Geochemical prospection in the Baghrodagh region, Khalkhal
The study area is located in the eastern portion of Ardebil Province, kilometer 30 of Ardebil-Khalkhal road. This region belongs to the Western Alborz-Azarbaijan structural zone and encompasses a mountain range with the same name, i.e. the Baghrodagh Mountains. From metallogeny viewpoint, the area is situated in the eastern section of Ahar gold-bearing zone. This zone contains Au, Cu, Mo, Pb, Zn, Hg, As, and Sb deposits and its continuation is detectable in the Armenia and Azerbaijan countries. Lithology of the area consists of intermediate to basic Eocene volcanic rocks and Neogene chemical and clastic sedimentary rocks. The oldest rock unit is a megaporphyry andesite that is also the dominant rock unit.
The activity of Seyedabad, Mahmudabad, Qarachaman, and Dashbolaq faults with SiO2 and CO2 bearing hydrothermal fluids caused propylitic and argillic alterations. The main alteration zones include southeast area, Mahmudabad-Firuzabad axis, Qarachaman, Gavarqale, and Seyedabad. The intrusion of hydrothermal fluids in these zones have caused mineralization of copper, such as Qarachaman abandoned copper mine, and copper indications near Qarachaman and Mahmudabad.
Considering the geochemical maps, Au, Cu, Mo, As, Ta, Te, Bi, and Hg anomalies are correlating with alterations. Important heavy minerals include malachite, gold, galena, native lead, native copper and brochantite. In four samples between 1 to 3 gold particles existed. The samples were taken from the Seyedabad alteration zone. Malachite is the main heavy mineral in these samples with maximum concentration in the Mahmudabad-Firuzabad axis and Qarachaman alteration zones. It may be related to the abandoned copper mine and indications in the area.
Finally, three alteration zones of Qarachaman, Mahmudabad, and Seyedabad are considered as favorable mineralized zones that totally have 30 square kilometers area. Based on calculation of production and mineralization coefficients, the Qarachaman anomaly is the first priority for copper exploration.