Chronology of Middle Pleistocene Coastal Karst Evolution and Relative Sea-Level Changes in Mallorca

Sea-level change affects the geomorphic evolution of littoral regions in multiple ways. In carbonate coastal regions, sea-level oscillations control the type and occurrence of karst processes such as mixing corrosion, speleothem deposition, and collapse. A variety of cave deposits exist above, below, and at sea level. Among these, the vadose speleothems can provide indirect constraints on maximum sea-level boundaries, record changes from vadose to phreatic phases as littoral groundwaters flood the caves due to sea-level rise, and document different coastal speleogenetic stages. Here, new LTseries ages for speleothems from three sites along the eastern coast of Mallorca (Cala Falco, Dimoni, and Sa Ferradura) are presented and used to discuss the effects of relative sea-level oscillations upon coastal karst evolution between similar to 1500 and similar to 440 kyr before present. The paleo-speleothem record provides new tirrieframes for periods of vadose conditions allowing to place some relative sea-level constraints in the western Mediterranean, particularly for the Marine Isotope Stages 16 to 12. Periodic sea-level oscillations following glacial/interglacial cycles caused morphological changes within the paleo-caves. The sequences of collapsed karst features and vadose speleothems, coupled with geomorphological evidence and previous published sea-level records, support an interpretation for the occurrence of breakdown events during cold intervals following MIS 11, 9, and 7 sea-level high stands. Further collapses and dismantling of caves happened after MIS 5 high sea stands and throughout the Holocene.