Modern stratigraphic analysis utilizes unconformity-bounded, genetically related units to subdivide and then interpret stratigraphic successions. In alluvial plain deposits, an important challenge represents means to subdivide and date the complex internal stratigraphy. Here, De Santis et al. use physical sedimentologic characterization, coupled with amino acid racemization (AAR) and 14C dating, to recognize and date Quaternary units in an Italian alluvial plain to the scale of marine isotope stages. Detailing and dating stratigraphy to this level reveals the influences of subsidence events, climate variability, and sea-level change on the region. This level of resolution is interpreted to represent an important advance, compared to other Quaternary alluvial fan successions that are subdivided and dated using their relative stratigraphic position alone.
Unconformity-bounded stratigraphic units (UBSUs) in an Italian alluvial-plain area: recognizing and dating by Vincenzo De Santis, Massimo Caldara, Luigi Pennetta, Trinidad Torres, and José Eugenio Ortiz