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Pleistocene

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Not to be confused with Plasticine.

Subdivisions of the Quaternary System
System	Series	Stage (stratigraphy)= ">Stage	Age (Ma)
Quaternary	Holocene	0=E2=80=930.0117
Pleistocene	Late Pleistocene">Tarantian	0.0117=E2=80=930.126
Ionian	0.126=E2=80=930.781
Calabrian (stage)">Calabrian	0.781=E2=80=931.806
Gelasian	1.806=E2=80=932.588
Neogene	Pliocene	Piacenzian	older
In Europe and North America, the Holocene is subdivide= d into Preboreal, Boreal (period)" class=3D"mw-re= direct">Boreal, Atlantic, Subboreal, and Subatlantic stages of the Blytt-Sernander time scale. = There are many regional subdivisions for the Upper or Late Pleistocene, = usually these represent locally recognized cold (glacial) and warm (Interglacial">interglacial) period= s. The last glacial period ends with the cold Younger Dryas substage.

The Pleistocene /=CB=88<= span class=3D"IPA nopopups">p= l= a=C9=AAst=C9=99si=CB=90n/ (symbol P_S^{[= 1]}) is the geological Epoch (geology)">epoch which lasted from about 2,588= ,000 to 11,700 years ago, spanning the world's recent period of repeated= glaciations.

Charles Lyell= introduced this term in 1839 to describe strata in Sicily that had at least 70% of their moll= uscan fauna still living today. This distinguished it from the older Pliocene Epoch, which Lyell had originally thought to be the yo= ungest fossil rock layer. He constructed the name "Pleistocene" ("Most N= ew" or "Newest") from the Greek =CF=80=CE=BB=CE=B5=E1=BF=96=CF=83=CF=84=CE=BF=CF=82= , ple=C4=ABstos, "most", and =CE=BA=CE=B1=CE=B9=CE=BD=CF=8C=CF=82= , kain=C3=B3s (latinized<= /a> as c=C3=A6nus), "new";[2= ] this contrasting with the immediately preceding= P= leiocene ("More New" or "Newer", from =CF=80=CE=BB=CE=B5=CE=AF=CF=89= =CE=BD, ple=C3=AD=C5=8Dn, "more", and kain=C3=B3s; usual s= pelling: Pliocene), and the immediately subsequent Holocene ("wholly new" or "entirely new", f= rom =E1=BD=85=CE=BB=CE=BF=CF=82, h=C3=B3los, "whole", and kain= =C3=B3s) epoch, which extends to the present time.

The Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era (geology)">Era.^[3] The end of the Pleistocene corresponds with the en= d of the last glacial period. It also corresponds with the end of the Paleolithic age us= ed in archaeology. In the ICS timescale, t= he Pleistocene is divided into four stages or ages, the Gelasian, Calabrian, Ionian and Tarantian. All of th= ese stages were defined in southern Europe. In addition to this international su= bdivision, various regional subdivisions are often used.

Before a change finally confirmed in 2009 by the International Union of Geological Sciences, th= e time boundary between the Pleistocene and the preceding Pliocene was r= egarded as being at 1.806 million years before the present, as opposed t= o the currently accepted 2.588 million years BP: publications from the p= receding years may use either definition of the period.

Contents

• 1 Dating
• 2 Paleoge= ography and climate
  • 2.1 Glacial feature= s
  • 2.2 Major events=
  • 2.3 Palaeocycles=
    • <= span class=3D"tocnumber">2.3.1 Milankovit= ch cycles
    • 2.3.2 Ox= ygen isotope ratio cycles
• 3 Fauna
• 4 Humans
• 5 Deposits
=
• 6 See also
=
• 7 References<= /li>
• 8 External links

Dating[edit]

The Pleistocene has been dated from 2.588 million (=C2=B15,000) to 11= ,700 years before present (BP), with the end date expressed = in year" class=3D= "mw-redirect">radiocarbon years as 10,000 carbon-14 years BP.^[4] It covers most of the latest period of repe= ated glaciation, up to and including the Younger Dryas cold spell. The end of th= e Younger Dryas has been dated to about 9640 BC (11,590 calendar years B= P).

In 2009 the International U= nion of Geological Sciences (IUGS) confirmed a change in time period= for the Pleistocene, changing the start date from 1.806 to 2.588 millio= n years BP, and accepted the base of the Gelasian as the base of the Pleistocene, namely the b= ase of the Monte San Nicola GSSP.^[5] The IUGS has yet to= approve a type section, Global Boundary Stratotype Section and Point (GSSP), for the u= pper Pleistocene/Holocene boundary (i.e. the upper boundary). The= proposed section is the North Greenland Ice Core Project ice cor= e 75=C2=B0 06' N 42=C2=B0 18' W.^[6] The = lower boundary of the Pleistocene Series is formally defined magnetostratigr= aphically as the base of the Matuyama (C2r) chronozone, isotopic stage 103. Above this= point there are notable extinctions of the calcareous nanofossils: = Discoaster pentarad= iatus and Discoaster surculus.^[7][8]

The Pleistocene covers the recent period of repeated glaciations. The= name Plio= -Pleistocene has in the past been used to mean the last ice age. The= revised definition of the Quaternary, by pushing back the start date of the Pleistocene t= o 2.58 Ma, results in the inclusion of all the recent repeated glaciatio= ns within the Pleistocene.

