Melts, fluids, crystals: equilibrium and disequilibrium processes in magmatic systems

挥发物(水、二氧化碳、S、氟、氯、溴等)在岩浆系统中起着至关重要的作用。它们的浓度影响相平衡、火山喷发的时间和强度以及矿床的形成。它们在月球形成的巨大撞击后地球的演化中发挥了重要作用，在大型火成岩省喷发期间向大气中注入它们与地球历史上的重大灭绝事件有关。岩浆体系中的主要挥发物是H2O，但其他挥发物也普遍存在于100ppm的S和1000ppm的S之间。虽然我们对水在岩浆系统中的影响知道得最多，但一些涉及水的基本过程仍然未知。对于岩浆中水的溶出和气泡生长的机制和速率，我们还没有完全了解。水对结晶动力学和硅酸盐熔体与矿物之间的平衡的影响鲜为人知，其中一些矿物是微量元素和关键矿石金属的重要储存库。对少量岩浆挥发物的影响更是知之甚少，这些挥发物不仅影响岩浆过程，而且当脱气进入大气时，会严重影响地球表面环境。由于其在熔体中的低溶解度，少量挥发物在流体相的出溶中起着基本作用，可能会引发火山喷发。此外，这些微量挥发性元素中至少有两种元素Cl和S在矿床的形成中发挥了关键作用，特别是关键金属(如Li、Be、B、Co、稀土元素等)的形成。重要的是，我们对这些少量挥发物在岩浆系统中的行为没有足够的了解，无法对它们的运输和储存进行定量建模。这项研究计划将研究涉及主要和次要挥发分的平衡和不平衡过程，以及它们与地球和太阳系其他行星体内岩浆系统中的晶体和熔体的相互作用。我们将研究它们从熔体中释放形成气泡，开发新的方法来估计古代岩浆中的挥发分并脱气到大气中，并提高我们对挥发分在类似于地壳岩浆系统的条件下和月球形成撞击后输送氯、S和金属矿石的能力的理解。这项研究计划以实验、建模和与该领域工作的同事合作为中心，将实验结果应用于自然样品。由于研究计划将定量测量关键金属的储存和运输，该计划的结果不仅将提高我们对岩浆系统脱气的理解，还将用于模拟矿石金属运输，可用于我们在加拿大寻找关键矿产资源。

Volatiles (H2O, CO2, S, F, Cl, Br, etc.) play a vital role in magmatic systems. Their concentrations affect phase equilibria, the timing and intensity of volcanic eruptions, and the formation of ore deposits. They played a major role in the evolution of the Earth following the Moon-forming giant impact, and their injection into the atmosphere during eruptions of large igneous provinces has been linked to major extinction events in Earth's history. The dominant volatile in magmatic systems is H2O, however the other volatiles are also commonly present at concentrations of 100's to 1000's of ppm. Although we know most about the effects of water in magmatic systems, some fundamental processes involving water remain unknown. We still do not understand completely the mechanisms and rates of water exsolution and bubble growth in magmas. The influence water exerts on the kinetics of crystallization and the equilibria between silicate melts and minerals, some of which are important reservoirs of trace elements and critical ore metals, is little understood. Even less is known about the effects of minor magmatic volatiles, which not only influence magmatic processes, but when degassed into the atmosphere severely impact Earth's surficial environment. Because of their low solubilities in melts, minor volatiles play a fundamental role in the exsolution of a fluid phase, possibly initiating volcanic eruptions. Additionally, at least two of these minor volatile elements, Cl and S, play a crucial role in the formation of ore deposits, particularly of critical metals (e.g., Li, Be, B, Co, rare earth elements, etc.). Importantly, we do not know enough about the behaviour of these minor volatiles in magmatic systems to quantitatively model their transport and storage. This research program will investigate equilibrium and disequilibrium processes involving major and minor volatiles and their interactions with crystals and melts in magmatic systems on Earth and other planetary bodies in the solar system. We will investigate their exsolution from the melt to form bubbles, develop new ways to estimate volatiles in ancient magmas and degassed into the atmosphere, and improve our understanding of the ability of volatiles to transport Cl, S and ore metals at conditions similar to those in crustal magmatic systems and following the Moon-forming impact. This research program is centered around experiments, modeling, and collaboration with colleagues working in the field applying the experimental results to natural samples. Because the research program will quantitatively measure storage and transport of critical metals, the results of the program will not only improve our understanding of the degassing of magmatic systems, but also will be used to model ore metal transport that can be applied to our search for critical mineral resources in Canada.