CHRONOLOGY OF SUTURING AND POST-COLLISIONAL DEFORMATION OF THE ANATOLIAN OROGENY, TURKEY: INSIGHTS FROM GEOCHRONOLOGY AND SEDIMENTOLOGY OF THE SARICAKAYA BASIN, WESTERN ANATOLIA

Central Anatolia is a complex assemblage of terranes that collided during the late Cretaceous and Paleogene (80–25 Ma). The most significant central Anatolian collisional orogen, between the Pontide and Tauride-Anatolide terranes­, is demarcated by the >1800 km Izmir-Ankara-Erzincan suture zone. This collision closed the Neotethys Sea and had a profound impact on Eurasian and African fauna by shaping land bridges and favoring local endemism. Understanding the chronology of suturing and the mechanisms of post-collisional deformation is particularly important to test kinematic reconstructions, geodynamic models and paleo-biogeographic scenarios of the Mediterranean region. However, the precise timing and mechanisms of suturing, post-collisional deformation and orogenic development remain controversial.

Here, we investigate the timing and dynamics of suturing and deformation in the Saricakaya Basin, a 100 km long basin on the Pontides developed along the Izmir-Ankara-Erzincan suture zone. The Saricakaya basin exposes a thick, Paleocene(?)-Eocene sedimentary sequence thrusted by post-collisional orogenic build-up, making this basin an ideal location to determine the chronology of collision and early fold and thrust belt development. New age constraints from U/Pb dating of volcanic deposits, and new data from U/Pb detrital zircon geochronology, sandstone petrology and sedimentary facies reveal changes in provenance and depositional environments related to the post-collisional evolution of the suture zone. These results improve understanding of how the Anatolian orogeny evolved through time and provide key constraints to investigate how regional geodynamics influenced Middle Eastern biogeography.