透闪石玉的微区原位年代学研究

Tremolite jade, or Nephrite, has a long history in China. According to the archaeological evidence, the history of nephrite extraction in China dates back to the Neolithic age (nearly 8000 years). Chinese ancient jade, especially thenephrite, incomparable in many aspects, such as its properties of raw material, function, and design. Nephrite served as raw material for many valuable pieces of artwork. The jade culture of China is based on the abundance of nephrite resources. There are numerous nephrite deposits around China. The abundant ne.phrite resources not only enriched the nephrite market, but also brought a lotof challenges to identify the deposit characteristics. One of the main issues in jade archaeology is the study of the provenance of nephrite. Various studies by artists, historians, archaeologists, and gemologists focus on the comparison between the mineralogical and geochemical properties of nephrite raw materials and ancient samples. However, the uncertainties regarding the nephriteprovenance remains, due to the question of the dating of nephrite from different occurrences are still unanswered. The lack of a database of appropriate nephrite samples with known provenance and the limited amount of provenance-directed research has caused problems in prehistorical jade research which may tell the life style about the people who have no word records. Without extensive sampling and a proven method, the ability to provenance nephrite jade is limited. A new method for discrimination of the nephrite through the use of age datais required. Methods for the discrimination of three geographically similar nephrite sources are being developed. The composition, textures, and age of nephrite from Xiuyan district (Liaoning province), Hetian district (Xinjiang province), and Luanchuan district (Henan province) will be investigated by means of optical and electron microscopy, Electron Micro probe Analysis (EMPA), and Secondary Ion Mass Spectrometry (SIMS). The age of nephrite will be determinedby the U-Pb dating of titanite which intergrown with tremolite. The results will develop a new method for dating nephrite and broad the horizon of nephrite mineralization process,.The database necessary for determination of nephriteprovenance will be enlarged as well. It will also serve as a tool for futureresearch in archaeology to detect the raw material of ancient art wares.

透闪石玉(和田玉)在我国的使用历史可以追溯到新石器时代，是我国悠久文明的见证。我国能拥有世界上最灿烂的玉文化，是因为我国分布着广泛的透闪石玉资源。丰富的资源既给玉文化的发展提供了基础，也给研究者和消费者区分产地带来了困难。透闪石玉的产地鉴别一直是古玉研究的重点，这是考古学家研究缺少文字记载的史前文明的重要手段，而缺少已知产地的透闪石玉基础数据使得这一问题难以解决。已有的研究主要集中在透闪石玉的矿物学方面，其成矿年龄却一直悬而未决。本项目研究旨在利用二次离子质谱，偏光显微镜，电子探针，拉曼光谱等多种现代分析技术，在系统研究辽宁岫岩，河南栾川和新疆和田三个透闪石玉矿的岩矿特征的基础上，利用透闪石的同生矿物榍石建立透闪石玉的微区原位定年方法，并对比此三地区透闪石玉产地特征数据。这将为原位研究透闪石玉的年代学提供新的方法；将加深对透闪石玉成矿过程的地质学理解；更为古玉的原料溯源研究提供参考数据。

透闪石玉(和田玉)是一种重要的非金属矿产资源，以前的研究主要集中在透闪石玉的矿物学方面，其成矿年龄却一直悬而未决。本项目利用二次离子质谱， 偏光显微镜，电子探针，拉曼光谱等多种现代分析技术，在系统研究辽宁岫岩，河南栾川和新疆和田三个透闪石玉矿的岩矿特征的基础上， 利用透闪石的同生矿物榍石建立透闪石玉的微区原位定年方法。该工作提供了一个透闪石玉定年的可行性新方法，为其年代学研究提供了新思路。也加深对透闪石玉成矿过程的地质学理解。