Linking high spatial resolution accessory mineral chemistry and geochronology to large-scale ore-forming hydrothermal processes in the crust.

热液矿床形成过程中流体的化学性质和条件可以通过与矿石矿物结晶的附属矿物的组成来记录。为了评价辅助矿物作为矿床形成过程和条件的记录者，需要通过高分辨率的原位化学分析，在单晶到矿床尺度上进行详细的矿物表征。这项研究计划的长期目标是开发矿物化学的新应用，以解决有关形成矿床的过程和条件的不确定性。该研究将研究磷矿化学的控制和变化，重点研究两种热液环境中的磷灰石（地壳中最常见的磷酸盐）：加拿大科迪勒拉的高温W矽卡岩矿床和萨斯喀彻温省阿萨巴斯卡盆地的低温不整合型U矿床（UTUD）。本提案的短期目标是阐明以下关于磷酸盐矿物和这些热液系统的不确定性：1)评估磷酸盐的组成和变异性（特别是矿石和伴生金属含量）如何解决热液矿石系统（如W矽卡岩和UTUDs）中流体和金属的来源；2)解决不同高T和低T反应带的磷酸盐矿物学、矿物化学和同位素系统；Iii)确定同时期矿物如何影响金属和其他微量元素在流体磷酸盐之间的分配，iv)评估二次热液事件对磷酸盐组成的影响，以评估微量元素的保留，以及磷酸盐被改变和/或破坏的条件。为实现上述目标，提出了五个项目。这些项目将由博士、理学硕士和理学士级别的HQP学员在申请人的指导下完成。磷酸盐的化学性质将在各种尺度上使用微分析技术进行研究，包括电子探针微分析仪、激光烧蚀电感耦合等离子体质谱和二次离子体质谱。研究结果将通过HQP的会议报告和同行评议的科学文章定期向公众公布。所提出的研究活动对地球科学家和工业具有创新和重要意义，因为它将揭示热液系统中磷酸盐中矿石金属的控制，分布和影响。这些信息将与同位素数据联系起来，从而扩展磷酸盐矿物的应用范围，以推断热液环境中的金属和流体来源，并及时确定导致矿床沉积的其他过程。从长远来看，该研究计划将继续开发在贫瘠和矿化热液系统中空间分解的辅助矿物化学的新应用。

The chemistry of fluids and conditions during the formation of hydrothermal ore deposits can be recorded by the composition of accessory minerals that crystallize with ore minerals. In order to evaluate accessory minerals as recorders of the processes and conditions under which ore deposits form, detailed mineral characterization, at a single crystal to deposit scale, is required through high resolution, in-situ, chemical analysis. The long-term goal of this research program is to develop new applications of mineral chemistry in order to resolve uncertainties regarding the processes and conditions which form ore deposits. The proposed research will examine the controls and variation of phosphate mineral chemistry, with a focus on apatite (the most common phosphate in the crust) in two hydrothermal settings: high temperature W skarn deposits of the Canadian Cordillera, and low temperature unconformity-type U deposits (UTUD) of the Athabasca Basin, Saskatchewan. The short-term objectives of this proposal are to elucidate the following uncertainties regarding phosphate minerals & these hydrothermal systems: i) evaluate how the composition & variability of phosphates (particularly the ore and associated metal content) can resolve the source of fluids & metals in hydrothermal ore systems such as W skarn & UTUDs, ii) resolve phosphate mineralogy, mineral chemistry & isotope systematics in distinct high T & low T reaction zones; iii) determine how coeval minerals impact partitioning of metals & other trace elements between fluid-phosphate, and iv) assess the effects of secondary hydrothermal events on the composition of phosphates in order to evaluate the retention of trace elements, & conditions in which phosphates are altered &/or destroyed. Five projects are proposed to address the above objectives. These projects will be completed by PhD, MSc and BSc level HQP trainees under the applicant's supervision. The chemistry of phosphates will be investigated at a variety of scales using microanalytical techniques including electron probe microanalyser, laser ablation inductively coupled plasma mass spectrometry, and secondary ion mass spectrometry. The results will be regularly communicated to the public through conference presentations by HQP, and peer-reviewed scientific articles. The proposed research activities are innovative & significant to geoscientists & industry, as it will reveal the controls, distribution, & implications of ore metals in phosphates in hydrothermal systems. This information will be linked with isotopic data allowing the application of phosphate minerals to be extended to infer metal & fluid sources in hydrothermal environments, & identify other processes in time that led to ore deposition. In the long term, the proposed research program will continue to develop new applications for spatially resolved accessory mineral chemistry in barren and mineralized hydrothermal systems.