Palaeozoic stratigraphy: past, recent advances and future challenges

Abstract

The Palaeozoic Era ranged from 541.0 ±1.0 Ma to 252.17 ±0.006 Ma based on the latest International Chronostratigraphic Chart. Of the 48 stages, 12 have no defined and/or ratified GSSPs (mostly in Cambrian, Carboniferous and Permian) and at least six boundaries are in the process of being revised. For some better-resolved series and stages, international subcommissions are now working on refining the time scale and on the definition of substages or formal stage slices based primarily on biostratigraphic or bio-chemostratigraphic subdivisions. Future challenges in stratigraphy will focus on integrating different lines of stratigraphic evidence when defining a GSSP and on the refinement of the numerical calibration of the geologic time scale. Keywords: Palaeozoic, Stratigraphy