
The Pleistocene Epoch is part of the geologic timescale, usually dated as 1.8-1.6 million to 10,000 years before present, with the end date expressed in radiocarbon years. It covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold. The end of the Younger Dryas has been dated to about 9600 BC (11550 calendar years BP). The GSSP for the start of the Pleistocene is in a reference section at Virca in Italy that has unresolved dating ambiguities. The Pleistocene follows the Pliocene epoch and is followed by the Holocene epoch. The Pleistocene is the third epoch of the Neogene period or 6th epoch of the Cenozoic era. The end of the Pleistocene corresponds with the end of the Paleolithic age used in archaeology. ==Pleistocene dating== As with other older geologic periods, the rock (geology) beds that define the start of the Pleistocene are well identified, but the exact dates of the start and end of the period are slightly uncertain. To cover the recent period of repeated glaciations, however, the start was set too late and some early cooling and glaciation are now set in the Pliocene. Some would prefer a start date of around 2.5 million years BP. ==Pleistocene paleogeography and climate== [[Image:Pleistocene north ice map.jpg|thumb|right|The maximum extent of ice age in the north polar area during Pleistocene time.]] The modern continents were essentially at their present positions during the Pleistocene, probably moving no more than 100km. The Pleistocene climate was characterized by repeated glacial cycles where continental glaciers pushed to the 40th parallel (latitude) in some places. Four major glacial events have been identified, as well as many minor intervening events. The four major identified glacial excursions were the Nebraskan-Gunz, Kansan-Mindel, Illinoian-Riss, and Wisconsin-Würm. There may have been as many as 14 additional unnamed advances whose results have been largely erased by the later glaciers. Each glacial advance tied up huge volumes of water in continental ice sheets 1500-3000 meters thick, resulting in temporary sea level drops of 100 meters or more. Antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene. ==Pleistocene fauna== There are no faunal stages defined for the Pleistocene or Holocene. Both marine and continental faunas were essentially modern. It is believed by most scientists that humans evolved into modern man during the Pleistocene. Major extinctions of large mammals, including mammoths, mastodons, Smilodon, glyptodons and Ground sloths, started late in the Pleistocene and continued into the Holocene. The extinctions were especially severe in North America where native horses and camels were eliminated. ==Pleistocene deposits== Pleistocene continental deposits are found primarily in lakebeds and caves as well as in the large amounts of material moved about by glaciers. Pleistocene marine deposits are found primarily in areas within a few tens of kilometers of the modern shoreline. In a few geologically active areas such as the Southern California coast, Pleistocene marine deposits may be found at elevations of several hundred meters. Pleistocene zh-cn:更新世
The arithmetic for the length of the Pliocene in previous paragraph doesn't seem quite right. I think a 2000 year correction to the end of the period has morphed into a 200,000 year shift in the beginning, but maybe I'm missing something. ... And Radiocarbon dating in only good for about 100,000 years? Won't cover the whole Pleistocene, right? So 11,000 is a radiocarbon date, but 1.6 or 1.8 million isn't? Right? But I try not to rewrite things that might be correct. Is a clarification or correction needed? ---- The current versions of the dates are mine: but this was my "best guess" after examining several web sites, which were unclear and/or disagreed with each other. What you write about limits on radiocarbon dating had puzzled me at the time, I'd guessed some other kind radiometric dating was indended for the earlier dates, but then the 10% or so radiocarbon calibration is irrelevant. However I've seen the 1.6 million vs 1.8 million elsewhere. Please clarify and correct if you know any better, ideally with an authoritive reference if such a thing exists -- Hagedis --- The start date depends on the dating of marine clays at the Global Stratotype Section and Point at Vrica in Italy. As best I can determine, the ambiguity in the date there is in fact about 200,000 years. Try a search on GSSP and Vrica. Maybe you can make more sense out of the papers on the subject than I could. They seem to me to be somewhat long on jargon and a bit short on content. DJK If you're happy with 1.8-1.6 for the start of the Pleistocene, just delete this talk:Pleistocene.
