Tracing element migration in the geosphere and biosphere

追踪地球圈和生物圈中的元素迁移

• 批准号: RGPIN-2014-03626
• 负责人: Kyser, T
• 金额: $ 5.25万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=565988
• 关键词: Tracing; element; migration; geosphere; biosphere

The long-term goal of my research is to understand the migration of elements throughout the near-surface environment (i.e. geosphere) and across the interface between the geosphere and plants and animals (i.e. biosphere). This research involves both environmental sciences and mineral exploration, is comprised of both pure and applied research components, and will involve 3 BSc, 2 MSc, 5 PhD, 5 PDF and 2 Research Associates. The science behind this research is that sources of elements can be definitively identified in environments near the surface through their isotopes (same number of protons but different number of neutrons for an element) and concentrations, thereby identifying prospective areas for buried metal deposits and inputs of pollution in pristine areas. My research program during the next five years will focus along two diverse yet related themes: (1) mineral resources, which will involve tracing element migration from ore deposits at depth via their isotopes and trapping of them in the near-surface, and (2) geosphere-biosphere interactions, which will distinguish elements that have migrated from undercover ore deposits from those that have come from global pollution, using these elements in soils and tree-rings to help find more buried ore deposits, and to better track the migratory habits of animals because they have interacted with specific rock units. (1) Mineral resources have become more difficult to find since most of those exposed at the surface have been discovered. We will study areas of known deposits that include uranium in Saskatchewan and copper and nickel in Manitoba. Samples of drill core from the deposit, the overlying geology, and soils and trees at the surface will be collected. Drill core and overlying samples will collected, their mineral compositions characterized, and their chemistry and isotopes of elements measured. Techniques we have developed will be used to measure both element contents and their location in the samples, as well as their isotopes. For the soils, the clay minerals will be extracted because they are able to trap migrating elements. Their chemical and isotopic compositions will be measured to identify elements mobilized from the deposits. Hydrocarbons from clays and soils and their isotopic compositions also will be extracted to understand the role of microbes in mobilizing elements and fixing them in the near-surface environment. In the process, several HQP will be trained in multi-dimensional research and analytical geochemistry. (2) Geosphere-biosphere interactions will involve the use of tree-rings and complementary data from other surface media to distinguish deposit and pollution sources of metals. Also, as part of a collaborative effort over the next five years, I will be engaged in research using isotopes to trace element migration from oceanic, lake and wind-blown sources to produce carbonates in soils. This research will involve deciphering the character of carbonates in arid lake environments and in soils using “bio-active” trace elements and selected isotopes to reveal the effects of microbial processes on carbonate production. In a complementary study, migratory habits of birds will be traced with isotopes of hydrogen, carbon and nitrogen (all bio-active) and trace elements in feathers, blood and toenails to reflect the geology in which the birds grow these organs. This project will be the first to integrate isotope, trace elements, tissue morphology and biologic data to trace factors affecting the declining populations of migrating birds. Despite the seeming disparity, all of this research involves using isotopes and element contents to effectively trace the movement of elements in the near-surface environment for both pure and applied research goals.

我的研究的长期目标是了解元素在整个近地表环境（即地圈）和地圈与植物和动物（即生物圈）之间的界面上的迁移。这项研究涉及环境科学和矿产勘探，由纯研究和应用研究组成，将涉及3个理学士，2个硕士，5个博士，5个PDF和2个研究助理。这项研究背后的科学原理是，可以通过元素的同位素（一种元素的质子数相同，但中子数不同）和浓度，在地表附近的环境中确定元素的来源，从而确定潜在的埋藏金属矿床区域和原始地区的污染输入。我在未来五年的研究计划将集中在沿着两个不同但相关的主题：（1）矿产资源，这将涉及通过同位素追踪元素从矿床深处迁移并将其捕获在近地表，以及（2）地圈-生物圈相互作用，这将区分从地下矿床迁移的元素和来自全球污染的元素，利用土壤和树木年轮中的这些元素来帮助寻找更多的地下矿藏，并更好地跟踪动物的迁徙习惯，因为它们与特定的岩石单元相互作用。(1)由于大多数暴露在地表的矿产资源已经被发现，因此矿产资源变得更加难以找到。我们将研究已知的矿床，包括萨斯喀彻温省的铀和马尼托巴省的铜和镍。将采集存款、上覆地质、土壤和地表树木的岩芯样本。将收集岩芯和上覆样品，表征其矿物成分，并测量其化学和元素同位素。我们开发的技术将用于测量样品中的元素含量及其位置，以及它们的同位素。对于土壤，粘土矿物将被提取，因为它们能够捕获迁移的元素。将测量其化学和同位素组成，以确定从矿床中调动的元素。还将提取粘土和土壤中的碳氢化合物及其同位素组成，以了解微生物在动员元素并将其固定在近地表环境中的作用。在此过程中，将对几名HQP进行多维研究和分析地球化学方面的培训。(2)地圈-生物圈的相互作用将涉及利用树木年轮和来自其他表面介质的补充数据来区分金属的存款和污染源。此外，作为未来五年合作努力的一部分，我将从事利用同位素追踪海洋、湖泊和风吹来源的元素迁移以在土壤中产生碳酸盐的研究。这项研究将涉及使用“生物活性”微量元素和选定的同位素来破译干旱湖泊环境和土壤中碳酸盐的特征，以揭示微生物过程对碳酸盐生产的影响。在一项补充研究中，将用氢、碳和氮（所有生物活性）的同位素以及羽毛、血液和脚趾甲中的微量元素来追踪鸟类的迁徙习惯，以反映鸟类生长这些器官的地质情况。这一项目将是第一个将同位素、微量元素、组织形态和生物数据结合起来追踪影响候鸟数量下降的因素的项目。尽管表面上存在差异，但所有这些研究都涉及使用同位素和元素含量来有效地追踪元素在近地表环境中的运动，以实现纯研究和应用研究目标。