215-ka History of sea-level oscillations from marine and continental layers in Argentarola Cave speleothems (Italy)

Abstract Several Quaternary sea-level changes are recorded by speleothems in the Argentarola Cave (Italy), which is currently flooded by the Mediterranean Sea. Speleothems with a sequence of continental layers and marine biogenic overgrowths (serpulid colonies), all presently covered by living serpulids, were sampled at water depths between −3.5 and −21.7 m. The composite sequence contains five marine and four continental layers, formed over the last 215 ka. The Mediterranean Sea flooded the cave during two short periods of MIS 7 (7.3 and 7.1), as well as during an episode at the end of MIS 6 and during MIS 5, when a thick biogenic overgrowth grew during MIS 5.2 and 5.4. Thin continental layers also formed during the LGM. This final speleothem layer was interrupted during the Holocene sea-level rise, but at different times in each speleothem. A Holocene sea-level curve has been constructed from this same layer. A thin marine layer, found only in the deeper stalagmites at −21.5 and −21.7 m, is tentatively related to the short marine transgression of Termination II, after 145 ka BP and before MIS 5.5. The island of Argentarola lies in a tectonically stable area and our data generally agree with the results obtained by other authors on speleothems from the Bahamas. The data presented here are compared with the SPECMAP curve and other recently published sea-level curves.