大陆深俯冲过程中水分布的不均一性: 大别山碧溪岭榴辉岩中石榴石的红外光谱分析
首发时间:2004-01-08
摘要:利用傅立叶变换红外光谱技术, 对大别山碧溪岭地区10个榴辉岩中的石榴石进行了详细的结构水分析. 结果显示, 所有的石榴石中都含有以OH-形式存在的结构水. 结构水含量变化范围大, 为164~2034ppm (H2O), 多数在500ppm以上. 因此, 与绿辉石一样,石榴石也是超高压榴辉岩中重要的携水矿物. 石榴石结构水的含量不仅在同一露头(~150m)不同岩石样品间存在较大差异, 而且在同一样品(~1cm)的不同颗粒间也明显不同. 水分布的不均一性表明: (1)超高压变质过程中自由流体的活动范围是非常有限的(可能在cm级的尺度上); (2)板块的俯冲和折返都是十分快速的.
关键词: 结构水 石榴石 不均一性 碧溪岭 大别山
For information in English, please click here
Heterogeneity of water in UHP eclogites from Bixiling in Dabieshan: evidence from garnet
Abstract: Garnets in UHP eclogites from Bixiling in Dabieshan were investigated by Fourier transform infrared spectrometer (FTIR). The results demonstrate that all garnets contain structural water which occurs as hydroxyl (OH), with contents ranging from 164 to 2034ppm (H2O wt.) and mostly higher than 500ppm. Like omphacite which is another major OH-rich mineral in eclogites, garnet is an important carrier that can recycle the surface water into deep mantles. Heterogeneity of water in garnets exists not only among different samples of the same outcrop (~150m), but also among different crystals of the same sample (~1cm). This indicates that the mobility of fluids during UHP metamorphism is very limited, possibly on centimeter scales; and that both subduction and exhumation processes of UHP rocks are very fast.
Keywords: heterogeneity structural water garnet UHP eclogites Bixiling Dabieshan
论文图表:
引用
No.1271136107357032****
同行评议
共计0人参与
勘误表
大陆深俯冲过程中水分布的不均一性: 大别山碧溪岭榴辉岩中石榴石的红外光谱分析
评论
全部评论0/1000