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Geologic timescale
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Geologic timescale

A timeline of geologic periods in accordance with the dates and nomenclature proposed by the International Commission on Stratigraphy.

(not shown to scale)

Years Ago3,6 Epoch Period/Age4,5 Era Eon Major Events
Present day Holocene Quaternary Cenozoic Phanerozoic  
11430 Pleistocene Extinction of many large mammals. Evolution of fully modern humans
1.81 million Pliocene Tertiary Neogene  
5.33 million Miocene
23.0 million Oligocene Paleogene
37.2 million Eocene Appearance of first "modern" mammals
55.8 million Paleocene  
65.5 million*   Cretaceous Mesozoic Dinosaurs reach peak, become extinct. Primitive placental mammals
146 million Jurassic Marsupial mammals, first birds, first flowering plants
200 million Triassic First dinosaurs, Egg-laying mammals
251 million* Permian Paleozoic Permian extinction event- 95% of life on Earth becomes extinct
299 million Carboniferous1 Pennsylvanian Abundant insects, first reptiles, coal forests
318 million Mississippian Large primitive trees
359 million Devonian First amphibians, clubmosses and horsetails appear, progymnosperms (first seed bearing plants) appear
416 million* Silurian First land plant fossils
443 million* Ordovician Invertebrates dominant
488 million* Cambrian Major diversification of life in the Cambrian explosion
542 million* Ediacaran Neoproterozoic Proterozoic2 First multi-celled animals
620 million*,8 Cryogenian Possible snowball Earth period
850 million Tonian  
1.0 billion Stennian Mesoproterozoic
1.2 billion Ectasian
1.4 billion Calymmian
1.6 billion Statherian Paleoproterozoic First Complex single-celled life
1.8 billion Orosirian  
2.05 billion Rhyacian
2.3 billion Siderian
2.5 billion   Neoarchean Archaean2
2.8 billion Mesoarchean
3.2 billion Paleoarchean
3.6 billion Eoarchean Simple single-celled life
3.8 billion   Hadean2,7 4.1 billion- Oldest known rock;
4.4 billion- Oldest known mineral;
4.57 billion- Formation of Earth

1) In North America, the Carboniferous is subdivided into Mississippian and Pennsylvanian Periods.

2) The Proterozoic, Archean and Hadean are often collectively referred to as Precambrian Time, and sometimes also as the Cryptozoic.

3) Dates are slightly uncertain with differences of a few percent between various sources being common. This is largely due to uncertainties in radiometric dating and the problem that deposits suitable for radiometric dating seldom occur exactly at the places in the geologic column where we would most like to have them. Dates with an * are radiometrically determined based on internationally agreed to GSSPs. The dates quoted above are according to the International Commission on Stratigraphy 2004 time scale. All dates given are for the end of the interval in question.

4) Paleontologists often refer to faunal stages rather than geologic Periods. The Stage Nomenclature is quite complex. See Harland for an excellent time ordered list of faunal stages. Also see the article on GSSPs.

5) In common usage the Tertiary-Quaternary and Paleogene-Neogene-Quaternary Periods are treated as equivalents to the Mesozoic and Paleozoic Periods. The term 'Period|Age' (e.g. 'Neogene Period|Age') is sometimes used instead of 'Period'.

6) The time shown in the "Years Ago" column is that of the end of the interval named beside it.

7) Hadean was sometimes called Priscoan.

8) The GSSP for the base of the Ediacaran, ratified in 2004, is a climatic/geochemical marker rather than biostratigraphic. It represents the end of a widespread glaciation event.


