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Pliocene Epoch
Pliocene EpochIn geologic time , the Pliocene Epoch occurs during the Tertiary Period (65 million years ago [mya] to 2.6 mya) of the Cenozoic Era of the Phanerozoic Eon . The Tertiary Period is sometimes divided into—or referred to in terms of—a Paleogene Period (65 mya to 23 mya) and a Neogene Period (23 mya to 2.6 mya). The Pliocene Epoch is the last epoch on the Tertiary Period or, in the alternative, the last epoch in the Neogene Period. The Pliocene Epoch spans the time 5 mya to 2.6 mya. The Pliocene Epoch is further subdivided into Zanclian (5 mya to 3.9 mya) and Placenzian (3.9 mya to 2.6 mya) stages. By the end Pliocene Epoch, Earth's continents assumed their modern configuration. The Pacific Ocean separated Asia and Australia from North America and South America ; the Atlantic Ocean separated North and South America from Europe (Eurasian plate) and Africa . The Indian Ocean filled the basin between Africa, India, Asia, and Australia. The Indian plate driving against and under the Eurasian plate uplifted both and resulted in rapid mountain building. As a result of the ongoing collision, ancient oceanic crust bearing marine fossils was uplifted into the Himalayan chain. The collision between the Indian and Eurasian plate continues. The reemergence of the land bridge between North America and South America at the isthmus of Panama about 3 mya allowed migration of species and mixing of gene pools in subspecies. Climatic cooling increased during Pliocene Epoch, and grasslands continued the rapid development found in the Miocene Epoch . Eventually, glaciation became well established and a general glacier advance started that continued into the subsequent Pleistocene Epoch of the Quaternary Period . The Pliocene Epoch spanned that period of geologic time during which the evolution of humans becomes increasingly well documented in the fossil record . Notable in the development of primates and human evolution, are fossilized remains of Ardipithecus ramidus, Australopithecus anamensis, Australopithecus afarensis, Australopithecus garhi, and Australopithecus africanus that date to the Pliocene Epoch. Although these species became extinct during the Pliocene Epoch, they at a minimum co-existed with the ancestors of humans (Homo sapiens ); analysis of remains indicate that these species walked upright. Anthropologists argue that apes and humans diverged six to eight mya from a common ancestor that lived during the Miocene Epoch. By the end of the Pliocene Epoch, the subsequent extinctions of Homo habilis and Homo rudolfensis were almost contemporaneous with the appearance of Homo ergaster, a species some anthropologists argue is one of the earliest identifiable direct ancestors of Homo sapiens. The last major impact crater with a diameter over 31 mi (50 km) struck Earth near what is now Kara-Kul, Tajikistan at the Pliocene Epoch and Pleistocene Epoch geologic time boundary. See also Archean; Cambrian Period; Cretaceous Period; Dating methods; Devonian Period; Eocene Epoch; Evolution, evidence of; Evolutionary mechanisms; Fossils and fossilization; Historical geology; Holocene Epoch; Jurassic Period; Mesozoic Era; Mississippian Period; Oligocene Epoch; Ordovician Period; Paleocene Epoch; Paleozoic Era; Pennsylvanian Period; Precambrian; Proterozoic Era; Silurian Period; Triassic Period |
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"Pliocene Epoch." World of Earth Science. 2003. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "Pliocene Epoch." World of Earth Science. 2003. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1G2-3437800476.html "Pliocene Epoch." World of Earth Science. 2003. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1G2-3437800476.html |
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Pliocene
Pliocene In 1833 Charles Lyell proposed to use the rate of extinction of molluscan species throughout what we know as Cenozoic time as a ‘palaeontological clock’. Each Cenozoic epoch was characterized by a molluscan fauna which contained both extinct and extant species, the proportion of extant forms increasing with time. The Pliocene was one of his original divisions of time, itself divided into Newer Pliocene with 90 per cent of its mollusc species living to the present, and Older Pliocene with 33–50 per cent of its species still alive. The Pliocene is today defined as the later epoch of the Neogene period, between 1.8 and 5.3 Ma. It contains two stages based on sections in mainland Europe. Pliocene deposits in Britain are limited to thin shelly sands and clays in East Anglia and small patches of sands in southern England.
