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Capotes Formation
The Capotes Formation ( es, Formación Capotes, Kic) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consists of calcareous black shales containing gypsum and ammonites and dates to the Early Cretaceous period; Early Albian epoch and has an approximate thickness at its type section of . Etymology The formation was defined in 1969 by Cáceres and Etayo as a member of the Socotá Formation.Acosta & Ulloa, 2002, p.41 The name is derived from Hacienda Capotes, southeast of Viotá.Vargas & Barrantas, 2013, p.8 Description Lithologies The Capotes Formation has a thickness at its type section of approximately , and is characterised by a sequence of organic rich calcareous shales with gypsum. Fossils of '' Douvilleiceras solitae'', '' Neodeshayesites columbianus'' and '' Paracrioceras sp.'' have been found in the Capotes Formation.Acosta & Ulloa, 2002, p.42Moreno Bedmar et al., 2015 Stratigraphy and depositional env ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma (million years ago). The Albian is preceded by the Aptian and followed by the Cenomanian. Stratigraphic definitions The Albian Stage was first proposed in 1842 by Alcide d'Orbigny. It was named after Alba, the Latin name for River Aube in France. A Global Boundary Stratotype Section and Point (GSSP), ratified by the IUGS in 2016, defines the base of the Albian as the first occurrence of the planktonic foraminiferan '' Microhedbergella renilaevis'' at the Col de Pré-Guittard section, Arnayon, Drôme, France. The top of the Albian Stage (the base of the Cenomanian Stage and Upper Cretaceous Series) is defined as the place where the foram species '' Rotalipora globotruncanoides'' first appears in the stratigraphic column. The Albia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altiplano Cundiboyacense
The Altiplano Cundiboyacense () is a high plateau located in the Eastern Cordillera of the Colombian Andes covering parts of the departments of Cundinamarca and Boyacá. The altiplano corresponds to the ancient territory of the Muisca. The Altiplano Cundiboyacense comprises three distinctive flat regions; the Bogotá savanna, the valleys of Ubaté and Chiquinquirá, and the valleys of Duitama and Sogamoso. The average altitude of the altiplano is about above sea level but ranges from roughly to . Etymology ''Altiplano'' in Spanish means "high plain" or "high plateau", the second part is a combination of the departments Cundinamarca and Boyacá. Geography The limits of the Altiplano are not strictly defined. The high plateau is enclosed by the higher mountains of the Eastern Ranges, with the Sumapaz mountains in the south and Chingaza to the east. The Tenza Valley is located to the east of the Altiplano and the Ocetá Páramo and Chicamocha Canyon are situated to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Highstand
A raised shoreline is an ancient shoreline exposed above current water level. These landforms are formed by a relative change in sea level due to global sea level rise, isostatic rebound, and/or tectonic uplift. These surfaces are usually exposed above modern sea level when a heavily glaciated area experiences a glacial retreat, causing water levels to rise. This area will then experience post-glacial rebound, effectively raising the shoreline surface. Examples of raised shorelines can be found along the coasts of formerly glaciated areas in Ireland and Scotland, as well as in North America. Raised shorelines are exposed at various locations around the Puget Sound of Washington State. See also * Isostasy * Landform * Machair * Marine terrace * Parallel Roads of Glen Roy * Raised beach * Terrace (geology) * Wave-cut platform A wave-cut platform, shore platform, coastal bench, or wave-cut cliff is the narrow flat area often found at the base of a sea cliff or along the shor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transgression (geology)
A marine transgression is a geologic event during which sea level rises relative to the land and the shoreline moves toward higher ground, which results in flooding. Transgressions can be caused by the land sinking or by the ocean basins filling with water or decreasing in capacity. Transgressions and regressions may be caused by tectonic events such as orogenies, severe climate change such as ice ages or isostatic adjustments following removal of ice or sediment load. During the Cretaceous, seafloor spreading created a relatively shallow Atlantic basin at the expense of deeper Pacific basin. That reduced the world's ocean basin capacity and caused a rise in sea level worldwide. As a result of the sea level rise, the oceans transgressed completely across the central portion of North America and created the Western Interior Seaway from the Gulf of Mexico to the Arctic Ocean. The opposite of transgression is regression in which the sea level falls relative to the land and expo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequence Stratigraphy
