The role of F-clinohumite in volatile recycling processes in subduction zones
The role of F-clinohumite in volatile recycling processes in subduction zones
复制标题
DOI：
10.1130/g38788.1
复制
发表时间：
2017-05
期刊：
影响因子：
5.8
通讯作者：
T. Grützner;S. Klemme;A. Rohrbach;F. Gervasoni;J. Berndt
中科院分区：
文献类型：
--
作者：
T. Grützner;S. Klemme;A. Rohrbach;F. Gervasoni;J. Berndt
不同的地幔岩石或矿物中究竟含有多少水和其他挥发物，以及这些挥发物如何在俯冲带中被运送到更深的地幔中，目前还不清楚。在这里，我们提出了新的实验数据，表明在俯冲带岩石中发现的一种常见矿物，水合镁硅酸盐斜辉石，在地幔中比以前预期的要稳定得多。我们发现，即使少量的F -取代OH -也足以使斜殖石稳定在远高于正常地幔地热的温度。基于这一发现，我们提出在俯冲带，斜殖岩有效地将水和其他挥发物从浅层输送到地幔的过渡带。这可以大大增加循环进入地幔深处的氟和水的数量。
It is not well understood how much water and other volatiles are really contained in different mantle rocks or minerals, and how these volatiles are transported down into the deeper mantle in subduction zones. Here we present new experimental data showing that a common mineral found in subduction zone rocks, the hydrated Mg-silicate clinohumite, is much more stable in the mantle than previously anticipated. We show that even small amounts of F – substituting for OH – are sufficient to stabilize clinohumite to temperatures well above the normal mantle geotherm. Based on this finding we propose that in subduction zones, clinohumite effectively transports water and other volatiles from shallow depths to the transition zone of the mantle. This can drastically increase the amount of fluorine and water recycled into the deep mantle.