Structure And Kinematics Of The Central Sivas Basin (Turkey): Salt Deposition And Tectonics In An Evolving Fold-And-Thrust Belt

The Sivas Basin in central-eastern Anatolia is a north-verging salt-bearing fold-and-thrust belt including synorogenic salt tectonics. It formed between the northern leading edge of the Taurides platform and the Kirsehir block since Late Cretaceous time. We have constructed five regional cross-sections supported by field data and 2D seismic to constrain the structure of the basin and its evolution. The area is divided into three tectonic domains from south to north: (1) a Maastrichtian to Eocene north-verging fold-and-thrust belt, which terminates by a regional Eocene evaporitic level; (2) an Oligo-Miocene salt domain which contains two generations of minibasins separated by a salt canopy, forming a salt-and-thrust belt; and (3) a late Miocene to present day foreland basin. The cross-sections show the along-strike variations and the increasing shortening in the fold-and-thrust belt from west (c. 15 km) to east (c. 25 km). The thick salt allows for the intracutaneous propagation of the fold-and-thrust belt below a domain of salt withdrawal minibasins, decoupled as the initial salt thickness increases. In that case, the salt domain is thrusted both frontward and backward. Efficient exhumation followed by erosion of the fold-and-thrust resulted in synorogenic salt tectonics in the foreland and thus increased the mechanical resistance between them.