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Lead Camp Limestone
The Lead Camp Limestone is a geologic formation in the San Andres Mountains of New Mexico. It preserves fossils dating back to the middle Pennsylvanian. Description The Lead Camp Limestone consists of 75% medium- to dark-gray cherty limestone and 21-24% calcareous shale. The base of the formation contains minor sandstone and conglomerate. The limestone forms prominent cliffs capping the southern San Andres Mountains. The total thickness is . The formation rests unconformably on the Lake Valley Limestone to the south and conformably on the Sandia Formation to the north. Deposition began in the late Morrowan ( Bashkirian) to the south, spread to the north in the Atokan (early Moscovian, and continued into the Missourian (Kasimovian) Age. Fossils The formation contains marine fossils in the calcareous shale beds. It contains fusulinids characteristic of the middle Pennsylvanian. History of investigation The formation was first defined by George Bachman and Donald Myers in 1969, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (stratigraphy)
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 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 Abraham Gottlob W ... [...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 bed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous Formations Of New Mexico
The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago (Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferous'' means "coal-bearing", from the Latin '' carbō'' (" coal") and '' ferō'' ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern 'system' names, it was coined by geologists William Conybeare and William Phillips in 1822, based on a study of the British rock succession. The Carboniferous is often treated in North America as two geological periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial animal life was well established by the Carboniferous Period. Tetrapods (four limbed vertebrates), which had originated from lobe-finned fish during the preceding Devonian, became pentadactylous in and diversified during the Carboniferous, including early amphibian lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology In New Mexico
Paleontology in New Mexico refers to paleontological research occurring within or conducted by people from the U.S. state of New Mexico. The fossil record of New Mexico is exceptionally complete and spans almost the entire stratigraphic column. More than 3,300 different kinds of fossil organisms have been found in the state. Of these more than 700 of these were new to science and more than 100 of those were type species for new genera. During the early Paleozoic, southern and western New Mexico were submerged by a warm shallow sea that would come to be home to creatures including brachiopods, bryozoans, cartilaginous fishes, corals, graptolites, nautiloids, placoderms, and trilobites. During the Ordovician the state was home to algal reefs up to 300 feet high. During the Carboniferous, a richly vegetated island chain emerged from the local sea. Coral reefs formed in the state's seas while terrestrial regions of the state dried and were home to sand dunes. Local wil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In New Mexico
This article contains a list of fossil-bearing stratigraphic units in the state of New Mexico, U.S. Sites See also * Paleontology in New Mexico References * {{DEFAULTSORT:Fossiliferous stratigraphic units in New Mexico New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ... Stratigraphic units Stratigraphy of New Mexico New Mexico geography-related lists United States geology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusulinid
The Fusulinida is an extinct order within the Foraminifera in which the tests are traditionally considered to have been composed of microgranular calcite. Like all forams, they were single-celled organisms. In advanced forms the test wall was differentiated into two or more layers. Loeblich and Tappan, 1988, gives a range from the Lower Silurian to the Upper Permian, with the fusulinid foraminifera going extinct with the Permian–Triassic extinction event. While the latter is true, a more supported projected timespan is from the Mid-Carboniferous period. Taxonomy Thirteen superfamilies are presently recognised, based on taxa (families) included in the three superfamilies given in the Treatise. Three are based on families in the Parathuramminacea, 1964, and 2.9 million families in the Endothyracea, 1964. The Fusulinacea remains the same in both sources (Treatise 1964 and Loeblich and Tappan, 1988). The term fusulinata has traditionally been used to refer to all palaeozoic for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age (geology)
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardized international units of geologic time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kasimovian
The Kasimovian is a geochronologic age or chronostratigraphic stage in the ICS geologic timescale. It is the third stage in the Pennsylvanian (late Carboniferous), lasting from to Ma.; 2004: ''A Geologic Time Scale 2004'', Cambridge University Press. The Kasimovian Stage follows the Moscovian and is followed by the Gzhelian. The Kasimovian saw an extinction event which occurred around 305 mya, referred to as the Carboniferous Rainforest Collapse. It roughly corresponds to the Missourian in North American geochronology and the Stephanian in western European geochronology. Name and definition The Kasimovian is named after the Russian city of Kasimov. The stage was split from the Moscovian in 1926 by Boris Dan'shin (1891-1941), who gave it the name ''Teguliferina horizon''. The name was posthumously changed in ''Kasimov horizon'' by Dan'shin in 1947. The name Kasimovian was introduced by Georgy Teodorovich in 1949. The base of the Kasimovian Stage is at the base of the fusu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moscovian (Carboniferous)
The Moscovian is in the ICS geologic timescale a stage or age in the Pennsylvanian, the youngest subsystem of the Carboniferous. The Moscovian age lasted from to Ma, is preceded by the Bashkirian and is followed by the Kasimovian. The Moscovian overlaps with the European regional Westphalian stage and the North American Atokan and Desmoinesian stages. Name and definition The Moscovian Stage was introduced by Sergei Nikitin (1850 - 1909) in 1890, using brachiopods in the Moscow Basin of European Russia. Nikitin named the stage after Moscow, then a major city and now the capital of Russia. The base of the Moscovian is close to the first appearances of the conodonts '' Declinognathodus donetzianus'' and '' Idiognathoides postsulcatus'' or otherwise the fusulinid ''Aljutovella aljutovica''. Because the fusulinid species are regionally different, they can not be used for worldwide correlation. A Global Boundary Stratotype Section and Point for the Moscovian Stage has yet t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bashkirian
The Bashkirian is in the ICS geologic timescale the lowest stage or oldest age of the Pennsylvanian. The Bashkirian age lasted from to Ma, is preceded by the Serpukhovian and is followed by the Moscovian. The Bashkirian overlaps with the upper part of the Namurian and lower part of the Westphalian stages from regional European stratigraphy. It also overlaps with the North American Morrowan and Atokan stages and the Chinese Luosuan and lower Huashibanian stages. Name and definition The Bashkirian was named after Bashkiria, the then Russian name of the republic of Bashkortostan in the southern Ural Mountains of Russia, home of the Bashkir people. The stage was introduced by Russian stratigrapher Sofia Semikhatova in 1934. The base of the Bashkirian is at the first appearance of conodont species ''Declinognathodus noduliferus''. The top of the stage (the base of the Moscovian) is at the first appearance of the conodonts ''Declinognathodus donetzianus'' or ''Idiognathoides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unconformity (geology)
An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger layer, but the term is used to describe any break in the sedimentary geologic record. The significance of angular unconformity (see below) was shown by James Hutton, who found examples of Hutton's Unconformity at Jedburgh in 1787 and at Siccar Point in 1788. The rocks above an unconformity are younger than the rocks beneath (unless the sequence has been overturned). An unconformity represents time during which no sediments were preserved in a region or were subsequently eroded before the next deposition. The local record for that time interval is missing and geologists must use other clues to discover that part of the geologic history of that area. The interval of geologic time not represented i ... [...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] |
