"Implications of the tectonic setting, magma-wallrock interaction and postemplacement evolution of carbonatites for their rare-metal (REE, Nb, Ta, Zr and U) potential"

碳酸盐岩和成因相关的碳酸盐岩是稀有金属的重要经济来源。近年来，人们越来越认识到碳酸盐岩可能有多种成因，并根据其构造环境和地幔来源表现出根本的差异。碳酸盐岩的构造和地球化学之间的这些关系（因此也包括它们的经济潜力）迄今尚未得到系统的研究。岩浆-围岩相互作用对稀有元素运移和封存的影响，以及就位后结构和化学变化对碳酸盐岩矿体的几何和组成的影响都没有得到足够详细的研究。拟议的研究将解决这些现有的差距，以期查明促进碳酸盐中镧系元素、铌、钽和其他稀有金属经济集中发展的主要因素。提出的研究计划的新颖之处在于，它将涉及对不同构造背景下含有有记录的稀有元素矿化的碳酸盐岩进行系统和综合研究。该项目将建立在申请人对这些地质系统的丰富经验的基础上，并将涉及获取以前未研究过的新材料，但这些材料代表了重要的地质上独特的碳酸盐岩类型。该项目将包括一个大型培训部分，并将遵循多分析方法，以确保在碳酸盐岩演化的背景下可以解释不同类型的矿化。这项分析工作将包括样品的地球化学特征、矿物鉴定、物源研究和岩石成因建模。这项工作的三个主要成果将是：(1)提高对碳酸盐形成的来源和过程的认识；(2)完善碳酸盐岩矿床的找矿标准；(3)培养高素质人才。拟议的研究结果将通过同行评议的国际期刊、网络媒体、会议报告、矿产勘探公约和和记黄埔巡回演讲等出版物加以传播。

Carbonatites and genetically related carbonate rocks are an economically important source of rare metals. In recent years, it has been increasingly recognized that carbonatites may have multiple origins and show fundamental differences specific to their tectonic setting and mantle sources. These relations between the tectonics and geochemistry of carbonatites (and, therefore, also their economic potential) have not been systematically studied to date. Neither the effects of magma-wallrock interactions on the transport and sequestration of rare elements, nor the impact of postemplacement textural and chemical changes on the geometry and composition of carbonatite-hosted ore bodies have been studied in adequate detail. The proposed research will address these existing gaps in an attempt to identify the principal factors that contribute to the development of economic concentrations of lanthanides, Nb, Ta and other rare metals in carbonatites. The novelty of the proposed research program is in that it will involve a systematic and integrated study of carbonatites containing documented rare-element mineralization from different tectonic settings. The program will build on the applicant's extensive experience with these geological systems and will involve acquisition of new material not studied previously, but representing important geologically distinct types of carbonatite. The program will include a large training component and will follow a multi-analytical approach to ensure that different styles of mineralization can be interpreted in the context of carbonatite evolution. This analytical work will involve geochemical characterization of samples, mineral identification, source-provenance studies, and petrogenetic modelling. The three major outcomes of this work will be: (1) an improved understanding of the sources and processes responsible for the formation of carbonatites; (2) refined exploration criteria for carbonatite-hosted ore deposits, and (3) training of highly qualified personnel. The results of the proposed research will be disseminated through publications in peer-reviewed international journals, web-based media, presentations at conferences, mineral exploration conventions and Hutchison lecture tour.