俯冲带榴辉岩中水的赋存机制及其溶解度的控制因素
Incorporation Mechanism and Solubility Control Factors of Water in Eclogite from Subduction Zone
殷常鑫 1康磊 1刘良1
作者信息
- 1. 西北大学 地质学系 大陆动力学国家重点实验室,西安 710069
- 折叠
摘要
榴辉岩是俯冲带重要的高压—超高压变质岩石类型之一,其主要组成矿物为石榴子石和绿辉石,是名义上无水矿物(NAMs).随着板片俯冲过程中温度压力的升高,富水流体被释放,但榴辉岩中的石榴子石和绿辉石仍然可以携带一定量的水,成为水向地球内部传输的重要载体.在超高压岩石折返过程中,由于压力的降低,石榴子石和绿辉石中的水以羟基出溶的方式释放,能够引起高压变质岩石的退变质甚至同折返岩浆等一系列重要地球动力学过程.文章论述了矿物含水性的研究方法、石榴子石和绿辉石中水的赋存机制、水溶解度的控制因素(例如化学组成、压力、温度、水逸度、氧逸度等)以及板片俯冲/折返过程中榴辉岩水的行为,在此基础上凝炼当前研究中面临的科学问题展望了未来的研究方向.
Abstract
Eclogite,an important high-pressure metamorphic rock in subduction zone,mainly consists of garnet and omphacite which are known as nominally anhydrous minerals(NAMs).With the increasing temperature and pressure during slab subduction,the water-rich fluid is released,but garnet and omphacite in eclogite can still carry a certain amount of water and therefore become important carriers of water transporting to the interior of earth.During the exhumation of ultra-high pressure rocks,garnet and omphacite can release water as hydroxyl exsolution due to the decreasing pressure,which can consequently cause a series of important geodynamic processes such as retrograde metamorphism and even syn-exhumation magmatism.This paper summarized the analytical methods of water in minerals,the mechanism of water dissolved in garnet and omphacite,the controlling factors of water solubility(e.g.,chemical composition,pressure,temperature,water fugacity,and oxygen fugacity)and the behavior of water in eclogite during slab subduction/exhumation.The future direction and key scientific problems are also prospected.
关键词
俯冲带/榴辉岩/名义上无水矿物/矿物含水量Key words
subduction zone/eclogite/nominally anhydrous minerals/water content引用本文复制引用
基金项目
国家自然科学基金项目(42372064)
国家自然科学基金项目(42030307)
出版年
2024
国家科技期刊平台
NSTL
万方数据