Integrated Biostratigraphy of the Saiq Formation (Al Jabal al-Akhdar, Oman Mountains) and its Implication for the Regional Correlation of Khuff Time-equivalent Deposits

We present a multi-disciplinary approach (sequence-biostratigraphy, palaeoenvironmental analysis, gamma-ray, and carbon isotopes) for the stratigraphic subdivision of Khuff timeequivalent deposits in Oman (Saiq and lower Mahil Formation, Al Jabal al-Akhdar). The Khuff is herein subdivided into six third-order depositional sequences. According to the proposed biostratigraphic zonation, the KS6 to KS5 is Middle Permian (Roadian?–Wordian– Capitanian), the KS4 to basal KS2 is Late Permian and the remaining part of KS2 and KS1 is Early Triassic. Major biotic crises occurred during the upper KS5 (“end-Guadalupian faunal crisis”) and in the basal KS2 (“end-Permian faunal extinction”). The transition from Middle to Late Permian is further accompanied by a palaeoenvironmental shift from a differentiated bioclastic ramp to more uniform microbial-mediated platform deposits. The biozonation and biotic events have been applied to correlate outcrop sections and subsurface on a regional scale across the Arabian Platform.