Closed system fluid-mineral-mediated trace element behaviour in peralkaline rare metal pegmatites: Evidence from Strange Lake

摘要

Large peralkaline complexes are 'factories' that have produced a variety of 'exotic' minerals including high field strength element minerals. In most cases, these minerals are secondary and crystallise in a hydrothermal paragenesis that is extremely difficult to decipher due to the complexity of the textural relationships. The Strange Lake pluton is one of these complexes, and contains 37 exotic minerals, most of which are secondary. Adding to the difficulty in establishing a comprehensive paragenesis for these minerals and an alteration/precipitation path for the pluton is the fact that there were several stages of crystallisation of the same exotic and common secondary minerals, e.g., bastnasite, fluocerite, gadolinite, aegirine, fluorite, and zircon.