Using Tephrocronology and palynology to date the MIS 13 lacustrine sediments of the Mercure basin (Southern Apennines - Italy)

The paper deals with the chronostratigraphy of the lacustrineinfilling of the Mercure basin, an intramontane depression of theSouthern Apennines, located along the Calabria-Lucania boundary.A preliminary tephrochronologic investigation and pollen analyseswere carried out on the infilling succession exposed along V-shapedtributary valleys of the Mercure river. Lithological and chemicalfeatures of the thickest and best preserved tephra layer were fullycharacterised, and single crystal 40Ar/39Ar dating was performedyielding an age of 514±16 ka. Pollen analyses revealed the occurrenceof warm and humid interglacial conditions that were correlatedto MIS 13 on the basis of the age determination. The chemicalcompositions of glasses indicate that the Sabatinian volcanic field isthe most probable source of the investigated tephra layer. Althoughchemical features support a correlation with the Tufo Giallo della ViaTiberina multiphase eruption that occurred between 561 and 548 ka,the integration of tephrochronology and pollen analysis points to ayounger age, falling within MIS 13. We propose a correlation withone of the four explosive events that occurred in the Latial districtfrom 514-449 ka. The Mercure tephra layer, owing to its age and greatdistance from the presumed source, represents a valid correlatingtool for MIS 13 in central-southern Italy.