The first radiometric age by isochron 26Al/10Be burial dating for the Early Pleistocene Yuanmou hominin site, southern China

Abstract The Yuanmou H. erectus site is generally considered to be one of the oldest hominin sites in southern China. The chronology of this site has been repeatedly investigated using magnetostratigraphy since its first discovery in the 1960s. However, there are multiple interpretations of the magnetostratigraphy due to the complexity of the sedimentary environment, resulting in a one million year age discrepancy by different studies. Because Yuanmou's age has yet to be verified radio-isotopically, we apply isochron 26Al/10Be burial dating to constrain the existing magnetostratigraphy. Six samples from a gravel bed 38 m above the fossil layer were collected, yielding an age of 1.54 ± 0.06 (0.11) My. Based on the estimated sedimentation rate, we interpolate an age of 1.72 ± 0.03 My for the fossil layer. This result is consistent with the most recent paleomagnetic stratigraphy of 1.7 My for the Yuanmou H. erectus fossils. Combined with other recent chronological studies of paleoanthropological sites across Asia, this study supports a model for earlier hominin dispersals out of Africa.