The Santa Cesarea Terme cave system: thermal sulphur springs in the Apulian foreland (southern Italy)

The sulphur springs of Santa Cesarea Terme (Apulia, southern Italy) flow out along a coastal sector of the Salento peninsula, part of the Apulian carbonate platform. The carbonate succession, consisting of over 5 km-thick Jurassic and Cretaceous limestone and dolostone, rests above Late Triassic evaporites, and is unconformably overlain by Cenozoic calcareous successions. Starting from the Early Triassic, the area was part of the Apulia carbonate platform, characterized by shallow-water carbonate sedimentation. Since Cretaceous times, it experienced a number of transgression-regression phases, giving rise to a succession characterized by multiple unconformities. Eventually, during the Middle Pleistocene, the area underwent a severe regional uplift. As concerns the main geological structures, the Santa Cesarea Terme area shows extensional and transtensional structures, with related pull-apart features. The NW-SE faults are the most diffuse, with subordinate presence of SW-NE, E-W and N-S fault systems. In particular, the NW-SE transtensional faults appear to be the youngest, also controlling the development of the main karst landforms identified. The thermal springs, used as spa since several decades, are, together with the village of Santa Cesarea Terme, in a structural high, with the caves located along the NW-SE fault zones.