Abstract:

Recently, significant breakthroughs have been made in the exploration of rich iron deposits in Yucheng, Shandong. However, there are still multiple local magnetic anomalies in the area that have not been verified, which have a promising ore-prospecting potential. However, the Cenozoic Erathem in this area is very thick, about 900-1,100 m, and the magnetite orebody is deeply buried, which leads to weak signals of geophysical anomaly, making it challenging to find the iron ores through surface exploration. In order to systematically summarize the abnormal characteristics of magnetite in this area and provide a basis for drilling deployment, the paper focuses on analyzing the abnormal characteristics of airborne gravity and magnetic plane and the abnormal characteristics of high-precision magnetic survey on the ground in Litun area, Yucheng, and summarizes the main prospecting signs of gravity and magnetic anomalies of skarn type iron ore, which are mainly the anomaly centers of polarized magnetic anomalies, residual magnetic anomalies, vertical derivatives and total gradient modes. Accordingly, two prospecting targets in Diedao Village and Yuzhuang village were delineated. Through the 2.5D gravity and magnetic profile inversion based on the electrical seismic constraints, we delineated two ore target areas, which can further guide the deploying the locations of the verification drilling holes. Significant breakthroughs in ore prospecting have been made in the Litun area of Yucheng City after the drilling verification of stacked-channel anomalies. The results in this study are of great significance and guidance for the future mineral exploration in this area and the search for iron-rich skarn-type ores in other deep ore hidden areas.

Key words: Litun Area, iron-rich ore, gravity and magnetic anomaly, ore-prospecting predictions