All evidence points to the Pliocene as a time of continuing cooling of world climate, with major pulses of ice-rafted rock debris being released into the North Atlantic. The warm Gulf Stream and the cold Labrador Current were in operation and climate was highly seasonal. About halfway through the Pliocene epoch several important tectonic events occurred. The continuing activity of the African Rift system saw the opening of the Red Sea rift to the point where oceanic crust was generated there for the first time. Orogenic activity in the Himalayan ranges reached its climax and the Andean cordilleras were given a major uplift, raising the land to about 4000m. The Panama ithsmus connecting North and South America was established, allowing many of the northern mammals to migrate southwards and displace their counterparts. Many modern mammals evolved during this epoch: apes, horses, camels, bears, and pigs. Grazing animals spread into the great grasslands of North America, Africa, and Asia. The horse appeared in North America. In Africa evolution took important steps; the Australopithecines were active in the early part of the epoch, and Homo habilis and Homo erectus appeared at about 2.5 Ma and 1.7 Ma respectively. D. L. Dineley Bibliography Stanley, S. M. (1987) Extinction. Scientific American Library. W. H. Freeman, New York. |
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PAUL HANCOCK and BRIAN J. SKINNER. "Pliocene." The Oxford Companion to the Earth. 2000. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. PAUL HANCOCK and BRIAN J. SKINNER. "Pliocene." The Oxford Companion to the Earth. 2000. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O112-Pliocene.html PAUL HANCOCK and BRIAN J. SKINNER. "Pliocene." The Oxford Companion to the Earth. 2000. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O112-Pliocene.html |
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Pliocene epoch
Pliocene epoch , fifth epoch of the Cenozoic era of geologic time (see Geologic Timescale , table), from 5.1 to 2 million years ago. By the beginning of the Pliocene, the outlines of North America were almost the same as in recent time. Encroachments by the sea were limited to a narrow strip along the coasts of the Carolinas, Georgia, Florida, and the Gulf Coast states, and an embayment, smaller than that of the preceding Miocene epoch , in California. The Pliocene formations on the Atlantic coast are chiefly marine marls; on the Gulf they are nonmarine sediments resulting from erosion. In California they contain much volcanic ash and some are oil-bearing. The Pliocene formations of the western interior are small and scattered. In western interior North America and on the west coast, volcanic activity continued into the Pliocene from the Miocene. The close of the Pliocene was marked in North America by the Cascadian revolution, in the course of which the Sierra Nevada was elevated and tilted to the west. The Cascades, Rockies, Appalachians, and the Colorado plateau were uplifted, and there was activity in the mountains of Alaska and in the Great Basin ranges of Nevada and Utah. In Europe the Pliocene sea covered small parts of the northwest of the continent and a large area around the present Mediterranean; a number of volcanoes were active, among them Vesuvius and Etna. There was considerable mountain building, including the folding and thrusting of the Alps. The climate of the Pliocene was markedly cooler and drier than that of the Miocene and foreshadowed the glacial climates of the Pleistocene epoch . The life of the Pliocene was notable for its modern appearance; the Pliocene marked the climax, and perhaps the initial decline, of the supremacy of the mammals. |
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"Pliocene epoch." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "Pliocene epoch." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1E1-Pliocene.html "Pliocene epoch." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-Pliocene.html |
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Pliocene
Pliocene The fifth and final epoch of the Tertiary period. Preceded by the Miocene and followed by the Pleistocene, it began about 5 million years ago and lasted for about 3 million years. Mammals similar to modern forms existed during the epoch and the australopithecines (see Australopithecus), early forerunners of humans, appeared.
