Global Boundary Stratotype Section and Point (GSSP) for the Anthropocene Series: Where and how to look for potential candidates
Résumé
The Anthropocene as a potential new unit of the International Chronostratigraphic Chart (which serves as the
basis of the Geological Time Scale) is assessed in terms of the stratigraphic markers and approximate boundary
levels available to define the base of the unit. The task of assessing and selecting potential Global Boundary
Stratotype Section and Point (GSSP) candidate sections, a required part of the process in seeking formalisation of
the term, is now being actively pursued. Here, we review the suitability of different stratified palaeoenvironmental
settings and facies as potential hosts for a candidate GSSP and auxiliary sections, and the relevant
stratigraphical markers for correlation. Published examples are evaluated for their strengths and weaknesses in
this respect. A marked upturn in abundance of radioisotopes of 239Pu or 14C, approximately in 1952 and 1954 CE
respectively, broadly coincident with a downturn in δ13C values, is applicable across most environments.
Principal palaeoenvironments examined include: settings associated with accumulations of anthropogenic material,
marine anoxic basins, coral reefs, estuaries and deltas, lakes at various latitudes, peat bogs, snow/ice
layers, speleothems and trees. Together, many of these geographically diverse palaeoenvironments offer annual/
subannual laminae that can be counted and independently dated radiometrically (e.g. by 210Pb). Examples of
possible sections offer the possibility of correlation with annual/seasonal resolution. From among such examples,
a small number of potentially representative sites require the acquisition of more systematic and comprehensive datasets, with correlation established between sections, to allow selection of a candidate GSSPand auxiliary stratotypes. The assessments in this paper will help find the optimal locations for these sections.