榍石的高压结构研究  

RESEARCH OF HIGH-PRESSURE STRUCTURE OF TITANITE

作　　者：祝向平[1] 秦善[2] 刘景[3] 巫翔[3] 李晓东[3] 吴忠华[3] 

机构地区：[1]成都地质矿产研究所,四川成都610082 [2]北京大学地球与空间科学学院,造山带与地壳演化教育部重点实验室,北京100871 [3]中国科学院高能物理研究所同步辐射实验室,北京100039

出　　处：《矿物岩石》2006年第3期6-11,共6页Mineralogy and Petrology

基　　金：国家自然科学基金(40272023)

摘　　要：利用同步辐射和金刚石压腔(DAC)技术对天然矿物榍石进行原位高压能散模式X射线实验研究,结果表明榍石在3.9 GPa和10.9 GPa分别发生P 21/a→A 2/a和A 2/a→A 1结构相变,并首次确定10.9 GPa→25.1 GPa榍石结构很可能稳定保持A 1相。基于此认为榍石能在地球较深部位稳定存在,此外,本研究对探索地球深部T i和S i元素的地球化学行为也有一定帮助作用。By using synchrotron radiation energy dispersive X-ray diffraction and diamond-anvilcell technology at room temperature,the in-situ high pressure structure of natural titanite had been studied experimentally. In the experiment,with increasing pressure,titanite transforms from P21/a to A2/a at the pressure of 3.9 GPa and another phase transition A2/a→ occurs at the pressure of 10. 9 GPa. It is quite possible that titanite possesses the same stable phase between 10. 9 GPa and 25.1 GPa. Based on the result of experiment and the P-T phase boundary reported in lit- erature,it is concluded that titanite could behave stably within some range of depth in the upper mantle,which corresponds to the existence of aluminous titanite in eclogite-zone. This research is helpful for the understanding of the geochemical behavior of titanium and silicon in the depth of Earth.

关 键 词：榍石 高压 结构 同步辐射 

分 类 号：P578.949[天文地球—矿物学] O782.2[天文地球—地质学]