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"Pliocene." A Dictionary of Biology. 2004. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "Pliocene." A Dictionary of Biology. 2004. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O6-Pliocene.html "Pliocene." A Dictionary of Biology. 2004. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-Pliocene.html |
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Pliocene
Pli·o·cene / ˈplīəˌsēn/ • adj. Geol. of, relating to, or denoting the last epoch of the Tertiary period, between the Miocene and Pleistocene epochs. ∎ [as n.] (the Pliocene) the Pliocene epoch or the system of rocks deposited during it. |
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"Pliocene." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "Pliocene." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O999-pliocene.html "Pliocene." The Oxford Pocket Dictionary of Current English. 2009. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-pliocene.html |
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Pliocene
Pliocene Last era of the Tertiary period. It lasted from 5 to 2 million years ago and preceded the Pleistocene epoch. Animal and plant life was not unlike that of today.
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"Pliocene." World Encyclopedia. 2005. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "Pliocene." World Encyclopedia. 2005. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O142-Pliocene.html "Pliocene." World Encyclopedia. 2005. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-Pliocene.html |
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Pliocene
Pliocene The last (5.2–1.64 Ma) of the Tertiary epochs, comprising the Zanclian (Tabianian) and Piacenzian Ages.
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AILSA ALLABY and MICHAEL ALLABY. "Pliocene." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "Pliocene." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O13-Pliocene.html AILSA ALLABY and MICHAEL ALLABY. "Pliocene." A Dictionary of Earth Sciences. 1999. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-Pliocene.html |
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Pliocene
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MICHAEL ALLABY. "Pliocene." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Pliocene." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O7-Pliocene.html MICHAEL ALLABY. "Pliocene." A Dictionary of Plant Sciences. 1998. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O7-Pliocene.html |
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Pliocene
Pliocene The last of the Tertiary epochs, about 5.3–1.81 Ma ago.
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MICHAEL ALLABY. "Pliocene." A Dictionary of Zoology. 1999. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Pliocene." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O8-Pliocene.html MICHAEL ALLABY. "Pliocene." A Dictionary of Zoology. 1999. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-Pliocene.html |
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Pliocene
Pliocene The last of the Tertiary epochs, about 5.2–1.8 Ma ago.
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MICHAEL ALLABY. "Pliocene." A Dictionary of Ecology. 2004. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Pliocene." A Dictionary of Ecology. 2004. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O14-Pliocene.html MICHAEL ALLABY. "Pliocene." A Dictionary of Ecology. 2004. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-Pliocene.html |
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pliocene
pliocene see EOCENE.
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T. F. HOAD. "pliocene." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. T. F. HOAD. "pliocene." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O27-pliocene.html T. F. HOAD. "pliocene." The Concise Oxford Dictionary of English Etymology. 1996. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O27-pliocene.html |
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Pliocene
Pliocene •gamine • bromine • thiamine
•dopamine • amphetamine • histamine
•quinine • strychnine • mezzanine
•spalpeen • Philippine • lycopene
•gangrene • terrene • silkscreen
•windscreen • citrine • Dexedrine
•putting green • Benzedrine
•Irene, polystyrene
•widescreen • sight screen
•chlorine, chorine, Doreen, Maureen, Noreen, taurine
•smokescreen • rood screen
•sunscreen • fluorine • helleborine
•Gadarene • Hippocrene
•glycerine (US glycerin), nitroglycerine (US nitroglycerin)
•nectarine • wintergreen • Methedrine
•evergreen • wolverine • vaccine
•glassine • Essene • Rexine • piscine
•epicene • glycine • pyroxene
•Palaeocene (US Paleocene)
•Pliocene • Miocene • Holocene
•damascene • kerosene • Plasticine
•Pleistocene
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"Pliocene." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "Pliocene." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O233-Pliocene.html "Pliocene." Oxford Dictionary of Rhymes. 2007. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O233-Pliocene.html |
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