Different stress states in the Burdur–Isparta region (SW Turkey) since Late Miocene times: a reflection of a transient stress regime

The Burdur–Isparta region is a transitional zone between two distinct neotectonic domains in Turkey: the Burdur graben system as the northeastern part of the Fethiye–Burdur fault zone and the Kovada graben at the apex of the Isparta angle. Each domain represents a particular stress regime. Fault data from unconsolidated Pliocene and Quaternary deposits were combined with stress states deduced from pre-Pliocene consolidated rocks in order to reconstruct the stress field evolution in the study area since Late Miocene. Different stress states were identified. They were put in a stratigraphic framework and U/Th dating of fault-related calcite precipitates proved to be an additional tool in constraining the history of the stress states. The reconstructed history reflects a transient stress regime. The evolving stress field indicates that the influence of the Kovada stress regime fades through time and that the influence of the Burdur stress regime is gaining importance, suggesting a northeastwards progression of the Fethiye–Burdur fault zone.