Geochronology of Senèze: 40Ar/39Ar Dating and Magnetostratigraphy, with Notes on an ESR/U-Series Dating Attempt
摘要
The age of the Senèze mammalian fauna has been discussed since it was first reported in 1892. 40Ar/39Ar ages reported by Nomade et al. (2014) and recalculated here to agree with current standards placed the deposits between 2.20 and 2.07 Ma. Paleomagnetic data collected in 2001 and 2004 help to narrow the age range, especially of the levels yielding fossils in 2001–2006. In the western sector, fossils can be securely dated between 2.10 and 2.08 Ma, while in the southeastern sector, they are slightly older, between 2.20 and 2.18 Ma. Senèze is one of the few later Cenozoic European sites dated by both argon geochronometry and paleomagnetism, which makes these ages so precise. Experiments with ESR/U-series datingESR/U-series dating on teeth proved unsuccessful as a result of the early U-uptake and high natural dose rate in the sediments of Senèze.