澳大利亚金刚石的成因类型及产地来源特征综述  

Genetic Types of Australian Diamonds and Their Origin Features

作　　者：莫默[1] 丘志力[1] 陈华[2] 陆太进[2] 李榴芬[1] 邱文珺[1] 王琦[1] 

机构地区：[1]中山大学地球科学系,广东广州510275 [2]国土资源部珠宝玉石首饰管理中心,北京100013

出　　处：《宝石和宝石学杂志》2013年第3期65-74,共10页Journal of Gems & Gemmology

摘　　要：对已经发表的数十篇关于澳大利亚金刚石的英文文献进行了梳理,从其金刚石的品质、颜色类型、形态及表面特征、生长结构及微量元素、包裹体、C同位素等方面探索了澳大利亚不同区域金刚石可能存在的产地来源特征。研究显示,澳大利亚金刚石可分为岩石圈地幔成因、超深地幔成因和俯冲环境来源等成因类型;大部分澳大利亚金刚石都因经历过强烈的晶格变形或熔蚀作用而晶体圆化,但不同产地来源的金刚石在颜色组合、橄榄岩型和榴辉岩型金刚石比例、C同位素组成特征等方面存在一定差异。上述结果表明,总体上,澳大利亚不同区域金刚石具有一定的产地来源个性,但无法简单确认澳大利亚金刚石"整体"的产地来源特征;只有结合成因来源进行分析,才能够较深入地理解不同区域金刚石的特征组合及其意义,从而为理解其产地来源的特殊性提供帮助。Based on a series of English literature about Australian diamonds, the possible ori- gin features of Australian diamonds from different fields are discussed, such as quality, col- our, shape, surface characteristics, growth structure and trace elements, inclusions, carbon isotopes of the diamonds. Research indicates that Australian diamonds have three genetic types, namely, lithospheric mantle, super deep mantle and subduction environment related origin. First, Arygle diamonds and Ellendale diamonds from North Australian Craton pres- ent similar trace element characteristics of Mn, Ni, Cr loss and rich in Na, K, Ti, Zn, Cu, Ga, Rb, St, which indicates a lithosphere mantle origin. The diamonds from the two locali- ties can be distinguished from the following aspects. Firstly, only a small percentage of gem quality diamonds are discovered from the Argyle mine, most of which are brown and less are rare pink. However, Ellendale diamonds （60%--90%） are of gem quality, and high qualityyellow diamonds are famous. Secondly, primary inclusions of Argyle diamonds are over- whelmingly of eclogitic paragenesis （75%）, and these eclogitic diamonds, unlike the small percentage of Argyle peridotitic diamonds, show marked corrosion and deformation features, which display a certain relationship between inclusions and crystal morphology. However, the diamonds from Ellendale pipes NO. 4 and NO. 9 contain approximately equal proportions of peridotitic and eclogitic inclusions, and no relation between inclusions and crystal mor- phology is indicated. Thirdly, by carbon and nitrogen isotope features and nitrogen con- tents, diamonds from Argyle and Ellendale can be distinguished. On a plot of 13C and con tent of N, the diamonds from Argyle and Ellendale are clustered into two separate groups. Ellendale diamonds show a negative correlation of 313C and Ntot with a large range of N con- tents, whereas Argyle diamonds show no correlation of 313 C--N,o, and low N and ~13C con- tents. Furthermore, on a plot of ~5N--~13C, the Ellendal

关 键 词：金刚石 产地特征 澳大利亚 

分 类 号：TS93[轻工技术与工程]