High temperature hydrothermal activity in the deep oceanic crust: Experiments and investigations on natural rocks in the Oman ophiolite

深洋地壳的高温热液活动：阿曼蛇绿岩天然岩石的实验和研究

基本信息

批准号：
116858737
负责人：
Professor Dr. Jürgen Koepke
金额：
--
依托单位：
Institut für Mineralogie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2009
资助国家：
德国
起止时间：
2008-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/116858737?language=en
关键词：
temperature hydrothermal activity deep oceanic

项目摘要

The Oman ophiolite is regarded to present the best proxy of fast-spreading oceanic crust on land. Most petrologists/geochemists built on the evidence from Oman ophiolite and favour a general accretion model for fast-spread oceanic crust that deep plutonic crust is formed by multiple intrusions of gabbroic sills. A requirement for this model, however, is a substantial cooling of the deep oceanic crust, and many scientists believe that a seawater-derived high-temperature hydrothermal circulation system must exist. Recent studies based on experimental work revealed that Oman gabbros show characteristic parageneses indicating that partial melting triggered by water-rich fluids proceeded in the deep crust. These can be interpreted as result of hightemperature hydrothermal convection, implying that the distinction between primary magmatic and seawater-induced metamorphic processes is blurred. The present study will combine the investigation of natural rocks of the Oman ophiolite and experimental work on relevant natural systems, and finally theoretical work on thermal modelling, in order to understand one important aspect of fast-spread ocean crust generation: the interplay between magmatic accretion and hydrothermal processes ongoing at high temperatures, and the way how the hydrothermal cooling of the deep crust proceeds.

阿曼蛇绿岩被认为是在陆地上呈现出快速扩展海洋壳的最佳代理。大多数岩石学家/地球化学家建立在阿曼蛇绿岩的证据上，并赞成一种对快速扩张的海壳的通用积聚模型，即深plutonic壳是由gabbroic sills的多次入侵形成的。但是，对该模型的需求是对深海壳的实质性冷却，许多科学家认为必须存在海水衍生的高温水热循环系统。基于实验工作的最新研究表明，阿曼甘布罗斯（Aman Gabbros）表明特征性副介质表明，在深层地壳中进行了富含水的液体触发的部分融化。这些可以解释为Hightemperature水热对流的结果，这意味着原代岩浆和海水诱导的变质过程之间的区别是模糊的。本研究将结合对阿曼蛇绿岩的自然岩石的研究，并在相关天然系统上进行实验性研究，最后是对热建模的理论研究，以了解快速蔓延的海壳生成的一个重要方面：岩浆积聚和水热过程之间的相互作用，在高温下，以及在高温凉爽的过程中进行的，这是如何进行的。