Chapter 2 - The Permian and Triassic Chronostratigraphic Scales—Framework for Ordering Events

Abstract

The Permian and Triassic chronostratigraphic scales provide the basic temporal framework for understanding all geological and biotic events that took place during most of the Pangean interval of Earth history. Nearly two centuries of research have developed these chronostratigraphic scales, and their current integration with radioisotopic ages, magnetostratigraphy, and chemostratigraphy continues to refine and improve the resolution of geological age assignments and correlation during the Permo-Triassic. In 1841, Murchison coined the term Permian for strata in the Russian Urals. Recognition of the Permian outside of Russia and Central Europe soon followed, but it took about one century for Permian to be accepted globally as a distinct geological system. The work of the Subcommission on Permian Stratigraphy began in the 1970s and resulted in the current chronostratigraphic scale of nine Permian stages in three series: Cisuralian (lower Permian)—Asselian, Sakmarian, Artinskian, Kungurian; Guadalupian (middle Permian)—Roadian, Wordian, Capitanian; and Lopingian (upper Permian)—Wuchiapingian and Changhsingian.