MIS 13 and MIS 11 aggradational successions of the Paleo-Tiber delta: Geochronological constraints to sea-level fluctuations and to the Acheulean sites of Castel di Guido and Malagrotta (Rome, Italy)

Abstract

This contribution presents an application of the conceptual model of 'aggradational succession' (i.e., the sedimentary record deposited in response to sea-level rise during the glacial terminations) to a series of geological sections of the Paleo-Tiber delta cropping out along the Via Aurelia near Rome, Italy. The geochronological constraints provided here through 40Ar/39Ar dating of volcanic layers intercalated within the sedimentary deposits of the MIS 13 and MIS 11 aggradational successions resulted in some remarkable outcomes:1) we reconstruct an independent chronology of the Mediterranean sea-level oscillations 450 through 380 ka, in good agreement with the δ18O and the Red Sea relative sea level curve chronology;2) the Glacial Termination V is here bracketed in the interval 423.1 ± 4.4–438.7 ± 1.2 ka;3) we show that the aggradational successions of MIS 11 and MIS 13 display similar spatial/geometric features despite the significantly different amplitude of their Oxygen isotope records, challenging the regression models linking absolute values of benthic foraminifera δ18O and ice-volume;4) we show the relevance of a climatic-stratigraphic approach in dating coastal-to-fluvial sedimentary contexts;5) we provide indirect age constraints with the precision of a few ka for two important palaeoanthropological and archaeological sites in central Italy bearing Acheulean lithic industries and human remains.