Document Type : Research - Paper
Authors
1
Ph.D Student, Dept. of Mining Engineering, Islamic Azad University, Ahar Branch, Ahar, Iran
2
Associate Professor, Dept. of Geology, Islamic Azad University, Tabriz Branch, Tabriz, Iran
3
Assistant Professor, Dept. of Mining Engineering, Islamic Azad University, Ahar Branch, Ahar, Iran
4
Assistant Professor, Dept. of Geology, Natural Sciences Faculty, Tabriz University, Tabriz, Iran
Abstract
The epithermal part of copper-gold porphyry deposits are important due to their high grade, low exploitation costs and the presence of precious elements. The main rock outcrops in the area from old to new include Eocene volcanoclastic deposits, Oligo-Miocene intrusive bodies and Quaternary deposits. The Sonajil area is known as a site of porphyry deposit and copper mining, but the characteristics, style and origin of the mineralization of its epithermal part has not been described in the scientific literature. On the basis of results achieved from studying satellite images and field and laboratory controls, the presence of kaolinite, quartz, alunite and hydroxyl minerals, has been confirmed, which are the indicator of phyllic, propylitic, argillic, siliceous and tourmalinization in the epithermal part. The Interpretation of the stream sediments geochemistry, data analysis and lithology along with classical statistical methods, grade-number and grade-area fractal models showed that the grade-number fractal method with a high reliability coefficient is the most effective for separating the epithermal part from the porphyry mineralization in the region, which has been used as the basis for the interpretation of the maps. The maximum values of Au element anomaly are consistent with epithermal-related siliceous veins in the western part of the area and the lowest anomaly is related to the northeast of the deposit. According to the results of geometallurgical studies in Canada's ActLab laboratory, the occurrence of gold mineral is accompanied by quartz less than ten microns in size. Therefore, the origin of gold mineralization in the Sonajil deposit belongs to epithermal deposits. The presence of colloform texture, hydrothermal breccia’s along with the geochemical correlation of elements and principle component statistical analysis results are all consistent with features of low sulfidation epithermal deposits.
Keywords
Main Subjects