Integrated analysis of fluvial drainage pattern, digital topography and regional tectonics allows to determine the lateral extent of high topography linked to the extensional system of faults that parallels the coastline of the northeastern Iberia. The development and rise of the present morphotectonic units of Sierra Prelitoral (upper Oligocene-Lower Miocène) and Sierras Transversales (upper Miocene to present) as rift flarik processes, reorganized the previous fluvial drainage system and originated thé present one.
The Sierra Prelitoral bounds the NE-SW trend of faults that limit the El Camp and Vallès-Penedès grabens whereas the Sierras Tansversals bound the NNW-SSE trend of faults related to the Empordà graben system. The different relative positions of external normal fault, maximum local relief and water divide in the Sierras Tansversals support the idea of very young topography related to active normal faulting