Scientific Study On Early Copper And Bronze Objects In The Gansu-Qinghai Region

The Gansu-Qinghai region in China,an important channel for cultural exchanges between the Central Plains of China and the Eurasian Steppe,has yielded the largest number of early copper and bronze objects.The Qijia and Siba are two main cultures in the early bronze age,which play important role in the study of the origin and early development of Chinese civilization.This dissertation has conducted a systematic examination of copper and bronze objects of the Qijia culture from the Mogou site in Lintan County,using optical microscope and scanning electronic microscope to reveal their microstructures and elemental compositions.Their lead isotope ratios have also been measured.In addition,the development of copper and bronze technology in the late Bonze Age in the Gansu-Qinghai region has also been discussed,with the scientific analysis of copper and bronze objects from the Huoshaogou site and the Zhanqi site.The study of copper and bronze objects from the Mogou site has revealed the characterisics of the late stage of the Qijia culture,showing that the shape of copper and bronze objects is more diverse,the tools mainly consist of knives and axes,while the ornaments mainly consist of earrings and buttons,some special types indicate that local traditions coexist with external factors.In the stage of Qijia culture,bronzes began to appear in large quantities as burial articles,and there was no obvious gender differences in the use of tools and ornaments.The manufacture and material characteristics are corresponding to the object types,such as the ornaments were mainly manufactured by hot-forging,while implements were mainly made by casting,with cold-working as well at the final stage of shaping.Considering the alloy materials,tin bronze was the most important alloy used in Mogou,and mainly for the ornaments,while copper was mainly used for implements.The copper and bronze objects unearthed at the Huoshaogou site have the similar manufacturing and material characteristics.As a whole,the copper and bronze technology of the Qijia culture shows the dominance of tin bronze in the late stage,and there also exist some regional differences,especially in the Qinghai region,arsenical copper seemed to have played a more important role.The Siba culture has similar copper and bronze technical characteristics with Qijia culture,but the proportion of arsenical copper is higher.The regional differences of copper and bronze technology in the late Bronze Age in Gansu are more obvious,as it has been revealed that Cu-Sn-Pb became prevalent in the Siwa culture sites in eastern Gansu,while copper was still the main material in the Shanma culture in the Hexi Corridor in western Gansu.The process of the development of early copper and bronze technology in Qijia culture indicates that in the middle stage,there were potential cultural connections with the Hexi Corridor,while in the late stage,there were more possibilities to have cultural interaction with the Central Plains.