Paleog= eography and climate[edit]

The maximum extent of glacia= l ice in the north polar area during the Pleistocene period.

The modern continents= were essentially at their present positions during the Pleistocene,= the plates upon which they sit probably having moved no mor= e than 100 km relative to each other since the beginning of the per= iod.

According to Mark L= ynas (through collected data), the Pleistocene's overall climate cou= ld be characterized as a continuous El Ni=C3=B1o with trade winds in the south <= a href=3D"/wiki/Pacific_ocean" title=3D"Pacific ocean" class=3D"mw-redir= ect">Pacific weakening or heading east, warm air rising near Peru, warm water spreading from the w= est Pacific and the [9]

Glacial features= [edit]

Pleistocene climate was marked by repeated glacial cycles where continental glaciers pushed to the 40th parallel in some places. It is estimated that, at maximum glacial= extent, 30% of the Earth's surface was covered by ice. In addition, a z= one of permafrost = stretched southward from the edge of the glacial sheet, a few hundred ki= lometres in Nort= h America, and several hundred in Eurasia. The mean annual temperature at the edge of the ic= e was =E2=88=926 =C2=B0C (21 =C2=B0F); at the edge of= the permafrost, 0 =C2=B0C (32 =C2=B0F).

Each glacial advance tied up huge volumes of water in continental ice= sheets 1,500 to 3,000 metres (4,900=E2=80=939,800 ft) thick, resul= ting in temporary sea level drops of 100 metres (300 ft) or more ov= er the entire surface of the Earth. During interglacial times, such as a= t present, drowned coastlines were common, mitigated b= y isostatic or other emergent motion of some regions.

The effects of glaciation were global. Antarctica was ice-bound throughout the Pleistoc= ene as well as the preceding Pliocene. The Andes were covered in the south by the Patagonian ice cap. There were glacier= s in New Zealand= and Tasmania. The cur= rent decaying glaciers of Mount Kenya, Mount Kilimanjaro, and the Ruwenzori Range<= /a> in east and central Africa were larger. Glaciers existed in the moun= tains of Ethiopia and = to the west in the Atlas mountains.

In the northern hemisphere, many glaciers fused into one. The Cordilleran ice sheet" class=3D= "mw-redirect">Cordilleran ice sheet covered the North American north= west; the east was covered by the Laurentide. The Fenno-Scandian ice= sheet rested on northern Europe, including Great Britain; the Alpine ice sheet on the Alps. Scattered domes stretched acr= oss Siberia and the Arct= ic shelf. The northern seas were ice-covered.

South of the ice sheets large lakes accumulated because outlets were = blocked and the cooler air slowed evaporation. When the Laurentide ice s= heet retreated, north central North America was totally covered by Lake Agassiz. Over = a hundred basins, now dry or nearly so, were overflowing in the North Am= erican west. Lake Bonneville, for example, stood where Great Salt Lake now does. In Eura= sia, large lakes developed as a result of the runoff from the glaciers. = Rivers were larger, had a more copious flow, and were braided. African lakes were fu= ller, apparently from decreased evaporation. Deserts on the other hand w= ere drier and more extensive. Rainfall was lower because of the decrease= in oceanic and other evaporation.

Major events<= span class=3D"mw-editsection">[edit]

Further information: Timeline of glaciation=

Ice ages as reflected in atmospheric CO₂, stored in bubbles f= rom glacial ice of Ant= arctica.

Over 11 major glacial events have been identified, as well as many mi= nor glacial events.^[10]= A major glacial event is a general glacial excursion, = termed a "glacial." Glacials are separated by "interglacials". During a = glacial, the glacier experiences minor advances and retreats. The minor = excursion is a "stadial"; times between stadials are "interstadials".

These events are defined differently in different regions of the glac= ial range, which have their own glacial history depending on latitude, t= errain and climate. There is a general correspondence between glacials i= n different regions. Investigators often interchange the names if the gl= acial geology of a region is in the process of being defined. However, i= t is generally incorrect to apply the name of a glacial in one region to= another.

For most of the 20th century only a few regions had been studied and = the names were relatively few. Today the geologists of different nations= are taking more of an interest in Pleistocene glaciology. As a conseque= nce, the number of names is expanding rapidly and will continue to expan= d. Many of the advances and stadials remain unnamed. Also, the terrestri= al evidence for some of them has been erased or obscured by larger ones,= but evidence remains from the study of cyclical climate changes.

The glacials in the following tables show historical usages, a= re a simplification of a much more complex cycle of variation in climate= and terrain, and are generally no longer used. These names have been ab= andoned in favor of numeric data because many of the correlations were f= ound to be either inexact or incorrect and more than four major glacials= have been recognized since the historical terminology was established.<= sup id=3D"cite_ref-RichmondOther1_10-1" class=3D"reference">[10][11]^[12]

Historical names of the "four major" glacials in four regions.<= /caption>

Region	Glacial 1	Glacial 2	Glacial 3	Glacial 4
Alps	G=C3=BC= nz	Mindel	Riss	Last Glacial Maximum= ">W=C3=BCrm
North Europe	Eburonian	Elsterian	Saalian	Beesto= nian	Anglian	Wolsto= nian	Devensian
Midwest U.S.	Illinoian">Nebraskan	Kans= an	Illi= noian	Wisconsinan

Historical names of interglacials.

