Breda Formation
Encyclopedia
The Breda Formation is a geologic formation in the 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....

 of the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

. The formation consists of 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...

 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...

 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...

s and 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...

s that were deposited during the Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 epoch
Epoch (geology)
An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...

. Although the formation is not very rich in fossils, sometimes bones of fishes, shell
Exoskeleton
An exoskeleton is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton of, for example, a human. In popular usage, some of the larger kinds of exoskeletons are known as "shells". Examples of exoskeleton animals include insects such as grasshoppers...

s and shark teeth are found.

Stratigraphy and lithology

The Breda Formation was deposited in the shallow sea that covered the Netherlands during the Miocene. It is mostly on top of the Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...

 clays of the Rupel Formation
Rupel Formation
The Rupel Formation is a geologic formation in the subsurface of the Netherlands that consists of Oligocene marine sands and clays. The Rupel Formation is part of the Middle North Sea Group and correlates exactly with the Belgian Rupel Group....

 or late Oligocene sands and clays of the Veldhoven Formation
Veldhoven Formation
The Veldhoven Formation is a geologic formation in the subsurface of the Netherlands. The formation consists of an alternation of marine clay and sand from the Oligocene epoch.-Lithology:...

. The Breda Formation can be a couple of meters to (in the Roerdal Graben) more than 700 meters thick. The top is formed by an erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

al nonconformity
Nonconformity
Nonconformity may refer to:* Nonconformity , a memoir by Nelson Algren, published posthumously in 1992* Nonconformity , a term in quality management* A type of unconformity in geology...

 in the south and east of the Netherlands. In the west the contact with the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...

 Oosterhout Formation is more gradual. In the Roerdal Graben the mostly Pliocene Kiezeloolite Formation is sometimes on top of the Breda Formation.

Locally the Breda Formation can be subdivided into members: the Aalten Member (silt
Silt
Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...

y calcareous clay, rich in shells), the Eibergen Member (clay alternating with thin sand layers, with a basal conglomerate
Conglomerate (geology)
A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...

 in which shark teeth and whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...

 bones were found), the Zenderen Member (green, glauconiferous fine sand) and the Delden Member (sandy, glauconite and goethite
Goethite
Goethite , named after the German polymath Johann Wolfgang von Goethe, is an iron bearing oxide mineral found in soil and other low-temperature environments. Goethite has been well known since prehistoric times for its use as a pigment. Evidence has been found of its use in paint pigment samples...

 bearing clay and loam
Loam
Loam is soil composed of sand, silt, and clay in relatively even concentration . Loam soils generally contain more nutrients and humus than sandy soils, have better infiltration and drainage than silty soils, and are easier to till than clay soils...

.

The Breda Formation corresponds largely with the Berchem Formation of northern Belgium
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...

.

Literature

; 1975: Formaties van het Kwartair en Boven-Tertiair in Nederland, in: (eds.): Toelichting bij geologische overzichtskaarten van Nederland, Rijks Geologische Dienst, Haarlem, pp. 11-56.

External links

; 2003: Formatie van Breda, TNO
Netherlands Organisation for Applied Scientific Research
Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek or TNO is a not-for-profit organization in the Netherlands that focuses on applied science. The main office of TNO is located in Delft...

website
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