Ore mineralogy and uraninite trace element chemistry of hydrothermal polymetallic U-Ag-(Co-Ni-As-Bi-Sb-Cu) vein deposits, Eldorado Mine, Port Radium, NWT

Abstract

The paragenetic sequence of uranium enriched polymetallic deposits at the Eldorado mine in the N.W.T, Canada, is poorly understood. Few studies have used modern analytical techniques to characterize the deposit. This study aims to update paragenetic models by use of petrographic work as well as SEM analysis. This data will be used in conjunction with LA-ICPMS to characterize the trace element composition of uraninite (interpreted to be UO[subscript 2], U[subscript 3]O[subscript 8] mixture). The data show that there are alternating sequences of coprecipitation between uraninite and Co-Ni arsenides. This indicates that the fluid is carrying multiple metals (U, Ni and Co) simultaneous and that a major factor in their precipitation is an increase in fO[subscript 2]. Our paragenetic sequence closely follows previous models.