Region	Interglacial 1	Interglacial 2	Interglacial 3
Alps	G=C3=BCnz-Mindel	Mindel-Riss<= /a>	Riss-W=C3=BCrm
North Europe	Waalian	Holsteinian	Eemian
British Isles	Cromerian	Hoxnian<= /td>	Ipswichian
Midwest U.S.	Aftonian=	Yarmouthian	Sangamonian Stage" clas= s=3D"mw-redirect">Sangamonian

Corresponding to the terms glacial and interglacial, the terms pluvia= l and interpluvial are in use (Latin: pluvia, rain). A pluvial is= a warmer period of increased rainfall; an interpluvial, of decreased ra= infall. Formerly a pluvial was thought to correspond to a glacial in reg= ions not iced, and in some cases it does. Rainfall is cyclical also. Plu= vials and interpluvials are widespread.

There is no systematic correspondence of pluvials to glacials, howeve= r. Moreover, regional pluvials do not correspond to each other globally.= For example, some have used the term "Riss pluvial" in Egyptian context= s. Any coincidence is an accident of regional factors. Only a few of the= names for pluvials in restricted regions have been strategraphically de= fined.

Palaeocycles<= span class=3D"mw-editsection">[edit]

The sum of transient factors acting at the Earth's surface is cyclica= l: climate, ocean currents and other movements, wind currents, temperatu= re, etc. The waveform response comes from the underlying cyclical motion= s of the planet, which eventually drag all the transients into harmony w= ith them. The repeated glaciations of the Pleistocene were caused by the= same factors.

Milankovitch = cycles[Milankovitch cycles">ed= it]

Main article: Milankovitch cyc= les

Glaciation in the Pleistocene was a series of glacials and interglaci= als, stadials and interstadials, mirroring periodic changes in climate. = The main factor at work in climate cycling is now believed to be Milankovitc= h cycles. These are periodic variations in regional and planetary so= lar radiation reaching the Earth caused by several repeating changes in = the Earth's motion.

Milankovitch cycles cannot be the sole factor responsible for the var= iations in climate since they explain neither the long term cooling tren= d over the Plio-Pleistocene, nor the millennial variations in the Greenl= and Ice Cores. Milankovitch pacing seems to best explain glaciation even= ts with periodicity of 100,000, 40,000, and 20,000 years. Such a pattern= seems to fit the information on climate change found in oxygen isotope = cores. The timing of our present interglacial interval (known as the Holocene, Postglacial, or= the Present Interglacial) to that of the previous interglacial, beginni= ng about 130,000 years ago (The Eemian Interglacial), suggests that the = next glacial would likely begin in about 3,000 years.

Oxyge= n isotope ratio cycles[edit]

Main article: Ox= ygen isotope ratio cycle

In oxygen isotope ratio analysis, variations in the rat= io of 18
O t= o 16
O (two = isot= opes of oxygen) by mass (measured by a mass spectrometer) present in the calcite of oceanic core samples is used as a diagnostic of ancient ocean t= emperature change and therefore of climate change. Cold oceans are riche= r in 18
O, w= hich is included in the tests of the microorganisms (foraminifera) contributing the ca= lcite.

A more recent version of the sampling process makes use of modern gla= cial ice cores. Although less rich in 18
O than sea water, the snow that fell on the= glacier year by year nevertheless contained 18
O and 16
O in a ratio that depended on the mean = annual temperature.

Temperature and climate change are cyclical when plotted on a graph o= f temperature versus time. Temperature coordinates are given in the form= of a deviation from today's annual mean temperature, taken as zero. Thi= s sort of graph is based on another of isotope ratio versus time. Ratios= are converted to a percentage difference from the ratio found in standa= rd mean ocean water (SMOW).

The graph in either form appears as a waveform with overtones. One half of a period is a = Marine isotopic stage (MIS). It indicates a gl= acial (below zero) or an interglacial (above zero). Overtones are stadia= ls or interstadials.

According to this evidence, Earth experienced 102 MIS stages beginnin= g at about 2.588 Ma BP in the Early Pleistocene Gelasian. Early Pleistocene stages were shallow and frequ= ent. The latest were the most intense and most widely spaced.

By convention, stages are numbered from the Holocene, which is MIS1. = Glacials receive an even number; interglacials, odd. The first major gla= cial was MIS2-4 at about 85=E2=80=9311 ka BP. The largest glacials were = 2, 6, 12, and 16; the warmest interglacials, 1, 5, 9 and 11. For matchin= g of MIS numbers to named stages, see under the articles for those names= .

Fauna[edit]

See also: New World Pleistocene extinctions

Both marine and continental faunas were essentially modern and many a= nimals, specifically, mammals were much larger than their modern relativ= es .

Pleistocene of Northern Spain showing woolly mammoth, cave lions eating a reindeer, tarpans, a= nd wooll= y rhinoceros.

