There have been four major periods of glaciation in the Earth's past. The second, and possibly most severe, is estimated to have occurred from 850 Ma to 635 Ma (million years ago, in the late Proterozoic Age) and it has been suggested that it produced a "Snowball Earth" in which the earth iced over completely. It has been suggested also that the end of this cold period was responsible for the subsequent Cambrian Explosion, a time of rapid diversification of multicelled life during the Cambrian era. However, this theory is still controversial.^[1][2] Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years For the animated movie, see Ice Age (movie). ... Annum is a Latin noun meaning year. ... The Neoproterozoic Era is the unit of geologic time from 1,000 to 542 +/- 0. ... One computer simulation of conditions during the Snowball Earth period. ... The Cambrian explosion is the geologically kukko sudden appearance in the fossil record of the ancestors of familiar animals, starting about 542 million years ago (Mya). ... The Cambrian is a major division of the geologic timescale that begins about 542 ± 1. ...

A minor series of glaciations occurred from 460 Ma to 430 Ma. There were extensive glaciations from 350 to 250 Ma. The present Pleistocene ice age has seen more or less extensive glaciation on 40,000 and later, 100,000 year cycles. The last glacial period ended about 10,000 years ago. The Pleistocene epoch (IPA: ) on the geologic timescale is the period from 1,808,000 to 11,550 years BP. The Pleistocene epoch had been intended to cover the worlds recent period of repeated glaciations. ... Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years For the animated movie, see Ice Age (movie). ...

Pleistocene glacial cycles

Glacial and interglacial cycles as represented by Atmospheric CO₂, measured from ice core samples going back 650,000 years

Originally, the periods were named after characteristic geological features, and these names varied from region to region. It is now more common to refer to periods by their marine isotopic stage number.^[3] The marine record preserves all the past glaciations; the land-based evidence is less complete because successive glaciations may wipe out evidence of their predecessors. Ice cores from continental ice accumulations also provide a complete record, but do not go as far back in time as marine data. Pollen data from lakes and bogs as well as loess profiles provided important land-based correlation data.^[4] The names system has not been completely filled out since the technical discussion moved to using marine isotopic stage numbers. For example, there are five Pleistocene glacial/interglacial cycles recorded in marine sediments during the last half million years, but only three classic interglacials were originally recognized on land during that period (Mindel, Riss and Würm).^[5] Image File history File links Download high resolution version (939x680, 48 KB)This graph shows the newest Ice Core data for Atmospheric CO2 from air bubbles in the ice. ... Image File history File links Download high resolution version (939x680, 48 KB)This graph shows the newest Ice Core data for Atmospheric CO2 from air bubbles in the ice. ... Marine isotopic stages (MIS) are alternating warm and cool periods in the Earths palaeoclimate, deduced from oxygen isotope data reflecting temperature curves derived from data from deep sea core samples. ... An ice core is a tube of ice removed from an ice sheet. ... SEM image of pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomoea purpurea), prairie hollyhock (Sidalcea malviflora), oriental lily (Lilium auratum), evening primrose (Oenothera fruticosa), and castor bean (Ricinus communis). ... This article or section does not cite any references or sources. ... The Kansan Glaciation (known in UK as the Anglian Glaciation and sometimes referred to as the Illinoian Glaciation, Elster glaciation in northern Europe and the Mindel glaciation in the Alps) was a very severe glacial period in the Pleistocene. ... The Wolstonian glaciation is a name for an ice age period which occurred between 200,000 and 125,000 years ago. ... The Wisconsin (in North America), Devensian (in the British Isles), Midlandian (in Ireland), Würm (in the Alps), and Weichsel (in northern central Europe) glaciations are the most recent glaciations of the Pleistocene epoch, which ended around 10,000 BCE. The general glacial advance began about 70,000 BCE, and...

Land-based evidence works acceptably well back as far as MIS 6, but it has been difficult to coordinate stages using just land-based evidence before that. Hence, the "names" system is incomplete and the land-based identifications of ice ages previous to that are somewhat conjectural. Nonetheless, land based data is essentially useful in discussing landforms, and correlating the known marine isotopic stage with them.^[4]

The last glacial and interglacial phases of the Pleistocene are named, from most recent to most distant, as follows. Dates shown are in thousand years BCE.

Land-based chronology

Older periods of the Pleistocene Annum is a Latin noun meaning year. ... Marine isotopic stages (MIS) are alternating warm and cool periods in the Earths palaeoclimate, deduced from oxygen isotope data reflecting temperature curves derived from data from deep sea core samples. ... The Flandrian interglacial or stage is the name given by geologists and archaeologists in the British Isles to the first, and so far only, stage of the Holocene, covering the period from around 10,000 years ago when the last ice age ended to the present day. ... The Holocene epoch is a geological period that extends from the present day back to about 10,000 radiocarbon years, approximately 11,430 ± 130 calendar years BP (between 9560 and 9300 BC). ... The Wisconsin (in North America), Devensian (in the British Isles), Midlandian (in Ireland), Würm (in the Alps), and Weichsel (in northern central Europe) glaciations are the most recent glaciations of the Pleistocene epoch, which ended around 10,000 BCE. The general glacial advance began about 70,000 BCE, and... The Pleistocene epoch (IPA: ) on the geologic timescale is the period from 1,808,000 to 11,550 years BP. The Pleistocene epoch had been intended to cover the worlds recent period of repeated glaciations. ... The Eemian interglacial era (Sangamon era in North America) is the second-to-latest interglacial era of the Ice age. ... Two ice core temperature records; the Eemian is at a depth of about 1500-1800 meters in the lower graph The Eemian interglacial era (known as the Sangamon era in North America, the Ipswichian interglacial in the UK, and the Riss-Würm interglacial in the Alps) is the second... The Wolstonian glaciation is a name for an ice age period which occurred between 200,000 and 125,000 years ago. ... The Hoxnian interglacial (and is analogous to the Yarmouth interglacial in North America, the Holstein interglacial in northern Europe and the Mindel-Riss interglacial in the Alps) is a name for an interglacial period which occurred between 300,000 and 200,000 years ago. ... The Kansan Glaciation (known in UK as the Anglian Glaciation and sometimes referred to as the Illinoian Glaciation, Elster glaciation in northern Europe and the Mindel glaciation in the Alps) was a very severe glacial period in the Pleistocene. ... The Cromerian interglacial is a name for an interglacial period which occurred between 600,000 and 450,000 years ago. ... The Beestonian stage is the name for an early Pleistocene glacial stage used in the British Isles. ...

