Simplifying the stratigraphy of time

Abstract

We propose ending the distinction between the dual stratigraphic terminology of time-rock units (of chronostratigraphy) and geologic time units (of geochronology). The long-held, but widely misunderstood, distinction between these two essentially parallel time scales in stratigraphy has been rendered unnecessary by the widespread adoption of the global stratotype sections and points (GSSP-golden spike) principle in defining intervals of geologic time within rock strata. We consider that the most appropriate name for this stratigraphic discipline is chronostratigraphy, which would allow geochronology to revert to its mainstream and original meaning of numerical age dating. This in turn makes the little- used formal term geochronometry redundant. The terms eonothem, erathem, system, series, and stage would become redundant, in favor of eon, era, period, epoch and (disputably) age. Our favored geologic time units may be qualified by early and late, but not by lower and upper. These suggested changes should simplify stratigraphic practice, encompass both stratified and nonstratified rocks, and help geologic understanding, while retaining precision of meaning