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Castilletes Formation
The Castilletes Formation ( es, Formación Castilletes, N1c) is a fossiliferous geological formation of the Cocinetas Basin in the northernmost department of La Guajira, Colombia. The formation consists of fossiliferous mudstones, siltstones and medium-grained to conglomeratic fossiliferous lithic to quartzitic sandstones. The Castilletes Formation dates to the Neogene period; Burdigalian to Langhian stages, Colloncuran and Friasian in the SALMA classification, and has a maximum thickness of . Etymology The formation was defined by Rollins in 1965 and named after the village of Castilletes.Moreno et al., 2015, p.27 Description Lithologies The Castilletes Formation consists of fossiliferous mudstones, siltstones and medium-grained to conglomeratic fossiliferous lithic to quartzitic sandstones.Moreno et al., 2015, pp.27-32 Stratigraphy and depositional environment The Castilletes Formation overlies the Jimol Formation and is overlain by the Ware Formation. The a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burdigalian
The Burdigalian is, in the geologic timescale, an age or stage in the early Miocene. It spans the time between 20.43 ± 0.05 Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian, the Burdigalian was the first and longest warming period of the MioceneEdward Petuch, Ph.D. Florida Atlantic University, Department of Geosciences. and is succeeded by the Langhian. Stratigraphic definition The name Burdigalian comes from ''Burdigala'', the Latin name for the city of Bordeaux, France. The Burdigalian Stage was introduced in scientific literature by Charles Depéret in 1892. The base of the Burdigalian is at the first appearance of foram species ''Globigerinoides altiaperturus'' and the top of magnetic chronozone C6An. , an official GSSP for the Burdigalian had not yet been assigned. The top of the Burdigalian (the base of the Langhian) is defined by the first appearance of foram species ''Praeorbulina glomerosa'' and is also coeval with the top of magnetic chronozo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Departments Of Colombia
Colombia is a unitary republic made up of thirty-two departments ( Spanish: ''departamentos'', sing. '' departamento'') and a Capital District ('' Distrito Capital''). Each department has a governor (''gobernador'') and an Assembly (''Asamblea Departamental''), elected by popular vote for a four-year period. The governor cannot be re-elected in consecutive periods. Departments are country subdivisions and are granted a certain degree of autonomy. Departments are formed by a grouping of municipalities (''municipios'', sing. '' municipio''). Municipal government is headed by mayor (''alcalde'') and administered by a municipal council (''concejo municipal''), both of which are elected for four-year periods. Some departments have subdivisions above the level of municipalities, commonly known as provinces. Chart of departments Each one of the departments of Colombia in the map below links to a corresponding article. Current governors serving four-year terms from 2015 to 2019 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Falcón Basin
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Cerro Pelado Formation
Cerro is Spanish for "hill" or "mountain". Toponyms ;Bolivia: * Cerro Rico, the "Rich Mountain" containing silver ore near Potosi, Bolivia ;Brazil: *Cerro Branco, a municipality of Rio Grande do Sul *Cerro Grande, Rio Grande do Sul, a municipality of Rio Grande do Sul * Cerro Largo, a municipality of Rio Grande do Sul ;Chile * Cerro de Los Inocentes, in the Juan Fernández Islands ;Cuba: * Cerro, Havana, a district (''municipio'') ;Italy: *Cerro (Bottanuco), a subdivision of Bottanuco in the province of Bergamo *Cerro al Lambro, in the province of Milano * Cerro al Volturno, in the province of Isernia * Cerro Maggiore, in the province of Milano *Cerro Tanaro, in the province of Asti * Cerro Veronese, in the province of Verona ;Mexico: * Cerro Potosí ;United States: * Cerro, New Mexico ;Uruguay: * Cerro Largo Department * Villa del Cerro, in Montevideo * Fortaleza del Cerro, in Montevideo Football clubs * C.A. Cerro, a football club from Montevideo, Uruguay * Clu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South American Land Mammal Age
The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene (0.011 Ma). These periods are referred to as ages, stages, or intervals and were established using geographic place names where fossil materials where obtained.Flynn & Swisher, 1995 The basic unit of measure is the first/last boundary statement. This shows that the first appearance event of one taxon is known to predate the last appearance event of another. If two taxa are found in the same fossil quarry or at the same stratigraphic horizon, then their age-range zones overlap. Background South America was an island continent for much of the Cenozoic, or the "Age of Mammals". As a result, its mammals evolved in their own unique directions, as Australia and Madagascar still have today. Paleogeographic timeline A simplified paleogeographic timeline of South America: * 66 Ma – Sout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neogene
The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago (Mya) to the beginning of the present Quaternary Period Mya. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first humans ('' Homo habilis'') appeared in Africa near the end of the period. Some continental movements took place, the most significant event being the connection of North and South America at the Isthmus of Panama, late in the Pliocene. This cut off the warm ocean currents from the Pacific t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Quartz-bearing sandstone can be changed into quartzite through metamorphism, usually r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartzite
Quartzite is a hard, non- foliated metamorphic rock which was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to grey, though quartzites often occur in various shades of pink and red due to varying amounts of hematite. Other colors, such as yellow, green, blue and orange, are due to other minerals. The term ''quartzite'' is also sometimes used for very hard but unmetamorphosed sandstones that are composed of quartz grains thoroughly cemented with additional quartz. Such sedimentary rock has come to be described as orthoquartzite to distinguish it from metamorphic quartzite, which is sometimes called metaquartzite to emphasize its metamorphic origins. Quartzite is very resistant to chemical weathering and often forms ridges and resistant hilltops. The nearly pure silica co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithic Sandstone
Lithic sandstones, or lithic arenites, or litharenites, are sandstones with a significant (>5%) component of lithic fragments, though quartz and feldspar are usually present as well, along with some clayey matrix. Lithic sandstones can have a speckled (salt and pepper) or gray color, and are usually associated with one specific type of lithic fragment (i.e., igneous, sedimentary, or metamorphic).Prothero, D. R. and Schwab, F., 1996, Sedimentary Geology, pg. 100, Tectonically, lithic sandstones often form in a wide variety sedimentary depositional environments (including fluvial, deltaic, and alluvial sediments) associated with active margins. This tectonic setting provides the source of the lithic fragments, either through arc volcanism, thin-skinned faulting, continental collisions, unroofing, and subduction roll-back. See also *Arkose Arkose () or arkosic sandstone is a detrital sedimentary rock, specifically a type of sandstone containing at least 25% fel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conglomerate (geology)
Conglomerate () is a clastic sedimentary rock that is composed of a substantial fraction of rounded to subangular gravel-size clasts. A conglomerate typically contains a matrix of finer-grained sediments, such as sand, silt, or clay, which fills the interstices between the clasts. The clasts and matrix are typically cemented by calcium carbonate, iron oxide, silica, or hardened clay. Conglomerates form by the consolidation and lithification of gravel. They can be found in sedimentary rock sequences of all ages but probably make up less than 1 percent by weight of all sedimentary rocks. In terms of origin and depositional mechanisms, they are closely related to sandstones and exhibit many of the same types of sedimentary structures, e.g., tabular and trough cross-bedding and graded bedding.Boggs, S. (2006) ''Principles of Sedimentology and Stratigraphy.'', 2nd ed. Prentice Hall, New York. 662 pp. Friedman, G.M. (2003) ''Classification of sediments and sedimentary rocks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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