夏商青铜器铜料资源产地变迁初探——基于微量元素统计分析

A study of the variation of the copper material provenances of Xia and Shang bronzes based on trace element analysis

夏商青铜器金属矿料来源一直都是学界关注的焦点。前人研究基本厘清了夏商周三代青铜器的铅同位素变化规律,但是加铅工艺的普遍应用导致铅同位素数据主要指征了铅料来源,铜料产地及变迁仍然扑朔迷离。本研究搜集了目前已公布的夏商青铜器的微量元素数据,对微量元素数据进行多元统计分析,发现二里头与郑州二里岗期出土铜器的微量元素数据存在相似性,呈现出与铅料相似的变化规律,说明夏与商的铜、铅原料具有传承性。二里岗上、下层青铜器的微量元素未发生明显变化,即该时期铜料来源未发生转变,而铅料从低比值铅转变成高放射性成因铅。郑州二里岗期与盘龙城青铜器微量元素有很多共性,两地之间应该存在铜料的流通。郑州二里岗期铜器与小胡村、殷墟、三星堆等晚商遗址的的微量元素差异较大,与高放射性成因铅表现出来的铅料延续性不同,表明商代早晚期铜料产地发生了重大变迁。殷墟时期中原地区不同遗址出土的青铜器的微量元素数据存在相似性,说明殷墟时期各地之间不仅存在着高放铅铅料的共享,还有部分铜料在各地间流通。但山东、陕北和成都平原的遗址可能使用了不同的铜料。二里头至二里岗期铜料的延续、二里岗至殷墟时期铜料产地的转变与中条山铜矿开采和废弃的时间较为吻合,从侧面说明二里头至二里岗时期铜料主要产自中条山铜矿。殷墟时期的铜料转变可能与铜岭、铜绿山等长江中下游地区铜矿的大规模开采有关。

Scholars have long been interested in the sources of metal minerals used for Xia and Shang bronzes.The pattern of lead isotopic variation in bronzes from the Xia,Shang and Zhou Dynasties has been largely clarified,but the widespread use of the lead addition process has resulted in lead isotopic data primarily indicating the sources of lead materials,while the provenances and variation of copper materials remain unclear.This study gathered the published trace element data of Xia and Shang bronzes and conducted a multivariate statistical analysis,revealing similarities of the trace element data between bronzes excavated from Erlitou and the Erligang phase of Zhengzhou,which showed a similar pattern of variation to that of the lead material,and implied an inheritance of copper and lead materials used for Xia and Shang bronzes.The trace elements of the Upper and Lower Erligang bronzes did not change significantly,indicating that the source of the copper material had not shifted during the period,whereas the lead material changed from the low ratio lead to the highly radioactive one.There were many similarities of the trace elements between Erligang-phase bronzes from Zhengzhou and those from Panlongcheng,suggesting that the copper material had been circulated between the two locations.The trace element differences between Erligang-phase bronzes from Zhengzhou and those from the late Shang sites of Xiaohucun,Yinxu and Sanxingdui were significant,and differed from the continuity of lead material shown by the highly radioactive lead,suggesting a significant shift in the provenance of copper material from the early to the late Shang Dynasty.The similarity of trace element data of bronzes excavated from different sites in the Central Plains during the Yinxu period suggests that there was not only a sharing of highly radioactive lead material between different areas during that time,but also circulation of some copper materials between them.However,different copper materials may have been used at sites in Shandong,northern Shaanxi and the Chengdu Plain.The continuation of similar copper material from Erlitou to the Erligang period,and the shift in the provenance of copper material from the Erligang to the Yinxu period coincide with the mining and abandonment of the Zhongtiao Mountain copper mine,implying that the copper material from Erlitou to the Erligang period was primarily produced from the mine.The copper material shift during the Yinxu period may be attributed to the large-scale copper mining activities in the middle and lower reaches of Yangtze River,such as Tongling and Tonglushan.