Neogene Archaeology
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Words begining with Pleistocene:
Pleistocene
Pleistocene
Pleistocene
Pleistocene_craters
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Pleistocene_epoch
Pleistocene_megafauna
Pleistocene_megafauna
Pleistocene
The Pleistocene Epoch is part of the geologic timescale, usually dated as 1.8-1.6 million to 10,000 years before present, with the end date expressed in radiocarbon years. It covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold. The end of the Younger Dryas has been dated to about 9600 BC (11550 calendar years BP). The GSSP for the start of the Pleistocene is in a reference section at Virca in Italy that has unresolved dating ambiguities. The Pleistocene follows the Pliocene epoch and is followed by the Holocene epoch. The Pleistocene is the third epoch of the Neogene period or 6th epoch of the Cenozoic era. The end of the Pleistocene corresponds with the end of the Paleolithic age used in archaeology. ==Pleistocene dating== As with other older geologic periods, the rock (geology) beds that define the start of the Pleistocene are well identified, but the exact dates of the start and end of the period are slightly uncertain. To cover the recent period of repeated glaciations, however, the start was set too late and some early cooling and glaciation are now set in the Pliocene. Some would prefer a start date of around 2.5 million years BP. ==Pleistocene paleogeography and climate== [[Image:Pleistocene north ice map.jpg|thumb|right|The maximum extent of ice age in the north polar area during Pleistocene time.]] The modern continents were essentially at their present positions during the Pleistocene, probably moving no more than 100km. The Pleistocene climate was characterized by repeated glacial cycles where continental glaciers pushed to the 40th parallel (latitude) in some places. Four major glacial events have been identified, as well as many minor intervening events. The four major identified glacial excursions were the Nebraskan-Gunz, Kansan-Mindel, Illinoian-Riss, and Wisconsin-Würm. There may have been as many as 14 additional unnamed advances whose results have been largely erased by the later glaciers. Each glacial advance tied up huge volumes of water in continental ice sheets 1500-3000 meters thick, resulting in temporary sea level drops of 100 meters or more. Antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene. ==Pleistocene fauna== There are no faunal stages defined for the Pleistocene or Holocene. Both marine and continental faunas were essentially modern. It is believed by most scientists that humans evolved into modern man during the Pleistocene. Major extinctions of large mammals, including mammoths, mastodons, Smilodon, glyptodons and Ground sloths, started late in the Pleistocene and continued into the Holocene. The extinctions were especially severe in North America where native horses and camels were eliminated. ==Pleistocene deposits== Pleistocene continental deposits are found primarily in lakebeds and caves as well as in the large amounts of material moved about by glaciers. Pleistocene marine deposits are found primarily in areas within a few tens of kilometers of the modern shoreline. In a few geologically active areas such as the Southern California coast, Pleistocene marine deposits may be found at elevations of several hundred meters. Pleistocene zh-cn:更新世
Pleistocene
The arithmetic for the length of the Pliocene in previous paragraph doesn't seem quite right. I think a 2000 year correction to the end of the period has morphed into a 200,000 year shift in the beginning, but maybe I'm missing something. ... And Radiocarbon dating in only good for about 100,000 years? Won't cover the whole Pleistocene, right? So 11,000 is a radiocarbon date, but 1.6 or 1.8 million isn't? Right? But I try not to rewrite things that might be correct. Is a clarification or correction needed? ---- The current versions of the dates are mine: but this was my "best guess" after examining several web sites, which were unclear and/or disagreed with each other. What you write about limits on radiocarbon dating had puzzled me at the time, I'd guessed some other kind radiometric dating was indended for the earlier dates, but then the 10% or so radiocarbon calibration is irrelevant. However I've seen the 1.6 million vs 1.8 million elsewhere. Please clarify and correct if you know any better, ideally with an authoritive reference if such a thing exists -- Hagedis --- The start date depends on the dating of marine clays at the Global Stratotype Section and Point at Vrica in Italy. As best I can determine, the ambiguity in the date there is in fact about 200,000 years. Try a search on GSSP and Vrica. Maybe you can make more sense out of the papers on the subject than I could. They seem to me to be somewhat long on jargon and a bit short on content. DJK If you're happy with 1.8-1.6 for the start of the Pleistocene, just delete this talk:Pleistocene.
Pleistocene
Neogene Archaeology
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PA | PB | PC | PD | PE | PF | PG | PH | PI | PJ | PK | PL | PM | PN | PO | PR | PS | PT | PU | PW | PX | PY | PZ |Words begining with Pleistocene:
Pleistocene
Pleistocene
Pleistocene
Pleistocene_craters
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Pleistocene_megafauna
Pleistocene_megafauna
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