中山大学学报自然科学版 ›› 2018, Vol. 57 ›› Issue (2): 1-11.

• 论文 •    下一篇

甘肃马衔山软玉成矿及玉料产地来源地质地球化学特征分析

张钰岩1,丘志力1,4,杨江南2,张跃峰1,杨翰1,杨炯3,李榴芬1,4   

  1. 1.中山大学地球科学与工程学院∥宝玉石研究鉴定(评估)中心,广东 广州510275;
    2. 兰州大学博物馆,甘肃 兰州 730000;
    3. 泰山学院旅游学院,山东 泰安271021;
    4.广东省地质过程与矿产资源探查重点实验室,广东 广州510275
  • 收稿日期:2017-05-31 出版日期:2018-03-25 发布日期:2018-03-25
  • 通讯作者: 通信作者:丘志力(1963年生),男;研究方向:宝玉石成矿与重大地质作用过程及古玉文明演化;E-mail:qiuzhili@mail.sysu.edu.cn

The geological and geochemical characteristics of nephrites in Maxianshan, Gansu province and their implication for raw material source of the Qijia Culture jadewares

ZHANG Yuyan1, QIU Zhili1,4,YANG Jiangnan2, ZHANG Yuefeng1, YANG Han1, YANG Jiong3, LI Liufen1,4   

  1. 1.School of Earth Science and Engineering∥Gem Testing and Appraisal Center, Sun Yat-sen University, Guangzhou 510275, China;
    2. Museum of Lanzhou University, Lanzhou 730000, China; 
    3. School of Tourism, Taishan University,Tai'an 271021, China;
    4. Guangdong Provincial Key Lab of Geological Processes and Mineral Resources, Guangzhou 510275, China
  • Received:2017-05-31 Online:2018-03-25 Published:2018-03-25

摘要:

甘肃马衔山软玉矿矿化见于新元古界马衔山群一套混合岩、大理岩、黑云母片岩组成的变质地层内,被认为是新石器时代晚期齐家文化玉器玉料的重要来源之一。在野外考察采样基础上,采用X射线粉末衍射、扫描电镜、电子探针、ICPMS、LAICPMS等测试技术,对马衔山成矿围岩及其软玉玉料进行了矿物、岩石及地球化学分析,确定了该地软玉矿物组成、结构构造和主微量、稀土元素组成;在此基础上探讨了马衔山软玉成矿及产地来源的地质地球化学特征。获得以下主要认识:① 马衔山软玉具片状变晶结构和纤维交织结构,玉料主要由透闪石、少量榍石、微量黝帘石及磷灰石组成,优质玉料透闪石含量可达98%以上;② 透闪石为3个不同时期矿化产物,成玉主要和中晚期的透闪石化有关。玉料属于镁质大理岩成因,成玉主要和晚期的碱性花岗岩侵入形成的交代变质作用有关;③ 马衔山软玉微量元素组成,稀土元素含量及分布模式和新疆和田、青海地区及辽宁的软玉有所不同。微量元素具有Th/U高、Cu低特点,稀土元素含量低、具有“海鸥式”稀土元素配分模式等可以作为该产地玉料的源区特征。

关键词: 软玉, 成矿, 地球化学, 产地来源特征, 甘肃马衔山

Abstract:

Maxianshan nephrite ore in Gansu Province was found in the Neoproterozoic Maxianshan group, a set of metamorphic strata consisting of migmatite, marble and biotite schist, which was regarded as one of the most important material sources of the nephrite jadewares of the Qijia Culture. In order to find out the probability of the Maxianshan nephrites as the raw materials of the nephrite jadewares of the Qijia Culture, the combined field investigation and instrumental analyses of XRD, SEM, EMPA, ICP-MS and LA-ICP-MS are applied to analyze the mineralogy, petrology and geochemisty of Maxianshan nephrites and their country rocks, including mineral composition, structure feature, and chemical composition of the nephrites such as major & trace elements, rare earth elements, and therefore to explore the mineralization of the Maxianshan nephrite mine. The main findings are summarized as follows: ① Maxianshan nephrites are yellow-white to yellow-green (mostly green) in color, characterized by lamellar amorphous structure and fiber interwoven structure, and composed of more than 98% amount of tremolite mineral and tiny amount of sphene, zoisite and apatite minerals; ② The tremolite minerals in nephrites were formed in three mineralization periods, and the principal nephrite ore is mainly related to the tremolites of middle and late periods. The formation of jade grade nephrites was associated with marbleization caused by metasomatism in connection with late intruded alkali granites; ③ The Maxianshan nephrite is characterized by high Th/U, low Cu and REE element, and seagull REE distribution pattern, being different from other nephrites from Hetian of Xinjiang, Qinghai and Liaoning.

Key words: nephrite, mineralization, geochemistry, origin characteristics, Maxianshan of Gansu

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