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| This epoch is part of the Quaternary period. |
| Holocene |
| 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 period that interrupted the final deglaciation. 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 first of the two epochs of the Quaternary period or 6th epoch of the Cenozoic era.
As with other older geologic periods, the rock 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. The Pleistocene was originally intended 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.
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 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. AntarcticaAntarctica (from Greek nu;ταρκτικ&sigmaf opposed to the arctic) is a continent surrounding the Earth's South Pole. It is the coldest place on earth and is almost entirely covered by ice. It is not to be confused with the was ice-bound throughout the Pleistocene as well as the preceding Pliocene.
There are no faunal stageFaunal stages are a subdivision of geologic time used primarily by paleontologists who study fossils rather than by geologists who study rock formations. Typically, a faunal stage will consist of a series of rocks that contain similar fossils. There wills defined for the Pleistocene or Holocene. Both marine and continental faunas were essentially modern. HumanHuman beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. Biologically, they are classified as Homo sapiens ( Latin for knowing man , a primate species of mammal with a highly developed brain. In spirituas evolved into modern man during the Pleistocene. Major extinctionIn biology and ecology, extinction is the disappearance of a species or group of species. The moment of extinction is generally considered to be the death of the last individual of that species. In species which reproduce sexually, extinction of a speciess of large mammalSubclass Monotremata Monotremata Subclass Marsupialia Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Subclass Placentalia Xenarthra Dermoptera Desmostylia Scandentia Primates Rodentia Lagomorps, including mammoths, mastodons, saber-toothed cats, 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 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.
The end of the Pleistocene corresponds with the end of the Paleolithic age used in archaeology.
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