Maastricht Formation

Maastricht Formation Stratigraphic range: Maastrichtian–Danian PreЄ Є O S D C P T J K Pg N
Type	Geological formation
Location
Region	Europe
Country	Netherlands  Belgium

Old stone quarry at Kunrade, where the Kunrade Member of the Maastricht Formation crops out.

The Maastricht Formation (Dutch: Formatie van Maastricht; abbreviation: MMa), named after the city of Maastricht, the Netherlands, is a geological formation in the Netherlands and Belgium whose strata date back to the Late Cretaceous, within 500k years of the Cretaceous–Paleogene boundary,^[1] now dated at 66 million years ago. The formation is part of the Chalk Group and is between 30 and 90 metres 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.^[2]

Lithology

The Maastricht Formation consists of soft, sandy shallow marine limestone (in Limburg locally called "mergel"), 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 can possibly be Danian (early Paleocene) in age.

The type locality is at the ruins of Lichtenberg castle on the Sint-Pietersberg, Maastricht.

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.^[3]

The Maastricht Formation is overlain by the Paleocene Houthem Formation and was deposited on top of the older Gulpen Formation.

Vertebrate paleofauna

Dinosaurs

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Dinosaurs reported from the Maastricht Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Betasuchus[2]	B. bredai[2]	Geographically present in the Dutch province of Limburg.		"Femur."[4]	An Abelisauroid.
Indeterminate euhadrosaurian remains[2]		Geographically present in the Dutch province of Limburg.[2]
Megalosaurus[2]	M. bredai[2]	Geographically present in the Dutch province of Limburg.[2]			Reclassified as Betasuchus bredai.
Orthomerus.[2]	O. dolloi.[2]	Geographically present in the Dutch and Belgian provinces of Limburg.[2]			A dubious Hadrosaurid.
"Unnamed ornithurine "[1]	Unnamed				A primitive ornithurine[1]
"Unnamed enantiornithine"[1]	Unnamed				An enantiornithine[1]

Mammals

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Mammals reported from the Maastricht Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Maastrichtidelphys[5]	M. meurismeti[5]	Geographically present in the Dutch province of Limburg.[5]		"Right upper molar."[5]	A Herpetotheriid Marsupial.[5]

Mosasaurs

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Mosasaurs reported from the Maastricht Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Carinodens	C. belgicus
	C. fraasi				Junior synonym of C. belgicus.
Globidens	G. fraasi				Reclassified as Carinodens fraasi
Liodon	L. sectorius
Mosasaurus	M. hoffmanni
	M. lemonnieri
Plioplatecarpus	P. marshi

See also

• List of dinosaur-bearing rock formations

References

1. Longrich, N.R., Tokaryk, T. and Field, D.J. (2011). "Mass extinction of birds at the Cretaceous–Paleogene (K–Pg) boundary." Proceedings of the National Academy of Sciences, 108(37): 15253-15257. doi:10.1073/pnas.1110395108
2. Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 588-593. ISBN 0-520-24209-2.
3. See for example: Stratigraphy of the ENCI quarry, by H. Zevenberg
4. "Table 4.1," in Weishampel, et al. (2004). Page 78.
5. A New European Marsupial Indicates a Late Cretaceous High-Latitude Transatlantic Dispersal Route James Martin, Judd Case, ... Eric Mulder. J Mamm Evol 12(3):495-511 (2005)