Exploring variation in hydrothermal alteration of the oceanic crust

大西洋中脊是海底山脉，代表了地球外层的两块岩石由于地球内部的热循环而相互分离的地方。这个扩张的区域经历了大量的火山活动，这些火山活动产生了新的岩石，形成了大西洋的海底。随着地球这一区域的扩展，海水可以通过进入开阔的空间或岩石的裂缝与新形成的岩石相互作用。了解海水是如何在海底岩石中移动的，以及它在扩张区域的不同区域是如何变化的，是很重要的。海水与岩石发生化学反应，根据温度、岩石的化学性质和岩石中流体空间的类型，会改变岩石中矿物质的类型。这些岩石的化学变化控制着这些地区的岩石对地震的反应方式，岩浆如何通过这些岩石到达地表，以及扩展区域如何通过岩石和海水之间的化学反应对地球的碳循环做出贡献。通过在雷克雅内斯海岭（Reykjanes Ridge）等这些扩散区域打井，我们可以对海底岩石与海水反应时发生的变化类型进行取样和检查。我们还可以将特殊工具放入这些井中，记录图像和数据，让我们了解允许海水在岩石中移动的空间和裂缝，在扩展脊的不同部分是如何变化的。该项目将使用这些类型的科学数据来调查我们对海底扩张的一些问题：1)海底岩石的空间和裂缝在扩张区域的不同部分是否会发生变化？2)如果存在变化，它们是否受到海底岩石性质变化的控制，例如厚度、引起扩散的力的差异或附近大断层的存在？3)海水和海底岩石之间发生什么类型的微观相互作用，使其发生化学反应？在扩展区的不同地区，它们是否不同？4)如果在海底扩展区的不同区域，微观相互作用的类型发生了变化，那么海底岩石的哪些特性控制了这种变化，比如它们的厚度以及让海水进入岩石的空间和裂缝的类型？

The Mid-Atlantic Ridge is the line of undersea mountains that represent where two pieces of the Earth's outer layer of rock are pulling away from each other due to heat circulating in the planet's interior. This spreading region experiences a lot of volcanic activity which creates new rock that forms the ocean floor in the Atlantic. As this region of the Earth spreads, seawater can interact with newly formed rocks by moving into open spaces or cracks in the rock. Understanding how seawater moves around in ocean floor rocks, and how it changes in different areas of the spreading regions, is important. The seawater chemically interacts with the rock and depending on temperature, the chemistry of the rock, and the type of fluid spaces in the rock, changes the types of minerals found there. These chemical changes to the rock control the way rocks respond to earthquakes in these areas, how magma makes its way to the surface through these rocks, and how spreading regions contribute to the carbon cycle of the planet through chemical reaction between rock and seawater. By drilling wells in an example of these spreading areas such as the Reykjanes Ridge, we can sample and examine the type of changes happening to the ocean floor rocks when they react with seawater. We can also lower special tools into these wells to record images and data that will let us understand how the spaces and cracks that allow seawater to move around in the rocks, change in different parts of the spreading ridges. This project will use these types of scientific data to investigate a number of questions we have about spreading ocean floors:1) Do the spaces and cracks in ocean floor rocks change in different parts of the spreading region?2) If changes exist, are they controlled by changing properties of the ocean floor rocks, for example, thickness, differences in the forces that cause spreading, or the nearby presence of large faults?3) What types of microscopic interactions occur that allow chemical reactions between seawater and ocean floor rocks and are they different in different parts of the spreading regions?4) If the types of microscopic interactions change in different areas of ocean floor spreading regions, what properties of the ocean floor rocks control this, such as their thickness and the types of spaces and cracks that let seawater into the rocks?