Melts, fluids, crystals: Equilibrium and disequilibrium processes in magmatic systems and ore deposits

熔体、流体、晶体：岩浆系统和矿床中的平衡和不平衡过程

• 批准号: RGPIN-2015-06355
• 负责人: Baker, Don
• 金额: $ 3.64万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=644500
• 关键词: Melts; fluids; crystals; Equilibrium; disequilibrium

This research programme investigates processes involving volatiles and their interactions with crystals and melts in magmatic systems. I, together with students and colleagues, will investigate volatile exsolution from melts to form bubbles, develop new ways to estimate volatiles in ancient magmas and degassed into the atmosphere, explore the role of minor volatiles in volcanic eruptions, quantify the ability of volatiles to transport Cl, S and ore metals at magmatic conditions and explore their influence on the delayed nucleation of crystals in magmatic systems. This research program is centred around experimental measurements and computer simulations, and involves collaboration with colleagues working in the field. ******More specifically, the goals of this research program for the next five years are to:***1. Quantify the partitioning of sulfur and halogens between melts and aqueous fluids in experiments to measure the solubility of the minor volatiles and their effects on the ability of hydrous fluids to transport critical ore metals (e.g., Pt, Sc, Li, rare earth elements, etc.). ***2. Measure the partitioning of minor volatiles (sulfur and halogens) between experimentally produced silicate melts and nominally volatile-free minerals (e.g., feldspar, clinopyroxene, olivine) in order to constrain pre-eruption magmatic volatile concentrations. The experimental results will be combined with measurements on natural minerals to estimate the volatile release from ancient flood basalts and those results provided to atmospheric scientists for modelling the effects of flood basalts on the terrestrial environment.***3. Investigate the role of minor volatiles on the exsolution (nucleation and growth) of bubbles from melts and their role in the initiation of volcanic eruptions through laboratory experiments and X-ray microtomographic studies. These measurements will be combined with computer models to determine the effects of different bubble size distributions on the permeabilities and strengths of magmatic foams.******4. Determine the role volatiles play in the supersaturation of magmatic melts with respect to crystallization of ore-rich minerals (e.g., sulfide, spodumene, iron oxides) and the formation of pegmatites through experimental studies of crystal nucleation and growth.******This research program will provide us with an improved picture of how volatiles behave and the role they play in magmatic systems. In five years we will better understand volatiles in magmas and will have advanced our abilities to model the evolution of magmas, the magmatic degassing of pre-historic eruptions, the formation of magmatic ore deposits, and the eruption of volcanoes.**

这项研究计划调查涉及挥发分的过程及其与岩浆系统中的晶体和熔体的相互作用。我将与学生和同事一起，研究从熔体中挥发出来形成气泡，开发新的方法来估计古代岩浆中的挥发分并将其脱气到大气中，探索少量挥发分在火山喷发中的作用，量化挥发分在岩浆条件下输送氯、S和矿石金属的能力，并探索它们对岩浆系统中晶体延迟成核的影响。这项研究计划以实验测量和计算机模拟为中心，并涉及与该领域的同事合作。*更具体地说，这项研究计划未来五年的目标是：*1.在实验中量化硫和卤素在熔体和水相流体中的分配，以测量次挥发物的溶解度及其对含水流体运输关键矿石金属(如铂、钪、锂、稀土元素等)能力的影响。*2.测量少量挥发物(硫和卤素)在实验生产的硅酸盐熔体和名义上不挥发的矿物(例如长石、单斜辉石、橄榄石)之间的分配，以限制喷发前岩浆的挥发浓度。实验结果将与对天然矿物的测量相结合，以估计古代溢流玄武岩的挥发性释放，并将这些结果提供给大气科学家，用于模拟洪泛玄武岩对陆地环境的影响。*3.通过实验室实验和X射线显微断层摄影研究，研究微量挥发物对熔岩中气泡的出溶(成核和生长)的作用及其在火山喷发启动中的作用。这些测量结果将与计算机模型相结合，以确定不同气泡大小分布对岩浆泡沫渗透率和强度的影响。4.通过对晶体成核和生长的实验研究，确定挥发分在岩浆熔体过饱和和富矿石矿物(如硫化物、锂辉石、氧化铁)结晶和伟晶岩形成中所起的作用。这项研究计划将为我们提供一幅更好的图像，了解挥发分的行为及其在岩浆系统中的作用。在五年内，我们将更好地了解岩浆中的挥发分，并将提高我们对岩浆演化、史前喷发的岩浆脱气、岩浆矿床的形成和火山喷发的模拟能力。