Editing Geologic time scale (section)

=== Modern international geological time scale ===
The establishment of the IUGS in 1961<ref name="Harrison_1978">{{Cite journal |last=Harrison |first=James M. |title=The Roots of IUGS |date=1978-03-01 |journal=Episodes |volume=1 |issue=1 |pages=20–23 |doi=10.18814/epiiugs/1978/v1i1/005 |issn=0705-3797|doi-access=free }}</ref> and acceptance of the Commission on Stratigraphy (applied in 1965)<ref name="ICS_statutes_1986">{{Cite book |author=International Union of Geological Sciences. Commission on Stratigraphy |url=https://www.worldcat.org/oclc/14352783 |title=Guidelines and statutes of the International Commission on Stratigraphy (ICS) |date=1986 |publisher=Herausgegeben von der Senckenbergischen Naturforschenden Gesellschaft |others=J. W. Cowie |isbn=3-924500-19-3 |location=Frankfurt a.M. |oclc=14352783}}</ref> to become a member commission of IUGS led to the founding of the ICS. One of the primary objectives of the ICS is "the establishment, publication and revision of the ICS International Chronostratigraphic Chart which is the standard, reference global Geological Time Scale to include the ratified Commission decisions".<ref name="ICS_statutes" />

Following on from Holmes, several ''A Geological Time Scale'' books were published in 1982,<ref name="GTS82">{{Cite book |url=https://www.worldcat.org/oclc/8387993 |title=A geologic time scale |date=1982 |publisher=Cambridge University Press |author=W. B. Harland |isbn=0-521-24728-4 |location=Cambridge [England] |oclc=8387993}}</ref> 1989,<ref name="GTS1989">{{Cite book |url=https://www.worldcat.org/oclc/20930970 |title=A geologic time scale 1989 |date=1990 |publisher=Cambridge University Press |author=W. B. Harland |isbn=0-521-38361-7 |location=Cambridge |oclc=20930970}}</ref> 2004,<ref name="GTS2004">{{Cite book |url=https://www.worldcat.org/oclc/60770922 |title=A geologic time scale 2004 |date=2004 |publisher=Cambridge University Press |author1=F. M. Gradstein |author2=James G. Ogg |author3=A. Gilbert Smith |isbn=0-511-08201-0 |location=Cambridge, UK |oclc=60770922}}</ref> 2008,<ref name="GTS2008">{{Cite journal |last1=Gradstein |first1=Felix M. |last2=Ogg |first2=James G. |last3=van Kranendonk |first3=Martin |date=2008-07-23 |title=On the Geologic Time Scale 2008 |url=http://www.schweizerbart.de/papers/nos/detail/43/63825/On_the_Geologic_Time_Scale_2008?af=crossref |journal=Newsletters on Stratigraphy |language=en |volume=43 |issue=1 |pages=5–13 |doi=10.1127/0078-0421/2008/0043-0005 |issn=0078-0421}}</ref> 2012,<ref name="GTS2012">{{Cite book |url=https://www.worldcat.org/oclc/808340848 |title=The geologic time scale 2012. Volume 2 |date=2012 |publisher=Elsevier |author=F. M. Gradstein |isbn=978-0-444-59448-8 |edition=1st |location=Amsterdam |oclc=808340848}}</ref> 2016,<ref name="GTS2016">{{Cite book |last=Ogg |first=James G. |url=https://www.worldcat.org/oclc/949988705 |title=A concise geologic time scale 2016 |date=2016 |publisher=Elsevier |others=Gabi Ogg, F. M. Gradstein |isbn=978-0-444-59468-6 |location=Amsterdam, Netherlands |oclc=949988705}}</ref> and 2020.<ref name="GTS2020">{{Cite book |url=https://www.worldcat.org/oclc/1224105111 |title=Geologic time scale 2020 |date=2020 |author1=F. M. Gradstein |author2=James G. Ogg |author3=Mark D. Schmitz |author4=Gabi Ogg |isbn=978-0-12-824361-9 |location=Amsterdam, Netherlands |oclc=1224105111}}</ref> However, since 2013, the ICS has taken responsibility for producing and distributing the ICC citing the commercial nature, independent creation, and lack of oversight by the ICS on the prior published GTS versions (GTS books prior to 2013) although these versions were published in close association with the ICS.<ref name="ICC_Cohen_2013" /> Subsequent ''Geologic Time Scale'' books (2016<ref name="GTS2016" /> and 2020<ref name="GTS2020"/>) are commercial publications with no oversight from the ICS, and do not entirely conform to the chart produced by the ICS. The ICS produced GTS charts are versioned (year/month) beginning at v2013/01. At least one new version is published each year incorporating any changes ratified by the ICS since the prior version.

{{Timeline geological timescale}}