Water in Subduction Zones

俯冲带中的水

• 批准号: 0309292
• 负责人: Anne Peslier
• 金额: $ 13.69万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0309292&HistoricalAwards=false
• 关键词: Water; Subduction; Zones

EAR-0309292 PeslierWater has a strong influence on the chemical and physical properties of silicate minerals, fluids, and melts in the lithosphere. Water released from the mantle via melt transport to the crust, or degassing, may be recycled back into the mantle in subduction zones. Subduction processes likely add significant quantities of water back into the mantle. The reactions occurring during the dehydration of a down-going slab, the quantity of water being kept by the slab and that expelled to the overlying mantle wedge, how water is stored in these various components, and in what form it can be released, are therefore important factors in understanding the water budget of the mantle. This project proposes to estimate the water content of the down-going slab and that of the overlying mantle wedge, in order to shed light on the water transport budget at subduction zones. This study focuses on the primary phases of the mantle, olivine, pyroxene and garnet. These nominally anhydrous minerals may represent an important site for storing water (or more exactly hydrogen) in subducted slabs and in the mantle above slabs at depths where hydrous minerals may not be stable. The samples will be prepared for analysis at the University of Houston. The analyses of water will be performed by Fourier transform infrared spectrometry (FTIR) at NASA Johnson Space Center in Houston, Texas. Fe3+/Fe ratio measurements from which oxygen fugacities will be calculated will be performed with Mossbauer equipment at the Bavarian Research Institute at Bayreuth, Germany. The first broader impact of this project is that Anne Peslier will be able to work in a collaborative setting with local and international partners. This project will also provide infrastructure support for the laboratory facilities at the University of Houston. Finally this grant will help support an early-career female PI to maintain active research and as such will help increase the representation of women in the science enterprise.

水对岩石圈中硅酸盐矿物、流体和熔体的化学和物理性质有很强的影响。通过熔体运输或脱气从地幔中释放出来的水可能在俯冲带中再循环回到地幔中。俯冲过程可能会将大量的水重新注入地幔。在下降板块脱水过程中发生的反应，板块保持的水量以及被排出到上覆地幔楔的水量，水如何储存在这些不同的成分中，以及以什么形式释放出来，都是理解地幔水分平衡的重要因素。本项目提出估算下行板块和上覆地幔楔的含水率，以揭示俯冲带的水运收支。本文主要研究了地幔的初级阶段，橄榄石、辉石和石榴石。这些名义上的无水矿物可能代表了在俯冲板块和板块上方的地幔中储存水（或更确切地说，是氢）的重要场所，在这些地方，含水矿物可能不稳定。这些样品将在休斯敦大学进行分析。水的分析将在德克萨斯州休斯敦的美国宇航局约翰逊航天中心通过傅里叶变换红外光谱（FTIR）进行。计算氧逸度的Fe3+/Fe比值测量将在德国拜罗伊特巴伐利亚研究所的穆斯堡尔设备上进行。该项目的第一个更广泛的影响是Anne Peslier将能够与当地和国际合作伙伴合作。该项目还将为休斯顿大学的实验室设施提供基础设施支持。最后，这笔拨款将有助于支持早期职业女性PI保持积极的研究，因此将有助于增加女性在科学事业中的代表性。