Chronological study of Luohansi and Yuejiawan open-air paleolithic sites in the lower reaches of the Hanjiang River
Background,aim,and scope In recent years,numerous paleolithic sites in the Qinling Mountain Range have been discovered and dated.Conversely,relatively fewer paleolithic sites have been found and studied in the lower reaches of the Hanjiang River Valley in the southern Qinling Mountains.For this purpose,we conducted field surveys along the lower reaches of Hanjiang River in the summer of 2018.Luohansi(Luohansi-1 and Luohansi-2)and Yuejiawan paleolithic sites were found in Zhongxiang Basin and Jianghan Plain.In this study,five samples that were collected in the cultural layer of the Luohansi site and two samples that were collected in the Yuejiawan site were dated.Then,we obtained the luminescence chronologies of these sites.We also collected stone artefacts in situ and in the stratigraphic profile of these sites to obtain their industrial characteristics.Material and methods Single aliquot regeneration optically stimulated luminescence(SAR-OSL)and thermally transferred optically stimulated luminescence(TT-OSL)methods were used to obtain the chronology of these sites.Results According to the dating results,two corresponding cultural layers from Luohansi-1 and Luohansi-2 were dated to 53-30 ka and 187 ka,respectively,and one cultural layer from Yuejiawan site was dated to 172-138 ka.The stone artefacts found in Luohansi have the characteristics of both flake-tool and cobble-tool industries,which are distributed in Luohansi-1 and Luohansi-2,respectively.The stone artefacts found in Yuejiawan are typical cobble-tool industrial.Discussion Not only were hand axes found in a large number of sites,but a large number of flake-tool industrial sites were also found in the Qingling Mountain Range.This finding shows the diversity of paleolithic types in the region and the conditions that are suitable for the existence of these two industries.However,chronological studies of these sites are relatively scarce and need further improvement.On the basis of a comparative study of the sites that have been dated in the valley,we found that the hominin activities in the area decreased significantly during the last glacial period.We considered that this situation possibly occurred because the preference and selection requirements of hominins for the environment changed or because of other reasons,such as the change of industrial characteristics.Conclusions The discoveries in these two sites have effectively filled the chronological gap of paleolithic sites in the lower reaches of the Hanjiang River Valley.An analysis of the dating ages and industrial characteristics in these two sites shows that Luohansi and Yuejiawan fully conform to the overall development trend of paleolithic in Qinling Mountains.Recommendations and perspectives Although this study dated the two sites in the lower reaches of the Hanjiang River Valley,the sites in the lower reaches still need to be discovered,and the sites in the whole Hanjiang River Valley must be dated.In the future,we hope to obtain more chronological data to help us provide ideas for human evolution in this valley and also in the Qingling Mountain Range.
Hanjiang River ValleypaleolithicLuohansiYuejiawanSAR-OSLTT-OSL
万方数据
维普
