APPLICATION OF LA-ICP-MS SULFIDE ANALYSIS AND METHODOLOGY FOR DECIPHERING ELEMENTAL PARAGENESIS AND ASSOCIATIONS IN ADDITION TO MULTI-STAGE PROCESSES IN METAMORPHIC GOLD SETTINGS

Quantitative laser ablation inductively coupled plasma-mass spectrometry (LA-MP-MS) element distribution analysis represents a relatively new and powerful approach to assess gold mineralizing processes. Although there is a trend towards imaging in LA-ICP-MS, this article demonstrates that the compilation of the individual time-slice datasets (TSD) from LA analyses provides greater potential to explore and better understand ore systems. Based on several analyses of gold-bearing sulfides from a variety of lode gold mineralized settings, this study introduces new diagrams and geostatistical techniques as recommended procedures to be applied to any gold deposit environment to better understand its genesis, with possible exploration implications. The nature of the mineralizing fluid is investigated by studying Ni and Co variations in the sulfide grains in environments ranging from ultramafic to felsic, whereas upgrading of gold tenor within an ore deposit is identified using Au versus Ag plots grouped by element association and elemental geochemical affinity. Furthermore, the textural transformation and coupled dissolution/precipitation (CDP) in pyrite is documented using Ag versus Ni plots with associated defined fields (i.e., diagenetic versus metamorphic). Lastly, standard geostatistical tests are used to assess element associations through agglomerative hierarchical clustering and exploratory statistical methods. Meanwhile, a multidimensional scaling approach can evaluate the geochemical affinity of the mineralizing fluids.