三星堆遗址出土大玉料溯源研究

A Study on the Origin of Large Jade Materials Unearthed at Sanxingdui Site

三星堆遗址区北端发现的4件灰褐色大玉料备受关注,相关研究推断玉料或产自遗址附近龙门山脉南段,但缺乏实地调查与玉器、玉料及产地岩矿的科学鉴定材料支撑。以三星堆出土的两件大玉料为研究对象,考虑当时运输条件及运力,以及对龙门山地区地质资料和矿产资源调查资料研究的基础上,采用溯源调查方法,由近及远从三星堆遗址循湔江往上游根据河流漂卵石成分进行示踪研究,初步确定玉料产地靶区后刻槽取样,对比分析靶区岩层、河流漂卵石及三星堆大玉料的岩石薄片测试数据,寻找与玉料生成环境相匹配的矿带。溯源调查及详细的岩矿薄片鉴定表明:彭州红岩山蛇纹石矿区附近存在与三星堆大玉料的体量、蛇纹石含量相当的矿石。通过对比二者的矿物组成、原岩类型、结构、构造、硬度等指标可以得出:两件大玉料原岩均属于超基性岩中产出的蛇纹石,三星堆遗址出土的大玉料产自四川彭州红岩山蛇纹石矿区。

The four large chunks of grayish-brown jade material found at the northern end of Sanxingdui site have attracted much attention.It is preliminarily inferred that they came from the southern section of the nearby Longmen Mountains,which lacks the support of on-site investigation and scientific identification of jade articles,materials and ores from the origin.This paper discusses and analyzes the origin of large jade materials based on two large chunks of jade material unearthed at Sanxingdui site,fully considering the transport conditions and capacity in antiquity,and integrates it with the geological data and results of mineral resource survey in the Longmen Mountains.Through source investigation method,the composition tracer study of river pebbles was conducted from the close to the distant along the upper reaches of the Yangtze River.After initial identification of the target origin of the jade,groove sampling is conducted for comparative analysis of the rock formations in the target area,river pebbles and ore flakes of Sanxingdui jade materials,in order to find ore belts that match the environment where the jade materials were generated.Source investigation and detailed thin-section identification show that ore from the serpentine mine at Hongyan Mountain in Pengzhou has similar volume and serpentine content with the large jade materials at Sanxingdui,by comparing their mineral compositions,original rock natures,structures,hardness and other indicators,it can be concluded that the original rock of the two large jade materials belong to the serpentine produced in the ultrabasic rock,and the large chunks of jade material at Sanxingdui site originated from the Pengzhou Serpentine Mine.