Fluid processes during the exhumation of high-P metamorphic belts
Fluid processes during the exhumation of high-P metamorphic belts
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DOI：
10.1180/0026461026610016
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发表时间：
2002-02
影响因子：
2.7
通讯作者：
J. Miller;I. Buick;I. Cartwright;A. Barnicoat
中科院分区：
文献类型：
--
作者：
J. Miller;I. Buick;I. Cartwright;A. Barnicoat
摘要流体通过影响折返机制及其驱动过程，在折返过程中起着直接的作用。此外，掘出过程导致与流体有关的特征的形成，而这些特征本身可能并不驱动掘出。折返过程中的流体通常来自减压过程中发生的脱水反应，但在地壳较浅的层面上，也可能涉及外来流体的引入。流体的成分参加发掘一般是盐水- CO2的混合物，但N2，CH 4，H2O的混合物也有记录。对与折返作用有关的流体特征的研究发现，流体可能有助于密度变化和减压过程中部分熔融的开始，以及广泛的矿脉系统的发展。然而，保存地球化学签名有关的流体过程之前发生的高磷和超高磷变质作用表明，大规模的普遍的流体流动系统，一般来说，不运作在任何阶段的折返历史。大规模的沟道流体流动可能在与折返有关的拆离断层和剪切带中起作用，这需要进一步研究。流体在折返过程中最重要的作用似乎是它们对高磷或超高磷岩石保存的控制影响。
Abstract Fluids can play a direct role in exhumation by influencing exhumation mechanisms and the driving processes for these mechanisms. In addition, the process of exhumation leads to the development of fluid-related features that in themselves may not drive exhumation. Fluids involved in exhumation are generally derived from dehydration reactions occurring during decompression, but at shallower crustal levels may also involve the introduction of exotic fluids. The composition of fluids attending exhumation are generally saline - CO2 mixtures, but N2, CH4, H2O mixtures have also been recorded. Studies of fluid features related to exhumation have found that fluids may contribute to density changes and the initiation of partial melting during decompression, as well as the development of extensive vein systems. However, the preservation of geochemical signatures related to fluid processes occurring prior to high-P and ultrahigh-P metamorphism indicates that large-scale pervasive fluid flow systems, in general, do not operate at any stage during the exhumation history. Large-scale channelled fluid flow may have operated in detachment faults and shear zones related to exhumation, and this requires further study. The most significant role of fluids during exhumation appears to be their controlling influence on the preservation of high-P or ultrahigh-P rocks.