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: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=522535
• 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块，其中一些板块在俯冲带相互会聚。这些俯冲带是地球系统中物质（岩石和水）在地质时期（数百万至数十亿年）内在深层固体地球（地壳和地幔）与海洋和大气之间流动的关键位置。该研究计划的重点是俯冲带的三个组成部分，这些组成部分影响某些元素或金属的流动性，并最终影响它们在地表环境中的可用性，在那里它们可能形成矿石资源，或污染和影响生物圈。在接下来的五年里，我们研究：（1）在构成板块的不同岩石类型的俯冲过程中硫的释放，（2）金属（如铜）在俯冲带附近的地幔深处的流动性，并向上进入地壳形成矿床，以及（3）有毒微量金属（如铅或砷）通过活火山脱气进入大气。为此，我们在实验室中模拟了在非常高的压力（P）和温度（T）下板块俯冲的条件，并研究了这些参数如何影响某些岩石类型中硫的行为。反过来，俯冲板块释放的金属，或它们在地幔深处的行为，往往与P、T和/或硫的行为有着内在的联系，有助于我们了解哪种金属是移动的，以及它们如何通过岩浆在地壳中向上富集，在俯冲带上方形成某些矿产资源。此外，我们还可以在实验室中模拟高温下火山岩浆中有毒微量金属的释放，并在较低的温度下将这些金属从气相中冷凝出来。这些实验告诉我们，火山可能会释放出哪些有毒金属物质，有多少会流失到大气中，以及它们会在多大程度上污染环境，并可能影响生物圈，无论是现在还是过去。