ImageSize = width:800 height:100 PlotArea = left:65 right:15 bottom:20 top:5 AlignBars = justify Colors = id:epoch value:rgb(0.7,0.7,1) # light yellow id:period value:rgb(1,0.7,0.7) # light red id:age value:rgb(0.7,1,0.7) # light green id:era value:rgb(1,1,0.7) # light blue id:eon value:rgb(1,0.7,1) # light purple id:black value:black Period = from:-4500 till:0 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:500 start:-4500 ScaleMinor = unit:year increment:100 start:-4500 Define $markred = text:"*" textcolor:red shift:(0,3) fontsize:10 PlotData= align:center textcolor:black fontsize:8 mark:(line,black) width:25 shift:(0,-5) bar:eon color:eon at: 0 align:right $markred at: -545 align:left $markred from: -545 till: 0 text:Phanerozoic from:-4500 till: 0 text:Precambrian bar:era color:era from: -64.3 till: 0 text:C~z shift:(0,1.5) from: -251.1 till: -64.3 text:Meso~zoic shift:(0,1.5) from: -545 till: -251.1 text:Paleo~zoic shift:(0,1.5) from:-4500 till: -545 text:Proterozoic bar:period color:period fontsize:6 from: -1.6 till: 0 from: -64.3 till: -1.6 from: -146 till: -64.3 from: -208 till: -146 from: -251.1 till: -208 from: -286 till: -251.1 from: -360 till: -286 from: -408.5 till: -360 from: -443.5 till: -408.5 from: -490 till: -443.5 from: -545 till: -490 fontsize:8 from: -900 till: -545 text:Neoprote-~rozoic shift:(0,1.8) from:-1600 till: -900 text:Mesoproterozoic from:-2500 till: -1600 text:Paleoproterozoic from:-3800 till: -2500 text:Archaean from: start till: -3800 text:Hadean ImageSize = width:800 height:120 PlotArea = left:65 right:15 bottom:20 top:15 AlignBars = justify Colors = id:epoch value:rgb(0.7,0.7,1) # light yellow id:period value:rgb(1,0.7,0.7) # light red id:age value:rgb(0.7,1,0.7) # light green id:era value:rgb(1,1,0.7) # light blue id:eon value:rgb(1,0.7,1) # light purple id:filler value:gray(0.8) # background bar id:black value:black Period = from:-545 till:0 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:100 start:-500 ScaleMinor = unit:year increment:10 start:-540 Define $markred = text:"*" textcolor:red shift:(0,3) fontsize:10 Define $markgreen = text:"*" textcolor:green shift:(0,3) fontsize:10 PlotData= align:center textcolor:black fontsize:8 mark:(line,black) width:25 shift:(0,-5) bar:eon color:eon at: 0 align:right $markred at: -545 align:left $markred from: -545 till: 0 text:Phanerozoic bar:era color:era at: 0 align:right $markgreen at: -64.3 align:left $markgreen from: -64.3 till: 0 text:Cenozoic from: -251.1 till: -64.3 text:Mesozoic from: -545 till: -251.1 text:Paleozoic bar:period color:period fontsize:8 from: -1.6 till: 0 from: -64.3 till: -1.6 text:Tertiary from: -146 till: -64.3 text:Cretaceous from: -208 till: -146 text:Jurassic from: -251.1 till: -208 text:Triassic from: -286 till: -251.1 text:Permian from: -360 till: -286 text:Carboniferous from: -408.5 till: -360 text:Devonian from: -443.5 till: -408.5 text:Silurian from: -490 till: -443.5 text:Ordovician from: -545 till: -490 text:Cambrian bar:age color:age fontsize:6 from: start till: end from: -23 till: -1.6 text:Neo-~gene shift:(0,0.5) from: -64.3 till: -23 text:Paleo~gene shift:(0,0.5) from: -286 till: -251.1 # mark end of Paleozoic from: -325 till: -286 text:Pennsyl-~vanian shift:(0,0.5) from: -360 till: -325 text:Missis-~sippian shift:(0,0.5) ImageSize = width:800 height:120 PlotArea = left:65 right:15 bottom:20 top:15 AlignBars = justify Colors = id:epoch value:rgb(0.7,0.7,1) # light yellow id:period value:rgb(1,0.7,0.7) # light red id:age value:rgb(0.7,1,0.7) # light green id:era value:rgb(1,1,0.7) # light blue id:black value:black Period = from:-65.5 till:0 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:10 start:-60 ScaleMinor = unit:year increment:1 start:-65 Define $markgreen = text:"*" textcolor:green shift:(0,3) fontsize:10 PlotData= align:center textcolor:black fontsize:8 mark:(line,black) width:25 shift:(0,-5) bar:era color:era at: 0 align:right $markgreen at: start align:left $markgreen from:start till: 0 text:Cenozoic bar:period color:period from: -1.6 till: 0 text:Qua~ter~nary fontsize:6 align:left shift:(-7,5) from:start till: -1.6 text:Tertiary bar:age color:age from: -1.6 till: 0 from: -23 till: -1.6 text:Neogene from:start till: -23 text:Paleogene bar:epoch color:epoch from: -0.1 till: 0 from: -1.6 till: -0.1 text:P from: -5 till: -1.6 text:Plio~cene shift:(0,1) fontsize:6 from:-23 till: -5 text:Miocene from:-38 till:-23 text:Oligocene from:-55 till:-38 text:Eocene from:start till:-55 text:Paleocene

See also

References