Collaborative Research: Using Trace and Ore Elements to Track Volatile Behavior and Fluid Migration within Intermediate-silicic Magma Chambers

包括水、二氧化碳、硫和氯在内的岩浆挥发性成分的释放和移动，对火山喷发的条件和潜在矿物质的迁移和沉积起着重要的控制作用。许多对理解这些过程至关重要的参数对于直接观测是看不见的，因为它们发生在地球表面以下几公里处。研究人员提出，岩浆和在岩浆中形成的晶体中的其他微量元素可以用来解释岩浆和流体中的挥发行为。然而，描述这些元素如何结合到晶体中的许多基本变量是未知的或有问题的。这项研究建立在对最近(2004年)圣海伦斯火山喷发的晶体中分析的不同微量元素的观察基础上，方法是：1)在各种条件下进行热液实验，试图更好地约束许多这些可疑的变量；2)扩大圣海伦斯火山的工作，以寻找其他火山的类似元素变化，包括Mt.菲律宾的皮纳图博；阿拉斯加的奥古斯丁火山；以及守护神，利帕里。具体地说，这项工作将集中在对元素Li、铜、锌、铅、钨和钼的实验和分析研究。这些元素特别令人感兴趣，因为先前的研究表明，它们可能通过挥发物(如水、二氧化碳等)运输。实验结果将与来自多个火山中心的观测相结合，以充分了解这些元素富集物的来源，这与硅质岩浆系统中挥发分的运动如何相关，以及挥发分转移如何影响喷发和矿床形成过程。

The release and movement of magmatic volatile components, including water, carbon dioxide, sulfur, and chlorine, exert significant control on the conditions of volcanic eruptions and on the transport and deposition of potential ore metals. Many of the parameters critical for understanding these processes are invisible to direct observations because they occur up to several kilometers beneath the surface of the Earth. Researchers have suggested that other trace elements both in the magma and in crystals forming within it may be used as a proxy for interpreting volatile behavior in magma and fluids. However many of the basic variables which describe how these elements are incorporated into crystals are unknown or are in question. This study builds off observations about enrichment in different trace elements analyzed in crystals from the recent eruption (2004) of Mount St. Helens by 1) conducting hydrothermal experiments at various conditions to try to better constrain many of these questionable variables and 2) expand on the work at Mount St. Helens to look for similar elemental variations at other volcanoes, including Mt. Pinatubo, Philippines; Augustine volcano, Alaska; and Mt. Guardia, Lipari. Specifically, this work will focus on an experimental and analytical study of the elements, Li, Cu, Zn, Pb, W, and Mo. These elements are of particular interest as prior studies have suggested they are likely to be transported by volatiles (such as water, CO2, etc). The experimental results will be integrated with observations from multiple volcanic centers to fully understand the origins of these element enrichments and how this relates to the movement of volatiles in silicic magma systems and how volatile transfer influences processes of eruption and mineral deposit formation.