Experimental Study of Noble Gas Behavior in the Mantle

地幔中稀有气体行为的实验研究

• 批准号: 1019229
• 负责人: Stephen Parman
• 金额: $ 35万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-15 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1019229&HistoricalAwards=false
• 关键词: Experimental; Study; Noble; Gas; Behavior

The motions of the Earth's interior control and organize much of what goes on at the surface. From earthquakes and volcanoes, to oil and mineral deposits, even the evolution of life itself; the world humans live in is largely the product of the deep processes within our planet's interior. Because one cannot directly sample the deep Earth, one has to use indirect physical and chemical measurements to understand what is happening below our feet. The proposed study seeks to further our understanding of the inner motions and composition of the Earth's interior using the concentrations of noble gases (He, Ne, Ar, Kr, Xe) and their isotopes in lavas as probes of the high pressure processes that have such a large effect on our lives.Due to their lack of charge, it has generally been assumed that noble gases are inert and are not retained in mantle minerals. A number of paradigms about the Earth use this as a key assumption: from the understanding structure of mantle convection to quantifying the volatile content of the planet. However, recent high-pressure experimental studies suggest that in fact noble gases have surprisingly high solubilities in the mantle, potentially requiring a wide range of theories to be revamped. In fact, there are few experimental measurements of noble gas behavior at mantle conditions. Utilizing new analytical and experimental advances, this study will measure the partitioning and diffusivities of noble gases in a range of mantle minerals, many for the first time, including orthopyroxene, garnet, wadsleyite, ringwoodite and majorite. A range of high-pressure devices (piston-cylinder, multi-anvil, internally-heated gas pressure) will be employed to produce pressures over 20 GPa and temperatures up to 2000 oC, simulating conditions in the upper and lower mantle. Samples will be measured by new generation laser-ablation mass spectrometry. The unprecedented data set will be used to reevaluate current ideas about the structure and composition of the Earth.

地球内部控制的运动并组织了表面上发生的大部分情况。 从地震和火山到石油和矿藏，甚至是生命本身的进化；人类生活的世界在很大程度上是我们星球内部深处过程的产物。 因为一个人无法直接采样深层地球，所以必须使用间接的物理和化学测量来了解我们的脚下发生的事情。 The proposed study seeks to further our understanding of the inner motions and composition of the Earth's interior using the concentrations of noble gases (He, Ne, Ar, Kr, Xe) and their isotopes in lavas as probes of the high pressure processes that have such a large effect on our lives.Due to their lack of charge, it has generally been assumed that noble gases are inert and are not retained in mantle minerals. 关于地球的许多范式都将其用作关键假设：从地幔对流的理解结构来量化行星的挥发性含量。但是，最近的高压实验研究表明，实际上，贵重气体在地幔中具有令人惊讶的高溶解度，可能需要对广泛的理论进行修改。 实际上，在地幔条件下，几乎没有实验性的气体行为。利用新的分析和实验进步，本研究将测量一系列地幔矿物质中贵重气体的分配和扩散性，其中许多是首次，包括Orthopyroxene，Garnet，Garnet，Wadsleyite，Wadsleyite，Ringwoodite，Ringwoodite和Maledite。将采用一系列高压设备（活塞缸，多动力，内部加热的气压），以产生20 GPA的压力，并在2000 oC的温度上产生压力，从而模拟上下地幔中的条件。 样品将通过新一代激光质谱法测量。 前所未有的数据集将用于重新评估有关地球结构和组成的当前思想。