Behavior of chalcophile elements in subduction zones

俯冲带中亲铜元素的行为

• 批准号: 616-2009
• 负责人: Hattori, Keiko
• 金额: $ 3.5万
• 依托单位: University of Ottawa
• 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=568137
• 关键词: Behavior; chalcophile; elements; subduction; zones

I will investigate the behaviour of chalcophile (copper-like) elements in subduction zones where arc volcanoes form. Such elements have an affinity for sulphur in shallow crustal rocks, and include many metals that are necessary for our society, such as copper. Most rocks consist largely of silicates, and the chalcophile elements are present in only trace concentrations. Metal deposits that are economic to mine occur in volcanic arcs that are formed where oceanic rocks are subducted. This spatial association between metal deposits and subduction zones indicates a linkage; however, metal behaviour at great depths, where subduction causes melting of rocks that leads to arc volcanism, is little known. In past research, my team has shown that oxidized magmas contain high concentrations of sulphur and metals, and that the oxidation state reflects the nature of the underlying mantle. The discharge of huge amounts of SO2 from Mt. Pinatubo, Philippines, was a consequence of the highly oxidized mantle below the volcano. We have also shown from work in the Himalayas and S. America that the mantle oxidation condition is affected by the subducted material. The mantle has low sulfur, requiring the large discharge of sulfur from volcanoes to be supplied from the subducted plates. My research will help to answer several questions: How are sulfur and metals transferred from the subducting plate to the mantle, then to magmas that may erupt, and how do these metals occur in the S-poor mantle? For our research, we will study three types of rocks; those that have been deeply subducted and brought back to the surface, pieces of mantle that were uplifted during mountain building, and mantle fragments that were brought to the surface by explosive volcanoes. The project will contribute to targeting the regions that may contain major metal deposits, and volcanoic regions that dangerously discharge SO2. Students participating to this project gain valuable research experience and theoretical and practical knowledge in geoscience that are not available in classrooms and useful in their career advances.

我将研究弧形火山形成的俯冲带（铜）元素的行为。这些元素对浅层地壳中的硫具有亲和力，其中包括我们社会所需的许多金属，例如铜。 大多数岩石主要由硅酸盐组成，而果酱元素仅以痕量浓度存在。在俯冲的海洋岩石中，发生了经济的金属沉积物发生在火山弧中。金属沉积物和俯冲带之间的空间关联表明是连接的。然而，在俯冲造成岩石融化的大深度的金属行为却鲜为人知。在过去的研究中，我的团队表明氧化岩浆含有高浓度的硫和金属，并且氧化状态反映了基础地幔的性质。从菲律宾Pinatubo山排放大量SO2是火山下方高度氧化的地幔的结果。我们还在喜马拉雅山脉和美国的工作中表明，地幔氧化条件受俯冲材料的影响。地幔具有低硫，需要从俯冲板提供的火山中大量排放硫。我的研究将有助于回答几个问题：硫和金属如何从俯冲板转移到地幔，然后转移到可能爆发的岩浆中，这些金属如何发生在S-Poor地幔中？在我们的研究中，我们将研究三种类型的岩石。那些被深深地俯冲并带回地面的人，在山区建筑期间抬高的地幔块，以及爆炸性火山带来的地幔碎片。 该项目将有助于针对可能包含主要金属沉积物的区域以及危险排出SO2的火山区域。参加该项目的学生获得了宝贵的研究经验以及地球科学的理论和实践知识，这些研究经验在课堂上不可用，并且在其职业发展中有用。