Editing Geologic time scale (section)

== Major proposed revisions to the ICC ==
=== Proposed Anthropocene Series/Epoch ===
{{Main|Anthropocene}}
First suggested in 2000,<ref name="Crutzen_2021">{{Citation |last1=Crutzen |first1=Paul J. |title=The 'Anthropocene' (2000) |date=2021 |url=https://link.springer.com/10.1007/978-3-030-82202-6_2 |work=Paul J. Crutzen and the Anthropocene: A New Epoch in Earth's History |volume=1 |pages=19–21 |editor-last=Benner |editor-first=Susanne |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-82202-6_2 |isbn=978-3-030-82201-9 |access-date=2022-04-15 |last2=Stoermer |first2=Eugene F. |series=The Anthropocene: Politik—Economics—Society—Science |s2cid=245639062 |editor2-last=Lax |editor2-first=Gregor |editor3-last=Crutzen |editor3-first=Paul J. |editor4-last=Pöschl |editor4-first=Ulrich}}</ref> the ''Anthropocene'' is a proposed epoch/series for the most recent time in Earth's history. While still informal, it is a widely used term to denote the present geologic time interval, in which many conditions and processes on Earth are profoundly altered by human impact.<ref>{{Cite web |title=Working Group on the 'Anthropocene' {{!}} Subcommission on Quaternary Stratigraphy |url=https://quaternary.stratigraphy.org/working-groups/anthropocene/ |archive-url=https://web.archive.org/web/20220407193255/https://quaternary.stratigraphy.org/working-groups/anthropocene/ |archive-date=2022-04-07 |access-date=2022-04-17 |language=en-US}}</ref> {{As of|2022|April}} the Anthropocene has not been ratified by the ICS; however, in May 2019 the [[Anthropocene Working Group]] voted in favour of submitting a formal proposal to the ICS for the establishment of the Anthropocene Series/Epoch.<ref name="Subramanian_2019">{{Cite journal |last=Subramanian |first=Meera |date=2019-05-21 |title=Anthropocene now: influential panel votes to recognise Earth's new epoch |url=http://www.nature.com/articles/d41586-019-01641-5 |journal=Nature |language=en |pages=d41586–019–01641–5 |doi=10.1038/d41586-019-01641-5 |pmid=32433629 |s2cid=182238145 |issn=0028-0836}}</ref> Nevertheless, the definition of the Anthropocene as a geologic time period rather than a geologic event remains controversial and difficult.<ref name="Gibbard_2021">{{Cite journal |last1=Gibbard |first1=Philip L. |last2=Bauer |first2=Andrew M. |last3=Edgeworth |first3=Matthew |last4=Ruddiman |first4=William F. |last5=Gill |first5=Jacquelyn L. |last6=Merritts |first6=Dorothy J. |last7=Finney |first7=Stanley C. |last8=Edwards |first8=Lucy E. |last9=Walker |first9=Michael J. C. |last10=Maslin |first10=Mark |last11=Ellis |first11=Erle C. |date=2021-11-15 |title=A practical solution: the Anthropocene is a geological event, not a formal epoch |journal=Episodes |volume=45 |issue=4 |pages=349–357 |language=en |doi=10.18814/epiiugs/2021/021029 |s2cid=244165877 |issn=0705-3797|doi-access=free }}</ref><ref name="Head_2021">{{Cite journal |last1=Head |first1=Martin J. |last2=Steffen |first2=Will |last3=Fagerlind |first3=David |last4=Waters |first4=Colin N. |last5=Poirier |first5=Clement |last6=Syvitski |first6=Jaia |last7=Zalasiewicz |first7=Jan A. |last8=Barnosky |first8=Anthony D. |last9=Cearreta |first9=Alejandro |last10=Jeandel |first10=Catherine |last11=Leinfelder |first11=Reinhold |date=2021-11-15 |title=The Great Acceleration is real and provides a quantitative basis for the proposed Anthropocene Series/Epoch |journal=Episodes |volume=45 |issue=4 |pages=359–376 |language=en |doi=10.18814/epiiugs/2021/021031 |s2cid=244145710 |issn=0705-3797|doi-access=free }}</ref><ref name="Zalasiewicz_2021">{{Cite journal |last1=Zalasiewicz |first1=Jan |last2=Waters |first2=Colin N. |last3=Ellis |first3=Erle C. |last4=Head |first4=Martin J. |last5=Vidas |first5=Davor |last6=Steffen |first6=Will |last7=Thomas |first7=Julia Adeney |last8=Horn |first8=Eva |last9=Summerhayes |first9=Colin P. |last10=Leinfelder |first10=Reinhold |last11=McNeill |first11=J. R. |date=2021 |title=The Anthropocene: Comparing Its Meaning in Geology (Chronostratigraphy) with Conceptual Approaches Arising in Other Disciplines |journal=Earth's Future |language=en |volume=9 |issue=3 |doi=10.1029/2020EF001896 |bibcode=2021EaFut...901896Z |s2cid=233816527 |issn=2328-4277|doi-access=free }}</ref><ref name="Bauer_2021">{{Cite journal |last1=Bauer |first1=Andrew M. |last2=Edgeworth |first2=Matthew |last3=Edwards |first3=Lucy E. |last4=Ellis |first4=Erle C. |last5=Gibbard |first5=Philip |last6=Merritts |first6=Dorothy J. |date=2021-09-16 |title=Anthropocene: event or epoch? |url=https://www.nature.com/articles/d41586-021-02448-z |journal=Nature |language=en |volume=597 |issue=7876 |pages=332 |doi=10.1038/d41586-021-02448-z |pmid=34522014 |bibcode=2021Natur.597..332B |s2cid=237515330 |issn=0028-0836}}</ref>

=== Proposals for revisions to pre-Cryogenian timeline ===
==== Shields et al. 2021 ====
The ICS Subcommission for Cryogenian Stratigraphy has outlined a template to improve the pre-Cryogenian geologic time scale based on the rock record to bring it in line with the post-Tonian geologic time scale.<ref name="Shields_2022_pre-Cryogenian" /> This work assessed the geologic history of the currently defined eons and eras of the Precambrian,{{Efn|name=Precam|group=note}} and the proposals in the "Geological Time Scale" books ''2004,''<ref name="GTS2004_Precambrian">{{Citation |last=Bleeker |first=W. |title=Toward a "natural" Precambrian time scale |date=2005-03-17 |url=https://www.cambridge.org/core/product/identifier/CBO9780511536045A067/type/book_part |work=A Geologic Time Scale 2004 |pages=141–146 |editor-last=Gradstein |editor-first=Felix M. |edition=1 |publisher=Cambridge University Press |doi=10.1017/cbo9780511536045.011 |isbn=978-0-521-78673-7 |access-date=2022-04-09 |editor2-last=Ogg |editor2-first=James G. |editor3-last=Smith |editor3-first=Alan G.}}</ref> ''2012,''<ref name="GTS2012_Precambrian" /> and ''2020.''<ref name="GTS2020_Precambrian">{{Citation |last1=Strachan |first1=R. |title=Precambrian (4.56–1 Ga) |date=2020 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780128243602000164 |work=Geologic Time Scale 2020 |pages=481–493 |publisher=Elsevier |language=en |doi=10.1016/b978-0-12-824360-2.00016-4 |isbn=978-0-12-824360-2 |access-date=2022-04-09 |last2=Murphy |first2=J.B. |last3=Darling |first3=J. |last4=Storey |first4=C. |last5=Shields |first5=G.|s2cid=229513433 }}</ref> Their recommend revisions<ref name="Shields_2022_pre-Cryogenian" /> of the pre-Cryogenian geologic time scale were as below (changes from the current scale [v2023/09] are italicised). This suggestion was unanimously rejected by the International Subcommission for Precambrian Stratigraphy, based on scientific weaknesses.
* Three divisions of the Archean instead of four by dropping Eoarchean, and revisions to their geochronometric definition, along with the repositioning of the Siderian into the latest Neoarchean, and a potential Kratian division in the Neoarchean.
