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Neogene
Neogene The Neogene is the later of the two sub-periods that comprise the Cenozoic era. It includes the Miocene and Pliocene epochs and is succeeded by the Quaternary. Thus it extends from about 23 Ma to about 1.6 Ma. Some authors have included the Pleistocene and Holocene epochs (divisions within the Quaternary) within the Neogene, but this convention has not been followed by the International Commission on Stratigraphy. Charles Lyell's original subdivision of Tertiary time (1833) was made on the basis of the percentage of modern species in the fossil molluscan faunas. He found a big difference between the figures for the Eocene (3.5 per cent) and the Miocene (17 per cent). (The Oligocene had yet to be identified.) Lyell's original Eocene division comprised the entire sequence that today we would call the Palaeogene, making it a very large unit. However, recent re-examination of the percentages to be found at different levels in these rocks reveals that less than 5 per cent of modern gastropod species were present at the opening of the Miocene.
Lyell's concept of the Miocene was of a moment in geological time when some 17 per cent of the molluscan species were modern. Even in the type-area of the Paris basin it would be difficult to apply this criterion to the definition of a specific body of rocks. The attempt to repeat the kind of measurement that Lyell carried out gives no encouragement to use palaeontological methods of this kind as means of defining a global criterion for the base of the Neogene. If (despite the fact that it is only a sub-system) the Neogene is to be defined in a similar way to the main stratigraphical systems, the first appearance of a species in an unbroken succession and within an established lineage is needed. With the growing provincialism of marine faunas during the Cenozoic this becomes the more difficult, and the search for a suitable species is not completed yet. Palaeomagnetic, stable isotope, and radiometric criteria may prove to be of much greater immediate assistance in correlation than have biostratigraphical data. D. L. Dineley |
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PAUL HANCOCK and BRIAN J. SKINNER. "Neogene." The Oxford Companion to the Earth. 2000. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. PAUL HANCOCK and BRIAN J. SKINNER. "Neogene." The Oxford Companion to the Earth. 2000. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O112-Neogene.html PAUL HANCOCK and BRIAN J. SKINNER. "Neogene." The Oxford Companion to the Earth. 2000. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O112-Neogene.html |
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Neogene
Neogene The later of the two periods which comprise the Tertiary sub-Era, preceded by the Palaeogene, followed by the Quaternary, and dated at 23.3–1.64 Ma ( Harland et al., 1989). The Neogene Period is subdivided into the Miocene and Pliocene Epochs.
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AILSA ALLABY and MICHAEL ALLABY. "Neogene." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "Neogene." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O13-Neogene.html AILSA ALLABY and MICHAEL ALLABY. "Neogene." A Dictionary of Earth Sciences. 1999. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-Neogene.html |
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Neogene
Neogene The later of the two periods comprising the Tertiary sub-Era, preceded by the Palaeogene, followed by the Quaternary, and dated at 23.3–1.64 Ma. The Neogene Period is subdivided into the Miocene and Pliocene Epochs.
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MICHAEL ALLABY. "Neogene." A Dictionary of Ecology. 2004. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Neogene." A Dictionary of Ecology. 2004. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O14-Neogene.html MICHAEL ALLABY. "Neogene." A Dictionary of Ecology. 2004. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-Neogene.html |
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Neogene
Neogene The term used to describe collectively the last two epochs of the Tertiary, i.e. the Miocene and Pliocene, and sometimes including the Quaternary in addition.
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MICHAEL ALLABY. "Neogene." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Neogene." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O7-Neogene.html MICHAEL ALLABY. "Neogene." A Dictionary of Plant Sciences. 1998. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O7-Neogene.html |
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Neogene
Neogene The second period of the Cenozoic Era, comprising the Pliocene and Pleistocene Epochs, and lasting from 23.03 Ma ago to 1.81 Ma.
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MICHAEL ALLABY. "Neogene." A Dictionary of Zoology. 1999. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Neogene." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O8-Neogene.html MICHAEL ALLABY. "Neogene." A Dictionary of Zoology. 1999. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-Neogene.html |
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