Geological characteristics and mineralization patterns of gold mines in Danghe Nanshan Area, Gansu Province: a case study of the Baishitougou gold deposit

To reveal the metallogenic regularity of gold deposits in the Danghe Nanshan Area, Gansu Province, this study focuses on the Baishitougou altered cataclastic rock-type gold deposit and integrated regional geological, geophysical and geochemical data. The area is located in the western segment of the South Qilian magmatic arc, divided into north-south tectonic units by the Danghe concealed fault. The Ordovician System is the main ore-bearing and material source horizon, Caledonian intermediate-acid intrusive rocks provide metallogenic heat sources and part of ore-forming materials, and NW-SE trending faults are ore-controlling structures. The Baishitougou deposit contains 7 NW-SE trending ore veins, with core orebodies occurring in the F₂ alteration zone. Ores are divided into three types, with silicification as key mineralization alteration. Geochemically, it shows “Au-As-Sb-Hg” anomalies, and geophysically corresponds to the superposition area of gravity-aeromagnetic positive anomalies. Regional gold deposits follow the “magmatic hydrothermal-fault ore-controlling” model, with three metallogenic stages and controlled by “tectonic-stratigraphic-magmatic” factors. The prospecting direction of “Ordovician + Caledonian intrusions + NW-trending faults” is proposed to support regional exploration.