|
Letná Formation
The Letná Formation is a Late Ordovician (Sandbian, or in the regional stratigraphy Berounian) geologic formation of the Prague Basin, Bohemian Massif in the Czech Republic. The formation crops out in the Czech capital, more specifically at Letná Hill, after which the formation is named. The type locality is located at Malá Strana, Holešovice district.Kříž & Steinová, 2009 The more than thick formation comprises a rhythmic alternation of sandstones (greywackes and subgreywackes), quartzites, intercalated with siltstones and shales deposited in marine flysch-like environments. Because of the excellent preservation, including gut remains, of a wide assemblage of early Paleozoic taxa in which trilobites dominate, the formation, which is lean in fossils in many areas but exceptionally rich in what has been interpreted as storm beds, has been designated a '' Konservat-Lagerstätte''. Description The Letná Formation was first formally defined in 1966 by Havlíček an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandbian
The Sandbian is the first stage of the Upper Ordovician. It follows the Darriwilian and is succeeded by the Katian. Its lower boundary is defined as the first appearance datum of the graptolite species '' Nemagraptus gracilis'' around million years ago. The Sandbian lasted for about 5.4 million years until the beginning of the Katian around million years ago. Naming The name Sandbian is derived from the village Södra Sandby (Lund Municipality, Skåne County, Sweden). The name was proposed in 2006. GSSP The GSSP of the Sandbian is the Fågelsång section () at Sularp Brook, east of Lund (Skåne, Sweden). It is an outcrop of shale and mudstone. The lower boundary of the Sandbian is defined as the first appearance datum of graptolite Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greywacke
Greywacke or graywacke (German ''grauwacke'', signifying a grey, earthy rock) is a variety of sandstone generally characterized by its hardness, dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or lithic fragments set in a compact, clay-fine matrix. It is a texturally immature sedimentary rock generally found in Paleozoic strata. The larger grains can be sand- to gravel-sized, and matrix materials generally constitute more than 15% of the rock by volume. The term "greywacke" can be confusing, since it can refer to either the immature (rock fragment) aspect of the rock or its fine-grained (clay) component. The origin of greywacke was unknown until turbidity currents and turbidites were understood, since, according to the normal laws of sedimentation, gravel, sand and mud should not be laid down together. Geologists now attribute its formation to submarine avalanches or strong turbidity currents. These actions churn sediment and cause mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chrustenice
Chrustenice is a municipality and village in Beroun District in the Central Bohemian Region of the Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The .... It has about 1,000 inhabitants. References Villages in the Beroun District {{CentralBohemia-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zdice
Zdice is a town in Beroun District in the Central Bohemian Region of the Czech Republic. It has about 4,000 inhabitants. Administrative parts Villages of Černín and Knížkovice are administrative parts of Zdice. Geography Zdice is located about southwest of Beroun and southwest of Prague. It lies mostly in the Hořovice Uplands, including the built-up area. The northwestern part of the municipal territory extends into the Křivoklát Highlands and Křivoklátsko Protected Landscape Area, and includes the highest point of Zdice, which is the hill Kalce at above sea level. The town is situated at the confluence of the Litavka River and the Červený Stream. History The first written mention of Zdice is from 1148. It was probably founded in 1039. Until 1302, it was owned by the bishopric in Prague, then it was joined to the town of Beroun. In 1357, the village was merged with the newly established Karlštejn estate, owned by the royal chamber. During the rule of King Sigism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly dolomite, a closely related rock, which contains a high percentage of the mineral dolomite, . ''Magnesian limestone'' is an obsolete and poorly-defined term used variously for dolomite, for limes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beroun
Beroun (; german: Beraun) is a town in the Central Bohemian Region of the Czech Republic. It has about 20,000 inhabitants. It lies at the confluence of the Berounka and Litavka rivers. Beroun creates a conurbation with Králův Dvůr, former part of Beroun. The town centre is well preserved and is protected by law as an urban monument zone. Administrative parts Beroun is made up of seven town parts: Beroun-Centrum, Beroun-Hostim, Beroun-Jarov, Beroun-Město, Beroun-Zavadilka, Beroun-Závodí and Beroun-Zdejcina. Geography Beroun is located about southwest of Prague. The town is a part of the Prague metropolitan area. Beroun lies at the confluence of the Berounka and Litavka rivers, in the valley of the rivers. The surrounding landscape is hilly. The southern part of the municipal territory, including the built-up area, lies in the Hořovice Uplands. The northern part lies in the Křivoklát Highlands. The highest point is the Děd hill at above sea level. The lowest point is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Úvaly
Úvaly (german: Auwal) is a town in Prague-East District in the Central Bohemian Region of the Czech Republic. It has about 7,000 inhabitants. Geography Úvaly is located about east of the centre of Prague. It lies in the Prague Plateau on the Výmola stream. There are several small fish ponds in the municipal territory. History The first written mention of Úvaly is from 1290. The settlement lied on the important trade route Prague–Český Brod–Kutná Hora, which helped to its growth. In 1654 it was first mentioned as a market town. In 1845, the railroad Prague–Olomouc, which goes through Úvaly, was built, and its population grew up from hundreds to thousands. In 1969, Úvaly became a town. Demographics Sights The main landmark is the Church of the Annunciation of the Virgin Mary. It was built on the site of a chapel founded in 1342. Notable people *Marie Majerová Marie Majerová (1 February 1882 – 16 January 1967) was a Czech writer and translator. Biogra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rokycany
Rokycany (; german: Rokitzan) is a town in the Plzeň Region of the Czech Republic. It has about 14,000 inhabitants. The town centre is well preserved and is protected by law as an Cultural monument (Czech Republic)#Monument zones, urban monument zone. Administrative parts Rokycany is made up of town parts of Střed ("Centre"), Nové Město ("New Town") and Plzeňské předměstí ("Plzeň Suburb"), and the village of Borek (Rokycany), Borek. Geography Rokycany is located about east of Plzeň. It lies in the Švihov Highlands. The highest point of the municipal territory is Čilina hill at above sea level. Rokycany is situated at the confluence of the Klabava River and Holoubkovský Brook. There is another smaller brook (Rakovský) which flows through the western part of the town. The largest body of water is Klabava Reservoir with an area of . Today it serves as flood protection and as a recreational area. The second notable body of water is Borecký Pond. History The are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagerstätte
A Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These formations may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus delaying the decomposition of both gross and fine biological features until long after a durable impression was created in the surrounding matrix. ''Lagerstätten'' span geological time from the Neoproterozoic era to the present. Worldwide, some of the best examples of near-perfect fossilization are the Cambrian Maotianshan shales and Burgess Shale, the Silurian Waukesha Biota, the Devonian Hunsrück Slates and Gogo Formation, the Carboniferous Mazon Creek, the Jurassic Posidonia Shale and Solnhofen Limestone, the Cretaceous Yixian, Santana, and Agua Nueva formations, the Eocene Green River Formation, the Miocene Foulden Maar and Ashfall F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period () and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last extant trilobites finally disappeared in the mass extinction at the end of the Permian about 252 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton, they left an extensive fossil record. The stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Úvaly")
.jpg "Click for more on -> Trilobite")