Combined Gravity, Magnetic, and Electrical Survey of the Gongchangling Iron Deposit, North China Craton

To address the technical challenges in exploring concealed high-grade iron deposits in China, this study focuses on Banded Iron Formation, BIF, which represents the largest reserves and hosts the greatest number of large-scale deposits in the country. The Gongchangling iron deposit, a typical high-grade iron deposit in the Anben region, was selected as the main study area. In situ measurements and statistical analysis of the geophysical parameters of rocks and ores were conducted, with an emphasis on evaluating their sensitivity to high-grade magnetite mineralization. Based on this analysis, an integrated gravity, magnetic, and electrical survey method was identified as the optimal exploration approach. Building on this foundation, high-precision gravity and magnetic surveys were performed to investigate the geophysical anomaly response mechanisms of the Gongchangling-type high-grade ores. Forward and inverse modeling were applied to identify deep-seated concealed iron ore bodies, with results further validated by audio-frequency magnetotellurics. This study enhances the methodological framework for mineral exploration, improves prospecting efficiency, and provides practical insights to support new breakthroughs in exploration initiatives.