High-precision U-series dating of Locality 1 at Zhoukoudian, China

Thermal ionization mass spectrometric ²³⁰Th/²³⁴U dating has been carried out on intercalated speleothem samples from the limestone cave occupied by Homo erectus at Zhoukoudian, China. The samples were recently collected in proper stratigraphic context after detailed field examinations. The results show that the age of the No. 5 Skull from Layer 3 is >400 ka, possibly in the range of about 400-500 ka, and that the hominid fossils from the lower strata are at least 600 ka and possibly >800 ka, much older than previously thought. The near-equilibrium ²³⁰Th/²³⁴U ratios and internal consistency of the dates and stratigraphy lend credence to the results and allow us to comment on their important implications for human evolution.