Experimental Study of Water Leakage from Melt Inclusions in Quartz During Laboratory Heating

玻璃状的硅酸盐熔体包裹体被捕获在火成岩矿物中，其中含有活火山下岩浆房中的熔体样品。这些包裹体提供了一个最好的工具，可用于确定水在岩浆中的浓度，并已被用来确定挥发分存在于岩浆中。此外，因为水在硅酸盐熔体中的溶解度作为P、T和X的函数是众所周知的，所以捕获时的压力可以从水含量估计。利用熔融包裹体来理解岩浆房过程的一个基本假设是，包裹体在捕获后没有损失或获得组分。虽然这一假设通常是有效的，大多数熔体成分，它是已知的，水（或氢）扩散通过大多数矿物非常容易，可以从（或获得）包裹体以下entrapment.This项目涉及一个系统的研究，使用天然和合成硅酸盐熔体包裹体，以确定那些实验室加热技术，最有可能保持原来的水含量的熔体包裹体。天然和合成硅酸盐熔体包裹体将在加热前进行表征，以确定尺寸、形状和与晶体表面或裂缝的距离，然后通过几种技术之一进行加热，然后对熔体进行拉曼分析以确定水含量。 这些结果将被用来制定一个协议，选择和结晶硅酸盐熔体包裹体，将尽量减少水loss.broader影响，这个项目包括培训研究生和本科生在现代实验和分析技术。该项目的一个重要外联部分是建立罗德数字图书馆。该图书馆将包括罗德博士在其68年职业生涯中发表的所有流体包裹体的数字图像。这些图像将通过万维网提供给教育和研究使用，并成为在广泛的地球科学领域进行教学和研究的重要资源。

Glassy, silicate melt inclusions trapped in igneous minerals contain samples of the melt that was present in the magma chamber beneath an active volcano. These inclusions provide one of the best tools available for determining water concentrations in magmas, and have been used to determine the volatiles present in magmas. Moreover, because the solubility of water in silicate melts as a function of P, T and X is well known, the pressure at trapping may be estimated from the water content. A basic assumption required to use melt inclusions to understand processes in magma chambers is that the inclusions have not lost or gained components following trapping. While this assumption is generally valid for most melt components, it is known that water (or hydrogen) diffuses through most minerals very easily and can be lost from (or gained by) inclusions following entrapment.This project involves a systematic study using both natural and synthetic silicate melt inclusions to identify those laboratory heating techniques that are most likely to preserve the original water content of the melt inclusions. Natural and synthetic silicate melt inclusions will be characterized before heating to determine the size, shape, and distance from the crystal surface or fracture, and then heated by one of several techniques, followed by Raman analysis of the melt to determine the water content. These results will be used to develop a protocol for selecting and homogenizing crystallized silicate melt inclusions that will minimize water loss.Broader impacts of this project include the training of both graduate and undergraduate students in modern experimental and analytical techniques. An important outreach component of this project involves the establishment of the Roedder Digital Library. The library will include digital images of all the fluid inclusions that Dr. Roedder has published over his 68-year professional career. These images will be made available for educational and research usage through the worldwide web and become an important resource for those teaching and conducting research in a broad range of earth science areas.