** Archean (4000–''2450'' Ma)
*** Paleoarchean (4000–''3500'' Ma)
*** Mesoarchean (''3500–3000'' Ma)
*** Neoarchean (''3000–2450'' Ma)
**** ''Kratian'' (no fixed time given, prior to the Siderian) – from Greek κράτος (''krátos'') 'strength'.
**** Siderian (?–''2450'' Ma) – moved from Proterozoic to end of Archean, no start time given, base of Paleoproterozoic defines the end of the Siderian
* Refinement of geochronometric divisions of the Proterozoic, Paleoproterozoic, repositioning of the Statherian into the Mesoproterozoic, new Skourian period/system in the Paleoproterozoic, new Kleisian or Syndian period/system in the Neoproterozoic.
** Paleoproterozoic (''2450–1800'' Ma)
*** ''Skourian'' (''2450''–2300 Ma) – from Greek σκουριά (''skouriá'') 'rust'.
*** Rhyacian (2300–2050 Ma)
*** Orosirian (2050–1800 Ma)
** Mesoproterozoic (''1800''–1000 Ma)
*** ''Statherian'' (1800–1600 Ma)
*** Calymmian (1600–1400 Ma)
*** Ectasian (1400–1200 Ma)
*** Stenian (1200–1000 Ma)
** Neoproterozoic (1000–538.8 Ma){{Efn|Geochronometric date for the Ediacaran has been adjusted to reflect ICC v2023/09 as the formal definition for the base of the Cambrian has not changed.|name=EdiacaranDate|group=note}}
*** ''Kleisian'' or ''Syndian'' (''1000–800'' Ma) – respectively from Greek κλείσιμο (''kleísimo'') 'closure' and σύνδεση (''sýndesi'') 'connection'.
*** Tonian (''800''–720 Ma)
*** Cryogenian (720–635 Ma)
*** Ediacaran (635–538.8 Ma)
Proposed pre-Cambrian timeline (Shield et al. 2021, ICS working group on pre-Cryogenian chronostratigraphy), shown to scale:{{Efn|Kratian time span is not given in the article. It lies within the Neoarchean, and prior to the Siderian. The position shown here is an arbitrary division.|name=kratian|group=note}}
<timeline>
ImageSize = width:1300 height:100
PlotArea = left:80 right:20 bottom:20 top:5
AlignBars = justify
Colors =
  id:proterozoic value:rgb(0.968,0.207,0.388)
  id:neoproterozoic value:rgb(0.996,0.701,0.258)
  id:ediacaran value:rgb(0.996,0.85,0.415)
  id:cryogenian value:rgb(0.996,0.8,0.36)
  id:tonian value:rgb(0.996,0.75,0.305)
  id:kleisian value:rgb(0.996,0.773,0.431)
  id:mesoproterozoic value:rgb(0.996,0.705,0.384)
  id:stenian value:rgb(0.996,0.85,0.604)
  id:ectasian value:rgb(0.996,0.8,0.541)
  id:calymmian value:rgb(0.996,0.75,0.478)
  id:paleoproterozoic value:rgb(0.968,0.263,0.44)
  id:skourian value:rgb(0.949,0.439,0.545)
  id:statherian value:rgb(0.968,0.459,0.655)
  id:orosirian value:rgb(0.968,0.408,0.596)
  id:rhyacian value:rgb(0.968,0.357,0.537)
  id:archean value:rgb(0.996,0.157,0.498)
  id:neoarchean value:rgb(0.976,0.608,0.757)
  id:mesoarchean value:rgb(0.968,0.408,0.662)
  id:paleoarchean value:rgb(0.96,0.266,0.624)
  id:hadean value:rgb(0.717,0,0.494)
  id:black value:black
  id:white value:white
Period = from:-4600 till:-538.8
TimeAxis = orientation:horizontal
ScaleMajor = unit:year increment:500 start:-4500
ScaleMinor = unit:year increment:100 start:-4500
PlotData = 
 align:center textcolor:black fontsize:8 mark:(line,black) width:25 shift:(0,-5)
  bar:Eonothem/Eon
    from: -2450 till: -538.8 text:Proterozoic color:proterozoic
    from: -4000 till: -2450 text:Archean color:archean