Pleistocene of S= outh America showing Megatherium and two Glyptodon.

The severe climatic changes during the ice age had major impacts on t= he fauna and flora. With each advance of the ice, large areas of the con= tinents became totally depopulated, and plants and animals retreating so= uthward in front of the advancing glacier faced tremendous stress. The m= ost severe stress resulted from drastic climatic changes, reduced living= space, and curtailed food supply. A major= extinction event of large mammals (megafauna<= /a>), which included mammoth= s, mastodons, saber-toothed = cats, glyptodons= , ground sloths, Irish elk, cave bears, and short-faced be= ars, began late in the Pleistocene and continued into the Holocene. = Neanderthals als= o became extinct during this period. At the end of the last ice age, cold-blooded anim= als, smaller mammals like wood mice, migratory birds, and swifter animals like whi= tetail deer had replaced the megafauna and migrated north.

The extinctions were especially severe in North America where native horses and camels were eliminated.

• Asian land mammal ages (ALMA) include Zho= ukoudianian, Nihewanian, and Yushean.
• European land mammal ages (ELMA) i= nclude Gelasian (2.5=E2= =80=941.8 Ma).
• North American land mammal= ages (NALMA) include Bl= ancan (4.75=E2=80=931.8), Irvingtonian (1.8=E2=80=930.24) and Rancholabrean (0.24=E2=80=930.01= ) in millions of years. The Blancan extends significantly back into the = Pliocene.
• South American land mammal= ages (SALMA) include Uqui= an (2.5=E2=80=931.5), Ensenadan (1.5=E2=80=930.3) and Lujanian (0.3=E2=80=930.01) in millions of years. The Uqu= ian extends significantly back into the Pliocene.

Humans[edit]

Main articles: evolution">Human evolution, Paleolithic, and <= a href=3D"/wiki/Models_of_migration_to_the_New_World" title=3D"Models of= migration to the New World" class=3D"mw-redirect">Models of migration t= o the New World

Scientific evidence^[13] indicates t= hat humans evolved into thei= r present form during the Pleistocene.^{[14] In the beginning of the Pleistocene Paranthropus species are still present= , as well as early human ancestors, but during the lower Palaeolithic th= ey disappeared, and the only hominid species found in fossilic records i= s Homo erectus<= /a> for much of the Pleistocene. The Middle and late Palaeolithic sa= w the appearance of new types of humans, as well as the development of m= ore elaborate tools than found in previous eras. According to mitochondr= ial timing techniques, modern humans migrated from Africa after the Riss glaciation" class=3D"mw-redirect">Riss gla= ciation in the middle Palaeolithic during the Eemian Stage, = spreading all over the ice-free world during the late Pleistocene.[<= /span>15][16][17]} A 2005 study posits that humans in = this migration interbred with archaic human forms already outside of Afr= ica by the late Pleistocene, incorporating archaic human genetic materia= l into the modern human gene pool.^[18]=

Hominin species during Pleistocene

Deposits[edit]

Pleistocene non-marine = sediments are found primarily in fluvial deposits,= lakebeds, slope and loess d= eposits as well as in the large amounts of material moved about by glaci= ers. Less common are cave depo= sits, travertines = and volcanic deposits (lavas, ashes). Pleistocene marine deposits are fo= und primarily in shallow marine basins mostly (but with important except= ions) 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 hund= red meters.

See also[edit]

• Abbass= ia Pluvial
• Geologic time scale">= Geologic time scale
• Glacial history of Minnesota
• Ice age
• Mo= usterian Pluvial
• Paleontological Museum in Tocuila
• Pleistocene megafauna
• Pleist= ocene Park
• Terasecond and longer

References[edit]

