"Mineralogy and petrology of carbonatites, alkaline rocks and kimberlites"

“碳酸岩、碱性岩和金伯利岩的矿物学和岩石学”

• 批准号: 8706-2012
• 负责人: Mitchell, Roger
• 金额: $ 2.77万
• 依托单位: Lakehead University
• 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=568611
• 关键词: Mineralogy; petrology; carbonatites; alkaline; rocks

The objectives of the proposed research are to understand the origin and evolution of alkaline rocks, carbonatites and kimberlites, together with their associated strategic metal economic mineral deposits. Alkaline and peralkaline syenites are host to Zr, Ti, rare earth element (REE), and P mineralization, carbonates host REE, Ti, Fe, Th, P, F and Nb deposits, and kimberlites are a source of diamond. Although alkaline rocks are of small volume relative to common silicate rocks their parental magmas are typically derived from greater depths in the Earth's upper mantle than those of such rocks, and investigation of their mineralogy and geochemistry provides insights into the metasomatic process occurring in the deeper parts of the lithospheric mantle and the asthenosphere. The research involves a combination of laboratory and experimental work with minor field work. Laboratory work uses electron beam methods (BSE-petrography, energy dispersive X-ray spectrometry, SEM, CL etc) and X-ray diffraction (including Rietveld methods) for quantitative analysis of minerals and their parageneses. Both secondary ion mass spectrometry and laser ablation inductively coupled mass spectrometry are used for in-situ trace and isotopic studies of minerals and melt inclusions. Experimental work includes studies of synthetic analogs of carbonatite magmas at diverse pressures and temperatures using rapid-quench hydrothermal methods, and low temperature hydrothermal experiments using Parr reaction vessels to investigate the decomposition of some rare metal bearing minerals. The outcomes of the work will be a better understanding of the processes which lead to the formation of strategic metal ore deposits. This is of use in prospecting for and evaluation of such ore deposits.

拟议研究的目标是了解碱性岩、碳酸岩和金伯利岩的起源和演变，以及与之相关的战略金属经济矿藏。碱性和过碱性正长岩是Zr、Ti、稀土元素（REE）和P矿化的宿主，碳酸盐岩是REE、Ti、Fe、Th、P、F和Nb矿床的宿主，金伯利岩是金刚石的来源。虽然碱性岩石相对于普通硅酸盐岩石体积较小，但它们的母岩浆通常来自地球上地幔的更深处，对它们的矿物学和地球化学研究提供了对岩石圈地幔和软流圈更深处发生的交代过程的见解。 这项研究涉及实验室和实验工作与小型实地工作相结合。实验室工作使用电子束方法（BSE岩相学，能量色散X射线光谱法，SEM，CL等）和X射线衍射（包括Rietveld方法）对矿物及其共生体进行定量分析。二次离子质谱和激光烧蚀电感耦合质谱都用于矿物和熔融包裹体的原位痕量和同位素研究。实验工作包括在不同的压力和温度下使用快速淬火热液方法的碳酸岩岩浆的合成类似物的研究，以及使用帕尔反应容器的低温热液实验，以调查一些稀有金属轴承矿物的分解。 这项工作的成果将是更好地了解导致战略金属矿床形成的过程。 这对此类矿床的找矿和评价具有一定的参考价值。