First Balanced Cross Section Across the Taurides Fold-Thrust Belt: Geological Constraints on the Subduction History of the Antalya Slab in Southern Anatolia

摘要

Eastern Mediterranean subduction accommodated Africa-Eurasia convergence since Mesozoic time and produced multiple subducted slab fragments in the mantle below Anatolia. These included the north dipping Cyprus and ENE-dipping Antalya slabs, which are currently separated by an upper mantle slab gap. Segmentation of these slabs, and associated mantle flow, may have contributed to 8 Ma uplift of the Central Anatolian Plateau. The western Central Taurides fold-thrust belt in southern Turkey is in the upper plate above the Antalya slab and contains a geological record of its subduction. We present the first orogen-scale balanced cross section of the Taurides and find that it formed in two stages: (1) Cretaceous to middle Eocene thrusting resulted in a minimum of 73-km shortening, and (2) Mio-Pliocene thrusting resulted in a minimum of 17.5-km shortening. Eocene shortening accounts for only similar to 5 Myr of Africa-Eurasia plate convergence. It is unlikely that 400 km of post to middle Eocene plate convergence was accommodated between the Taurides and its Beydalar platform foreland and instead must have been accommodated south of Beydalar. The associated southward plate boundary jump separated the Antalya slab from the African plate and the Cyprus slab. The isolated Antalya slab was left in an intraplate setting and is probably still attached to Beydalar today. We suggest the continental composition of the Antalya slab may have prevented its detachment. Finally, the gap between the Antalya and Cyprus slabs existed since at least Eocene time; their decoupling likely did not contribute to late Neogene Central Anatolian Plateau uplift.