Abstract

The geologic time scale is still evolving as stratigraphic resolution continues to increase. Establishment of a single world standard will facilitate communication and minimize intercontinental miscorrelations. The International Union of Geological Sciences serves to coordinate committees and formally ratify components of the proposed world standard, and has erected a set of criteria and procedures for selecting pertinent chronostratigraphic units as references.

Knowledge of the Permian System has advanced considerably over the past decade. International concensus on its chronostratigraphic components will permit timely adoption of a world Permian standard. The working scheme currently under consideration is reviewed, and its status evaluated. That scheme comprises early Permian references in the Ural Mountains, middle Permian references in West Texas, and late Permian references in South China.

Whereas the early and late Permian references have received general acceptance from the international community, there is some reservation in adopting the West Texas standards. Reluctance to incorporate West Texas into the world scheme is based on a general sense that paleotethyan standards would provide simpler correlations across the broad expanse of Eurasia. Superiority of the West Texas references is reviewed and contrasted with the paleotethyan standards. The long-established tradition of detailed stratigraphic work in the Permian Basin is a major factor strengthening the candidacy of the West Texas references.