Gypsum karst evolution in a diapir: a case study (Pinoso, Alicante, Spain)

Gypsum deposits are highly soluble, and can undergo rapid weathering, especially where water intervenes, though certain human activities can accelerate the karstification processes. An example of karst formed in gypsum at Pinoso (Alicante, Spain) is analysed to show how human activity has impacted on its evolution. The karst here is associated with a huge diapir in the Triassic terrain that boasts of a large number of highly unusual exokarstic landforms. Here, rock salt has been extracted commercially for over 25 years using solution mining via deep boreholes. The brine extracted contains in excess of 300 g/L; over the whole period, more than 12 million tonnes of salt have been extracted using this method. After preliminary treatment to remove impurities, it travels along a brine pipeline to the coast. The enormous volume of the voids generated have probably favoured the acceleration of certain exokarstic and endokarstic processes.