论文部分内容阅读
利用Fourier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164~2034 mg/g (H2O), 多数在500 mg/g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(约150 m)不同岩石样品间存在较大差异, 而且在同一样品(约1 cm)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(可能在厘米级的尺度上); (2) 板块的俯冲和折返过程都是十分快速的.
Fourier transform infrared spectroscopy was used to analyze the structure of garnet in 10 eclogites in the Bixiling area, Dabieshan. The results show that all the garnets contain structural water in the form of OH- The water content ranged from 164 to 2034 mg / g (H2O), mostly above 500 mg / g Therefore, garnet, like omphacite, is also an important water-carrying mineral in the ultra-high pressure eclogites. The structural water content is not only significantly different between rock samples of the same outcrop (about 150 m), but also between different particles of the same sample (about 1 cm). The heterogeneity of water distribution indicates that: (1) The range of free fluid activity during UHP metamorphism is very limited (possibly on the centimeter scale); and (2) the subduction and return processes of plates are very fast.