Identification and application of a Carlin-type gold mineral system for exploration targeting in the Takab geothermal basin, NW Iran

Abstract

In this research, a mineral system approach applied in a GIS environment to predict favorable gold potential areas in a district to deposit scale at the north Takab geothermal basin, NW Iran. In a context of mineral system, initially the world class Zarshuran gold deposit studied and modeled to identify important conceptual controls on gold mineralization. Conceptual controls such as sources of heat, metals and mineralizing hydrothermal fluids, active fluid flow pathways, lithological and geochemical accumulation environments were identified in a deposit scale and converted to mappable spatial controls or targeting elements for district-scale gold exploration. Intermediate magma and metamorphosed ophiolites respectively considered as the main heat and gold sources. Major particular faults and their intersections with the axis of anticlines, strongly brecciated dacite lithic tuff and its contact with the favorable host lithologies presented as the most important indicators of active fluid flow pathways. The intersection of the main faults and anticline boundaries were determined as an important factor in fluid accumulation and gold mineralization. Silicified carbonate and black shale considered as the favorable chemical scrubber or reactive host. Dome-like structure such as Iman Khan anticline, formed through uplifting, was introduced as an important physical throttle. Finally, by introducing a mineral system model for the Zarshuran Carlin-type gold deposit, these critical processes converted to mappable gold exploration features by using the district-scale geological map and remotely- sensed hydrothermal alterations of the area in a GIS environment. Based on the proposed gold mineral system, the identified exploration features ranked by appropriate weighting for targeting gold mineralization. A final gold potential map of the area was created by using weighted index overlay data integration modeling to locate high gold potential areas for future exploration in the surrounding areas of the Zarshuran deposit.