Breccia Mechanisms and Hydrothermal Evolution from Both Colombian Emerald Belts

This study presents the conditions of pressure, temperature, and breccia mechanisms that allow the migration of emerald-bearing hydrothermal fluids within the emerald belts of Colombia. Based on detailed petrographic analysis, three different hydrothermal events were determined, establishing a chronological framework that enhances our understanding of geological processes in these emerald belts. The first event is characterized by the high presence of albite, due to an albitization event that altered the rock. The other events are marked by an early stage of carbonatization (second) and a late carbonatization stage (third). After understanding the hydrothermal events, Fermi diad bands were obtained by Raman spectroscopy in fluid inclusions. This approach permits the calculation of the rock pressure using the vibrational modes of the CO2 and their relationship with its density. These analysis was performed in minerals associated with each hydrothermal event. The data obtained from these analyses provides the evolution of the pressure in the whole hydrothermal history. 

Finally, a fractal analysis applied to breccias from both (western and eastern) emerald belts was performed. This analytical approach aimed to understand the breccia mechanisms throughout the entire hydrothermal history, providing a view of the geological evolution of these emerald belts. Even though both belts present similar events, the western emerald belt reveals higher mechanical energy in comparison with the eastern emerald belt, in which the pressure is generally lower and breccia mechanisms show a higher-intensity corrosive event, the presence of fluidization breccias manifests that the migration of the fragments may be fluid assisted against Halokinesis