湖南扬子地台砂矿金刚石的红外、拉曼特征及指示意义

产于湖南沅水地区的十颗砂矿金刚石的红外光谱和拉曼光谱的研究结果表明：湖南砂矿金刚石多为I_aAB型，且往往表现为A型氮相对富集;金刚石中的氮含量介于38.30～840.67 μg·g-1之间，且不同金刚石晶体中氮含量差别极大;金刚石在地幔中的存储时间介于0.043～3.315 Ga之间，不同的样品在地幔中的存储时间相差较大，且最长存储时间(3.315 Ga)要大于湘鄂黔桂毗邻区最老岩体的年龄(3.285 Ga);湖南砂矿金刚石在其形成过程中经历过较为显著的环境变化，且菱形十二面体金刚石晶体的形成深度大于八面体金刚石晶体。

Study on the Micro-FTIR and Raman Spectra of the Alluvial Diamonds from Yangtze Craton and Their Geological Significances

The FTIR and Raman spectra of 10 diamonds from Yuanshui, Hunan province show that the alluvial diamonds from this area are mostly IaAB type, with a significant character that the A-center is enriched relatively; the nitrogen concentration in the diamonds is between 38.20 and 840.67 μg·g-1, which has a tremendous distinction in different crystal. The residence time of the diamonds in the mantle are between 0.043 and 3.315 Ga, which is also has a great difference in different diamond grains. The remotest residence time (3.315 Ga) of one diamond is older than the most aged rock (3.285 Ga) in Xiang-E-Qian-Gui contiguous zone. A remarkable environment change had took place during the process of diamonds formation. The formation depth of dodecahedral diamonds is deeper than that of the octahedral ones.