Candidate sites and other reference sections for the Global boundary Stratotype Section and Point of the Anthropocene series

Abstract

We review and compare proposals for 12 reference sections submitted to the Anthropocene Working Group of the International Subcommission on Quaternary Stratigraphy, of which one will be recommended as the Global boundary Stratotype Section and Point (GSSP) to define the base of the Anthropocene as a series within the Geological Time Scale. The sites span five continents and are located in diverse environments, with all but one sampled by coring. Many sites show annually resolved laminae (here considered optimal for GSSP selection) that can be independently dated radiometrically to confirm a complete succession over the critical interval. An extensive range of proxies, documenting profound human modification of the Earth System at around the mid-20th century interval, has been analysed. Airborne signals (e.g. radioisotopes, fly ash, stable carbon and nitrogen isotopes) provide the most widespread and near-isochronous proxies, applicable across most environments. Additional means of correlation include the appearance of microplastics and persistent organic pollutants, and shifts in heavy metal concentrations and lead isotope ratios. Assemblage changes of microfossils (and some macrofossils) in marine, estuarine and lake settings reflect environmental changes and biological introductions. These systematic and comprehensive datasets, with correlation established between sections, provides the basis for a proposal to formalize the Anthropocene.

A 20th-centuryCannabispollen increase in a Pyrenean varved record and its potential causes

“…Another interesting observation is that the major vegetation shift documented above and the 20C occurred at or shortly after the onset of the “Anthropocene”, as currently defined by the Anthropocene Working Group (AWG) (Waters et al, 2023). Indeed, the AWG proposes that this boundary should be situated in the mid-20 th century, coinciding with the Great Acceleration, when the Earth System underwent a global transformation overcoming the range of variability of the Holocene (Steffen et al, 2015).…”

“…Other interesting observations are that the vegetation shift recorded in the 1960s occurred around the onset of the “Anthropocene” – as currently defined by the Anthropocene Working Group (AWG) in its prospect for the formalization of this new epoch (Waters et al, 2023) – whereas the 20C took place a couple of decades later. This, together with the high resolution (seasonal) of the Montcortès record, suggests that the sediments of this lake could be a suitable candidate to identify and date an eventual “Anthropocene” GSSP (Global Stratotype Section and Point), which is a requirement for the definition of a new formal chronostratigraphic unit (Waters et al, 2018).…”

Optimising the Anthropocene definition: an epistemological view with briefings on four 2022-23 conferences

“…With an incremental AWG-SQS-ICS-IUGC protocol underway to define the term, or not, as a GTS addition, we offer an epistemological view of the Anthropocene with its divergent approaches-as a recent and discrete epoch proposed by Waters et al (2022), Waters and Turner (2022) and Waters et al (2023) and as a gradually unfolding event proposed by Gibbard et al (2022), Edwards et al (2022) and Merritts et al (2023)-to what has become both a geological and historical concept. At issue is whether the Anthropocene is amply considered with the GSSP toolkit of chronostratigraphy: we think not.…”

The Anthropocene as an epoch is distinct from all other concepts known by this term: a reply to Swindles et al. (2023)

“…Numerous studies by the AWG (e.g. Zalasiewicz et al, 2019;Waters et al, 2022Waters et al, , 2023 have highlighted the many stratigraphic indicators that can be used to trace the base of the chronostratigraphic Anthropocene with strikingly high precision (a decade to a few calendar years in some cases), on a global scale, and in a wide range of sedimentary settings (Waters et al, 2018;Waters and Turner, 2022;Fig. 1).…”

“…Within this event array, the primary guide to the Global boundary Stratotype Section and Point is likely to be the plutonium isotopic signal, which reflects nuclear weapons testing from 1945 onwards (Waters et al, 2015(Waters et al, , 2019. This signal has a detectable global upturn in the stratigraphic record beginning around and soon after the year 1950 (Han et al, 2023;McCarthy et al, 2023;Waters and Turner, 2022;Waters et al, 2023;Fig. 1) and in a range of stratigraphic settings.…”