Detection of mineralization stages using zonality and multifractal modeling based on geological and geochemical data in the Au-(Cu) intrusion-related Gouzal-Bolagh deposit, NW Iran

The objective of this paper is to detect various gold and copper mineralization stages according to surface lithogeochemical data utilizing zonality index and spectrum-area (S-A) multifractal modeling along with geological data in the Au-(Cu) intrusion-related Gouzal-Bolagh deposit, northwestern Iran. Gold mineralization at Gouzal-Bolagh consists of quartz-sulfide veins within the Paleocene batholithic granitoid complex, which has intruded into the Mesozoic and older metamorphic rocks and shales. Considering the mineralization type, a zonality index was determined as (Au + Cu)/(As + Sb). Au, Cu, and zonality index values were categorized by the S-A multifractal model and the log-log plots. Moreover, multifractal modeling of the zonality index in correlation with geological (specifically mineralographical) data shows that there are three stages for mineralization including Pre-, main and post-mineralization (supergene enrichment). The main stage of mineralization formed from two sub-stages:A (Quartz vein and veinlet sulfidation), B (Quartz sulfide brecciation). In addition, various stages of mineralization contain zonality index values of 31.8, 31.8-507.3, 507.3-758.3, 758.3-1628.7 and 1628.7 for background, pre-mineralization, sub-stages A, B and supergene, respectively. The background is a granitic batholith containing silicic mineralized veins with a NE-SW trend. Results obtained by this study demonstrate that there are major occurrences of gold and copper mineralization in the sulfidation and brecciation sub-stages, respectively.

Automated summary

This study aims to detect the distribution of gold and copper mineralization stages in the Gouzal-Bolagh deposit in northwestern Iran using zonality index and S-A multifractal modeling based on geological and surface lithogeochemical data. The results indicate the presence of three mineralization stages (Pre-, main, and post-mineralization) with two sub-stages in the main stage (A: Quartz vein and veinlet sulfidation, B: Quartz sulfide brecciation). The study shows major occurrences of gold and copper mineralization in the sulfidation and brecciation sub-stages.