Metals in Magmas and Applications in Igneous and Environmental Geology

岩浆中的金属及其在火成岩和环境地质学中的应用

• 批准号: 154275-2013
• 负责人: Canil, Dante
• 金额: $ 3.5万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569404
• 关键词: Metals; Magmas; Applications; Igneous; Environmental

The Earth's surface is organized into a series of rigid moving plates, some of which converge into one another at subduction zones. These subduction zones are a key location in the earth system for the fluxes of mass (rock and water) between the deep solid earth (crust and mantle), and the oceans and atmosphere over geologic time (millions to billions of years). This research program focuses on three components of subduction zones that affect the mobility of certain elements or metals and ultimately their availability in the surface environment where they may form ore resources, or pollute and impact the biosphere. Over the next five years we examine: (1) the release of sulfur during the subduction of different rock types which make up the plates, (2) the mobility of metals (like Copper) deep in the mantle near subduction zones, and upward into the crust to make ore deposits, and (3) the degassing of toxic trace metals (like Lead or Arsenic) into the atmosphere by active volcanoes. To do this, we simulate the conditions of plate subduction at very high pressures (P) and temperatures (T) in the laboratory and examine how these parameters affect the behaviour of sulfur in certain rock types. In turn, the release of metals by the subducted plate, or their behaviour at depth in the mantle, is often intrinsically linked to the P, T and/or behaviour of sulfur, and helps us understand what kinds of metals are mobile and how they can be enriched upward in the crust by magmas to form certain ore resources above subduction zones. In addition, we can also simulate the release of toxic trace metals from magma in a volcano at high temperatures in the lab and condense those metals from the gas phase at cooler temperatures. These experiments inform us of what toxic metal species can emanate from volcanoes, how much can be lost to the atmosphere, and to what degree they can pollute the environment, and potentially impact the biosphere, both now and in the past.

地球表面被组织成一系列刚性移动的板，其中一些板在俯冲带上相互融合。这些俯冲带是地球系统中的地球系统中的一个关键位置（岩石和水）之间的质量（地壳和地幔），以及地质时间（数百万到数十亿年）的海洋和大气层。该研究计划的重点是影响某些元素或金属的活动性的俯冲带的三个组成部分，并最终在它们可能形成矿石资源的表面环境中的可用性，或污染并影响生物圈。在接下来的五年中，我们检查：（1）在构成板的不同岩石类型的俯冲期间释放硫，（2）金属的迁移率（如铜）在俯冲带附近的地幔深处，然后向上进入将矿石沉积的外壳和（3）有毒的痕量金属（例如铅或砷）通过活火山脱离大气。为此，我们模拟了实验室中非常高的压力（P）和温度（T）处的板俯冲条件，并检查这些参数如何影响某些岩石类型中硫的行为。反过来，俯冲板释放金属，或者其在地幔中深度的行为通常与硫的P，T和/或行为固有地联系在一起，并帮助我们了解哪些金属类型是移动的以及它们如何岩浆可以在地壳中向上富集，以在俯冲带上方形成某些矿石资源。此外，我们还可以模拟实验室高温下火山中岩浆中岩浆中有毒痕量金属的释放，并在凉爽温度下从气相中凝结这些金属。这些实验告诉我们，哪些有毒金属物种可以从火山中散发出什么，在大气中损失了多少，它们在多大程度上可以污染环境，并可能影响生物圈，无论是现在还是过去。