Gentbrugge Formation

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Gentbrugge Formation
Stratigraphic range: Ypresian
~50  Ma
O
S
D
C
P
T
J
K
Pg
N
Type Geological formation
Unit of Ieper Group
Sub-unitsEgemkapel & Kortemark Members
Underlies Aalter & Brussel Formations
Overlies Mons-en-Pévèle Formation
Thicknessup to 50 m (160 ft)
Lithology
Primary Sandstone, siltstone
Other Claystone
Location
Region West Flanders, East Flanders, & Antwerp
CountryFlag of Belgium (civil).svg  Belgium
Extent Campine Basin
Type section
Named for Gentbrugge
Region East Flanders

The Gentbrugge Formation (Dutch : Formatie van Gentbrugge, abbreviation: Ge; named after the town of Gentbrugge in East Flanders) is a geologic formation in the west of Belgium. The formation crops out in East Flanders and West Flanders and also occurs in the subsurface of the Province of Antwerp. It consists of marine clay, silt and sand, deposited in the shallow sea that covered northern Belgium during the Ypresian age (around 50 million years ago, part of the early Eocene). [1] [2]

Contents

Description

The Gentbrugge Formation reaches its greatest thickness in the north of Belgium, where it can be maximally 50 metres (160 ft) thick. It is subdivided into three members. The base of the formation is formed by silty clay and clayey silt (Merelbeke Member). On top of this are laminae of silt (Pittem Member) and beds of very fine sand, disturbed by bioturbation (Vlierzele Member). The sands can have horizontal bedding as well as cross bedding, and are often lithified into sandstone. [2]

Stratigraphy

The Gentbrugge Formation is part of the Ieper Group and is stratigraphically on top of the older Mons-en-Pévèle Formation (micaceous sandstone), another formation of the same group. On top of the Gentbrugge Formation are deposits of the Lutetian Zenne Group. In the north of Belgium this is often the Aalter Formation (marine clays and sands). In the south the Aalter Formation often lacks and the younger Brussel Formation (marine sand and marl) and Lede Formation (marine calcareous sand) can be found directly on top of the Gentbrugge Formation. [1] [2]

See also

Related Research Articles

Ypresian First age of the Eocene Epoch

In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between 56 and47.8 Ma, is preceded by the Thanetian age and is followed by the Eocene Lutetian age. The Ypresian is consistent with the lower Eocene.

The Hesbaye Group is a stratigraphic group in the subsurface of northeastern Belgium. This group was deposited during the early Paleocene epoch and is subdivided into two formations: the Houthem Formation (lower) and the Opglabbeek Formation (upper). The group is named after the region of Hesbaye in the south of Limburg.

The Opglabbeek Formation is a geologic formation in the subsurface of the eastern part of Belgian Limburg. The formation consists of lagoonal and fluvial clay and sand and was deposited during the early Selandian. The formation is named after the town of Opglabbeek in Limburg.

The Hannut Formation is a geologic formation in the subsurface of northern Belgium. The formation consists of marine clay and silt, alternating with moer sandy layers. On top of this the lithology changes to limestone, siltstone and sandstone and the top of the formation is formed by a layer of glauconite bearing sand. The Hannut Formation was formed during the early to middle Thanetian age.

The Heers Formation is a geologic formation in the subsurface of Belgium. The formation consists of sand and marl and was deposited in the shallow sea that covered Belgium during the middle to late Selandian age of the Paleocene epoch.

The Landen Group is a lithostratigraphic unit in the Belgian subsurface. The group consists of two formations of Thanetian to Ypresian age. The Landen Group is named after the town of Landen in Flemish Brabant.

The Tienen Formation is a geologic formation in the subsurface of northern Belgium. The formation crops out in the province of Hainaut and the Hesbaye region in the province of Limburg. It has a late Thanetian (Paleocene) to early Ypresian (Eocene) age.

Ieper Group

The Ieper Group is a group of rock strata in the subsurface of northwest Belgium. The group is subdivided into three marine formations, all formed during the Ypresian, a single age of the geologic timescale. Both age and group are named after the West-Flemish town of Ypres, for which the Dutch name is "Ieper".

The Dongen Formation is a geologic formation in the subsurface of the Netherlands. The formation consists of early Eocene marine clay and sand. It is named after the town of Dongen in North Brabant.

The Rupel Group is a stratigraphic group of rock strata in the subsurface of Belgium. It is subdivided into three formations that are all marine deposits of Oligocene age.

The Zenne Group is a group of rock strata in the subsurface of central and northwest Belgium. The group consists of three formations, all from the Ypresian and Lutetian ages. These formation have their shallow marine facies in common.

The Aalter Formation is a geologic formation in the subsurface of northwest Belgium. The formation consists of marine clay and sand, deposited in the shallow sea that covered northern and central Belgium in the Eocene epoch.

The Tielt Formation 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.

The Kortrijk Formation is a geologic formation in the Belgian subsurface. This formation crops out in northern Hainaut, southern West- and East-Flanders and in Walloon Brabant. The formation consists of marine clay from the Ypresian age.

The Voort Formation or Voort Member is a stratigraphic unit in the subsurface of north Belgium and the south of the Netherlands. The unit has the status of a formation in Belgium but is seen as a member of the Veldhoven Formation in the Netherlands. The Voort Formation consists of shallow marine sands with a late Oligocene age.

The Maldegem Formation is a geologic formation in the Belgian subsurface. The formation consists of alternating marine clay and sand strata, deposited during the late Eocene.

The Brussel Formation is a geologic formation in the subsurface of central Belgium. The formation is named after the Belgian capital, Brussels. It consists of shallow marine sandstone and calcareous sands, deposited in the sea that covered Belgium 45 million years ago, in the Eocene.

The Lede Formation is a geologic formation in the subsurface of Belgium. The formation is named after the town of Lede in East Flanders. It consists of shallow-marine limestone and sandstone, deposited in the former sea that covered Belgium during the Eocene.

The Tongeren Group is a lithostratigraphic unit in the subsurface of Belgium. It consists of shallow marine, epicontinental and/or continental clays and sands from the late Eocene to early Oligocene epochs.

The geology of West Sussex in southeast England comprises a succession of sedimentary rocks of Cretaceous age overlain in the south by sediments of Palaeogene age. The sequence of strata from both periods consists of a variety of sandstones, mudstones, siltstones and limestones. These sediments were deposited within the Hampshire and Weald basins. Erosion subsequent to large scale but gentle folding associated with the Alpine Orogeny has resulted in the present outcrop pattern across the county, dominated by the north facing chalk scarp of the South Downs. The bedrock is overlain by a suite of Quaternary deposits of varied origin. Parts of both the bedrock and these superficial deposits have been worked for a variety of minerals for use in construction, industry and agriculture.

References

  1. 1 2 Steurbaut, 2006, p.76
  2. 1 2 3 Gentbrugge Formation

Bibliography