    from: start till: -4000 text:Hadean color:hadean
  bar:Erathem/Era
    from: -1000 till: -538.8 text:Neoproterozoic color:neoproterozoic
    from: -1800 till: -1000 text:Mesoproterozoic color:mesoproterozoic
    from: -2450 till: -1800 text:Paleoproterozoic color:paleoproterozoic
    from: -3000 till: -2450 text:Neoarchean color:neoarchean
    from: -3300 till: -3000 text:Mesoarchean color:mesoarchean
    from: -4000 till: -3300 text:Paleoarchean color:paleoarchean
    from: start till: -4000 color:white
  bar:System/Period fontsize:7
    from: -635 till: -538.8 text:Ed. color:ediacaran
    from: -720 till: -635 text:Cr. color:cryogenian
    from: -800 till: -720 text:Tonian color:tonian
    from: -1000 till: -800 text:?kleisian color:kleisian
    from: -1200 till: -1000 text:Stenian color:stenian
    from: -1400 till: -1200 text:Ectasian color:ectasian
    from: -1600 till: -1400 text:Calymmian color:calymmian
    from: -1800 till: -1600 text:Statherian color:statherian
    from: -2050 till: -1800 text:Orosirian color:orosirian
    from: -2300 till: -2050 text:Rhyacian color:rhyacian
    from: -2450 till: -2300 text:?Skourian color:skourian
    from: -2700 till: -2450 text:Siderian color:neoarchean
    from: -3000 till: -2700 text:?Kratian color:neoarchean
    from: start till: -3000 color:white
</timeline>

ICC pre-Cambrian timeline (v2024/12, current {{As of|2025|01|lc=y}}), shown to scale:
<timeline>
ImageSize = width:1300 height:100
PlotArea = left:80 right:20 bottom:20 top:5
AlignBars = justify
Colors =
  id:proterozoic value:rgb(0.968,0.207,0.388)
  id:neoproterozoic value:rgb(0.996,0.701,0.258)
  id:ediacaran value:rgb(0.996,0.85,0.415)
  id:cryogenian value:rgb(0.996,0.8,0.36)
  id:tonian value:rgb(0.996,0.75,0.305)
  id:mesoproterozoic value:rgb(0.996,0.705,0.384)
  id:stenian value:rgb(0.996,0.85,0.604)
  id:ectasian value:rgb(0.996,0.8,0.541)
  id:calymmian value:rgb(0.996,0.75,0.478)
  id:paleoproterozoic value:rgb(0.968,0.263,0.44)
  id:statherian value:rgb(0.968,0.459,0.655)
  id:orosirian value:rgb(0.968,0.408,0.596)
  id:rhyacian value:rgb(0.968,0.357,0.537)
  id:siderian value:rgb(0.968,0.306,0.478)
  id:archean value:rgb(0.996,0.157,0.498)
  id:neoarchean value:rgb(0.976,0.608,0.757)
  id:mesoarchean value:rgb(0.968,0.408,0.662)
  id:paleoarchean value:rgb(0.96,0.266,0.624)
  id:eoarchean value:rgb(0.902,0.114,0.549)
  id:hadean value:rgb(0.717,0,0.494)
  id:black value:black
  id:white value:white
Period = from:-4567 till:-538.8
TimeAxis = orientation:horizontal
ScaleMajor = unit:year increment:500 start:-4500
ScaleMinor = unit:year increment:100 start:-4500
PlotData = 
 align:center textcolor:black fontsize:8 mark:(line,black) width:25 shift:(0,-5)
    bar:Eonothem/Eon
    from: -2500 till: -538.8 text:Proterozoic color:proterozoic
    from: -4031 till: -2500 text:Archean color:archean
    from: start till: -4031 text:Hadean color:hadean
  bar:Erathem/Era
    from: -1000 till: -538.8 text:Neoproterozoic color:neoproterozoic
    from: -1600 till: -1000 text:Mesoproterozoic color:mesoproterozoic
    from: -2500 till: -1600 text:Paleoproterozoic color:paleoproterozoic
    from: -2800 till: -2500 text:Neoarchean color:neoarchean
