On-going reduction of endoreism in the central Anatolian plateaus.

International audienceSince Late Miocene in Anatolia, uplift, faulting and sliding have generated the encircling of a central zone limited south by the Taurus highlands with summits reaching 3000 m to >4000 m. Meantime, the uplift of the central zone reached 1000-1500 m asl while major strike-slip fault zones, sheared and faulted block systems. Rapidly, the uplift of the highlands encircling Anatolia caused the incision of valleys and deep canyons radiating from the highlands in direction of the seas surrounding the peninsula, while central Anatolia formed a more or less high depression at 1000-1500m asl. This central zone presents today patches of (i) plateaus and low hills corresponding to remains of erosion and structural surfaces truncating carbonate deposits, and (iii) volcanic massifs constructed after Late Miocene. During and after uplift, thick series of emerged carbonates were subjected to dissolution producing a high variety of surface and underground karstic features. In the highlands, stages in the deepening of the underground karst (eg. forming stepped floors separated by sloped to vertical tunnels) record slowing phases in the uplift. In parallel, the slower uplift of central Anatolia protected the central plateaus from incision, allowing karstic features to remain superficial, with low Plio-Pleistocene limestone plateaus alternating with poljes. As a result, the hydrography of central Anatolia is mostly endhoreic (ie. no outflow to the sea) with depressions often corresponding to faulted poljes in which water occurrences mostly occur as karstic springs, and freshwater to salty marshes and lakes.Recent interpretation of three large depressions bordering the northern slopes of the Taurus from the Isparta Angle to the Aladağlar range (Konya-Ereğli, Tuz Gölü and Sultansazlığı plains) evidence, together with hydrogeologic monitoring of underground water, that these closed depressions are being captured today by Mediterranean and Black Sea exhoreic drainage. This capturing is controlled by both the tectonic regimes that has affected Anatolia during Pleistocene, and by the karstic processes dissolving the carbonates. The result of these observations is that the combination of tectonics and karstic dynamics is opening a new stage in the dismantling of the endhoreic central Anatolia. In eastern Anatolia where the uplift is more recent and active, connections between underground and surface erosion processes are not as much developed. In this latter region, “capture-to-be” locations exist where (i) tectonically-controlled lines concentrate surface erosion in limestones (fault lines, canyons), and (ii) surface and deep karst features develop actively in limestone massifs separating tectonically mobile watersheds