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

将高空间分辨率辅助矿物化学和地质年代学与地壳中大规模成矿热液过程联系起来。

• 批准号: RGPIN-2019-05757
• 负责人: Adlakha, Erin
• 金额: $ 1.82万
• 依托单位: Saint Mary's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=738492
• 关键词: Linking; spatial; resolution; accessory; mineral

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.

热液矿床形成过程中的流体化学和条件可以通过与矿石矿物一起结晶的副矿物的组成来记录。为了评价作为矿床形成过程和条件记录器的副矿物，需要通过高分辨率的现场化学分析，在单晶到存款的尺度上进行详细的矿物特征鉴定。该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。 拟议的研究将研究磷酸盐矿物化学的控制和变化，重点是磷灰石（地壳中最常见的磷酸盐）在两个热液环境：加拿大科迪勒拉的高温W夕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有关磷酸盐矿物和这些热液系统的下列不确定性：i）评估磷酸盐的组成和变异性（特别是矿石和伴生金属含量）可以解析热液矿石系统中的流体和金属的来源，例如W夕卡岩和UTUD，ii）解析磷酸盐矿物学，不同高温和低温反应带的矿物化学和同位素系统学; iii）确定同时代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，和iv）评估次生热液事件对磷酸盐组成的影响以评价痕量元素的保留，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。这些项目将在申请人的监督下由博士、硕士和理学士水平的HQP学员完成。磷酸盐的化学将在各种规模的使用微量分析技术，包括电子探针微量分析仪，激光烧蚀电感耦合等离子体质谱法，和二次离子质谱法进行研究。研究结果将通过HQP的会议报告和同行评审的科学文章定期向公众传达。拟议的研究活动对地球科学家和工业界具有创新性和重要意义，因为它将揭示热液系统中磷酸盐中矿石金属的控制，分布和含义。这些信息将与同位素数据联系起来，使磷酸盐矿物的应用扩展到推断热液环境中的金属和流体来源，并及时识别导致矿石沉积的其他过程。从长远来看，拟议的研究计划将继续开发新的应用空间分辨辅助矿物化学在贫瘠和矿化热液系统。