In the past 20 years,Chinese scientists have discovered a large number of Paleolithic sites in the
Nihewan Basin,North China,ranging
from the Lower Paleolithic to the Upper Paleolithic.Among these sites,Xujiayao,Que'ergou and Banjingzi,situatd on the top of lake deposit or the third terrace,were dated to the Middle Paleolithic;the Lower Xinmiaozhuang,Shenquansi and Xibaimaying,found in the bottom of the second terrace,were dated to the early Upper Paleolithic;while Hutouliang,Jiqitan,Erheshanggou,the Upper Xinmiaozhuang,and Youfang were dated to the late Upper Paleolithic sites,and Toumafang and Yujiagou,situated in the upper section of the second terrace,were dated to Paleolithic-Neolithic transitional period.Stone artifacts collected from these sites provide basic
materials for the study of the change of raw material exploitation strategies from the Middle to the Upper Paleolithic in the
Nihewan Basin.Not all kinds of rock are suitable for stone tool manufacture,and the most frequently used materials by the Paleolithic people in the Nihewan Basin are vein quartz,chalcedony,volcano breccia,concealed crystal silicon,etc.Vein quartz is broadly distributed and can be easily obtained within the Nihewan Basin but with relatively low quality.Chalcedony and some volcanic rock are only located in limited areas,such as the Huiquanbao Village,Yangyuan Country and along some branches of the Sangganhe River.They can be easily obtained in these areas and have better quality than the vein quartz.Chalcedony materials are relatively hard with smooth and homogeneous internal consistency,but are generaly small in size,mostly smaller than 5 cm in diameter.Volcano breccia can be found in the cental areas of the basin,such as Guaijiawan and Xinmiaozhuagn.Concealed crystal silicon is distributed in the eastern areas of the basin,such as Youfang and Donggutuo.The latter two kinds of rock have very similar texture,that is,some part is fine while some is coarse.In order to compare raw material exploitation strategies between different ages and different areas,the basin where the target archaeological sites were located was divided into three parts:the East,Central, and the West. The East Part:Concealed crystal silicon is the principal raw material used in the eastern part of the Nihewan Basin.Though it is used as raw material by three sites——Banjingzi,Youfang and Toumafang,the exploitation degree is different from site to site.Among them,the Youfang site,the youngest in the sequence and nearest to the raw material source,yields well-made artifacts,which may be related to the application of microblade technology.The Central Part:Sites within the central part of the basin include Que'ergou,Daxiliangnangou,Hutouliang,Yujiagou and Xinmiaozhuang.Several kinds of raw material were exploited at these sites,but volcano breccia is the most frequently used material in this region.The West Part:Xujiayao,Shenquanis,Xibaimaying and Erheshenggou sites are situated in this district.While vein quartz and chalcedony are both used in the former three sites,the utilization of chalcedony here is unique.The exploitation of volcano breccia at the Erheshanggou site is another special character of this area.After comparing all the sites in the basin by their distance to the material sources,the preference of different raw materials selected,and the technology in processing these materials,some interesting phenomena were observed through time:The Middle Paleolithic:People at the three Middle Paleolithic sites,situated in different part in the basin,made use of different raw materials,i.e.,lava and vein quartz as the main raw material at Que'ergou,vein quartz and chalcedony at Xujiayao,and concealed crystal silicon at Banjingzi.However,they are all local materials,obtained near the sites,within 10 km in distance.The early Upper Paleolithic:No distinct change in the way raw material were handled can be observed at sites of this period from the previous one.However,a piec