Chlorine isotopes in hydrothermal systems and the global Cl cycle

热液系统中的氯同位素和全球氯循环

• 批准号: 250098-2012
• 负责人: Gleeson, Sarah
• 金额: $ 2.77万
• 依托单位: University of Alberta
• 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=570820
• 关键词: Chlorine; isotopes; hydrothermal; systems; global

The total value of all mining and mineral processing industries was $31.9 billion in 2009 (Natural Resources Canada 2011). Therefore, the mining industry is a significant contributor to the Canadian economy and their exploration and development of mineral deposits can have a significant economic and societal impact in remote areas with no other significant industry such as in Canada's North. This proposal is concerned with studying a range of hydrothermal mineral deposit types that form from large volumes of hot saline fluids at different temperatures and pressures in the Earth's crust. A common feature of these deposits is that all the mineralizing fluids contained significant amounts of dissolved chlorine, which forms chemical complexes with the metal ions and allows higher concentrations of metals to be transported by the water from the metal source regions to the area where the ore deposit formed. As such the chlorine in these fluids is a major component of the ore forming system. In ore deposits, droplets of the mineralizing solution can be trapped in minerals as fluid inclusions and retain evidence of the chemistry of the mineralizing fluids and the environment in which they formed. The research proposed here is concerned with the analyses of these ancient fluids for the bromine and chlorine isotopic composition of the fluids. These techniques have been successfully used to recognise the source of chlorine in mineralizing systems and, in some cases, also the source of the fluid itself, which allows us to constrain models of how a particular deposit was formed. Furthermore, we seek to use a new analytical technique, secondary ionisation mass spectrometry, to measure chlorine, bromine and chlorine isotopes in chlorine bearing minerals. Having the ability to measure chlorine isotopes in liquids and minerals in hydrothermal systems will enable us to understand the role that hydrothermal systems play in the global chlorine cycle (e.g. in transporting chlorine from the mantle to the surface of the Earth), will improve our understanding of the origin of mineral deposits and, will have a direct impact on exploration strategies for hydrothermal deposits in Northern Canada.

2009年，所有采矿和矿物加工业的总价值为319亿加元（加拿大自然资源部，2011年）。因此，采矿业是加拿大经济的重要贡献者，他们对矿藏的勘探和开发可以在没有其他重要工业的偏远地区（如加拿大北部）产生重大的经济和社会影响。这项提议涉及研究一系列热液矿物存款类型，这些类型是由地壳中不同温度和压力下的大量热盐水形成的。这些矿床的一个共同特征是，所有矿化流体都含有大量溶解的氯，氯与金属离子形成化学络合物，并允许水将更高浓度的金属从金属源区运输到形成矿石存款的区域。因此，这些流体中的氯是成矿系统的主要成分。 在矿床中，成矿溶液的液滴可以作为流体包裹体被捕获在矿物中，并保留成矿流体的化学性质及其形成环境的证据。这里提出的研究涉及这些古老的流体的溴和氯同位素组成的分析。 这些技术已被成功地用于识别矿化系统中的氯源，在某些情况下，还可以识别流体本身的来源，这使我们能够限制特定存款形成的模型。 此外，我们试图使用一种新的分析技术，二次电离质谱，测量氯，溴和氯同位素的含氯矿物。测量热液系统中液体和矿物中氯同位素的能力将使我们能够了解热液系统在全球氯循环中的作用（例如将氯从地幔输送到地球表面），将提高我们对矿床起源的理解，并将对加拿大北方热液矿床的勘探战略产生直接影响。