Stratigraphy and tectonosedimentary evolution of a late Aptian-Albian carbonate margin: the northeastern Jebel Akhdar (Sultanate of Oman)

Abstract

Upper Aptian-Albian shallow-water carbonates with rudists, large foraminifera and calcareous algae are described from northern Oman, in the northeastern part of the parautochton of Jebel Akhdar. The corresponding lithostratigraphic unit, the Al Hassanat Formation, is partly a time equivalent of the Nahr Umr Shales of Albian p.p. age which have a wide extent on the Arabian craton. The Al Hassanat platform developed in two main phases. First, during the late Aptian-early Albian, the platform was fringing an emerged area (central Jebel Akhdar) with a limited extent basinward. Then, during the middle Albian the flooding of the central Jebel Akhdar resulted in an extensive development of the platform and a connection with the Nahr Umr shelf. This sedimentary evolution and its palaeogeographic expressions were mainly controlled by structural patterns: extensive uplift and block faulting to the edge of the antecedent (early Aptian) platform, with a significant differential subsidence then a sag of the Arabian promontory. This tectonosedimentary dynamics was related to the migration of the oceanic adjacent Tethyan plate, and took place during the global geodynamic Albian revolution.