1. ^ "Geologic Age Symbo= l Font (StratagemAge)". USGS. 99-430. Retrieved 2011-06-22. 
2. = ^ "Pleistocene". Online E= tymology Dictionary. 
3. ^ G= ibbard, P. and van Kolfschoten, T. (2004) "The Pleistocene and Holocene = Epochs" Chapter 22 PD= F (3.1 MB) In Gradstein, F. M., Ogg, James G., and Smith, A. Gilbert (= eds.), A Geologic Time Scale 2004 Cambridge University = Press, Cambridge, ISBN 0-521-78142-6
4. ^ For the top o= f the series, see: Lourens, L., Hilgen, F., Shackleton, N.J., Laskar, J., Wilson, D= ., (2004) "The Neogene Period". In: Gradstein, F., Ogg, J., Smith= , A.G. (Eds.), A Geologic Time Scale 2004. Cambridge: Cambridge U= niversity Press.
5. ^ Riccardi, Alb= erto C. (30 June 2009) "IUGS ratified ICS Recommendation on redefinition of Pleist= ocene and formal definition of base of Quaternary" International Uni= on of Geological Sciences
6. ^ Svensson, A.,= S. W. Nielsen, S. Kipfstuhl, S. J. Johnsen, J. P. Steffensen, M. Bigler= , U. Ruth, and R. R=C3=B6thlisberger (2005) "Visual stratigraphy of the = North Greenland Ice Core Project (NorthGRIP) ice core during the last gl= acial period" Journal of Geophysical Research 110: (D02108)
7. = ^ Gradstein, Felix M.; Ogg, James G. and Smith, A. Gilbert = (eds.) (2005) A Geologic Time Scale 2004 Cambridge University Pre= ss, Cambridge, UK, p. 28, ISBN 0-521-78142-6
8. ^ Rio,= D.; Sprovieri, R.; Castradori, D. and Di Stefano, E. (1998) "The Gelasi= an Stage (Upper Pliocene): a new unit of the global standard chronostrat= igraphic scale" Episodes 21: pp. 82-87
9. ^ N= ational Geographic Channel, Six Degrees Could Change The World, Mark Lynas interview. Retrieved February 14, 2008.
10. = ^ ^{a b}<= /a> Richmond, G.M. and D.S. Fuller= ton, 1986, Summation of Quaternary glaciations in the United States o= f America. Quaternary Science Reviews. vol. 5, pp. 183-196.
11. <= b>^ Roy, M., P.U. Clark, R.W. Barendregt, J.R., Glasmann, a= nd R.J. Enkin, 2004, Glacial = stratigraphy and paleomagnetism of late Cenozoic deposits of the north-c= entral United States, PDF version, 1.2 MB. Geological Society of= America Bulletin.116(1-2): pp. 30-41; doi:10.1130/B25325.1
12. ^ Aber, J.S. = (1991) "Glaciations of Kansas" Boreas 20(4): pp. 297-314 - (conta= ins a summary of how and why the Nebraskan, Aftonian, Kansan, and Yarmou= thian stages were abandoned by modern stratigraphers).
13. ^ Rogers, A.R= . and Jorde, L.B. (1995) "Genetic evidence on modern human origins" H= uman Biology 67: pp. 1=E2=80=9336
14. ^ Wall, J.D. = and Przeworski, M. (2000) "When did the human population start increasin= g?" Genetics 155: pp. 1865=E2=80=931874
15. ^ Cann, R.L.;= Stoneking, M. and Wilson, A.C.(1987) "Mitochondrial DNA and human evolu= tion" Nature 325: pp. 31=E2=80=9336
16. ^ Stringer, C= .B. (1992) "Evolution of early modern humans" In: Jones, Steve; M= artin, R. and Pilbeam, David R. (eds.) (1992) The Cambridge encyclope= dia of human evolution Cambridge University Press, Cambridge, ISBN 0-521-32370-3, pp. 241=E2=80=93251.
17. ^ Templeton, = A. (2002) "Out of Africa again and again" Nature 416: p. 45
18. ^ Eswarana, V= inayak; Harpendingb, Henry and Rogers, Alan R. (2005) "Genomics refutes = an exclusively African origin of humans" Journal of Human Evolution 49(1): pp. 1=E2=80=9318 Abstract

• Ogg, Jim; June, 2004, Overview of Global Boundary Stratotype Sect= ions and Points (GSSP's, Stratigraphy.org, Acc= essed April 30, 2006.

External links[edit]

Wikimedia Commons has media= related to Pleistoce= ne.

• The SMU-in-Taos Resea= rch Publications digital collection of anthropological and archaeolo= gical monographs contains Late Pleistocene envi= ronments of the southern high plains.
• Pleistocene= Microfossils: 50+ images of Foraminifera

Quaternary
Ple= istocene	Holocene
Earl= y | Late	Preboreal | Boreal | Atlantic (period)">Atlantic= | Subboreal | <= a href=3D"/wiki/Subatlantic" title=3D"Subatlantic">Subatlantic

