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Bursum Formation
The Bursum Formation is a geologic formation in New Mexico.Bursum Formation at .org It preserves dating back to the . Description The Bursum Formation is primarily |
Oscura Mountains
Oscura Mountains, originally known to the Spanish as the ''Sierra Oscura'', are a ridge of mountains, trending north and south, east of the Jornada del Muerto and west of the Tularosa Valley. It is located in Socorro County and Lincoln County, New Mexico. Their highest elevation is Oscura Peak at 8,625 feet / 2,629 meters. Its southern end is at and its north end is at near North Oscura Peak. The Oscura Mountains lie northwest of the lower lying Little Burro Mountains divided by the Oscura Gap. The San Andres Mountains The San Andres Mountains are a mountain range in the southwestern U.S. state of New Mexico, in the counties of Socorro, Sierra, and Doña Ana. The range extends about 75 miles (120 km) north to south, but are only about 12 miles (19 ... lie beyond the Little Burro Mountains to the southwest divided from them by Mockingbird Gap. The Range is bounded on the north by Wash Hale Canyon, on the northeast by the Chupadera Mesa and on the east by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclothems
In geology, cyclothems are alternating stratigraphy, stratigraphic sequences of Marine (ocean), marine and non-marine sediments, sometimes interbedded with coal seams. Historically, the term was defined by the European coal geologists who worked in coal basins formed during the Carboniferous and earliest Permian periods. The cyclothems consist of repeated sequences, each typically several meters thick, of sandstone resting upon an unconformity, erosional surface, passing upwards to pelites (finer-grained than sandstone) and topped by coal. Depositional sequences have been thoroughly studied by oil geologists using geophysical profiles of continental and marine basins. A general theory of basin-scale deposition has been formalized under the name of sequence stratigraphy. Some cyclothems might have formed as a result of marine regressions and Transgression (geology), transgressions related to growth and decay of ice sheets, respectively, as the Carboniferous was a time of widespre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conodont
Conodonts (Greek ''kōnos'', "cone", + ''odont'', "tooth") are an extinct group of agnathan (jawless) vertebrates resembling eels, classified in the class Conodonta. For many years, they were known only from their tooth-like oral elements, which are usually found in isolation and are now called conodont elements. Knowledge about soft tissues remains limited. They existed in the world's oceans for over 300 million years, from the Cambrian to the beginning of the Jurassic. Conodont elements are widely used as index fossils, fossils used to define and identify geological periods. The animals are also called Conodontophora (conodont bearers) to avoid ambiguity. Discovery and understanding of conodonts The teeth-like fossils of the conodont were first discovered by Heinz Christian Pander and the results published in Saint Petersburg, Russia, in 1856. The name ''pander'' is commonly used in scientific names of conodonts. It was only in the early 1980s that the first fossil evidence of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asselian
In the geologic timescale, the Asselian is the earliest geochronologic age or lowermost chronostratigraphic stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Asselian lasted between and million years ago (Ma). It was preceded by the Gzhelian (the latest or uppermost subdivision in the Carboniferous) and followed by the Sakmarian. Stratigraphy The Asselian Stage was introduced into scientific literature in 1954, when the Russian stratigrapher V.E. Ruzhenchev split it from the Artinskian. At that moment the Artinskian still encompassed most of the lower Permian – its current definitions are more restricted. The Asselian is named after the Assel River in the southern Ural Mountains of Kazakhstan and Bashkortostan. The base of the Asselian Stage is at the same time the base of the Cisuralian Series and the Permian System. It is defined as the place in the stratigraphic record where fossils of the conodont ''Streptognathodus isolatus'' first appear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eostaffella
''Eostaffella'' is an extinct genus of fusulinid belonging to the family Eostaffellidae. Specimens of the genus have been found in Carboniferous to Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ... beds in Europe, Asia, and North America. Species *''E. acuta'' Grozdilova and Lebedeva 1950 *''E. donbassica'' Kireeva 1949 *''E. galinae'' Ganelina 1956 *''E. irenae'' Ganelina 1956 *''E. lepida'' Grozdilova and Lebedeva 1950 *''E. mosquensis'' Vissarionova 1948 *''E. pinguis'' Thompson 1944 *''E. postmosquensis'' Kireeva 1951 *''E. serotina'' Leven 1992 References Paleozoic life Fusulinida Radiolarian genera {{Foram-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bradyina
''Bradyina'' is an extinct genus of fusulinid belonging to the family Bradyinidae. Specimens of the genus have been found in Carboniferous to Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ... beds in Europe, Asia, and North America. The genus has been used as an index fossil in China. References Paleozoic life Fusulinida Radiolarian genera {{Foram-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foram
Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly an external shell (called a "test") of diverse forms and materials. Tests of chitin (found in some simple genera, and Textularia in particular) are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment (i.e., are benthic), while a smaller number float in the water column at various depths (i.e., are planktonic), which belong to the suborder Globigerinina. Fewer are known from freshwater or brackish conditions, and some very few (nonaquatic) soil species have been identified through molecular analysis of small subunit ribosomal DNA. Foraminifera typically produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in struc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triticites
The Schwagerinidae comprise a family of large, generally fusiform, foraminiferans included in the Fusulinacea, a superfamily of fusulinids, locally abundant during the later Carboniferous ( Pennsylvanian) and most of the Permian. M.L. Thompson (1964) gives the following diagnosis: Shell large, fusiform to irregularly cylindrical, planispiral, involute in most, irregularly uncoiled in some; spirotheca thick, composed of tectum and alveolar kariotheca; septa fluted in end zones of primitive genera, fluted completely across shell and to tops of chambers of more advanced genera; tummel singular in most forms, multiple in one genus; axial fillings absent to massive; chomata massive to slight. As with all fusulinaceans, the Schagerinidae are a shallow water form which in places make up a significant portion of the sediment, now limestone. More familiar genera include '' Schwagerina'', ''Triticites'', and ''Parafusulina ''Parafusulina'' is a genus of foraminifera included in the fusu ... [...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] |
Glacial Cycle
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and greenhouse periods, during which there are no glaciers on the planet. Earth is currently in the Quaternary glaciation. Individual pulses of cold climate within an ice age are termed ''glacial periods'' (or, alternatively, ''glacials, glaciations, glacial stages, stadials, stades'', or colloquially, ''ice ages''), and intermittent warm periods within an ice age are called '' interglacials'' or ''interstadials''. In glaciology, ''ice age'' implies the presence of extensive ice sheets in both northern and southern hemispheres. By this definition, Earth is currently in an interglacial period—the Holocene. The amount of anthropogenic greenhouse gases emitted into Earth's oceans and atmosphere is predicted to prevent the next glacial period for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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