    from: -3200 till: -2800 text:Mesoarchean color:mesoarchean
    from: -3600 till: -3200 text:Paleoarchean color:paleoarchean
    from: -4031 till: -3600 text:Eoarchean color:eoarchean
    from: start till: -4031 color:white
  bar:Sytem/Period fontsize:7
    from: -635 till: -538.8 text:Ed. color:ediacaran
    from: -720 till: -635 text:Cr. color:cryogenian
    from: -1000 till: -720 text:Tonian color:tonian
    from: -1200 till: -1000 text:Stenian color:stenian
    from: -1400 till: -1200 text:Ectasian color:ectasian
    from: -1600 till: -1400 text:Calymmian color:calymmian
    from: -1800 till: -1600 text:Statherian color:statherian
    from: -2050 till: -1800 text:Orosirian color:orosirian
    from: -2300 till: -2050 text:Rhyacian color:rhyacian
    from: -2500 till: -2300 text:Siderian color:siderian
    from: start till: -2500 color:white
</timeline>

==== Van Kranendonk et al. 2012 (GTS2012) ====
The book, ''Geologic Time Scale 2012,'' was the last commercial publication of an international chronostratigraphic chart that was closely associated with the ICS and the Subcommission on Precambrian Stratigraphy.<ref name="ICC_Cohen_2013" /> It included a proposal to substantially revise the pre-Cryogenian time scale to reflect important events such as the [[Formation and evolution of the Solar System|formation of the Solar System]] and the [[Great Oxidation Event]], among others, while at the same time maintaining most of the previous chronostratigraphic nomenclature for the pertinent time span.<ref name="GTS2012b">{{cite book |last=Van Kranendonk |first=Martin J. |chapter=A Chronostratigraphic Division of the Precambrian |title=The geologic time scale 2012 |date=2012 |publisher=Elsevier |isbn=978-0-44-459425-9 |editor=Felix M. Gradstein |edition=1st |location=Amsterdam |pages=359–365 |doi=10.1016/B978-0-444-59425-9.00016-0 |editor2=James G. Ogg |editor3=Mark D. Schmitz |editor4=abi M. Ogg}}</ref> {{As of|2022|April}} these proposed changes have not been accepted by the ICS. The proposed changes (changes from the current scale [v2023/09]) are italicised:

* Hadean Eon (4567''–4030'' Ma)
** [[Chaotian (geology)|''Chaotian'']] Era/Erathem (''4567–4404'' Ma) – the name alluding both to the [[Chaos (cosmogony)|mythological Chaos]] and the [[Chaos theory|chaotic]] phase of [[planet formation]].<ref name="GTS2012" /><ref name="Goldblatt_2010">{{cite journal |last1=Goldblatt |first1=C. |last2=Zahnle |first2=K. J. |last3=Sleep |first3=N. H. |last4=Nisbet |first4=E. G. |date=2010 |title=The Eons of Chaos and Hades |journal=Solid Earth |volume=1 |issue=1 |pages=1–3 |bibcode=2010SolE....1....1G |doi=10.5194/se-1-1-2010 |doi-access=free}}</ref><ref>{{cite journal |last=Chambers |first=John E. |date=July 2004 |title=Planetary accretion in the inner Solar System |url=http://www.astro.washington.edu/courses/astro321/Chambers_EPSL_04.pdf |archive-url=https://web.archive.org/web/20120419024812/http://www.astro.washington.edu/courses/astro321/Chambers_EPSL_04.pdf |archive-date=2012-04-19 |url-status=live |journal=Earth and Planetary Science Letters |volume=223 |issue=3–4 |pages=241–252 |bibcode=2004E&PSL.223..241C |doi=10.1016/j.epsl.2004.04.031}}</ref>
** ''Jack Hillsian'' or ''Zirconian'' Era/Erathem (''4404–4030'' Ma) – both names allude to the Jack Hills Greenstone Belt which provided the oldest mineral grains on Earth, [[zircon]]s.<ref name="GTS2012" /><ref name="Goldblatt_2010" />
* Archean Eon/Eonothem (''4030–2420'' Ma)