v t <= span title=3D"Edit this template" style=3D";background:#ee9;;background:= none transparent;border:none;;">e Geologic history of Earth   Precambrian supereon (4.567 Gya =E2=80=93 541.0 Mya) In left column are eons; right column: bold= are eras; n= ot bold are Hadean<= br /> (4.567 =E2=80=93 4 Gya) Chaotian (geology)"= >Chaotian (4.567 =E2=80=93 4.4 Gya) Zirconian(4.4 =E2=80=93 4 Gya) Archean (4 =E2=80=93 2.5 Gya)<= /small> Eoarchean = (4 =E2=80=93 3.6 Gya) Paleoarchea= n (3.6 =E2=80=93 3.2 Gya) Mesoarchean <= small>(3.2 =E2=80=93 2.8 Gya) Neoarchean (2.8 =E2=80=93 2.5 Gya) = Proterozoic (2.5 Gya =E2=80=93 541.0 Mya)= Paleoproterozoic">Pal= eoproterozoic (2.5 =E2=80=93 1.6 Gya): Siderian (2.5 =E2=80=93 2.3 G= ya) Rhyacian (2.3 =E2= =80=93 2.05 Gya) Orosirian (2.= 05 =E2=80=93 1.8 Gya) Statherian = (1.8 =E2=80=93 1.6 Gya) Mesoproterozoic">Mesop= roterozoic (1.6 =E2=80=93 1 Gya): Calymmian (1.6 =E2=80=93 1.4 Gya= ) Ectasian (1.4 =E2= =80=93 1.2 Gya) Stenian (1.2 =E2=80= =93 1 Gya) Neoproterozoic">Neoprot= erozoic (1 Gya =E2=80=93 541.0 Mya): Tonian (1 Gya =E2=80=93 850 Mya) Cryogenian = (850 =E2=80=93 635 Mya) Ediacaran (63= 5 =E2=80=93 541.0 Mya) Mya =3D millions years ago. Gya =3D billions years ago.   Phanerozoic eon (541.0 =E2=80=93 0 Mya) In horizontal bars are eras; in left column are periods; right column: bold= are epo= chs; not bold not italic are ages; italic are chrons:   Paleozoic (541.0 =E2=80=93 252.17 Mya) Cambrian (541.0 =E2=80=93 485.4 Mya) Terreneuvia= n (541.0 =E2=80=93 521 Mya): Fortunian (541.0 =E2=80=93 529 Mya) Cambrian Stage 2">Age 2*= (529 =E2=80=93 521 Mya) Cambrian Series 2">E= poch 2* (521 =E2=80=93 509 Mya): Cambrian Stage 3">Age 3* (521 =E2=80=93= 514 Mya) Cambrian Stage 4">Age 4*= (514 =E2=80=93 509 Mya) E= poch 3* (509 =E2=80=93 497 Mya): Age 5* (509 =E2=80=93= 504.5 Mya) Drumian (504.5 =E2= =80=93 500.5 Mya) Guzhangian = (500.5 =E2=80=93 497 Mya) Furongian = (497 =E2=80=93 485.4 Mya): Paibian (497 =E2=80=93 494 Mya) Jiangshanian <= small>(494 =E2=80=93 489.5 Mya) Cambrian Stage 10">Age = 10* (489.5 =E2=80=93 485.4 Mya) Ordovician (485.4 =E2=80=93 443.4 Mya) Early Ordovician (485.4 =E2=80=93 470.0 Mya): Trem= adocian (485.4 =E2=80=93 477.7 Mya) Floian (477.7 =E2=80= =93 470.0 Mya) Middle Ordovician (470.0 =E2=80=93 458.4 Mya= ): Dapin= gian (470.0 =E2=80=93 467.3 Mya) Darriwilian (467.3 =E2=80=93 458.4 Mya) Late Ordovician (458.4 =E2=80=93 443.4 Mya): Sandbian (458.4 =E2=80=93 453.0 Mya) Katian (453.0 =E2=80= =93 445.2 Mya) Hirnantian = (445.2 =E2=80=93 443.4 Mya) Silurian (443.4 =E2=80=93 419.2 Mya) Llandovery (443.4 =E2=80=93 433.4 Mya)= : Rhuddanian (443.4 =E2=80=93 440.8 Mya) = = Aeronian (440.8 =E2=80=93 438.5 Mya) Telychian (438.5 =E2=80=93 433.4 Mya) Wenlock (433.4 =E2=80=93 427.4 Mya): Sheinwoodian" class=3D"mw-redirect">Sheinwo= odian (433.4 =E2=80=93 430.5 Mya) = Homerian (430.5 =E2=80=93 427.4 Mya) Ludlow (427.4 =E2=80=93 423.0 Mya): Gorsti= an (427.4 =E2=80=93 425.6 Mya) Ludfordian (425.6 =E2=80=93 423.0 Mya) Pridoli (423.0 =E2=80=93 419.2 Mya)<= /li> Devonian (419.2 =E2=80=93 358.9 Mya) Early Devonian (419.2 =E2=80=93 393.3 Mya)<= /a>: Lochkovian (419.2 =E2=80=93 410.8 Mya) Pr= agian (410.8 =E2=80=93 407.6 Mya) Emsi= an (407.6 =E2=80=93 393.3 Mya) Middle Devonian (393.3 =E2=80=93 382.7 Mya): Eifelian (393.3 =E2=80=93 387.7 Mya) Givetian (387.7= =E2=80=93 382.7 Mya) Late Devonian (382.7 =E2=80=93 358.9 Mya): Frasnian (38= 2.7 =E2=80=93 372.2 Mya) Famennian (37= 2.2 =E2=80=93 358.9 Mya) Carboniferous">Carboniferous (358.9 =E2=80=93 298.9 Mya) Mississippian">Mississip= pian (358.9 =E2=80=93 323.2 Mya): Tournaisian">Tournaisian (358.9 =E2=80=93= 346.7 Mya) Vis=C3=A9an (346.7 =E2=80=93 330.9 Mya) Serpukhovian <= small>(330.9 =E2=80=93 323.2 Mya) Pennsylvanian">Pennsylva= nian (323.2 =E2=80=93 298.9 Mya): Bashkirian (323.2 =E2=80=93 31= 5.2 Mya) Moscovian (315.2 =E2=80=93 307.0 Mya) Kasimovian = (307.0 =E2=80=93 303.7 Mya) Gzhelian (303.7= =E2=80=93 298.9 Mya) Permian (298.9 =E2=80=93 252.17 Mya)<= /span> Cisuralian (298.9 =E2=80=93 272.3 Mya): Asselian (298.9 =E2=80= =93 295.0 Mya) Sakmarian (29= 5.0 =E2=80=93 290.1 Mya) Artinskian = (290.1 =E2=80=93 283.5 Mya) Kungurian (28= 3.5 =E2=80=93 272.3 Mya) Guadalupian (272.3 =E2=80=93 259.8 Mya):= Roadian (272.3 =E2=80= =93 268.8 Mya) Wordian (268.8 =E2= =80=93 265.1 Mya) Capitanian = (265.1 =E2=80=93 259.8 Mya) Lopingian (259.8 =E2=80=93 252.17 Mya): Wuchiapingian">Wuchiapingian (259.8 =E2=80=93 254.14 Mya) Changhsingian">Changhsingia= n (254.14 =E2=80=93 252.17 Mya) Kasimovian= and Gzhelian comp= rise Late Pennsylvanian (307.0 =E2=80=93 298.9= Mya) subepoch.   