Mountain range uplift & climate system interactions in the Southern Central Andes Two of the most controversial issues concerning the late Cenozoic evolution of the Andean orogen are the timing of uplift of the intraorogenic Puna plateau and its eastern border the Eastern Cordillera and ensuing changes in climatic and surface process conditions in the intermontane basins of the NW Argentine Andes. The Eastern Cordillera separates the internally drained arid Puna from semi arid intermontane basins and the humid sectors of the Andean broken foreland and the Subandean fold and thrust belt to the east. With elevations between 4 000 and 6 000 m the eastern flanks of the Andes form an efficient orographic barrier with westward increasing elevation and asymmetric rainfall distribution and amount with respect to easterly moisture bearing winds. This is mirrored by pronounced gradients in the efficiency of surface processes that erode and re distribute sediment from the uplifting ranges. Although the overall pattern of deformation and uplift in this sector of the southern central Andes shows an eastward migration of deformation a well developed deformation front does not exist and uplift and associated erosion and sedimentary processes are highly disparate in space and time. In addition periodic deformation within intermontane basins and continued diachronous foreland uplifts associated with the reactivation of inherited basement structures furthermore make a rigorous assessment of the spatiotemporal uplift patterns difficult.