The Grotta dei Fiori (Sardinia, Italy) stratigraphical successions: A key for inferring palaeoenvironment evolution and updating the biochronology of the Pleistocene mammalian fauna from Sardinia

Abstract

In Sardinia (western Mediterranean, Italy) studies of Quaternary climatic changes, faunal turnovers, and evolution of environments have mostly been performed autonomously in various scientific fields. The Grotta dei Fiori Cave, GFC (Carbonia, south-western Sardinia) is one of the numerous limestone caves in south-eastern Sardinia that contain deposits of large and small mammals with intercalated flowstones. A multidisciplinary study (palaeontological, sedimentological, soil micromorphological analyses, and U/Th dating) was performed on three stratigraphical successions (SA, SC and SD) for a finer time resolution and palaeoclimatical setting of the Quaternary fossiliferous deposits cropping out in the GFC karst cave. Relying on U/Th dating, results obtained by the stratigraphical and soil micromorphological analyses, integrated with a previously performed stable isotope analysis, indicate that the studied fossiliferous successions were deposited under warm, alternate wet and dry climatic conditions, albeit at different times. In particular, sediments of SC, older than 500 ka, were possibly deposited during the early Middle Pleistocene, those of SA in a time interval from about 500 to 250 ka, while the SD is older than about 350 ka. The presence of Microtus (Tyrrhenicola) henseli in deposits older than 500 ka is of particular interest, with regard to time and mode of the endemic vole evolution and to the biochronological arrangement of the late Early to Middle Pleistocene Sardinian fauna.