**Table data is based on Gibbard Figure 22.1.^[3] Annum is a Latin noun meaning year. ... Marine isotopic stages (MIS) are alternating warm and cool periods in the Earths palaeoclimate, deduced from oxygen isotope data reflecting temperature curves derived from data from deep sea core samples. ... The Pastonian interglacial is the name for an early Pleistocene glacial stage used in the British Isles. ... The Pre-Pastonian glaciation is the name for an early Pleistocene glacial stage used in the British Isles. ... The Bramertonian interglacial is the name for an early Pleistocene glacial stage used in the British Isles. ...

Ice core evidence

Main article: Ice core

Ice cores are used to obtain a high resolution record of recent glaciation. It confirms the chronology of the marine isotopic stages. Ice core data shows that the last 400,000 years have consisted of short interglacials (10-30,000 years) about as warm as the present alternated with much longer (70-90,000 years) glacials substanially colder than present. The new EPICA Antarctic ice core has revealed that between 400,000 and 780,000 years ago, interglacials occupied a considerably larger proportion of each glacial/interglacial cycle, but were not as warm as subsequent interglacials. Ice Core sample taken from drill. ... Epica may refer to: EPICA , the European Project for Ice Coring in Antarctica Epica (album), an album by the power metal band Kamelot Epica (band), a Dutch symphonic metal band Epica (RAID series), a series of storage arrays developed by Proware Technology Corporation Chevrolet Epica, one of the brand names...

Major glacial periods

500 million year record shows current and previous two major glacial periods

Description This figure shows the long-term evolution of oxygen isotope ratios during the Phanerozoic eon as measured in fossils, reported by Veizer et al. ... Description This figure shows the long-term evolution of oxygen isotope ratios during the Phanerozoic eon as measured in fossils, reported by Veizer et al. ... Annum is a Latin noun meaning year. ... Neogene Period is a unit of geologic time consisting of the Miocene, Pliocene, Pleistocene, and Holocene epochs. ... The Cenozoic Era (IPA pronunciation: ); sometimes Caenozoic Era or Cainozoic Era (in the United Kingdom), meaning new life (Greek (kainos), new, and (zoe), life), is the most recent of the three classic geological eras. ... The Karoo Ice Age from 350-250 million years ago was the second major period of Glaciation of the Phanerozoic Era. ... The Carboniferous is a major division of the geologic timescale that extends from the end of the Devonian period, about 359. ... The Permian is a geologic period that extends from about 299. ... The Paleozoic Era (from the Greek palaio, old and zoion, animals, meaning ancient life) is the earliest of three geologic eras of the Phanerozoic eon. ... The Andean-Saharan glaciation was from 450 mya to 420 mya, during most of the Silurian period and the beginning of the Devonian period. ... Artist impression of the Ordovician Sea. ... The Silurian is a major division of the geologic timescale that extends from the end of the Ordovician period, about 443. ... The Paleozoic Era (from the Greek palaio, old and zoion, animals, meaning ancient life) is the earliest of three geologic eras of the Phanerozoic eon. ... The Cryogenian Period (from Greek cryos ice and genesis birth) is the second geologic period of the Neoproterozoic Era, followed by the Ediacaran Period. ... The Cryogenian Period (from Greek cryos ice and genesis birth) is the second geologic period of the Neoproterozoic Era, followed by the Ediacaran Period. ... The Neoproterozoic Era is the unit of geologic time from 1,000 to 542 +/- 0. ... The Huronian glaciation was from 2400 mya to 2100 mya, during the Siderian and Rhyacian periods of the Paleoproterozoic era. ... The Siderian (from Greek sideros, iron) is the first geologic period in the Paleoproterozoic Era and lasted from 2500 million years ago to 2300 million years ago. ... From the GeoWhen Database: Rhyacian Period From 2300 +/- 0 To 2050 +/- 0 Ma Start Defined By: Fixed Date End Defined By: Fixed Date Start Based On: Gradstein, Ogg, Smith, et. ... The Paleoproterozoic is the first of the three sub-divisions of the Proterozoic occurring between 2500 to 1600 million years ago. ...

Notes

See also

• Geologic timescale
• Glacial history of Minnesota
• Ice age
• Varanger glaciation
• Brunhes-Matuyama reversal occurred about 780,000 years ago