Abstract
During the evolution of the Vallès-Penedès basin, several transgressive pulses in the upper Burdigalian led to a partial flooding of the western part of the basin, leaving locally sabkha-salina evaporite sediments in the area of the village of Vilobí. Due to its geometric configuration with a restricted access to the open sea, deeper marine evaporites do not occur in the basin. A mathematical model of fluid circulation, evaporation outflow, solute transport and evaporite deposition is applied in order to test possible paleogeographic, hydrological and climatic conditions which may have influenced salinity of sea water in the upper Burdigalian Vallès-Penedès embayment. Simulation results indicate that the absence of marine gypsum sediments in the basin may be related to a significant freshwater supply. The shift from the Neogene basin drainage pattern along the complete basin axis with elevated freshwater discharge to the river drainage towards the Barcelona area occurred at later stages of the basin evolution.