Chlorine isotopes in hydrothermal systems and the global Cl cycle

2009年，所有采矿和矿物加工行业的总价值为319亿美元(加拿大自然资源，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对偏远地区产生重大的经济和社会影响，而在加拿大北部等没有其他重要工业的地区。这一建议涉及研究一系列热液矿藏类型，这些矿藏是由地壳中不同温度和压力下的大量热盐水流体形成的。这些矿床的一个共同特征是，所有成矿流体都含有大量的溶解氯，这些溶解氯与金属离子形成化学络合物，使较高浓度的金属可以通过水从金属源区输送到矿床形成的区域。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和形成环境的证据。这里提出的研究是关于这些古老流体的溴和氯同位素组成的分析。这些技术已成功地用于识别成矿系统中氯的来源，在某些情况下，还识别了流体本身的来源，这使我们能够限制特定矿床形成的模型。此外，我们寻求使用一种新的分析技术，二次电离质谱仪，来测量含氯矿物中的氯、溴和氯同位素。能够测量热液系统中液体和矿物中的氯同位素，将使我们能够了解热液系统在全球氯循环中发挥的作用(例如，将氯从地幔输送到地球表面)，将提高我们对矿藏来源的理解，并将对加拿大北部热液矿床的勘探战略产生直接影响。

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.