Tectonic, Fluid, and Storm-Driven Evolution of a Collisional Evaporite System: Insights from the Multi-Stage Tekman-Karayazı Sub-Basin (Eastern Anatolia)-Türkiye

The Miocene Tekman–Karayazı Sub-basin (TKSB) in Eastern Anatolia records a key stage in the transition from marine to continental conditions during the final closure of the Neotethys. This study reveals a previously unrecognized evaporite system composed of clastic sulphates, primary selenite crystals, and fluidized sulphate domes, formed under the combined influence of tectonically active deformation and high energy surface processes. Field and petrographic data show that evaporitic activity began earlier than previously thought. The replacement of large benthic foraminifera such as Nummulites within older carbonate units, together with gypsum filled porosity, points to long lived sulphate circulation and repeated diagenetic overprinting. Occasional halite pseudomorphs further reflect episodic hypersaline conditions and early mineral transformation. A major outcome of this study is the evidence for vertical recycling of older marine derived brines into Miocene deposits. We link this process to tectonically driven fluid pumping, likely enhanced by lithospheric scale processes such as lithospheric dripping and lithospheric delamination. These mechanisms promoted uplift, increased permeability, and sustained fluid migration through the basin. Sedimentary structures such as hummocky and swaley cross stratification indicate repeated storm wave influence in a high energy shoreface setting. At the same time, deformation features including liquefaction structures, syn depositional faulting, and gypsum injections point to strong seismic control. While storm and tidal processes contributed to sediment instability, seismic events appear to have been the dominant trigger. Overall, the TKSB represents a dynamic evaporite system where tectonics, seismicity, and surface processes operated together to shape sedimentation, deformation, and fluid flow.