pISSN 0705-3797 eISSN 2586-1298
HOME Article View


Episodes 2010; 33(3): 152-158

Published online September 1, 2010


Copyright © International Union of Geological Sciences.

The newly-ratified definition of the Quaternary System/Period and redefinition of the Pleistocene Series/Epoch, and comparison of proposals advanced prior to formal ratification

Philip L. Gibbard1 and Martin J. Head2

1Chair of the ICS Subcommission on Quaternary Stratigraphy; Department of Geography, University of Cambridge, Downing Place, Cambridge CB2 3EN, United Kingdom. E-mail: plg1@cam.ac.uk
2Department of Earth Sciences, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario L2S 3A1, Canada. E-mail: mjhead@brocku.ca

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


The base of the Quaternary System is defined by the Global Stratotype Section and Point (GSSP) of the Gelasian Stage at Monte San Nicola in Sicily, Italy, currently dated at 2.58 Ma. The base of the Pleistocene Series is redefined by the same GSSP, having previously been defined by the GSSP at Vrica, Calabria, Italy, which is dated at 1.806 Ma. These important changes to the geological time scale were formulated through extensive consultation with the Quaternary community through the International Union for Quaternary Research (INQUA), proposed by the International Commission on Stratigraphy’s (ICS) Subcommission on Quaternary Stratigraphy, endorsed by the voting membership of the ICS, and ratified in June 2009 by the Executive Committee of the International Union of Geological Sciences. Two competing proposals had been advanced: a ‘Neogene’ proposal advocated by the ICS Subcommission on Neogene Stratigraphy, and a ‘Quaternary’ proposal championed by the ICS Subcommission on Quaternary Stratigraphy. The status quo position would have persisted had neither proposal received a majority of votes. These proposals are compared and evaluated, the ‘Quaternary’ proposal is presented in detail, and future directions are discussed.