P. jacquoti, Sphenodiscus binckhorsti, Menuites terminus, M. fresvillensis andHoploscaphites constrictus. Inoceramid bivalve: Tenuipteria argentea. Microfauna/flora: Thalassiphora pelagica, Palynodinium grallator. |
| Thickness | Between about 45 and 90 m. |
| Area of occurrence | With the exception of the area south of the line St Geertruid-Gulpen-Vaals and north of the Heerlerheide fault, where the formation is absent due to erosion, the unit occurs throughout southern Limburg and contiguous areas of Belgian Limburg and Liège. |
| Type locality | Stratotypes: – Valkenburg Member: disused quarry east of Valkenburg aan de Geul, Limburg, The Netherlands (co-ordinates 318.520/186.770). – Gronsveld Member: quarries Wijngaardsberg and Varkensgat at Riesenberg, east of Gronsveld, Limburg, The Netherlands (co-ordinates 314.050/180.150). -Schiepersberg Member: disused Schiepersberg quarry, Cadier en Keer, Limburg, The Netherlands (co-ordinates 315.880/182.680). – Emael Member: Marnebel quarry, Emael, Bassenge, Liège (co-ordinates 310.850/175.050). – Nekum Member: disused de Tombe Quarry, St Pietersberg, Maastricht, Limburg, The Netherlands (co-ordinates 315.130/175.350). – Meerssen Member: Ankerpoort-Curfs quarry, Geulhem, Limburg, The Netherlands (co-ordinates 320.120/182.100). |
| 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 Maastricht Formation, 01/01/2001. National Commission for Stratigraphy Belgium. http://ncs.naturalsciences.be/lithostratigraphy/Maastricht-Formation |
