The paper deals with the chronostratigraphy of the lacustrine infilling of the Mercure basin, an intramontane depression of the Southern Apennines, located along the Calabria-Lucania boundary. A preliminary tephrochronologic investigation and pollen analyses were carried out on the infilling succession exposed along V-shaped tributary valleys of the Mercure river. Lithological and chemical features of the thickest and best preserved tephra layer were fully characterised, and single crystal 40Ar/39Ar dating was performed yielding an age of 514±16 ka. Pollen analyses revealed the occurrence of warm and humid interglacial conditions that were correlated to MIS 13 on the basis of the age determination. The chemical compositions of glasses indicate that the Sabatinian volcanic field is the most probable source of the investigated tephra layer. Although chemical features support a correlation with the Tufo Giallo della Via Tiberina multiphase eruption that occurred between 561 and 548 ka, the integration of tephrochronology and pollen analysis points to a younger age, falling within MIS 13. We propose a correlation with one of the four explosive events that occurred in the Latial district from 514–449 ka. The Mercure tephra layer, owing to its age and great distance from the presumed source, represents a valid correlating tool for MIS 13 in central-southern Italy.