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Tongeren Group
The Tongeren Group is a lithostratigraphic unit (a sequence of rock strata) 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 (between 37 and 30 million years old). The Belgian Tongeren Group correlates with the Dutch Tongeren Formation. The name was introduced by André Hubert Dumont in 1849. Subdivision The Tongeren Group is subdivided into three formations. From top to bottom these are: *the Borgloon Formation, lagunal or fluvial shell rich sand and clay; *the Sint Huibrechts-Hern Formation, marine shell bearing sand and clay; *the Zelzate Formation, shallow marine glauconiferous sand with thin clay layers. Stratigraphic relations In northwest Belgium the Tongeren Group (represented in that area mostly by the Zelzate Formation) is stratigraphically lying on top of the Maldegem Formation (middle Eocene clay and sand). This formation is lacking in the east of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. In general, strata are primarily igneous or sedimentary relating to how the rock was formed. Sedimentary layers are laid down by deposition of sediment associated with weathering processes, decaying organic matter (biogenic) or through chemical precipitation. These layers are often distinguishable as having many fossils and are important for the study of biostratigraphy. Igneous layers occur as stacks of lava flows, layers of lava fragments (called tephra) both erupted onto the Earth's surface by volcanoes, and in layered intrusions formed deep underground. Igneous layers are generally devoid of fossils and represent magmatic or volcanic activity that occurred during the geologic history of an area. There are a number of principles that are used to explain the appearance of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
André Hubert Dumont
André — sometimes transliterated as Andre — is the French and Portuguese form of the name Andrew, and is now also used in the English-speaking world. It used in France, Quebec, Canada and other French-speaking countries. It is a variation of the Greek name ''Andreas'', a short form of any of various compound names derived from ''andr-'' 'man, warrior'. The name is popular in Norway and Sweden. Cognate names Cognate names are: * : Andrei, |
Lithostratigraphy Of Belgium
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. In general, strata are primarily igneous or sedimentary relating to how the rock was formed. Sedimentary layers are laid down by deposition of sediment associated with weathering processes, decaying organic matter (biogenic) or through chemical precipitation. These layers are often distinguishable as having many fossils and are important for the study of biostratigraphy. Igneous layers occur as stacks of lava flows, layers of lava fragments (called tephra) both erupted onto the Earth's surface by volcanoes, and in layered intrusions formed deep underground. Igneous layers are generally devoid of fossils and represent magmatic or volcanic activity that occurred during the geologic history of an area. There are a number of principles that are used to explain the appearance of str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Formations Of Belgium
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of Earth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Groups Of Europe
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of Earth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rupel Group
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 (sands and clays) of Oligocene age. Name The Rupel Group was first named by Belgian geologist André Hubert Dumont in 1849. It shares its name with the Rupelian age (34 to 28 million years ago) of the geological timescale. Both group and age are named after the Belgian river Rupel. The Rupel Group corresponds with the Rupel Formation in the Netherlands. Facies and lithologies The Rupel Group can be 250 meters thick at maximum. During the Rupelian age Belgium was covered by a shallow sea. The formations of the Rupel Group therefore have a shallow marine to near coastal facies. Stratigraphy The group is subdivided into three formations: the Bilzen Formation (yellow-white glauconiferous fine sand, containing fossils), the Boom Formation (a thick clay deposit, containing loam layers and septaria) and the Eigenbilzen Formation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landen Group
The Landen Group is a lithostratigraphic unit (a "group" of rock strata) in the Belgian subsurface. The group consists of two formations of Thanetian (late Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...) to Ypresian (early Eocene) age. The Landen Group is named after the town of Landen in Flemish Brabant. Subdivision The Landen Group is subdivided into two formations: * The Hannut Formation, an alternation of marine (ocean), marine clays, sands and limestones; * The Tienen Formation, a lagoonal-continental alternation of clay, sand and lignite. This formation is known for its fossils. Both formations can be found in the subsurface of all northern Belgium. They outcrop, crop out in the Hainaut (province), province of Hainaut. Stratigraphy The Landen Group is stratigra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maldegem Formation
The Maldegem Formation ( nl, Formatie van Maldegem; old name: Kallo Complex) is a geologic formation in the Belgian subsurface. The formation consists of alternating marine clay and sand strata, deposited during the late Eocene. The Maldegem Formation crops out in the provinces of East Flanders and West Flanders and in the area between the Zenne and Dender 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 of the province of Antwerp) the formation pinches out and can be only a few meters in thickness. Lithology The Maldegem Formation is an alternating sequence of grey glauconiferous fine sands and greyish blue glauconiferous heavy clay. It was deposited during the late Lutetian and Bartonian 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, Zome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glauconite
Glauconite is an iron potassium phyllosilicate ( mica group) mineral of characteristic green color which is very friable and has very low weathering resistance. It crystallizes with a monoclinic geometry. Its name is derived from the Greek () meaning 'bluish green', referring to the common blue-green color of the mineral; its sheen ( mica glimmer) and blue-green color. Its color ranges from olive green, black green to bluish green, and yellowish on exposed surfaces due to oxidation. In the Mohs scale it has hardness of 2. The relative specific gravity range is 2.4 - 2.95. It is normally found in dark green rounded brittle pellets, and with the dimension of a sand grain size. It can be confused with chlorite (also of green color) or with a clay mineral. Glauconite has the chemical formula . Glauconite particles are one of the main components of greensand, glauconitic siltstone and glauconitic sandstone. Glauconite has been called a marl in an old and broad sense of that word. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluvial
In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluvioglacial is used. Fluvial processes Fluvial processes include the motion of sediment and erosion or deposition on the river bed. The movement of water across the stream bed exerts a shear stress directly onto the bed. If the cohesive strength of the substrate is lower than the shear exerted, or the bed is composed of loose sediment which can be mobilized by such stresses, then the bed will be lowered purely by clearwater flow. In addition, if the river carries significant quantities of sediment, this material can act as tools to enhance wear of the bed ( abrasion). At the same time the fragments themselves are ground down, becoming smaller and more rounded (attrition). Sediment in rivers is transported as either bedload (the coarser fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagoon
A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') and ''atoll lagoons''. They have also been identified as occurring on mixed-sand and gravel coastlines. There is an overlap between bodies of water classified as coastal lagoons and bodies of water classified as estuaries. Lagoons are common coastal features around many parts of the world. Definition and terminology Lagoons are shallow, often elongated bodies of water separated from a larger body of water by a shallow or exposed shoal, coral reef, or similar feature. Some authorities include fresh water bodies in the definition of "lagoon", while others explicitly restrict "lagoon" to bodies of water with some degree of salinity. The distinction between "lagoon" and "estuary" also varies between authorities. Richard A. Davis Jr. restrict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tongeren Formation
The Tongeren Formation ( nl, Formatie van Tongeren; abbreviation: TO) is a geologic formation in the subsurface of the Netherlands. The formation consists of shallow marine, epicontinental and continental sediments, predominantly clay and sand from the late Eocene and early Oligocene epochs (between 37 and 30 million years old). The Tongeren Formation is part of the Middle North Sea Group and correlates with the Tongeren Group from Belgian stratigraphy. The name was introduced by Belgian geologist André Hubert Dumont in 1849. Lithologies and subdivision The Tongeren Formation is subdivided into three members: *the Goudsberg Member, an alternation of clay with chert nodules and thin lignite layers; *the Klimmen Member, micaceous fine sand; and *the Zelzate Member, shallow marine glauconiferous sand alternating with clay layers. Stratigraphic position In southern Limburg the Tongeren Formation is lies on top of formations of the Lower North Sea Group (in particular the lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
