Study On Processing And Analysis Of Geologic-related Anomaly Based On Gravity And Magnetic Data

Geophysical exploration technique is seen as a comparatively valuable method of mineral resources exploration,especially the combined technique of gravity and magnetic of which has been widely used.Given the complexation of interpreting and analyzing geologic-related anomaly information aliased in potential field,seeking for comparatively accurate-and-steady technology of processing and analyzing anomaly information in potential field is a trend of Geophysics,and the purpose of this study as well.In this study,study about“geologic-related anomaly information processing and analysis”has been carried out,based on gravity and magnetic data of Tongling ore district that is the experiment area of this study.Based on the validation of precedent studies in geology of Tongling ore district,this study aims at outstanding the function and value of processing and analyzing technology of anomaly information in potential field,which is applied in geophysical exploration and mineral resources exploration.To specific,results of this study are mainly involved as follows.?1?Based on the composite of spheres with various buried depth and radius,this study established the synthetic model,and calculated the synthetic anomaly itself and its reginal and local anomaly of potential field by forward modeling.And this study contaminated the synthetic potential field by 0.1%,0.5%,1%,3%gaussian random noises.?2?Based on the validation of applicability and effectiveness of denoising the above-mentioned contaminated synthetic potential field,this study used the SVD technique to realize the procedure of denoising the 1:50,000 scale original Bouguer gravity data?or reduction-to-the-pole magnetic data?in the experiment area,by determining the valid order k=7?or k=12?when reconstructing the singularity matrix used.?3?Based on the validation of applicability and effectiveness of bisection method in above-mentioned synthetic potential field,this study used the analytic upward continuation to realize the bisection processing of above-mentioned denoised Bouguer gravity data?or denoised reduction-to-the-pole magnetic data?,by plotting the correlation curve of correlation index among neighborhood regional anomaly using analytic upward continuation with a series of upward continuation heights and itself to determine the optimized upward continuation height 5000m?or 4000m?.Consequently,the corresponding gravity?or magnetic?regional anomaly and gravity?or magnetic?residual anomaly had been calculated by analytic upward continuation.?4?Based on the validation of applicability and effectiveness of BEMD technique extracting the weak anomaly in the above-mentioned residual anomaly of synthetic potential field,this study used BEMD technique to realize the procedure of weak anomaly extraction in above-mentioned residual gravity?or magnetic?anomaly in the experiment area,by determining the thresholds used in criterions of IMF and Res,i.e.,0.7 and 0.1?or 0.3 and0.1?to calculate the multiscale gravity?or magnetic?weak anomaly components IMF_G1,IMF_G2(or IMF_M1,IMF_M2)and gravity?or magnetic?residual component Res_G?or Res_M?.And this study consequently carried out the interpretation and analysis of geologic-related anomaly information among above-mentioned weak anomaly components and residual anomaly component.