橄榄石的后尖晶石相变研究进展  

Advances in the Study of Post-Spinel Phase Transformation of Olivine

作　　者：翟双猛[1] 夏斌[1] 陈汉林[2] 

机构地区：[1]中国科学院广州地球化学研究所,510640 [2]浙江大学理学院地球科学系,杭州310027

出　　处：《地球学报》2006年第1期75-79,共5页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目(编号:40402006);教育部高等学校优秀青年教师教学和科研奖励计划资助成果。

摘　　要：橄榄石在高温高压条件下分解为钙钛矿和方镁石(后尖晶石相变),这是地幔中最为重要的相变之一,被认为是660KM地震波速间断面的成因。现今所取得的重要进展表现在3个方面:①MG_2SI O_4的后尖晶石相变的原位X射线高温高压实验研究;②水、AL_2O_3以及压力标尺对后尖晶石相变的影响效应;③下地幔条件下地幔岩组分中的后尖晶石相变。在对研究进展进行概述的基础上,对目前存在的问题进行了分析并提出未来可能的研究方向。Ringwoodite, one of the high-pressure and high-temperature forms of olivine, can be decomposed into perovskite and periclase (post-spinel phase transformation). The process, which seems to be one of the most important transformations in the Earth′s mantle, is believed to be the cause of the 660-km seismic discontinuity dividing the mantle into upper and lower parts. The advances made in the researches are shown in three aspects: ① post-spinel phase transformation of Mg_2SiO_4 at high pressure and high temperature using in situ X-ray diffraction; ② the effects of H_2O, Al_2O_3 and equation of state of gold on the post-spinel phase transformation; ③ the post-spinel phase transformation in peridotite under lower mantle conditions. On the basis of a summary of recent advances, this paper analyzes the existing problems and indicates possible directions for further studies.

关 键 词：橄榄石 后尖晶石相变 进展 

分 类 号：P5[天文地球—地质学]