HYDROGEOCHEMICAL DISPERSION HALOS OF FLUORINE ASSOCIATED WITH CRYOLITE MINERALIZATION

Abstract

We studied the fluorine distribution in hydrogeochemical dispersion halos of a cryolite-bearing rare-metal deposit of quartz-albite-microcline metasomatite association near a fault. We have established for the first time that cryolite mineralization may generate high-contrast hydrogeochemical dispersion halos, whose fluorine content significantly exceeds the level in natural water anomalies associated with fluorite and fluorite-bearing rare-metal mineralization, and is comparable only to that of man-made dispersion trains. Above and near cryolite bodies, there is a unique kind of ultrafresh water, in which fluorine becomes the dominant anion and accounts quantitatively for as much as 23 to 35 percent of the total salinity, whereas its relative background concentrations generally do not exceed 0.3 percent. Being one of the elements in ore deposits that is used for a particular purpose and migrates most actively in water, fluorine can be efficiently employed in hydrogeochemical prospecting for ore mineralization of the given type, especially as water samples can be rapidly analyzed in the field for fluorine by the ion-selective potentiometric method.