This paper is the result of mineral exploration engineering.
Objective A nearly N-S trending gravity and magnetic anomaly zone with certain homologous characteristics was identified in the Qihe-Yuchen ore concentration area, Shandong Province. In the early stage, thick skarn iron-rich deposits were successively revealed in the northern Litun and southern Dazhang gravity and magnetic anomalies, and great progress has been made in iron ore exploration. However, the Pandian anomaly area, the central part of the ore concentration area is covered by ultra deep Cenozoic, with small scale and weak intensity, while the geophysical information of deep iron ore body is greatly weakened, and the ore-induced magnetic anomaly is covered by the large-scale magnetic anomaly of diorite to a certain extent, which makes it difficult to identify and extract. Therefore, no prospecting breakthrough has been made in-the Pandian anomaly.
Methods This article fully combines the successful prospecting experience of gravity and magnetic exploration in adjacent mining areas. From known to unknown, the plane analysis and profile quantitative inversion of Pandian gravity and magnetic anomalies were carried out, and the whole process interpretation of structural framework division, delineation of metallogenic geological body, anomaly analysis and 2.5D joint inversion is realized in the study area.
Results Based on comprehensive study of high-pricision gravity and magnetic data, the deep prospecting information under the ultra deep overburden is obtained, -and finally achieved a new prospecting breakthrough of skarn type rich iron ore in the central part of Qihe-Yucheng ore concentration area.-The three gravity and magnetic anomalies in the ore concentration area are closely related, which proves that the three iron deposits of Dazhang, Pandian and Litun are in the same nearly north-south neutral magmatic rock belt, opening up another important new prospecting space in the Qihe-Yucheng ore concentration area.
Conclusions The prospecting results provide important reference and instructions for further deep prospecting under ultra deep overburden. At the same time, it shows that there is a broad prospecting prospect for skarn iron-rich ore in Qihe-Yucheng ore concentration area.