Mesozoic (252.17 =E2=80=93 66.0 Mya) Triassic (252.17 =E2=80=93 201.3 Mya)<= /span> Early Triassic">Early T= riassic (252.17 =E2=80=93 247.2 Mya): Induan (252.17 =E2=80=93 251.2 Mya= ) Olenekian (25= 1.2 =E2=80=93 247.2 Mya) Middle Triassic">Middl= e Triassic (247.2 =E2=80=93 235 Mya): Anisian (247.2 =E2=80=93 242 Mya= ) Ladinian (242 =E2= =80=93 235 Mya) Late Triassic">Late Tria= ssic (235 =E2=80=93 201.3 Mya): Carnian (235 =E2=80=93 228 Mya) Norian (228 =E2=80=93= 208.5 Mya) Rhaetian (208.5= =E2=80=93 201.3 Mya) Jurassic (201.3 =E2=80=93 145.0 Mya) Early Jurassic">Early J= urassic (201.3 =E2=80=93 174.1 Mya): Hettangian (201.3 =E2=80=93= 199.3 Mya) Sinemurian = (199.3 =E2=80=93 190.8 Mya) Pliensbachian">Pliensbachia= n (190.8 =E2=80=93 182.7 Mya) Toarcian (182.7= =E2=80=93 174.1 Mya) Middle Jurassic">Middl= e Jurassic (174.1 =E2=80=93 163.5 Mya): Aalenian (174.1 =E2=80=93 170= .3 Mya) Bajocian (170.3= =E2=80=93 168.3 Mya) Bathonian (16= 8.3 =E2=80=93 166.1 Mya) Callovian (16= 6.1 =E2=80=93 163.5 Mya) Late Jurassic">Late Jura= ssic (163.5 =E2=80=93 145.0 Mya): Oxfordian (stage)">Oxfordian (163.5= =E2=80=93 157.3 Mya) Kimmeridgian <= small>(157.3 =E2=80=93 152.1 Mya) Tithonian (15= 2.1 =E2=80=93 145.0 Mya) Cretaceous (145.0 =E2=80=93 66.0 Mya) Early Cretaceous">Ear= ly Cretaceous (145.0 =E2=80=93 100.5 Mya): Berriasian (145.0 =E2= =80=93 139.8 Mya) Valanginian (139.8 =E2=80=93 132.9 Mya) Hauterivian (132.9 =E2=80=93 129.4 Mya) Barremian (12= 9.4 =E2=80=93 125.0 Mya) Aptian (125.0 =E2=80= =93 113.0 Mya) Albian (113.0 =E2=80= =93 100.5 Mya) Late Cretaceous">Late = Cretaceous (100.5 =E2=80=93 66.0 Mya): Cenomanian (100.5 =E2=80=93= 93.9 Mya) Turonian (93.9 = =E2=80=93 89.8 Mya) Coniacian (89= .8 =E2=80=93 86.3 Mya) Santonian (86= .3 =E2=80=93 83.6 Mya) Campanian (83= .6 =E2=80=93 72.1 Mya) Maastrichtian">Maastrichtia= n (72.1 =E2=80=93 66.0 Mya)   Cenozoic (66.0 =E2=80=93 0 Mya) Paleogene (66.0 =E2=80=93 23.03 Mya) Paleocene = (66.0 =E2=80=93 56.0 Mya): Danian (66.0 =E2=80=93 61.6 Mya) Selandian (61= .6 =E2=80=93 59.2 Mya) Thanetian (59= .2 =E2=80=93 56.0 Mya) Eocene (56.0 =E2= =80=93 33.9 Mya): Ypresian (56.0 =E2=80=93 47.8 Mya) Lutetian (47.8 = =E2=80=93 41.3 Mya) Bartonian (41= .3 =E2=80=93 38.0 Mya) Priabonian = (38.0 =E2=80=93 33.9 Mya) Oligocene = (33.9 =E2=80=93 23.03 Mya): Rupelian (33.9 =E2=80=93 28.1 Mya)<= /li> Chattian (28.1 = =E2=80=93 23.03 Mya) Neogene (23.03 =E2=80=93 2.588 Mya) Miocene (23.03= =E2=80=93 5.333 Mya): Aquitanian (stage)">Aquitanian (23.03 =E2=80=93 20.4= 4 Mya) Burdigalian (20.44 =E2=80=93 15.97 Mya) Langhian (15.97= =E2=80=93 13.82 Mya) Serravallian <= small>(13.82 =E2=80=93 11.62 Mya) Tortonian (11= .62 =E2=80=93 7.246 Mya) Messinian (7.= 246 =E2=80=93 5.333 Mya) Pliocene (5.= 333 =E2=80=93 2.588 Mya): Piacenzian (5.333 =E2=80=93 3.600 Mya) Zanclean (3.600= =E2=80=93 2.588 Mya) Quaternary (2.588 =E2=80=93 0 Mya) Pleistocene (2.588 Mya =E2=80=93= 11.7 kya): Gelasian (2.588 =E2=80=93 1.806 Mya) Cala= brian (1.806 Mya =E2=80=93 781 kya) Mi= ddle Pleistocene (Ionian) (781 =E2=80=93 126 kya) Late P= leistocene (Tarantian) (126 =E2=80=93 11.7 kya): <= a href=3D"/wiki/Oldest_Dryas" title=3D"Oldest Dryas">Oldest Dryas* (18 =E2=80=93 14.67 kya) B=C3=B8lling* (14.67 =E2=80=93 14 kya) Older Dryas* = (14 =E2=80=93 13.7 kya) Aller=C3=B8d* (13.7 =E2=80=93 12.8 kya)<= /i> Younger D= ryas* (12.8 =E2=80=93 11.7 kya) Holocene (11= .7 =E2=80=93 0 kya): Preboreal* (11.7 =E2=80=93 9 kya)= Boreal* (9 =E2=80=93 8 kya) A= tlantic* (8 =E2=80=93 5 kya) Subboreal* (5 =E2=80=93 2.5 kya) Subatlantic* = (2.5 =E2=80=93 0 kya) Paleogene= , Neogene= and early Pleistocene compri= se former Tertiary* (66.0 =E2=80=93 1.8 Mya) period. Gelasian and Calabrian comprise Early Pleistocene = (2.588 Mya =E2=80=93 781 kya) subepoch. ky= a =3D thousands years ago. Mya =3D millions years ago. * Not off= icially recognized by the I.C.S. Source: Intern= ational Chronostratigraphic Chart (January 2013). International Commission on Stratigraphy. Retrie= ved 27 March 2013. Divisions of Geologic = Time=E2=80=94Major Chronostratigraphic and Geochronologic Units USGS= Retrieved 10 March 2013.

