Niobium, zirconium, titanium, and rare earth elements in alkaline silica-undersatured magmas: experimental determination of solubility, complexation and phase relations and implications for the formation of magmatic Nb-Zr-REE deposits

碱性二氧化硅-欠饱和岩浆中的铌、锆、钛和稀土元素：溶解度、络合和相关系的实验测定以及对岩浆铌-锆-稀土矿床形成的影响

• 批准号: 441268636
• 负责人: Dr. Christian Schmidt
• 金额: --
• 依托单位: Saint Petersburg University
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/441268636?language=en
• 关键词: Niobium; zirconium; titanium; rare; earth

Peralkaline magmatic rocks host some the largest accumulations of Zr, Nb, Ta and rare earth elements (REE) on Earth. Of particular importance at present or in the near future are or will be deposits in silica-undersaturated alkaline rocks (Khibiny and Lovozero massifs, Kola Peninsula, Russia and deposits in the Gardar province, southern Greenland), which are characterized by a complex mineralogy. So far, these rocks are little studied experimentally, and thus fundamental data on solubility and complexation of these elements and even on phase relationships are missing. In the project proposed here, we would like to address some of the open questions and determine the solubility of Nb, Zr, Ti and REE from minerals that crystallize early upon cooling (lueshite, perovskite, loparite, eudialyte, parakeldyshite, zircon, baddeleyite) in alkali aluminosilicate melts as function of peralkalinity, and of the concentrations of F, Cl, CO2, and H2O). These experiments will also provide information on phase relationships. Moreover, we plan to study the coordination chemistry of Nb, Zr, Ti and REE in the produced glasses and the complexation of Nb in the melt in situ at high temperature.

Peralkaline Magmatic Rocks拥有地球上ZR，NB，TA和稀土元素（REE）的一些最大积累。目前或不久的将来，尤为重要的是，或将是硅粉饱和的碱性岩石（Khibiny和Lovozero地块，俄罗斯的Kola Peninsula，Russia和Sockits in Southern Greenland）的沉积物，这些岩石的特征是复杂的矿物学。到目前为止，这些岩石很少在实验中研究，因此缺少有关这些元素甚至相位关系的溶解性和络合的基本数据。 In the project proposed here, we would like to address some of the open questions and determine the solubility of Nb, Zr, Ti and REE from minerals that crystallize early upon cooling (lueshite, perovskite, loparite, eudialyte, parakeldyshite, zircon, baddeleyite) in alkali aluminosilicate melts as function of peralkalinity, and of the concentrations of F, CL，CO2和H2O）。这些实验还将提供有关阶段关系的信息。此外，我们计划在高温下在融化的原位研究NB，ZR，TI和REE的配位化学和NB的络合。