Micro-FTIR analysis system

虽然研究人员普遍认为，斑岩和浅成低温热液矿床中的金属和硫的来源是长英质岩浆，金属迁移的媒介是岩浆来源的含水流体，但对岩浆中这种流体的浓度、其成分，包括迁移金属的挥发性物质的浓度、其性质（液体或蒸汽）及其出溶的时间却知之甚少。硅酸盐玻璃包裹体，这是在岩浆结晶过程中形成的矿物中被困在深处，为回答这些问题提供了一个理想的信息来源。从火山学的角度来看，这些包裹体还提供了关于出溶挥发性物质（H2O，CO2，SO2）的性质和组成的重要信息，这些物质控制着岩浆上升的速度以及喷发的风格和强度。然而，为了能够正确地解释这些挥发性物质的出溶控制，更具体地说，它们在硅酸盐熔体和含水流体之间的分配，需要在已知的压力和温度条件下进行实验，用于已知成分的岩浆。麦吉尔大学和西蒙弗雷泽大学正在进行旨在解决这些问题的研究，这在很大程度上取决于分析硅酸盐玻璃挥发性成分的能力。从历史上看，获得这些数据的首选手段是二次离子质谱法（西姆斯）。然而，最近的发展，在微傅里叶变换红外光谱（傅里叶变换红外），使后者成为一个非常有吸引力的，廉价的和上级的手段，获得这样的数据。该提案是申请人和共同申请人的联合倡议，他们正在合作开展几个需要硅酸盐玻璃挥发性分析能力的项目。该申请要求提供资金，以获得用于此目的的微型傅里叶变换红外光谱仪和红外显微镜，这些仪器将被安置在麦吉尔大学。该设备将用于支持申请人和共同申请人以及13名研究生和2名博士后研究员的研究。

Although researchers are generally agreed that the source of the metals and sulphur in porphyry and epithermal mineral deposits is a felsic magma, and that the medium of metal transport is an aqueous fluid of magmatic origin, the concentration of this fluid in the magma, its composition, including the concentration of volatile species that transport metals, its nature (liquid or vapour) and the timing of its exsolution are poorly known. Silicate glass inclusions, which are trapped at depth in minerals forming during the crystallization of the magma, provide an ideal source of information for answering these questions. From the perspective of volcanology, such inclusions also provide essential information on the nature and composition of the exsolving volatile species (H2O, CO2, SO2) that control the rate of magma ascent and the style and intensity of eruptions. In order, however, to be able to properly interpret the controls on the exsolution of these volatiles, and more specifically, their partitioning between the silicate melt and the aqueous fluid, experiments are required at known pressure and temperature conditions for magmas of known composition. Research designed to address these issues is being conducted at McGill University and Simon Fraser University and depends heavily on the ability to be able to analyse the volatile composition of silicate glass. Historically, the preferred means of obtaining such data was secondary ion mass spectrometry (SIMS). However, recent developments in micro-FTIR (Fourier-Transform Infrared) spectroscopy make the latter a very attractive, inexpensive and superior means of obtaining such data. This proposal is a joint initiative of the applicant and co-applicants, who are collaborating in several projects requiring a capability for volatile analysis of silicate glasses. The application requests funds to obtain a micro-FTIR spectrometer and infrared microscope for this purpose, which will be housed at McGill University. The equipment will be used to support the research of the applicant and co-applicants and that of 13 graduate students and two post-doctoral fellows.