Tielt Formation

Tielt Formation
Stratigraphic range: Ypresian
~53 Ma
↓
TypeGeological formation
Unit ofIeper Group
Sub-unitsEgemkapel & Kortemark Members
UnderliesHyon Formation
OverliesKortrijk Formation
Thicknessup to 25 m (82 ft)
Lithology
PrimarySandstone
Location
RegionHainaut, West-, East Flanders, Flemish & Walloon Brabant
Country Belgium
ExtentCampine Basin
Type section
Named forTielt
RegionWest Flanders

The Tielt Formation (Dutch: Formatie van Tielt; French: Formation de Tielt; abbreviation: Tt; named after the town of Tielt in West Flanders) is a geologic formation in the subsurface of Belgium. The formation crops out in the north of Hainaut, in the southern and central parts of West- and East Flanders and in Walloon and Flemish Brabant. It consists of marine very fine sand and silt, deposited in the shallow sea that covered Belgium during the middle and late Ypresian age (early Eocene, about 53 million years ago).[1][2]

Description

The Tielt Formation is 25 m (82 ft) thick at most. It is subdivided into two members: the Kortemark and Egemkapel Members. The formation lies stratigraphically on top of the Kortrijk Formation (early Ypresian sandy clay and silt). In the northwestern part of Belgium, the Gentbrugge Formation (late Ypresian marine clay and silt) covers the Tielt Formation. If the Gentbrugge Formation is absent, the younger Brussel Formation (Lutetian calcareous sand) is directly found on top of the Tielt Formation.[1][2]

Fossil content

Chondrichthyes

Chondrichthyes reported from the Tielt Formation
Genus Species Location Stratigraphic position Material Notes Images
Urobatis U. molleni Kortemark Silt & Egem members.[3] Numerous teeth.[3] A round ray also known from the Aalter & Brussels Sand formations.

Crustaceans

Crustaceans reported from the Tielt Formation
Genus Species Location Stratigraphic position Material Notes Images
Loerenthopluma L. danielae Ampe sand & clay pit near Egem.[4] Egemkapel Clay Member.[4] A dozen well-preserved specimens.[4] A retroplumid crab.
Upogebia U. lambrechtsi Ampe sand & clay pit, Egem.[5] Egemkapel Clay Member.[5] Over 100 specimens.[5] An upogebiid mud shrimp.

See also

References

  1. ^ a b Steurbaut, 2006, p.76
  2. ^ a b Tielt Formation - National Commission on the Stratigraphy of Belgium
  3. ^ a b Hovestadt, Dirk; Hovestadt-Euler, M. (January 2010). "Urobatis molleni nov.sp. (Chondrichthyes, Myliobatiformes, Urolophidae) in the Eocene of Belgium". Geominpal Belgica. 1 (3): 66–69.
  4. ^ a b c Van Bakel, Barry; Artal, Pedro; Fraaije, R.; Jagt, John W. M. (January 2010). "Loerenthopluma Danielae, a new crab (Decapoda, Brachyura, Retroplumidae) from the lower Eocene of Northwest Belgium". Brachyura: A Homage to Danièle Guinot: 41–49.
  5. ^ a b c Fraaije, R. (January 2006). "Two new Paleogene species of mud shrimp (Crustacea, Decapoda, Upogebiidae) from Europe and North America". Bulletin of the Mizunami Fossil Museum (33): 81–89.

Bibliography