Age of the fossil Dali Man in north-central China deduced from chronostratigraphy of the loess-paleosol sequence

摘要

Dali Man, an archaic type of early Homo sapiens, is of great significance to the origin of Homo sapiens. Achievements have been made during the past decades in the understanding of the fossil human skull as well as the accompanying mammalian fossils and stone artifacts. However, the absolute age of the fossil Dali Man still remains unclear. Based on the magnetic susceptibility of loess sediments and the relationship of terracing process with climatic condition, we correlated the loess sequence and the subjacent terrace alluvium at the Dali Man site with the well-studied loess-paleosol sequence at Luochuan in the central part of the Chinese Loess Plateau. The correlation indicates that the loess-paleosol sequence at the Dali Man site extends down to the paleosol S2, and the underlying fluvial deposits correspond to the loess U. Because the Dali Man skull appears in the basal gravel layer of the terrace, and because the deposition of the terrace gravels would occur during the transition from S3 paleosol formation to L3 loess accumulation, the age of the fossil Dali Man is inferred to be ca 270 ka, which is equivalent to the age of the boundary between the loess L3 and paleosol S3 on the magnetic susceptibility time series of the Luochuan loess-paleosol sequence. (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 29]