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Episodes 2021; 44(3): 241-247

Published online September 1, 2021


Copyright © International Union of Geological Sciences.

Formal ratification of subseries for the Pleistocene Series of the Quaternary System

by Martin J. Head1*, Brad Pillans2, Jan A. Zalasiewicz3 and the ICS Subcommission on Quaternary Stratigraphy4

1 Department of Earth Sciences, 1812 Sir Isaac Brock Way, Brock University, St. Catharines, Ontario L2S 3A1, Canada
2 Research School of Earth Sciences, The Australian National University, Acton, ACT, 2601, Australia
3 School of Geography, Geology and the Environment, University of Leicester, University Road, Leicester LE1 7RH, UK
4 Table 1

Correspondence to:*E-mail: mjhead@brocku.ca

Received: February 9, 2020; Revised: September 8, 2020; Accepted: September 8, 2020

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 Pleistocene Series/Epoch of the Quaternary System/ Period has been divided unofficially into three subseries/ subepochs since at least the 1870s. On 30th January, 2020, the Executive Committee of the International Union of Geological Sciences ratified two proposals approved by the International Commission on Stratigraphy formalizing: 1) the Lower Pleistocene Subseries, comprising the Gelasian Stage and the superjacent Calabrian Stage, with a base defined by the GSSP for the Gelasian Stage, the Pleistocene Series, and the Quaternary System, and currently dated at 2.58 Ma; and 2) the term Upper Pleistocene, at the rank of subseries, with a base currently undefined but provisionally dated at ~129 ka. Defining the Upper Pleistocene Subseries and its corresponding stage with a GSSP is in progress. The Middle Pleistocene Subseries is defined by the recently ratified GSSP for the Chibanian Stage currently dated at 0.774 Ma. These ratifications complete the official division of the Pleistocene into three subseries/ subepochs, in uniformity with the similarly subdivided Holocene Series/Epoch.