U/TH DATING AND GEOCHEMISTRY OF CARBONATE CONCRETIONS ASSOCIATED WITH UPPER PLEISTOCENE FOSSIL SHORELINES OF THE SORRENTO PENINSULA (CONCA DEI MARINI, SOUTHERN ITALY)

Abstract

U-series dating and geochemical analyses were performed on carbonate concretions in order to put chronological constraints on the
associated fossil shorelines. In particular, samples were taken from concretions found at Conca dei Marini Cape where former shorelines ascribed to the Upper Pleistocene are present. From the chronological data the height of sea level during highstands of Late
Pleistocene is inferred; moreover, due to the tectonic stability of the area the estimated height could be taken as a close approximation
of eustatic sea level position. A +3.5 m a.s.l. sea level highstand which occurred during the end of Oxygen Isotopic Stage (OIS) 5e was
recognised by the U/Th age and elevation of the concretion covering a wave-cut platform. Furthermore, new interpretations for more
recent sea level highstands were obtained by analyses performed on two calcitic concretions associated with a marine biocalcarenite.
They indicate that the sea level at the end of OIS 3 was close to the present day one; such a conclusion disagrees with the generally
accepted sea levl position derived from proxy data taken from oceanic cores while it agrees with recent chronological data obtained
from marine deposits in the Gulf of Taranto (Southern Italy).