高温高压下含水矿物脱水对斜长岩纵波速度的影响  

EFFECTS OF DEHYDRATION ON THE P-WAVE VELOCITY OF ANORTHOSITE AT HIGH PRESSURE AND HIGH TEMPERATURE

作　　者：白利平[1] 杜建国[1] 刘巍[1] 张文兰[2] 

机构地区：[1]中国地震局分析预报中心,北京100036 [2]南京大学地球科学系,江苏南京210093

出　　处：《地质科技情报》2003年第2期17-20,共4页Geological Science and Technology Information

基　　金：国家自然科学基金资助项目(10032040;49874013);地震科学基金资助项目(101119))

摘　　要：在1GPa、室温至880°C条件下对斜长岩的纵波速度进行了测量,并对实验产物进行了鉴定分析,讨论了含水矿物脱水对岩石纵波速度的影响。实验结果表明,在680°C左右,由于斜长岩中的含水矿物绢云母和黝帘石开始脱水,矿物脱水产生的流体及其所引起岩石结构的变化可使岩石纵波速度降低10%左右。这意味着通过矿物脱水这一机制可以形成壳内低速层。The pwave velocities of anorthosite have been measured at 1 GPa,from room temperature to 880°C,then the analysis of the run products by optical microscope and electron microscope analyzer and the effects of dehydration of hydrous minerals on the pwave velocities of anorthosite have been discussed.The experiment results show that pwave velocities drop significantly when the hydrous minerals begin to dehydrate above 680°C,and the pwave velocities decrease about 10% from room temperature to 880°C at 1 GPa resulting from the change of rock structure and the occurrence of the fluid during dehydration.It is concluded that the dehydration of the minerals may be responsible for the generation of the lowvelocity zones in the crust.

关 键 词：含水矿物 脱水 斜长岩 纵波速度 鉴定分析 变质作用 

分 类 号：P588.12[天文地球—岩石学] P588.3[天文地球—地质学]