Carbonate platform in the context of "Reef"

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⭐ Core Definition: Carbonate platform

A carbonate platform is a sedimentary body which possesses topographic relief, and is composed of autochthonic calcareous deposits. Platform growth is mediated by sessile organisms whose skeletons build up the reef or by organisms (usually microbes) which induce carbonate precipitation through their metabolism. Therefore, carbonate platforms can not grow up everywhere: they are not present in places where limiting factors to the life of reef-building organisms exist. Such limiting factors are, among others: light, water temperature, transparency and pH. For example, carbonate sedimentation along the Atlantic South American coasts takes place everywhere but at the mouth of the Amazon River, because of the intense turbidity of the water there. Spectacular examples of present-day carbonate platforms are the Bahama Banks under which the platform is roughly 8 km thick, the Yucatan Peninsula which is up to 2 km thick, the Florida platform, the platform on which the Great Barrier Reef is growing, and the Maldive atolls. All these carbonate platforms and their associated reefs are confined to tropical latitudes. Today's reefs are built mainly by scleractinian corals, but in the distant past other organisms, like archaeocyatha (during the Cambrian) or extinct cnidaria (tabulata and rugosa) were important reef builders.

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Carbonate platform in the context of Limestone

Limestone 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 calcium carbonate CaCO3. 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, CaMg(CO3)2. Magnesian limestone is an obsolete and poorly defined term used variously for dolomite, for limestone containing significant dolomite (dolomitic limestone), or for any other limestone containing a significant percentage of magnesium. Most limestone was formed in shallow marine environments, such as continental shelves or platforms, though smaller amounts were formed in many other environments. Much dolomite is secondary dolomite, formed by chemical alteration of limestone. Limestone is exposed over large regions of the Earth's surface, and because limestone is slightly soluble in rainwater, these exposures often are eroded to become karst landscapes. Most cave systems are found in limestone bedrock.

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Carbonate platform in the context of Virgin Islands

The Virgin Islands (Spanish: Islas Vírgenes) is an archipelago between the North Atlantic Ocean and northeastern Caribbean Sea, located to the immediate east of the main island of Puerto Rico. It generally forms part of the Leeward Islands of the Lesser Antilles in the West Indies of the Caribbean region.

Geologically separated from the Lesser Antilles by the Anegada Passage and from the Greater Antilles by the Mona passage, all the islands except for Saint Croix lie on the same carbonate platform and insular shelf, known as the Puerto Rico Bank, and same tectonic plate, known as the Puerto Rico–Virgin Islands microplate.

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Carbonate platform in the context of Biofilm

A biofilm is a syntrophic community of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within the biofilm produce the EPS components, which are typically a polymeric combination of extracellular polysaccharides, proteins, lipids and DNA. Because they have a three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes".

Biofilms may form on living (biotic) or non-living (abiotic) surfaces and can be common in natural, industrial, and hospital settings. They may constitute a microbiome or be a portion of it. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single cells that may float or swim in a liquid medium. Biofilms can form on the teeth of most animals as dental plaque, where they may cause tooth decay and gum disease.

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Carbonate platform in the context of Spanish Virgin Islands

The Spanish Virgin Islands (Spanish: Islas Vírgenes Españolas), formerly called the Passage Islands (Spanish: Islas del Pasaje), commonly known as the Puerto Rican Virgin Islands (Spanish: Islas Vírgenes Puertorriqueñas), consist of the islands of Vieques and Culebra, which are administratively part of the archipelago of Puerto Rico as municipalities. Located between the main island of Puerto Rico and the U.S. Virgin Islands in the northeastern Caribbean, the islands are geographically part of the archipelago of the Virgin Islands in the Leeward Islands of the Lesser Antilles.

Geologically separated from the Greater Antilles island of Hispaniola by the Mona Passage and from the Lesser Antilles island arc by the Anegada Passage, the main island of Puerto Rico, the Spanish Virgin Islands of Vieques and Culebra, the British Virgin Islands, and the U.S. Virgin Islands except for the southernmost island of Saint Croix, all lie on the same carbonate platform and insular shelf, the Puerto Rico Bank, between the North Atlantic Ocean and the Caribbean Sea. The archipelagos of Puerto Rico and the Virgin Islands except for Saint Croix also lie on the same tectonic plate, the Puerto Rico–Virgin Islands microplate.

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Carbonate platform in the context of Bahama Banks

The Bahama Banks are the submerged carbonate platforms located in the archipelago of The Bahamas within the Lucayan Archipelago. The term is usually applied in referring to either the Great Bahama Bank around Andros Island, or the Little Bahama Bank of Grand Bahama Island and Great Abaco, which are the largest of the platforms, and the Cay Sal Bank. The three banks of the Turks and Caicos Islands, namely the Caicos Bank of the Caicos island group, the Turks Bank of the Turks island group, and the submerged Mouchoir Bank, and the two banks north of the Dominican Republic in Hispaniola, namely the submerged Silver Bank and Navidad Bank, are geographically and geologically part of the Lucayan Archipleago, which entire carbonate platform is often generally referred to as the Bahamas platform.

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Carbonate platform in the context of Puerto Rico Bank

The Puerto Rico Bank (PRB) (Spanish: Banco de Puerto Rico), also known as the Puerto Rican Bank (PRB), is a carbonate platform and insular shelf comprising the archipelagos of Puerto Rico and the Virgin Islands, located between the Greater Antilles and the Lesser Antilles in the northeastern Caribbean. Last subaerially exposed from the Last Glacial Maximum in the Last Glacial Period of the Late Pleistocene Age to the Northgrippian Age of the Holocene Epoch, the bank connected Puerto Rico and the Virgin Islands into a single landmass until sea level rise fragmented it into the present-day islands between 10,000 and 7,000 years Before Present (8,050 and 5,050 years Before Common Era). It is within the Puerto Rico–Virgin Islands microplate between the North American plate and Caribbean plate.

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Carbonate platform in the context of Carnian pluvial episode

The Carnian pluvial episode (CPE), often called the Carnian pluvial event, was a period of major change in global climate that coincided with significant changes in Earth's biota both in the sea and on land. It occurred during the latter part of the Carnian Stage, the first subdivision of the Late Triassic Epoch, and lasted for perhaps 1–2 million years (around 234–232 million years ago). Volcanic activity off the coast of North America led to global warming and increased rainfall on land, alongside a reduction of carbonate platforms in the oceans. Pluvial means "of or relating to rain; characterized by much rain, rainy."

The CPE corresponds to a significant episode in the evolution and diversification of many taxa that are important today. The earliest dinosaurs (which include the ancestors of birds), lepidosaurs (the ancestors of modern-day lizards, snakes, and the tuatara) and potentially mammaliaforms (ancestors of mammals) all diversified during the event. In the marine realm it saw the first appearance among the microplankton of coccoliths and dinoflagellates, with the latter linked to the rapid diversification of scleractinian corals through the establishment of symbiotic zooxanthellae within them. The CPE also saw the extinction of many aquatic invertebrate species, especially among ammonoids, bryozoans, and crinoids.

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