** Paleoarchean Era/Erathem (''4030–3490'' Ma)
*** ''Acastan'' Period/System (''4030–3810'' Ma) – named after the [[Acasta Gneiss]], one of the oldest preserved pieces of [[continental crust]].<ref name="GTS2012" /><ref name="Goldblatt_2010" />
*** ''Isuan'' Period/System (''3810–3490'' Ma) – named after the [[Isua Greenstone Belt]].<ref name="GTS2012" />
** Mesoarchean Era/Erathem (''3490–2780'' Ma)
*** ''Vaalbaran'' Period/System (''3490–3020'' Ma) – based on the names of the [[Kaapvaal craton|Kaapvaal]] (Southern Africa) and [[Pilbara craton|Pilbara]] (Western Australia) [[craton]]s, to reflect the growth of stable continental nuclei or proto-[[craton]]ic kernels.<ref name="GTS2012" />
*** ''Pongolan'' Period/System (''3020–2780'' Ma) – named after the Pongola Supergroup, in reference to the well preserved evidence of terrestrial microbial communities in those rocks.<ref name="GTS2012" />
** Neoarchean Era/Erathem (''2780–2420'' Ma)
*** ''Methanian'' Period/System (''2780–2630'' Ma) – named for the inferred predominance of [[methanotrophic]] [[prokaryote]]s<ref name="GTS2012" />
*** Siderian Period/System (''2630–2420'' Ma) – named for the voluminous [[banded iron formation]]s formed within its duration.<ref name="GTS2012" />
* Proterozoic Eon/Eonothem (''2420''–538.8 Ma){{efn|name=EdiacaranDate|group=note}}
** Paleoproterozoic Era/Erathem (''2420–1780'' Ma)
*** ''Oxygenian'' Period/System (''2420–2250'' Ma) – named for displaying the first evidence for a global oxidising atmosphere.<ref name="GTS2012" />
*** ''Jatulian'' or ''Eukaryian'' Period/System (''2250–2060'' Ma) – names are respectively for the Lomagundi–Jatuli δ<sup>13</sup>C isotopic excursion event spanning its duration, and for the (proposed)<ref name="El_Albani_2014">{{cite journal |last1=El Albani |first1=Abderrazak |last2=Bengtson |first2=Stefan |last3=Canfield |first3=Donald E. |last4=Riboulleau |first4=Armelle |last5=Rollion Bard |first5=Claire |last6=Macchiarelli |first6=Roberto |display-authors=etal |year=2014 |title=The 2.1 Ga Old Francevillian Biota: Biogenicity, Taphonomy and Biodiversity |journal=PLOS ONE |volume=9 |issue=6 |pages=e99438 |bibcode=2014PLoSO...999438E |doi=10.1371/journal.pone.0099438 |pmc=4070892 |pmid=24963687 |doi-access=free}}</ref><ref name="El_Albani_2010">{{cite journal |last1=El Albani |first1=Abderrazak |last2=Bengtson |first2=Stefan |last3=Canfield |first3=Donald E. |last4=Bekker |first4=Andrey |last5=Macchiarelli |first5=Roberto |last6=Mazurier |first6=Arnaud |last7=Hammarlund |first7=Emma U. |display-authors=etal |year=2010 |title=Large colonial organisms with coordinated growth in oxygenated environments 2.1 Gyr ago |url=http://www.afrikibouge.com/publications/Article%20Albani.pdf |archive-url=https://web.archive.org/web/20240616162702/https://www.afrikibouge.com/publications/Article%20Albani.pdf |url-status=dead |archive-date=16 June 2024 |journal=Nature |volume=466 |issue=7302 |pages=100–104 |bibcode=2010Natur.466..100A |doi=10.1038/nature09166 |pmid=20596019 |s2cid=4331375}}</ref> first fossil appearance of [[eukaryote]]s.