Investigation of tectonics, fault data and their relationship with mineralization and alteration in Asbkhan, Heris area (East Azerbaijan Province - Northwest Iran)

The study area is located in the south of Qushadagh mountain range, in the north of Asbkhan village, Heris township and in East Azarbaijan province. In terms of structural geology of Iran, this area is located in the main zone of Central Iran and Alborz-Azerbaijan sub-zone. The geological units of the region are including Eocene igneous and pyroclastic rocks with combination of andesitic, Trachyandesitic, basaltic, tuffic and ignembritic. The semi-deep intrusive mass with Oligocene age, with the combination of quartz diorite, diorite and quartz monzonite in the form of stock and dyke is exposed in the area. Structural studies, including fault plates, slickenside on them, and the joints system in various lithologies, indicate at least two general stress directions in the range, Which can be created following one tectonic regime or two tectonic regimes. If we consider the tectonic regime as a phase and consider the tensors with different directions as the result of rotation in the fault plates, We can introduce a general strike-slip regime with a general north-south trend that controls the existing structures of the region. At the same time, the infiltration of intrusive masses has caused the disintegration of these structures and made the issue more complicated. In general, faults with a northwest-southeast trend and a right on strike-slip mechanism, form the main structures of the area.Other faults are controlled by the main structures following the Riddle fractures system. Based on the system of joints in four different lithologies, lithological units from old to new include: basaltic andesite, quartz diorite, quartz monzonite (porphyry mass) and diorite, which from old to new reduces the diversity of the joints system. The northwest-southeast tectonic system has been involved in the development of argillic alteration and the northeast-southwest system has been important in the development of siliceous and mineralized veins.