Prospecting for concealed skarn iron deposits using the high-precision gravity-magnetic survey method
DONG Jian1,2(), LI Xiao-Peng1,2(), FU Chao3, DANG Zhi-Cai3, ZHAO Xiao-Bo4, ZENG Qing-Bin1,2, HU Xue-Ping1,2, WANG Jin-Hui1,2
1. Shandong Institute of Geological Survey, Jinan 250013, China 2. Shandong Technology Research Center of Land Quality Geochemistry and Pollution Prevention Engineering, Jinan 250013, China 3. Tianjin Center of China Geological Survey, Tianjin 300170, China 4. Geological Exploration Institute of Shandong Zhengyuan, China Metallurgical Geology Bureau, Jinan 250013, China
The Laiwu area in central Shandong Province, situated in the eastern North China Craton, is a significant production area of skarn iron-rich ores. Its ore deposits occur primarily in the contact zone between the mining rock mass and the Middle Ordovician carbonate formation. Based on the latest areal gravity and magnetic survey results, this study thoroughly investigated the characteristics of gravity and magnetic anomalies along the Shijiaquan-Liujiamiao area in the western periphery of the mine rock mass. Then, this study delineated the deep prospecting target combining the characteristics of gravity and magnetic fields of the known iron deposits in the Laiwu area. Large-scale gravity and magnetic profiles were arranged in the favorable mineralization area. With the known boreholes as constraints, the gravity and magnetic anomalies were qualitatively and quantitatively interpreted using the 2.5D gravity-magnetic joint inversion technique. The interpretation results provide a basis for the location and depth of the borehole to be placed, which revealed a 15.8 m-thick iron-rich ore deposit, suggesting remarkable prospecting effects. This study holds critical indicative significance for further exploration of skarn iron ore deposits in this area.
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