Study On The Gravity And Magnetism Anomalies And Metallogenic Target Prediction In Neihuang-xunxian Area Of Henan Province

The shallow iron ore resources in Henan Province(buried depth < 500m)were discovered successively in the 1960 s and 1970 s,the representative deposits are Wuyang Iron Mine,Xuchang Iron Mine and Anlin Iron Mine.At present,these mines have been exploited for many years.With the development of economy and society,there are fewer and fewer iron ore resources available for exploitation,and both mining and prospecting have gone deep.With the increase of ore prospecting depth,simply relying on magnetic anomaly location,and then drilling verified the ore prospecting model,the risk is higher and higher,especially when the thickness of the coverage area itself is large,it is more difficult to find iron ore of a larger scale.It is of great practical significance for Henan province to carry out the forecast research of prospecting target area on the basis of exploration projects.The Neihuang-Xunxian area of Henan Province(the study area)is located in the NeiHuang Uplift of the North China Platform.Its surface is covered by Cenozoic,and its basement is Archaeozoic and Palaeozoic,with large-scale and high-intensity gravity and magnetic anomalies.According to the successful experience of exploration of Nihe concealed iron deposit in Anhui Province,Qihe-Yucheng concealed iron deposit in Shandong Province,JiDong concealed iron deposit in Hebei Province and Xincai concealed iron deposit in Henan Province in recent years,it is possible to find BIF-type iron deposit or skarn-type iron deposit in this area.This paper relies on the project of Aeromagnetic Anomaly Verification in Neihuang-Xunxian Area of Henan Province.Aiming at predicting hidden magnetite target area,the Bouguer gravity anomaly and polarized magnetic anomaly are processed by potential field separation technology,potential field edge recognition technology and analytical signal amplitude extraction technology.The plane distribution characteristics of fault structures and the central and boundary positions of hidden magnets are obtained;The burial depth and spatial distribution of the concealed magnets were studied by Euler deconvolution and quantitative profile fitting.The corresponding characteristics of gravity and magnetism in favourable metallogenic areas are summarized through the corresponding analysis of gravity and magnetism.On the basis of the above research results,combined with geological,mineral and drilling data,the prospecting indicators are summarized and the target areas are predicted.Four prospecting target areas are proposed,which provide a basis for further deep prospecting and tapping the potential of resources in the study area.