The reality of GSSPs

Abstract

The proposal that chronostratigraphic and geochronologic units are un-necessary and confusing is based on a mistaken concept of GSSPs. Each GSSP does represent a specific point in time, and two successive GSSPs do mark the beginning and end of an interval of time that is a geochronologic unit. But the supposition that this unit in time then serves to define a corresponding chronostratigraphic unit is mistaken. First, there were chronostratigraphic units and geochronologic units more than 100 years before there were GSSPs. The historical chronostratigraphic units that are the basis for much of the Geological Time Scale were defined on distinctive stratigraphic successions, and the time during which it was deposited is the corresponding geochronologic unit. GSSPs were established to identify specific stratigraphic levels that define the bases of the chronostratigraphic units and to resolve the problems when gaps and overlaps between successive units were later discovered. Unfortunately, the GSSP for a specific boundary is too often presented only as the single stratigraphic signal at which the boundary is placed in the stratotype section. Yet, in reality it only has significance for chronostratigraphic correlation when compared to the distribution of other stratigraphic signals in the boundary interval. Keywords: GSSP, chronostratigraphy, geochronology