Experimental studies of the earth's mantle

地幔是地球上介于地壳和地核之间的80%，在动态地球系统中发挥着基础性的作用。地幔中的过程通过地震、火山喷发和物质从地表到地幔再回来的循环直接影响我们的地表环境。我们需要了解地幔的工作原理，以便更好地了解它们对地表环境的影响。 我的研究重点是“挥发物”--水和二氧化碳等化合物--在地幔中的行为，以及它们如何在地幔和地表之间传输。它们通过火山喷发从地幔来到地表，并通过俯冲作用返回地幔，当洋壳被推回到地幔中时，构成地球外壳的两个岩石圈板块在那里汇合。在数十亿年的地质时间尺度上，俯冲可以将所有地表水和二氧化碳输送到地幔中，因此了解俯冲后它们返回地表的过程对于了解这些挥发物的长期平衡和循环至关重要。 在地幔中，水和二氧化碳可以以矿物的形式存在，也可以以流体或熔体的形式存在。这些流体和熔体与地幔相互作用，并改变地幔。例如，这种相互作用的一个结果是钻石的结晶，但所涉及的流体或熔体的性质并没有受到很好的限制。 我的主要研究方法是在我的实验室里复制存在于地球上地幔内部的压力和温度条件。实际上，我是自己制作地幔岩石的。通过研究这些“自己动手”的样品，我可以模拟地幔中的过程，让我们更好地了解水和二氧化碳的行为，以及地幔中可能存在哪些类型的流体和熔体，包括那些形成(或破坏)钻石的流体和熔体。这些实验使我们能够检验根据对天然地幔样本的观察得出的假说，即这些熔体和流体如何与地幔相互作用，从而提供了一种重要的方式来“证实”这些想法。

The Earth's mantle, the 80% of our planet between the crust and the core, plays a fundamental role in the dynamic Earth system. Processes in the mantle directly affect our surface environment through earthquakes, volcanic eruptions, and the cycling of material from the surface to the mantle and back. We need to understand the workings of the mantle to better understand their impacts on the surface environment. My research focuses on how "volatiles" - compounds like water and carbon dioxide - behave in the mantle, and how they are transported between the mantle and the surface. They come to the surface from the mantle via volcanic eruptions, and are returned to the mantle by subduction, when oceanic crust is thrust back into the mantle where two of the lithospheric plates that make up the Earth's outer shell converge. Over geological time scales of billions of years, subduction could transport all of the surface water and carbon dioxide down into the mantle, so understanding the processes that allow them to return to the surface after subduction is vital to understanding the long-term balance and cycling of these volatiles. In the mantle, water and carbon dioxide can be present in minerals, or as fluids or melts. These fluids and melts interact with, and modify, the mantle. One outcome of this interaction, for example, is crystallization of diamond, but the nature of the fluids or melts involved is not well constrained. My primary research approach is to duplicate the pressure and temperature conditions that exist inside the Earth's upper mantle in my laboratory. In effect, I make my own mantle rocks. Studying these "do-it-yourself" samples allow me to simulate the processes in the mantle, to give us a better understanding of how water and carbon dioxide behave, and what types of fluids and melts can exist in the mantle, including those that form (or destroy) diamond. The experiments allow us to test hypotheses, derived from observations of natural mantle samples, of how these melts and fluids interact with the mantle, and thereby provide an important way to "ground-truth" these ideas.