Exploring variation in hydrothermal alteration of the oceanic crust

中大西洋海脊是一条海底山脉，代表着由于地球内部的热量循环，地球外层的两块岩石正在相互拉开的地方。这一扩张区域经历了大量的火山活动，产生了新的岩石，形成了大西洋的海底。随着地球上这一区域的扩散，海水可以通过进入开阔的空间或岩石中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，以及它在扩散区域的不同区域是如何变化的，这一点很重要。海水与岩石发生化学作用，根据温度、岩石的化学成分和岩石中流体空间的类型，那里发现的矿物类型会发生变化。岩石的这些化学变化控制着这些地区岩石对地震的反应方式，岩浆如何通过这些岩石到达地表，以及扩散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。通过在这些扩张区域的一个例子中钻探油井，例如雷克扬斯海脊，我们可以采样和检查海底岩石与海水反应时发生的变化类型。我们还可以将特殊的工具放入这些井中，以记录图像和数据，这将让我们了解允许海水在岩石中移动的空间和裂缝是如何在扩张的海脊的不同部分发生变化的。这个项目将使用这些类型的科学数据来研究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、导致扩张的力量的差异，或者附近是否存在大断层？3)发生了哪些类型的微观相互作用，使得海水和海底岩石之间发生化学反应，它们在扩张区域的不同部分是否有所不同？4)如果微观相互作用的类型在海底扩张区域的不同区域发生变化，海底岩石的什么性质控制着这一点，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?