<ref name="GTS2012" />
*** ''Columbian Period/System'' (''2060–1780'' Ma) – named after the [[supercontinent]] [[Columbia (supercontinent)|Columbia]].<ref name="GTS2012" />
** Mesoproterozoic Era/Erathem (''1780–850'' Ma)
*** ''Rodinian'' Period/System (''1780–850'' Ma) – named after the supercontinent [[Rodinia]], stable environment.<ref name="GTS2012" />

Proposed pre-Cambrian timeline (GTS2012), shown to scale:
<timeline>
ImageSize = width:1200 height:100
PlotArea = left:80 right:20 bottom:20 top:5
AlignBars = justify
Colors =
  id:proterozoic value:rgb(0.968,0.207,0.388)
  id:neoproterozoic value:rgb(0.996,0.701,0.258)
  id:ediacaran value:rgb(0.996,0.85,0.415)
  id:cryogenian value:rgb(0.996,0.8,0.36)
  id:tonian value:rgb(0.996,0.75,0.305)
  id:mesoproterozoic value:rgb(0.996,0.705,0.384)
  id:rodinian value:rgb(0.996,0.75,0.478)
  id:paleoproterozoic value:rgb(0.968,0.263,0.44)
  id:columbian value:rgb(0.968,0.459,0.655)
  id:eukaryian value:rgb(0.968,0.408,0.596)
  id:oxygenian value:rgb(0.968,0.357,0.537)
  id:archean value:rgb(0.996,0.157,0.498)
  id:neoarchean value:rgb(0.976,0.608,0.757)
  id:siderian value:rgb(0.976,0.7,0.85)
  id:methanian value:rgb(0.976,0.65,0.8)
  id:mesoarchean value:rgb(0.968,0.408,0.662)
  id:pongolan value:rgb(0.968,0.5,0.75)
  id:vaalbaran value:rgb(0.968,0.45,0.7)
  id:paleoarchean value:rgb(0.96,0.266,0.624)
  id:isuan value:rgb(0.96,0.35,0.65)
  id:acastan value:rgb(0.96,0.3,0.6)
  id:hadean value:rgb(0.717,0,0.494)
  id:zirconian value:rgb(0.902,0.114,0.549)
  id:chaotian value:rgb(0.8,0.05,0.5)
  id:black value:black
  id:white value:white
Period = from:-4567.3 till:-538.8
TimeAxis = orientation:horizontal
ScaleMajor = unit:year increment:500 start:-4500
ScaleMinor = unit:year increment:100 start:-4500
PlotData = 
 align:center textcolor:black fontsize:8 mark:(line,black) width:25 shift:(0,-5)
  bar:Eonothem/Eon
    from: -2420 till: -541 text:Proterozoic color:proterozoic
    from: -4030 till: -2420 text:Archean color:archean
    from: -4567 till: -4030 text:Hadean color:hadean
    from: start till: -4567 color:white
  bar:Erathem/Era
    from: -850 till: -541 text:Neoproterozoic color:neoproterozoic
    from: -1780 till: -850 text:Mesoproterozoic color:mesoproterozoic
    from: -2420 till: -1780 text:Paleoproterozoic color:paleoproterozoic
    from: -2780 till: -2420 text:Neoarchean color:neoarchean
    from: -3490 till: -2780 text:Mesoarchean color:mesoarchean
    from: -4030 till: -3490 text:Paleoarchean color:paleoarchean
    from: -4404 till: -4030 text:Zirconian color:zirconian
    from: -4567 till: -4404 text:Chaotian color:chaotian
    from: start till: -4567 color:white
  bar:System/Period fontsize:7
    from: -630  till: -541 text:Ediacaran color:ediacaran
    from: -850  till: -630 text:Cryogenian color:cryogenian
    from: -1780 till: -850  text:Rodinian color:rodinian
    from: -2060 till: -1780 text:Columbian color:columbian
    from: -2250 till: -2060 text:Eukaryian color:eukaryian
