Journal of International Geoscience

ArchivesVol 40 No 1 (Mar, 2017)

Sub-series and sub-epochs are informal units and should continue to be omitted from the International Chronostratigraphic Chart

DOI: 10.18814/epiiugs/2017/v40i1/017002


  • Paul N. Pearson (School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF103AT, UK)
  • Bridget S. Wade (Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK)
  • Jan Backman (Department of Geological Sciences, Stockholm University, Svante Arrhenius vag 8, SE-106 91 Stockholm, Sweden)
  • Isabella Raffi (Dipartimento di Ingegneria e Geologia, Universita ``G. D`Annunzio`` di Chieti-Pescara, Via dei Vestini 31-66013 Chieti, Italy)
  • Simonetta Monechi (Dipartimento di Scienze della Terra, Università di Firenze, Via La Pira 4, 50121-Firenze, Italy)


In June 2016 the Paleogene, Neogene, and Quaternary subcommissions (ISPS, SNS, SQS) of the International Commission on Stratigraphy (ICS) voted on whether to formalize sub-series and their geochronologic equiva-lents, sub-epochs. The vote required a 60 percent major-ity for the proposal to be forwarded to the ICS for further consideration. That majority was not achieved, albeit by a narrow margin, hence sub-series and sub-epochs are currently to be regarded as informal, and if used should carry a lower case modifier, as in lower Miocene and early Pleistocene. To accompany the vote, those who favoured continuation of informal usage were asked to prepare a short summary of the main arguments in support of their viewpoint, as were the proponents of the formalization case. Although this statement was not originally intended for publication, it is reproduced here at the request of the Former Chair of the ICS, so as to put it on record.

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