• Global Boundary Stratotype Sections and Points (GSSPs)
  compiled by J.Ogg for the International Commission on Stratigraphy - modified version by PLG March 2004.

Please note that this chart differs from that currently proposed by the International Commission on Stratigraphy (ICS), published in Episodes 27, issue 2, 2004 and the Global chronostratigraphical correlation chart for the last 2.7 million years (below). This is because the status of the term 'Quaternary' is disputed, with the ICS 'defining' the term as "traditionally considered to be the interval of oscillating climatic extremes... that was initiated at 2.6 Ma, therefore encompasses the Holocene and Pleistocene epochs and Gelasian Stage of late Pliocene. This composite epoch is not a formal unit in the chronostratigraphic heirarchy" (Table 1: Gradstein et al. 2004). By a very large majority, Quaternary scientists regard the 'Quaternary' as a fully formal chronostratigraphical unit of system/period status, a climatostratigraphical element has never previously been included in its definition. This definition has been established by historical precedent over two centuries. Also in keeping with historical precedent, the Neogene System/Period ends at the base of the Quaternary, as shown in the correlation charts on these pages.

The final status of this terminology has yet to be resolved since none of the changes proposed by Gradstein et al. (2004) have been subjected formally to examination or approval by representatives of the communities concerned. Gradstein et al.'s (2004) definitions therefore have the status of recommendations or suggestions.

For further discussion of these points, please consult:
Ogg, J. 2004 Introduction to concepts and proposed standardisation of the term'Quaternary'. Episodes 27, 125-6.
Pillans, B. 2004 Proposal to redefine the Quaternary Episodes 27, 127.