Prospecting for Gold Mineralization Using Geochemical, Mineralogical, and WorldView-2 Data: Siyah Jangal Area Case Study, Northern Taftan Volcano, SE Iran

摘要

This study applies a combination of geochemical, mineralogical, and WorldView-2 (WV-2) data for gold prospecting in the Siyah Jangal area, southeastern Iran. Geochemical and mineralogical studies, image processing, and field studies were used to identify areas of high-potential gold mineralization. Elemental concentrations in samples collected from exploration trenches in a well-known gold mineralization area were applied to identify Au pathfinders using bivariate and multivariate statistics. Visible-near infrared-shortwave infrared spectroscopy was applied to identify mineral phases. Correlation analysis, principal component analysis, and cluster analysis of measured element concentrations showed that Au has strong associations with As, Pb, Fe, and Cu, among which, Fe is the only element that forms major minerals in the area. The spectroscopy analyses showed that iron oxide-hydroxide bearing minerals including jarosite, hematite, and goethite are the major Fe-bearing phases in the surficial environment. Therefore, mineral fraction images of these minerals were produced by performing matched filtering method on WV-2 data, and the fractions of more than 0.25 of goethite, 0.15 of hematite, and 0.10 of jarosite were combined and converted as map layers to generate a false color composite (RGB) image for targeting potential areas of gold mineralization. The accuracy of iron oxide-hydroxides mapping was proven by field observations and XRD analyses of surficial samples. Moreover, concentrations of Au in samples collected from exploration boreholes in previously mapped areas showed good correlations between enhanced areas by remote sensing studies and gold occurrences.