Sequence stratigraphy is a branch of geology, specifically a branch of stratigraphy, that attempts to discern and understand historic geology through time by subdividing and linking sedimentary deposits into unconformity bounded units on a variety of scales. The essence of the method is mapping of strata based on identification of surfaces which are assumed to represent time lines (e.g. subaerial unconformities, maximum flooding surfaces), thereby placing stratigraphy in chronostratigraphic framework allowing understanding of the evolution of the earth's surface in a particular region through time. Sequence stratigraphy is a useful alternative to a purely lithostratigraphic approach, which emphasizes solely based on the compositional similarity of the lithology of rock units rather than time significance. Unconformities are particularly important in understanding geologic history because they represent erosional surfaces where there is a clear gap in the record. Conversely w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depositional Environment
In geology, depositional environment or sedimentary environment describes the combination of physical, chemical, and biological processes associated with the deposition of a particular type of sediment and, therefore, the rock types that will be formed after lithification, if the sediment is preserved in the rock record. In most cases, the environments associated with particular rock types or associations of rock types can be matched to existing analogues. However, the further back in geological time sediments were deposited, the more likely that direct modern analogues are not available (e.g. banded iron formations). Types of depositional environments Continental * – type of Fluvial deposit. Caused by moving water in a fan shape (Alluvial Fan) and containing mostly impermeable and nonporous sediments well sorted. * . Often in deserts and coastal regions and well sorted, large scale cross-beds * – processes due to moving water, mainly streams. Common sediments are grav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simití Formation
Simiti is a town and municipality located in the Bolívar Department, northern Colombia. History Simití was founded in 1537 by Antonio de Lebrija and Juan Maldonado, two soldiers of the expedition from Santa Marta to the Muisca Confederation, led by Gonzalo Jiménez de Quesada Gonzalo Jiménez de Quesada y Rivera, also spelled as Ximénez and De Quezada, (;1496 16 February 1579) was a Spanish explorer and conquistador in northern South America, territories currently known as Colombia. He explored the territory named .... - Banco de la República References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Douvilleiceras
''Douvilleiceras'' is a genus of ammonites from the Middle to Late Cretaceous. Its fossils have been found worldwide, in Africa, Asia, Europe, and North and South America. Description Shells of ''Douvilleiceras inaequinodum'' can reach a diameter of about . Species Species within the genus ''Douvilleiceras'' include: * ''D. clementium'' * ''D. inaequinodum'' (Quenstedt, 1849) * ''D. mamillare'' * ''D. mammillatum'' (Schlotheim, 1813) * ''D. meyendorffi'' * ''D. monile'' (Sowerby, 1836) * ''D. muralense'' Stoyanow 1949 * ''D. offarcinatum'' * ''D. orbignyi'' Hyatt, 1903 * ''D. scabrosum'' * ''D. solitae'' * ''D. spiniferum'' (Whiteaves, 1876) Distribution Fossils of ''Douvilleiceras'' are found in the Cretaceous of Angola, Brazil, Canada, Colombia ( Capotes Formation, Cundinamarca),Acosta & Garay, 2002, p.42 the Dominican Republic, Egypt, France, Iran, Japan, Madagascar, Mexico, Peru, South Africa, Switzerland, the former USSR, the United Kingdom, Alaska and Texas. ''D. inaeq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite.Blatt, Harvey and Robert J. Tracy (1996) ''Petrology: Igneous, Sedimentary and Metamorphic'', 2nd ed., Freeman, pp. 281–292 Shale is characterized by its tendency to split into thin layers ( laminae) less than one centimeter in thickness. This property is called '' fissility''. Shale is the most common sedimentary rock. The term ''shale'' is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the more narrow sense of clay-rich fissile mudrock. Texture Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks into thin layers, often splintery and usually parallel to the otherwise indistinguishable beddin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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