The end Permian negative d13C excursion is well known but its cause and chronology are still in question.
In an attempt to decipher the timing and reasons for this strong decrease, we established high-resolution
sedimentological, biostratigraphical and carbonate carbon isotopic studies in four sections in Iran (Abadeh,
Shareeza, Zal and Djulfa) and two in Oman (Wadi Sahtan). The position of the sections on two different
margins of the Neotethys has allowed us to distinguish between local and global signals. This highresolution
chemostratigraphy, tested for isochrony on the basis of an updated high-resolution conodont
and ammonoid biostratigraphy, allows the discrimination of nine successive isotopic events (IE 0–8) for
the Permian–Triassic Boundary Interval (PTBI).