Association of Silica Fractal Distribution with Gold Mineralization: a case study from the Takmeh-Dash Region, NW of Iran

Abstract

The Takmeh-Dash region comprises a wide variety of igneous bodies that have been developed from early to late Neogen. The granitic rocks and related aplite apophyses have been developed along fault-dominated structures which defines a well pronounced mineralized zone. According to isotopic and fluid inclusion studies, most of the quartz-pyrite units are solution-related with some traces of Cu, Pb, Zn and Au in an epithermal regime. In addition, well-developed alteration haloes are recorded around the intrusions and they include a variety of silica phases in which the textural patterns are similar to that of Queensland (Australia). This study introduces a new method for the prognosis of gold mineralization potentiality in an aplitic facies on the basis of self-organized silica textures as well as textural variations in vein type deposits. With the aid of sampling and microscopic investigation, necessary databases have been acquired from the mineralized region before a fractal analysis of silica distributions by power law relationships. It is an innovative approach toward prospecting the self-organized textures of which similarities have a legitimate relation with boiling point mineralization in epithermal environments. As a result, the Takmeh-Dash mineralogical patterns appear to include stepwise textural variations with peculiar zonal appearances due to post-magmatic procedures. For prospected sub-regions, the silica fractal dimensions not only indicate to maturity of quartzitic veins but represent an enough geological potential for the development of colloformed-crustified gold-bearing sequence in a deeper altered formation.