Uncertainty-volume fractal model for delineating copper mineralization controllers using geostatistical simulation in Nohkouhi volcanogenic massive sulfide deposit, Central Iran

Abstract

The aim of this study was to delineate copper mineralization controllers in Nohkouhi volcanogenic massive sulfide (VMS) deposit by using geostatistical and fractal simulation. In this study, concentration-volume (C-V) fractal model has been used to indicate various copper populations related to different host rocks and copper minerals. Accordingly, uncertainty-volume (U-V) fractal model was applied to probability values achieved through sequential indicator simulation (SIS). Copper ores of Nohkouhi deposit including chalcopyrite and malachite were simulated in 30 realizations. The U-V fractal model obtained by using a probability map was divided into four probability zones (high, moderate, low, and very low) for copper minerals. Furthermore, copper grades were simulated for 10 times by sequential Gaussian simulation (SGS). Combination of C–V and U-V fractal modeling resulted in a hybrid method which could be properly employed to determinate various mineralization zones based on the relationship between quantitative (e.g.copper grade) and qualitative (e.g. copper minerals) variables. Moreover, integrating the results of C–V and U-V fractal modeling with the most frequent occurrence of rock type modeling helps identify copper mineralization controllers in a VMS deposit.

Keywords

• nohkouhi copper deposit
• sequential gaussian simulation
• sequential indicator simulation
• concentration–volume fractal modeling
• uncertainty-volume fractal modeling
• volcanogenic massive sulfide