Experimental studies of the earth's mantle

地幔的实验研究

• 批准号: 46643-2011
• 负责人: Luth, Robert
• 金额: $ 2.04万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=568982
• 关键词: Experimental; studies; earth; mantle

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.

地球的地幔是我们的80％的地壳和核心之间的地球，在动态地球系统中起着基本作用。地幔中的过程直接通过地震，火山喷发以及从地面到地幔和背部的材料骑自行车的表面环境。我们需要了解地幔的运行，以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）如何在地幔中表现出来，以及它们在地幔和表面之间的运输方式。它们通过火山喷发从地幔从地面降到地面，并通过俯冲将海壳返回到地幔中，将两个构成地球外壳融合的岩石圈板汇回地幔。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向下运输到地幔中，因此了解使它们在俯冲后能够在理解这些挥发物的长期平衡和循环的过程中返回表面的过程。 在地幔中，水和二氧化碳可以存在于矿物质中，也可以作为液体或熔体存在。这些流体和熔体与地幔相互作用并修饰。例如，这种相互作用的一个结果是钻石的结晶，但是涉及的流体或熔体的性质并不是很好的约束。 我的主要研究方法是复制我实验室中地球上层内部的压力和温度条件。实际上，我做自己的地幔岩石。研究这些“动手动手”样品使我能够模拟地幔中的过程，使我们可以更好地了解水和二氧化碳的表现，以及地幔中可以存在哪些类型的液体和熔体，包括形成（或破坏）钻石的液体和融化。这些实验使我们能够测试从天然地幔样品观察到这些熔体和流体如何与地幔相互作用的假设，从而为“地面真实”提供了这些思想的重要方法。