The Permian-Triassic Boundary Beds in Central Tethys

Abstract The classical and most important areas for the study of Permian-Triassic boundary beds, with the exception of that at Kap Stosch, East Greenland, are in central Tethys. This report discusses the stratigraphy and paleontology of these boundary beds in the Salt Range and Trans-Indus ranges of West Pakistan, the Julfa region of northwest Iran, and at Guryul Ravine near Srinagar, Kashmir. The Permian-Triassic contact in the Salt Range and Trans-Indus ranges is interpreted as a paraconformity reflecting a recession of the sea and an emergent condition in latest Permian time followed by a transgression in the earliest Triassic as defined by the first appearance of Ophiceras. These earliest Triassic strata also contain a variety of Permian-type brachiopods which are interpreted as short-lived survivors from the underlying Permian. The controversial strata of the Dzhulfa region of Soviet Armenia, and now known from the adjacent region of northwest Iran that contains the so-called mixed faunas, are considered to be of Late Permian age. New finds of ammonites, especially genera known previously only from the Changhsing Limestone of Kwangsi, China, are part of the basis for this interpretation. In Guryul Ravine are strata with Claraia that contain Permian-type brachiopods. We interpret these beds as of Early Triassic age.