The Maldegem Formation is a geologic formation in the Belgian

Belgium

Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

 subsurface

Subsurface

Subsurface is the seventh studio album by British progressive metal band Threshold. The album was released in August 2004, and received an Album of the Month award in several European music magazines....

. The formation consists of alternating marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 clay

Clay

Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

 and sand

Sand

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

 strata

Stratum

In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...

, deposited during the late Eocene

Eocene

The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...

.

The Maldegem Formation crops out

Outcrop

An outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. -Features:Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial deposits are covered by a mantle of soil and vegetation and cannot be...

 in the provinces of East-Flanders and West-Flanders and in the area between the Zenne

Zenne

The Zenne or Senne is a small river that flows through Brussels, left tributary of the Dijle/Dyle. Its source is in the municipality of Soignies. It is an indirect tributary of the Scheldt, through the Dijle and the Rupel...

 and Dender

Dender

The Dendre or Dender is a 65 km long river in Belgium, right tributary of the river Scheldt. The confluence of both rivers is in the Belgian town Dendermonde....

 rivers. In the northern parts of Flanders it forms an up to 50 meters thick sequence in the subsurface. Further south and to the east (in the Campine

Campine

The Campine is a natural region situated chiefly in north-eastern Belgium and parts of the south-western Netherlands which once consisted mainly of extensive moors, tracts of sandy heath, and wetlands...

 of Antwerpen) the formation pinches out and can be only a few meters in thickness.

Lithology

The Maldegem Formation is an alternating sequence of grey glauconiferous

Glauconite

Glauconite is an iron potassium phyllosilicate mineral of characteristic green color with very low weathering resistance and very friable.It crystallizes with a monoclinic geometry...

 fine sands and greyish blue glauconiferous heavy clay. It was deposited during the late Lutetian

Lutetian

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

 and Bartonian

Bartonian

The Bartonian is, in the ICS's geological timescale, a stage or age in the middle Eocene epoch or series. The Bartonian age spans the time between and . It is preceded by the Lutetian and is followed by the Priabonian age.-Stratigraphic definition:...

 ages (between 42 and 37 million years old).

Stratigraphy

Seven members can be recognized within the Maldegem Formation: Wemmel Member, Asse Member, Ursel Member, Onderdale Member, Zomergem Member, Buisputten Member and Onderdijke Member.

The Maldegem Formation is not part of a stratigraphic group

Group (stratigraphy)

A group in stratigraphy is a lithostratigraphic unit, a part of the geologic record or rock column that consists of defined rock strata. Groups are divided into formations and are sometimes themselves grouped into "supergroups"....

 and forms an independent unit in the lithostratigraphy

Lithostratigraphy

Lithostratigraphy is a sub-discipline of stratigraphy, the geological science associated with the study of strata or rock layers. Major focuses include geochronology, comparative geology, and petrology...

 of Belgium. Stratigraphically on top of it is usually the Zelzate Formation (green grey sand with a Priabonian

Priabonian

The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene epoch or series. It spans the time between and...

 to Rupelian

Rupelian

The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene epoch/series. It spans the time between and . It is preceded by the Priabonian stage and is followed by the Chattian stage....

 age), part of the Tongeren Group

Tongeren Group

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 Belgian Tongeren Group correlates with the Dutch Tongeren Formation...

. The Maldegem Formation is usually found on top of the Lede Formation

Lede Formation

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....

 (calcareous grey sand with a middle Lutetian age), which belongs to the Zenne Group

Zenne Group

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...

.

1988

Formatie van Maldegem, in: (eds.): Voorstel lithostratigrafische indeling van het Paleogeen, Belgische Geologische Dienst, pp. 141-160. (eds.); 2001: Paleogene and Neogene lithostratigraphic units (Belgium), Geologica Belgica 4(1-2), p. 135-152