Deciphering the duration of fluid-rock interaction

地球的结晶岩石圈的巨大部分正在（并且已经）通过流体驱动的矿物反应进行化学修饰。这些反应驱动了几个相应的流体介导的岩石转化过程，包括那些管理山区的稳定性，热液矿床的形成和人为二氧化碳的封存，这些过程也可能导致巨大的影响，如在板块界面的大推力地震。然而，尽管流体-岩石相互作用对于地壳和地球化学储层的动态演化具有独特的意义，但这些相互作用的时间尺度基本上仍然不受约束。到目前为止，流体-岩石相互作用的持续时间，保留在岩石记录中，已根据计时建模，我们和其他人，到目前为止，认为正确地确定这些持续时间进行了评估。然而，没有研究证实这一点：计时模型的结果没有与实验研究的结果进行比较，因为没有进行这样的实验。因此，该项目的主要目标是开发实验来测试计时模型是否可以可靠地确定流体-岩石相互作用的持续时间。我们提出的突破性研究在于应用高度创新的实验装置来识别和验证，或者在需要时修改输入参数和数值计时建模方法的假设。在这样做的过程中，该项目还将导致更好地了解流体和岩石之间相互作用的关键过程，例如在反应性晶界处如何发生运输，孔隙度和渗透率的瞬态特性如何演变，以及晶界介导的运输如何有助于多晶材料的有效散装反应性和可运输性。

Enormous portions of the Earth’s crystalline lithosphere are being (and have been) chemically modified by fluid-driven mineral reactions. These reactions drive several consequential fluid-mediated rock transformation processes, including those that govern the stability of mountain belts, the formation of hydrothermal mineral deposits and the sequestration of anthropogenic CO2, and these processes can also lead to dramatic effects such as megathrust earthquakes at plate interfaces. However, despite the unique significance of fluid-rock interactions for the dynamic evolution of the Earth’s crust and Earth’s chemical reservoirs, the timescales of these interactions remain essentially unconstrained. To date, the durations of fluid-rock interactions, as retained in the rock record, have been assessed according to chronometric modelling, which we and others have, so far, considered to correctly determine these durations. However, no studies have verified this: The results of chronometric modelling have not been compared to those of experimental studies, because no such experiments have been performed. Therefore, the main goal of this project is to develop experiments to test whether chronometric modelling can reliably determine the duration of fluid-rock interactions. Our proposed breakthrough research lies in applying a highly innovative experimental setup to identify and verify or, wherever needed, modify the input parameters and the assumptions underlying the numerical chronometric modelling approach. In doing so, the project will also lead to a better understanding of key processes underlying the interaction between fluid and rocks, such as how transport occurs at reactive grain boundaries, how the transient properties of porosity and permeability evolve and how grain boundary-mediated transport contributes to the effective bulk reactivity and transportability of polycrystalline materials.