    from: -2420 till: -2250 text:Oxygenian color:oxygenian
    from: -2630 till: -2420 text:Siderian color:siderian
    from: -2780 till: -2630 text:Methanian color:methanian
    from: -3020 till: -2780 text:Pongolan color:pongolan
    from: -3490 till: -3020 text:Vaalbaran color:vaalbaran
    from: -3810 till: -3490 text:Isuan color:isuan
    from: -4030 till: -3810 text:Acastan color:acastan
    from: start till: -4030 color:white
</timeline>

ICC pre-Cambrian timeline (v2024/12, current {{As of|2025|01|lc=y}}), shown to scale:
<timeline>
ImageSize = width:1200 height:100
PlotArea = left:80 right:20 bottom:20 top:5
AlignBars = justify
Colors =
  id:proterozoic value:rgb(0.968,0.207,0.388)
  id:neoproterozoic value:rgb(0.996,0.701,0.258)
  id:ediacaran value:rgb(0.996,0.85,0.415)
  id:cryogenian value:rgb(0.996,0.8,0.36)
  id:tonian value:rgb(0.996,0.75,0.305)
  id:mesoproterozoic value:rgb(0.996,0.705,0.384)
  id:stenian value:rgb(0.996,0.85,0.604)
  id:ectasian value:rgb(0.996,0.8,0.541)
  id:calymmian value:rgb(0.996,0.75,0.478)
  id:paleoproterozoic value:rgb(0.968,0.263,0.44)
  id:statherian value:rgb(0.968,0.459,0.655)
  id:orosirian value:rgb(0.968,0.408,0.596)
  id:rhyacian value:rgb(0.968,0.357,0.537)
  id:siderian value:rgb(0.968,0.306,0.478)
  id:archean value:rgb(0.996,0.157,0.498)
  id:neoarchean value:rgb(0.976,0.608,0.757)
  id:mesoarchean value:rgb(0.968,0.408,0.662)
  id:paleoarchean value:rgb(0.96,0.266,0.624)
  id:eoarchean value:rgb(0.902,0.114,0.549)
  id:hadean value:rgb(0.717,0,0.494)
  id:black value:black
  id:white value:white
Period = from:-4567.3 till:-538.8
TimeAxis = orientation:horizontal
ScaleMajor = unit:year increment:500 start:-4500
ScaleMinor = unit:year increment:100 start:-4500
PlotData = 
 align:center textcolor:black fontsize:8 mark:(line,black) width:25 shift:(0,-5)
  bar:Eonothem/Eon
    from: -2500 till: -538.8 text:Proterozoic color:proterozoic
    from: -4031 till: -2500 text:Archean color:archean
    from: start till: -4031 text:Hadean color:hadean
  bar:Erathem/Era
    from: -1000 till: -538.8 text:Neoproterozoic color:neoproterozoic
    from: -1600 till: -1000 text:Mesoproterozoic color:mesoproterozoic
    from: -2500 till: -1600 text:Paleoproterozoic color:paleoproterozoic
    from: -2800 till: -2500 text:Neoarchean color:neoarchean
    from: -3200 till: -2800 text:Mesoarchean color:mesoarchean
    from: -3600 till: -3200 text:Paleoarchean color:paleoarchean
    from: -4031 till: -3600 text:Eoarchean color:eoarchean
    from: start till: -4031 color:white
  bar:System/Period fontsize:7
    from: -635 till: -538.8 text:Ediacaran color:ediacaran
    from: -720 till: -635 text:Cryogenian color:cryogenian
    from: -1000 till: -720 text:Tonian color:tonian
    from: -1200 till: -1000 text:Stenian color:stenian
    from: -1400 till: -1200 text:Ectasian color:ectasian
    from: -1600 till: -1400 text:Calymmian color:calymmian
    from: -1800 till: -1600 text:Statherian color:statherian
    from: -2050 till: -1800 text:Orosirian color:orosirian
    from: -2300 till: -2050 text:Rhyacian color:rhyacian
    from: -2500 till: -2300 text:Siderian color:siderian
    from: start till: -2500 color:white
</timeline>