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La Ciénega Formation, Bolivia
La Ciénega Formation is a Sandbian to Katian geologic formation of south-central Bolivia. The formation comprises silty, clayey, micaceous, fine-grained sandstones with thin intercalations of grey-green to light grey shales. at .org Fossil content The formation has provided the following fossils: * '' Dinorthis sp.'' * '' Lingula sp.'' * '' Lingulepis sp.'' * ''[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Southern Paleotemperate Deposits
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era, and the second of twelve periods of the Phanerozoic Eon. The Ordovician spans 41.6 million years from the end of the Cambrian Period Ma (million years ago) to the start of the Silurian Period Ma. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shale Formations
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 narrower 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 bedding plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone Formations
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains, cemented together by another mineral. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar, because they are the most resistant minerals to the weathering processes at the Earth's surface. Like uncemented sand, sandstone may be imparted any color by impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Because sandstone beds can form highly visible cliffs and other topographic features, certain colors of sandstone have become strongly identified with certain regions, such as the red rock deserts of Arches National Park and other areas of the American Southwest. Rock formations 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Bolivia
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era, and the second of twelve periods of the Phanerozoic Eon. The Ordovician spans 41.6 million years from the end of the Cambrian Period Ma (million years ago) to the start of the Silurian Period Ma. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Formations Of Bolivia
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology. It is integrated with 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. Geologists study the mineralogical composition of rocks in order to get insight into their history of formation. Geology determines the relative ages of rocks found at a given location; geochemistry (a branch of geology) determines their absolute ages. By combining various petrological, crystallographic, and paleontological tools, geologists are able to chronicle the geological history of the Earth as a whole. One aspect is to demonstrate the age of the Earth. Geology provides evidence for plate tectonics, the evolutionary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In Bolivia
This is a list of fossiliferous stratigraphic units in Bolivia. __NOTOC__ List of fossiliferous stratigraphic units See also * * Gomphothere fossils in Bolivia * South American land mammal ages * List of fossiliferous stratigraphic units in Paraguay * List of fossiliferous stratigraphic units in Peru References Bibliography * * ;Cajones Formation * ;Casira Formation * ;Cerdas beds * ;Honda Group * * * * ;Lacayani fauna * ;Mesón Group * ;Los Monos Formation * ;Ñuapua Formation * ;La Puerta Formation * ;Puncoviscana Formation * ;Quehua Formation * ;Salla Formation * * * ;Santa Lucía Formation * * * * * * * * * ;Tarija Formation * ;Toro Toro Formation * * ;Umala Formation * ;Yecua & Petaca Formations * Further reading * ;Mesozoic * L. Branisa. 1968. Hallazgo del amonite Neolobites en la Caliza Miraflores y de huellas de dinosaurios en la formación El Molino y su significado para la determinación de la edad d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthoceras
''Orthoceras'', from Ancient Greek ὀρθός (''orthós''), meaning "straight", and κέρας (''kéras''), meaning "horn", is a genus of extinct nautiloid cephalopod restricted to Middle Ordovician-aged marine limestones of the Baltic States and Sweden. This genus is sometimes called ''Orthoceratites''. Note it is sometimes misspelled as ''Orthocera'', ''Orthocerus'' or ''Orthoceros''. ''Orthoceras'' was formerly thought to have had a worldwide distribution due to the genus' use as a wastebasket taxon for numerous species of conical-shelled nautiloids throughout the Paleozoic and Triassic. Since this work was carried out and re-cataloging of the genus, ''Orthoceras'' '' sensu stricto'' refers to ''Orthoceras regulare'', of Ordovician-aged Baltic Sea limestones of Sweden and neighboring areas. These are slender, elongate shells with the middle of the body chamber transversely constricted, and a subcentral orthochoanitic siphuncle. The surface is ornamented by a network ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lingulepis
Obolidae is a family of extinct brachiopods. Species Obolidae species include:Emig C. C., Bitner M. A. & Álvarez F., 2019Linguliformea Brachiopoda database. Accessed 2020-09-27. *''Obolus apollinis The obol (, ''obolos'', also ὀβελός (''obelós''), ὀβελλός (''obellós''), ὀδελός (''odelós''). "nail, metal spit"; ) was a form of ancient Greek currency and weight. Currency Obols were used from early times. ...'' Eichwald, 1829 *'' Schmidtites celatus'' (Volborth, 1869) References Brachiopod families Lingulata {{brachiopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
