首页 | 本学科首页   官方微博 | 高级检索  
     检索      

Experimental Study of the Influence of Hydrous Minerals on the Melting Behaviour of Rocks at High Temperatures and Pressures
作者姓名:Zheng Haifei  Xie Hongsen  Xu Yousheng  Song Maoshuang  Zhang Yueming  Wang Mingzai and Xu Huigang
作者单位:Zheng Haifei;Xie Hongsen;Xu Yousheng;Song Maoshuang;Zhang Yueming;Wang Mingzai and Xu Huigang Department of Geology,Peking University,Beijing Institute of Geochemistry,Chinese Academy of Sciences,Guiyang,Guizhou
基金项目:Note:This study was supported by China National Natural Science Foundation Grant No.49070087.
摘    要:The experimental study on the melting of potassic basalt and eclogite with about 2% waterat 800-1300℃ and 1.0-3.5 GPa shows that the solidi of both rocks are significantly lower thanthose obtained from the previous experiments of the same type of rocks under dry conditions,and the former which is enriched in potassium has a lower melting point than the latter. It is con-sistent with the previous study. The melting temperature of eclogite increases with pressure,whereas potassic basalt has similar properties only at 1.5—2.5 GPa and>3.0 GPa, and at 2.5—3.0 GPa the melting temperature decreases with pressure. This can be explained as follows: (1)eclogite only has one hydrous mineral amphibole and the dehydous temperature is lower than thewet solidus of the rock. (2) Amphibole exists in potassic basalt at the pressures lower than 2.5GPa and phlogopite exists at pressures higher than 2.5 GPa, and the special compositions of bothminerals determine that amphibole has a dehydration temperature higher than or close to that ofthe wet solidus of the rocks, while phlogopite has a dehydration temperature lower than that ofthe wet solidus. On the other hand the features of the continuous solidus in the experiment ofhydrous eclogite were produced by the fact that the dehydration temperature of its amphibolelower than or close to the melting temperature of the hydrous conditions. So the melting tempera-ture lowers at higher pressures. Therefore, the composition of the rocks in the lithosphere and thetypes of hydrous minerals and their stable P-T conditions are the important factors controllingthe solidi of rocks. It can quite well explain the partial melting of rocks and the origin of the lowvelocity zone in the deep lithosphere.


Experimental Study of the Influence of Hydrous Minerals on the Melting Behaviour of Rocks at High Temperatures and Pressures
Authors:Zheng Haifei  Xie Hongsen  Xu Yousheng  Song Maoshuang  Zhang Yueming  Wang Mingzai and Xu Huigang
Institution:Zheng Haifei,Xie Hongsen,Xu Yousheng,Song Maoshuang,Zhang Yueming,Wang Mingzai and Xu Huigang Department of Geology,Peking University,Beijing Institute of Geochemistry,Chinese Academy of Sciences,Guiyang,Guizhou
Abstract:Abstract The experimental study on the melting of potassic basalt and eclogite with about 2% water at 800—1300°C and 1.0—3.5 GPa shows that the solidi of both rocks are significantly lower than those obtained from the previous experiments of the same type of rocks under dry conditions, and the former which is enriched in potassium has a lower melting point than the latter. It is consistent with the previous study. The melting temperature of eclogite increases with pressure, whereas potassic basalt has similar properties only at 1.5—2.5 GPa and >3.0 GPa, and at 2.5— 3.0 GPa the melting temperature decreases with pressure. This can be explained as follows: (1) eclogite only has one hydrous mineral amphibole and the dehydous temperature is lower than the wet solidus of the rock. (2) Amphibole exists in potassic basalt at the pressures lower than 2.5 GPa and phlogopite exists at pressures higher than 2.5 GPa, and the special compositions of both minerals determine that amphibole has a dehydration temperature higher than or close to that of the wet solidus of the rocks, while phlogopite has a dehydration temperature lower than that of the wet solidus. On the other hand the features of the continuous solidus in the experiment of hydrous eclogite were produced by the fact that the dehydration temperature of its amphibole lower than or close to the melting temperature of the hydrous conditions. So the melting temperature lowers at higher pressures. Therefore, the composition of the rocks in the lithosphère and the types of hydrous minerals and their stable P-T conditions are the important factors controlling the solidi of rocks. It can quite well explain the partial melting of rocks and the origin of the low velocity zone in the deep lithosphere.
Keywords:high-T/P  hydrous minerals  melting point of rock  experimental condition
本文献已被 CNKI 等数据库收录!
点击此处可从《Acta Geologica Sinica》浏览原始摘要信息
点击此处可从《Acta Geologica Sinica》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号