Static Compression of Hydrous Silicate Liquids

水合硅酸盐液体的静态压缩

• 批准号: 0509902
• 负责人: Carl Agee
• 金额: $ 25万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0509902&HistoricalAwards=false
• 关键词: Static; Compression; Hydrous; Silicate; Liquids

The primary goal of this project is to determine the density and compressibility of hydrous silicate liquids at high-pressure. This will be accomplished by performing static compression sink/float experiments in piston-cylinder and multi-anvil devices at pressures from 0.5 to 20 GPa. The sink/float technique has been used by this group in previous studies to determine high-pressure density and compressibility of anhydrous liquids that include peridotite, komatiite, terrestrial and lunar basalt, and Fe2SiO4. This study will build on this database and extend it to hydrous compositions by investigating these same liquids with added H2O. The proposed measurements will give new insight into the structure and physical properties of hydrous silicate liquids, and the mobility of water-bearing magmas in the Earth's mantle. Hydrous silicate liquid isothermal bulk moduli (KT) and the pressure derivative (K'), once established by these experiments, can then be applied to determine if equilibrium crystal-liquid density inversions exist during wet melting of the mantle.There is a growing realization that mantle magmatism, both primordial and recent, may frequently happen in the presence of water. This phenomenon could affect a wide range of the Earth's interior processes, from shallow crustal levels to the deep region at the boundary between the mantle and core. The main focus of this study is determine if there are regions in the Earth where certain magmas with dissolved water, also called hydrous silicate liquids, will become trapped or even sink, rather than rising buoyantly to the surface. We know from earlier experimental studies that some magmas, without water, become negatively buoyant at high pressure and can sink deep in the interiors of the Earth and the Moon, but this has never been determined for water-bearing or "hydrous" magmas. Therefore, this is to be one of the first systematic studies to determine the density and compressibility of hydrous silicate liquids at high pressures and temperatures in the laboratory that recreate conditions of magmatism in the Earth's mantle.This project is co-funded by the following programs: Petrology and Geochemistry, and Geophysics programs in the Division of Earth Sciences (GEO) together with the EPSCoR program (EHR).

本项目的主要目标是确定含水硅酸盐液体在高压下的密度和压缩性。这将通过在0.5至20 GPa的压力下在活塞缸和多砧装置中进行静态压缩下沉/浮动实验来实现。该小组在以前的研究中使用了沉/浮技术来确定无水液体的高压密度和可压缩性，包括橄榄岩，科马提岩，陆地和月球玄武岩和Fe 2SiO 4。本研究将建立在这个数据库，并通过研究这些相同的液体添加H2O将其扩展到含水组合物。拟议的测量将提供新的洞察含水硅酸盐液体的结构和物理性质，以及地幔中含水岩浆的流动性。含水硅酸盐液体等温体积模量（KT）和压力导数（K '）一旦通过这些实验建立，就可以用来确定地幔湿熔融过程中是否存在平衡晶体-液体密度反转。人们越来越认识到，无论是原始的还是现代的地幔岩浆活动，都可能经常在有水的情况下发生。这一现象可能会影响到地球内部的各种过程，从地壳浅层到地幔和地核边界的深层区域。这项研究的主要重点是确定地球上是否有某些溶解水的岩浆（也称为含水硅酸盐液体）会被困甚至下沉，而不是上升到地表。我们从早期的实验研究中知道，一些没有水的岩浆在高压下会产生负浮力，并可以沉入地球和月球的内部深处，但这从未被确定为含水或“含水”的岩浆。因此，这将是第一个系统的研究，以确定在高压和高温下的含水硅酸盐液体的密度和压缩性在实验室中，重现条件下的岩浆在地球的mantle.This项目是共同资助的以下项目：岩石学和地球化学，地球物理学计划在地球科学部（GEO）连同EPSCoR计划（EHR）。