Detrital sanidine dating of Middle Pleistocene sedimentary successions in the Paleotiber delta (Rome, Italy)

The large improvements in the electronics of the multi-collector mass spectrometers allows Pleistocene grains, smaller than 400–300μm to be dated with high precision. Combined with the continuous eruptive activity that characterized the Roman Magmatic Region during Middle-Upper Pleistocene, dating of sedimentary samples has been successfully used to provide absolute chronological constrains to the aggradational successions that deposited in response to sea-level rise during glacial terminations and interglacial periods.We present 40Ar/39Ar detrital sanidine ages from 12 sedimentary samples that have been collected from the gravel and sand sections in different aggradational successions of the Paleotiber delta that deposited between ~960 and ~600 ka and are located in southern Rome. We also present 40Ar/39Ar dating of two samples that were collected in a sub-primary volcaniclastic layer. Results show that the ages of the youngest crystal population are stratigraphically consistent within each of the sampled aggradational successions (i.e., at higher stratigraphic position corresponds a younger age) and complies with the age constraints provided by intercalated or laterally correlating primary volcanic deposits.