oa Biostratigraphy, chemostratigraphy and subsurface correlation of the Permian-Triassic interval in the Arabian Platform and the Musandam Peninsula, Ras Al-Kaimah, United Arab Emirates

This study examines the biostratigraphy and chemostratigraphy of the Permian-Triassic Khuff Formation. It integrates these disciplines with concepts of modern carbonate sedimentology and facies analysis and current sequence stratigraphic concepts to generate a basinwide, high-resolution chronostratigraphic framework. The Khuff Formation in the subsurface of the Arabian Platform and its time-equivalent strata span a range of approximately 12.5 million years (My). Based on foraminifera identification, chemostratigraphy, and regional correlation, age assignments for the Bih, Hagil, and Ghail formations are slightly younger than previously recorded. The base of the study interval (below prominent “white bed”/breccia within the Bih) is Midian-Capitanian in age based on regional correlation and is time-equivalent to the Khuff K5 interval in the subsurface. The Bih Formation correlates to the Khuff K4 and K3 in the subsurface. Regional correlation, suggest that the Hagil ranges in age from Griesbachian (possibly as old<br>as Changhsian) to Spathian and correlates to the Khuff K3 to K1 zones and the Sudair Formation. The Permian-Triassic (PT) boundary is tentatively placed in a zone straddling the Bih-Hagil contact. The Hagil–Ghail contact marks the base of the Anisian and not the PT boundary as previously published. The zone (10 ft) proximal to the Hagil-Ghail contact represents nearly 2–3 My of missing time. The Ghail is time-equivalent to the Sudair Formation in the subsurface. This framework provides a model for assessing the distribution of reservoir and seal during exploration, and for layering the reservoir during field development.