Late Cretaceous–Miocene sedimentary development of the Arabian continental margin in SE Turkey (Adıyaman region): Implications for regional palaeogeography and the closure history of Southern Neotethys

Abstract

The Middle Cretaceous–Late Miocene sedimentary successions that are exposed on the Arabian continental margin (near Adıyaman) provide valuable insights into sedimentary, tectonic and climatic processes that affected the Southern Neotethys and its continental margins. Deposition in the region began with Aptian–Early Campanian shelf carbonates, followed by deepening during the Mid-Campanian. Lithoclastic–bioclastic turbidites accumulated along the downfaulted northern margin of the Arabian platform during the Campanian. A flexurally controlled foredeep developed in advance of the emplacement of Mesozoic allochthonous continental margin and oceanic rocks during the latest Campanian–Early Maastrichtian (e.g. supra-subduction zone Koçali ophiolite). Alluvial detritus was shed from the emplaced allochthon in non-marine to shallow-marine deltaic settings during latest Campanian–Early Maastrichtian. A marine transgression resulted in the establishment of a shallow-marine shelf during the mid-Maastrichtian. During the latest Maastrichtian, the platform submerged, initiating deeper-water hemipelagic sedimentation. Uplift took place during the Palaeocene resulting in sediment instability, slumping and formation of high-density, subaqueous gravity flows. In response to regional faulting and tilting, some areas in the north and the southwest emerged during the Early–Middle Eocene generating alluvial fans in a warm, humid climate that favoured oxidation and reddening. The likely control of the tectonic instability was far-field compression related to the latest stages of subduction of the Southern Neotethys or the initial stages of collision of the Arabian and Tauride continents. An Oligocene hiatus is likely to reflect the formation of a collision-related forebulge, followed by flexural subsidence to form an Early Miocene foreland basin. This was finally over-ridden by the northerly, active continental margin of the Southern Neotethys during Early–Mid Miocene. Regional suture tightening (Mid–Late Miocene) and related non-marine coarse clastic sedimentation was followed by westward ‘tectonic escape’ of the Anatolian microplate towards the Aegean region during Plio-Quaternary time.