Magnetostratigraphic age of the Xiantai Paleolithic site in the Nihewan Basin and implications for early human colonization of Northeast Asia
【摘要】：正Timing of the early habitation and stone technologies in the Nihewan Basin,North China has provided insights into our understanding of early human adaptability to high northern latitudes in East Asia.Here we contribute to this topic with detailed magnetostratigraphic investigation,coupled with mineral magnetic measurements and palynological analyses on a lacustrine sequence in this basin,which contains the Xiantai Paleolithic site.Magnetite and hematite were identified as the main carriers for the characteristic remanent magnetizations. Magnetostratigraphic results show that the Xiantai lacustrine sequence recorded the Brunhes chron,the Jaramillo and the Olduvai subchrons,and successive reverse polarity portions of the intervening Matuyama chron.Stratigraphic correlation in terms of lithology,magnetic susceptibility and magnetic polarity sequences between the Xiantai and Xiaochangliang sections indicates that the Xiantai artefact layer is readily contemporary with the Xiaochangiiang artefact layer,which has been previously estimated to be about 1.36 Ma[RX.Zhu,K.A.Hoffman,R.Potts, C.L.Deng,Y.X.Pan,B.Guo,C.D.Shi,Z.T.Guo,B.Y.Yuan,Y.M.Hou,W.W.Huang,Earliest presence of humans in northeast Asia,Nature 413(2001) 413-417.].Early humans of the Xiantai Paleolithic site lived in a steppe paleoenvironment indicated from fossil pollens. Furthermore,the combined evidence of our magnetostratigraphy and previously published magnetochronology and paleoclimate data documents that early humans of North China were able to adjust to an increasing variability of paleoclimates and paleoenvironments over the Early Pleistocene.