The Permian-Triassic Boundary in the Kurdistan Region of Northern Iraq

Abstract

The well-preserved Upper Permian-Lower Triassic succession in the Kurdistan region of northern Iraq has provided an opportunity to study the Permian-Triassic boundary. This study presents the first ever stable isotope data for these rocks. One hundred and sixty-five samples from the Ora-Beduhe and CZO sections located within the Ora structure in the Thrust Zone were studied for lithological, stable isotope, trace fossil and invertebrate fossil variations.  Carbon and oxygen isotopic signals (d¹³C, d¹⁸O) and %CaCO₃ indicate dramatic changes within the CZO section (between samples 29 and 30) where d¹³C records a negative excursion of 6‰ VDP in a portion of the section previously interpreted as late Permian. The P-T boundary matching the lithic changes and extinction of Permian fauna, in addition to another boundary or contact were identify between (samples 16 and 17) which is marked due to severe decreasing in late Permian fauna and appearance of early Triassic. Paleontological record suggests a gradational extinction pattern for the boundary in northern Iraq. Faunal changes are consistent with other regional and global studies for the Permian-Triassic boundary.

Keywords: Permian-Triassic boundary, Kurdistan, Northern Iraq, Stable Isotopes, Neo-Tethys