Application of comprehensive geophysical and geochemical prospecting methods in exploration of molybdenum−polymetallic ore in Ganyu area, Jiangsu Province

The Sulu Orogenic Belt is the key research area of solid mineral exploration in Jiangsu Province. Due to the deep burial of ore bodies, the study area is relatively scarce. This article elaborated on the geological characteristics of the Ganyu area in the southern margin of the Sulu Orogenic Belt, including stratigraphy, structure, and magmatic rocks. Through geophysical and geochemical methods, including soil geochemistry, induced polarization gradient array surveying, and induced polarization sounding, a total of 8 Mo anomalies and 11 induced polarization gradient array anomalies were delineated, respectively. Based on the favorable anomalies selected, surface trenching verification and deep drilling verification were conducted on the induced polarization gradient array anomaly η_s5 and the geochemical prospecting Mo−2 anomaly, which showed good correlation with the geophysical and geochemical anomalies. As a result, a total of 7 molybdenum−copper ore bodies were discovered, indicating that the comprehensive geophysical and geochemical exploration methods have achieved promising prospecting results in the Ganyu area. Based on the geophysical and geochemical exploration work, this article focused on analyzing the prospecting prospects of the study area from the aspects of fault systems, alteration and mineralization, geophysical exploration, and geochemical exploration. All discovered ore bodies are hosted in NE- and NNE-trending faults, with their occurrence consistent with the fault structures. Mineralization and alteration are predominantly developed within the rock mass and along both sides of the faults, suggesting that the formation of the deposit is related to magmatic activity. The metallic mineralization mainly includes brass mineralization, molybdenite mineralization, pyrite mineralization, and magnetite mineralization. Geophysical and geochemical anomalies exhibit good correlation with faults, alteration and mineralization, and granite porphyry, indicating that areas where geophysical and geochemical anomalies, faults, and granite porphyry coincide hold significant prospecting potential.