Search

The Arcas pond complex in Cuenca (Spain) develops within an interstratified karst system that affects gypsum deposits of the Cretaceous-Tertiary transition period. The formation of this complex is influenced by fracturing, which acts both as the preferential pathway for groundwater movement and the connecting and upward flow mechanism across aquifer formations. Such fracturing also favors the development of karst morphologies in the form of collapse dolines that are connected to the aquifer and which display a permanent character. Hydrochemical studies have allowed the identification of four types of ponds that show varying degrees of behavior and connection with the confined gypsum aquifer. Evaporation, oversaturation and gypsum and limestone mud precipitation processes take place in the more disconnected ponds. The study of the annual evolution of the water column in two of the ponds that show differing degrees of connection with the groundwater allows for an evaluation of the manner in which groundwater influences the stratification/mixing processes that take place in such ponds, and of the physico-chemical characteristics governed by these processes.