The Middle Permian to Lower Triassic succession of Oman has been studied in the Oman Mountains and detailed sections are presented, from slope deposits in the Jabal Sumeini area (Wadi Maqam units), to distal tilted blocks (Ba’id), basinal carbonates (Wadi Wasit) and oceanic deep-water deposits (Buday’ah).
The early Middle to Late Permian opening and extension of the Neo-Tethys Ocean resulted in the formation of a basin (Hawasina) and an adjoining continental slope (Sumeini). These paleogeographic elements were connected with the adjacent Arabian Platform and together formed the southern continental passive margin of the Neo-Tethys. Furthermore early-rifted blocks, structurally detached from the edge of the Arabian Shield, occurred as isolated platforms along the continental slope and were later incorporated into the Hawasina Nappes. These isolated platforms identified as exotics in the Ba’id and Jabal Qamar areas mainly comprise Middle to Late Permian open-shelf carbonates. The facies represented by these carbonates were more open marine than in the autochthonous Khuff-equivalent succession in the Oman Mountains. They represent a completely different development, related to drowning during the Early Triassic.
This new understanding of the stratigraphy as well as the architecture of the Arabian Platform margin and its interpretation as a slope, oceanic plateau and basin succession, provides new insights into the evo- lution of the coeval Khuff platform. In particular, this synthesis provides evidence for an active tectonic history along this margin, which is at odds with the simpler sea-level model for Khuff sedimentation.