Rare earth element mineralizations in the Palabora Carbonatite Complex

碳酸盐岩是稀土元素的重要来源，在现代技术，特别是绿色技术中起着关键作用。因此，详细了解碳酸盐岩相关稀土矿床的形成地点和形成方式，对于这些重要资源的矿产勘探和未来开发至关重要。该项目将系统地调查迄今为止几乎没有记录的南非Palabora碳酸岩杂岩（PCC）的稀土矿化。PCC是一个非常适合的研究对象，以回答有关碳酸盐岩相关的稀土矿化的重要问题，因为它的矿物学变量和多阶段的稀土矿物组合和独特的可能性，系统地调查矿物学变化方面的稀土矿物在垂直距离约1500米。详细的岩相学，EMPA和LA-ICP-MS的工作将进行跟踪各种稀土矿物组合的结构和成分演变的空间变化。将通过XRF和ICP-MS进行全岩分析，包括高质量的REE数据，这将允许通过复杂的化学变化来识别。流体包裹体的表征（显微测温、拉曼光谱、气相色谱-IRMS）将与成岩矿物的稳定同位素数据相结合，这将有助于解释各种稀土矿化的形成和再活化所涉及的各种流体来源。这项研究的结果将增强我们对碳酸岩系统的侵位和岩浆-热液演化及其相关的稀土矿化随深度的认识，包括物理化学参数的潜在变化（例如，P、T、pH、fO_2、aH_2O、aCO_2、aHF、aHCl）和流体来源的变化对稀土-矿物组合类型有直接影响。

Carbonatites represent the most important source for REE, which play a key role for many modern, especially green technologies. Therefore, the detailed understanding of where and how carbonatite-related REE deposits form is critical to mineral exploration and future development of these important resources. This project will systematically investigate the so-far barely documented REE mineralization of the Palabora Carbonatite Complex (PCC) in South Africa. The PCC is a perfectly suited research object to answer important questions concerning carbonatite-related REE mineralizations because of its mineralogicaly variable and multi-stage REE-mineral assemblages and the unique possibility to systematically investigate mineralogical changes with respect to REE-minerals over a vertical distance of about 1500 m. Detailed petrography, EMPA and LA-ICP-MS work will be performed to track spatial variations in the textural and compositional evolution of the various REE-mineral assemblages. Whole-rock analyses, including high quality REE data, will be carried out by XRF and ICP-MS, which will allow for identifying chemical variations through the complex. Characterization of fluid inclusions (microthermometry, Raman spectroscopy, gas chromatography-IRMS) will be combined with stable isotope data for rock-forming minerals, which will allow for deciphering the various fluid sources involved in the formation and remobilization of the various REE mineralizations. The results of this study will enhance our knowledge concerning the emplacement and the magmatic to hydrothermal evolution of carbonatitic systems and their associated REE mineralization with depth, including potential changes in physico-chemical parameters (e.g., P, T, pH, fO2, aH2O, aCO2, aHF, aHCl) and changing fluid sources, which may have direct consequences on the type of REE-mineral assemblage.