The Lede Formation ( nl, Formatie van Lede; abbreviation: Ld) is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

in the subsurface of

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

. The formation is named after the town of

Lede Lede may refer to: * Lead paragraph (US English), the first paragraph of a composition Places * Lede, Belgium, a municipality in Flanders * Lède, a river in France * Lede Formation, a geologic formation in Belgium People * Marquess of Lede of ...

East Flanders , native_name_lang = , settlement_type = Province of Belgium , image_flag = Flag of Oost-Vlaanderen.svg , flag_size = , image_shield = Wapen van O ...

. It consists of shallow-marine

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

and

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates ...

, deposited in the former sea that covered Belgium during the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

. The Lede Formation crops out in East Flanders, Flemish Brabant, Antwerp and parts of Hainaut,

Walloon Brabant Walloon Brabant (french: Brabant wallon ; nl, Waals-Brabant ; wa, Roman Payis) is a province located in Belgium's French-speaking region of Wallonia. It borders on (clockwise from the North) the province of Flemish Brabant (Flemish Region) and ...

and

West Flanders ) , settlement_type = Province of Belgium , image_flag = Flag of West Flanders.svg , flag_size = , image_shield = Wapen van West-Vlaanderen.svg , shield_size = , image_map ...

. It forms a laterally continuous unit of calcareous and glauconiferous sandstone, sandy limestone and calcareous sandstone, which reaches a thickness of up to 15 metres. The formation is characterised by fossils of the

nummulite A nummulite is a large lenticular fossil, characterized by its numerous coils, subdivided by septa into chambers. They are the shells of the fossil and present-day marine protozoan ''Nummulites'', a type of foraminiferan. Nummulites commonly vary ...

'' Nummulites variolarius''. It is not subdivided into

members Member may refer to: * Military jury, referred to as "Members" in military jargon * Element (mathematics), an object that belongs to a mathematical set * In object-oriented programming, a member of a class ** Field (computer science), entries in ...

. The age of the Lede Formation is middle

Lutetian The Lutetian is, in the geologic timescale, a stage or age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the ...

(about 44 million years old) and it is part of the Zenne Group. On top of the Lede Formation is normally the younger Maldegem Formation (marine clays and sands of

Bartonian The Bartonian is, in the ICS's geologic time scale, a stage or age in the middle Eocene Epoch or Series. The Bartonian Age spans the time between . It is preceded by the Lutetian and is followed by the Priabonian Age. Stratigraphic defini ...

age). Below the Lede Formation are the Brussel Formation and Aalter Formation, both also part of the Zenne Group.

References

Bibliography

* Laga, P.; Louwye, S. & Geets, S. (eds.); 2001: ''Paleogene and Neogene lithostratigraphic units (Belgium)'', Geologica Belgica 4(1-2), p. 135-152 Geologic formations of Belgium Eocene Series of Europe Paleogene Belgium {{Europe-geologic-formation-stub