New Mexico Mineral Symposium — Abstracts

Fluid inclusions are pockets of fluid trapped during the growth of a crystal from a hydrothermal fluid. They represent the only remaining sample of the mineralizing fluid and therefore can provide valuable information about the conditions of formation of the minerals.

The inclusions typically consist of one or two liquid phases, a gas phase, and one or more solid phases. The relationship between these phases and their behavior during cooling and heating experiments can be used to determine the temperature at which the fluid inclusion was trapped by the growing crystal and the salinity of the mineralizing fluid. Other techniques can also be applied to obtain a more complete chemical and isotopic analysis of the fluid.

The data obtained from fluid inclusions are very valuable in ore-deposit studies to determine the origin of fluids, temperature of mineralization, fluid salinity, and mechanisms of deposition. Fluid inclusions have been studied at these sites among others in New Mexico: Hansonburg Pb-F deposit, Helen Rae Au deposit, Victorio Mts. W deposit, Capitan rare-earth-element quartz veins, and the Zn deposits of the Kelly district.