VOLCANIC SETTING, GEOLOGY, GEOCHEMISTRY, AND PALEOENVIRONMENT OF THE AU-RICH MINERALIZATION IN THE VOLCANOGENIC MASSIVE SULFIDE DEPOSITS IN THE ISKUT RIVER REGION OF NORTHWESTERN BRITISH COLUMBIA, CANADA

The Iskut River region, located in the Golden Triangle of northwestern British Columbia, Canada hosts several precious-metal enriched volcanogenic massive sulfide (VMS) deposits. These are hosted within the arc to back-arc successions of the Jurassic Hazelton Group. Representative prospects for the region were studied to evaluate and compare volcanic facies architecture setting, geology, geochemical signatures, paleoenvironmental setting, and sulfide mineralization of these deposits. Understanding these factors is key for constraining the processes related to precious-metal deposition in these deposits, resulting in more robust exploration models.

TV and Jeff are a stacked, precious-metal enriched VMS deposit located approximately 10 km south of the world-class Eskay Creek deposit. Graphical core logs were conducted to determine the local stratigraphy to better understand the volcanic setting, as well as the relationship between hydrothermal alteration and VMS mineralization. Representative drill core samples were collected for lithogeochemical and petrographic analyses to characterize volcanic facies and constrain metal precipitation mechanisms. Understanding this relationship can aid in the understanding of other VMS occurrences within the region.

The Spearhead prospect, located approximately 20 km south of the TV-Jeff deposits, was mapped at 1:2000 scale to evaluate volcanic facies, mineralization, and hydrothermal alteration. Structural measurements were obtained to understand the structural controls on sulfide mineralization and the effect of post-mineralization deformation. Representative samples were collected for lithogeochemical analysis and petrographic work to characterize the volcanic facies and sulfide mineralization. Reconstruction of the paleoenvironment in which the Spearhead occurrence formed, helped to constrain the relative timing between rhyolite dome emplacement into the volcaniclastic package and stringer sulfide formation. This study will provide a better understanding of the volcanic setting, geology, geochemistry, and VMS mineralization throughout the region that will aid in future exploration within the Golden Triangle.