Characteristics of Ground Magnetic Anomalies and Prospecting Direction in the Songshunangou Gold Deposit, North Qilian Orogenic Belt

The Songshunangou gold deposit is located on the southern margin of the central segment of the North Qilian Orogenic Belt, characterized by excellent metallogenic geological conditions. The eastern and western deposits have been discovered within the mining area, reaching large-scale deposit status. Although the area exhibits significant prospecting potential, the exploration direction requires further clarification to provide a scientific basis for the next phase of exploration planning. Based on this, this paper systematically summarizes the physical properties of rocks and ores in the Songshunangou gold deposit. It is concluded that the positive magnetic anomalies in the area are closely associated with the mineralized porphyry (Late Ordovician quartz diorite porphyry) and the ore-hosting volcanic rocks (basaltic andesite of the Upper Ordovician Koumenzi Formation). Ground magnetic survey data from the mining area were processed using methods such as reduction-to-the-pole and upward continuation, delineating seven positive magnetic anomaly zones (T1, T2, T3, T4, T5, T6, and T7). Among these, the T1 anomaly zone coincides with the location of the Western Deposit. Field verification was conducted on the T2 and T3 magnetic anomaly zones. Analysis of surface outcrop samples collected during verification showed gold grades of 0.07–1.65 g/t and 0.10 – 0.29 g/t, respectively. Trenching work carried out in the T2 anomaly zone revealed a maximum gold grade of 0.54 g/t. The results indicate that the positive magnetic anomaly zones possess favorable metallogenic geological conditions and promising prospecting potential, making them key target areas for further exploration.