Tectonic implications of fluvial incision and pediment deformation at the northern margin of the Central Anatolian Plateau based on multiple cosmogenic nuclides

We document Quaternary fluvial incision driven by fault-controlled surface deformation in the inverted intermontane Gökırmak Basin in the Central Pontide mountains along the northern margin of the Central Anatolian Plateau. In situ-produced ¹⁰Be, ²¹Ne and ³⁶Cl concentrations from gravel-covered fluvial terraces and pediment surfaces along the trunk stream of the basin (the Gökırmak River) yield model exposure ages ranging from 7.0 ± 0.6 ka to 337 ± 43 ka and average fluvial incision rates over the past ~340 ka of 0.28 ± 0.01 mm a^-1. Similarities between river incision rates and coastal uplift rates support the inference that regional uplift is responsible for the river incision. Model exposure ages of surfaces on deformed pediments along tributaries of the trunk stream range from 48 ± 4 ka to 96 ± 9 ka, demonstrating that the thrust faults responsible for the pediment deformation were active at least until those times, and possibly remained active afterwards. Together, our data demonstrate cumulative incision that is linked to active internal shortening and uplift of ~0.3 mm a^-1 in the Central Pontide orogenic wedge at the northern margin of the Central Anatolian Plateau.