Maastricht Formation

The Maastricht Formation, named after the city of Maastricht in the Netherlands, is a geological formation in the Netherlands and Belgium whose strata date back to the Late Cretaceous, within 500,000 years of the Cretaceous–Paleogene boundary, now dated at. The formation is part of the Chalk Group and is between thick. It crops out in southern parts of Dutch and Belgian Limburg and adjacent areas in Germany. It can be found in the subsurface of northern Belgium and southeastern Netherlands, especially in the Campine Basin and Roer Valley Graben. Dinosaur remains are among the fossils that have been recovered from the formation.

Lithology

The Maastricht Formation consists of soft, sandy shallow marine limestone, in fact chalk and calcareous arenite. These lithologies locally alternate with thin bands of marl or clay. The lower parts of the formation contain flint concretions. The upper parts can have shellrich layers. Its age is between about 70 and 66 million years, which puts it in the Maastrichtian, a stage that was named after the formation. The top of the formation has been identified as Danian in age. The type locality is at the ruins of Lichtenberg castle on Mount Saint Peter, Maastricht.

Depositional Environment

Two primary environment-types have been described in the Maastricht Formation. The lower Kunrade Chalk representing a shallow, semi-lagoonal area near land of low relief which supplied terrigenous material. The Biofacies of the Kunrade Chalk are dominated by burrowing bivalves and abundant seagrass. In contrast, the upper Maastricht Chalk was deposited further offshore in clean carbonate sands. Periods of non deposition resulted in the lithification of sands forming hardgrounds that supported a diversity of echinoids and corals.

Stratigraphy

The Maastricht Formation was first described by Belgian geologist André Dumont in 1849. The formation is subdivided in seven members, from top to bottom these are the Meerssen Member, Nekum Member, Emael Member, Schiepersberg Member, Gronsveld Member, Valkenburg Member and Kunrade Member. The members are often hard to distinguish.
The Maastricht Formation is overlain by the Paleocene Houthem Formation and was deposited on top of the older Gulpen Formation.

Vertebrate paleofauna

Plesiosauria

Indeterminate elasmosaurids

Plants

Taxa	Species	Locality	Material	Notes	Images
Araucaria?	A?. sp.		Seed-cone scales	Identified as Araucaria, in contradiction to reports citing no Araucarian pollen present.
Brachyphyllum	B. patens			Likely belongs to Cheirolepidiaceae.
Brachyphyllum	sp. 1			Belongs to Cheirolepidiaceae.
Brachyphyllum	sp. 2			Possibly conspecific with sp. 1.
Cryptomeriopsis	C. eluvialis			Belongs to Taxodiaceae.
Cunninghamites	C. ubaghsii			Likely belongs to Taxodiaceae.
Elatidopsis	E. cryptomerioides			Belongs to Taxodiaceae.
Mosacaulis	M. spinifer			Stems and associated foliage, Seagrass convergent.
Pityophyllum	P. sp.			Pinaceous needles.
Thalassocharis	T. bosquetii			Seagrass stems and roots.
Thalassotaenia	T. ''debeyi			Seagrass leaves, similar to Posidonia''.