v t e Continental glaciations = General Canadian Shield">Canadian= Shield Glacial history of Minnesota Lake Agassiz Lake Chicago Lake Tight List of prehistoric lakes Proglaci= al lake Teays River<= /li> Timeline of glaciation = Landforms Erosional Fjord Glac= ial striae Ribbon lake<= /li> Roche moutonn=C3=A9e Tunnel valle= y U-shaped= valley Depositional Drumlin Drumlin fiel= d Erratic = block Moraine Pulju moraine Rogen morain= e Termin= al moraine Till plain Veiki morain= e Glacifluvial Diluvium Esker Giant current ripples Kame Kame delta Kett= le hole Outwash fan<= /li> Sandur = North American places Canadian Arrowhead Provincial Park, Ontario Big Rock (glacial erratic), Alberta Cypress Hills (Canada), Saskatchewan Eramosa Rive= r, Ontario Eskers Provincial Park, British Columbia Foothills Erratics Train, Alberta Lion's Head Provincial Park, Ontario Origin of the Oak Ridges Moraine, Ontario<= /li> Ovayok Territorial Park, Nunavut United States Chippewa Moraine State Recreation = Area, Wisconsin = Coteau des Prairies, South Dakota Devil's Lake State Park, Wisconsin= Glacial Lake Wisconsin, Wisconsin Glacial Lakes State Park, Minnesota Horicon Mars= h State Wildlife Area, Wisconsin Ice Age Floods National Geologic T= rail, Idaho, Oregon & Washington Ice Age National Scientific Reserve,= Wisconsin Ice Age Trai= l, Wisconsin Intersta= te State Park, Minnesota & Wisconsin Kettle Moraine State Forest, Wisconsin Lake Bon= neville, Utah Lake Lahonta= n, Nevada Lake Missoul= a, Montana Mill Bluff State Park, Wisconsin Oneida Lake,= New York Two Creeks Buried Forest S= tate Natural Area, Wisconsin Withrow Moraine an= d Jameson Lake Drumlin Field, Washington Yosemite National Park, California = Eurasian and Antarctic places Antarctica Hardangerf= jord Killary = Harbour Lambert = Glacier Mont= e Rosa Massif Ross Ice S= helf Svalbard = Time periods Illi= noian Stage Interglacial Interstadial Last glacial period">= Last glacial period Little Ice= Age Older Dryas<= /li> Pleistocene Pre-Illinoia= n Stage Quaternary glaciation = Sangamonian Stage Wisconsin glaciation= ">Wisconsin glaciation Younger Drya= s Category

=

Retrieved from "http://en.wikipedia.org/w/index.ph= p?title=3DPleistocene&oldid=3D570472114"

Categories:

• Pleistocene
• Quater= nary
• Cenozoic

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