Three-Dimensional Weight Of Evidence(3D WofE) Based Concealed Gold Mineral Prospectivity Modeling In The Sanhetun Area Of Heilongjiang Province,China

With the continuous exploitation of surface and shallow mineral resources,the world’s need for deep-earth natural resources exploration is highly demanding.However,deep-earth mineral resources face serious challenges due to abrupt changes in elastic and rheological properties;thus,their exploitation requires significant efforts in terms of methods and technologies.Moreover,predictive thinking in this era of big data combined with the special exploration of deep resources gains importance.Especially,the three-dimensional（3D）geological modeling and 3D spatial analysis of multisource geoscientific data have greatly enhanced our understanding of deep geology,tectonics,and petrophysical properties,therefore,these methods can effectively improve 3D mineral prospectivity modeling and mineral resource assessment.Three-dimensional geological,geophysical,and geochemical models are beneficial to extract 3D prospecting factors for subsequent 3D mineral prospectivity modeling.NE China has been a hot area for interpreting mantle-crust interactions and crustal evolution and therefore is well known for mineral exploration.In terms of major ore deposits in NE China,the study area is located in the southwestern section of the Duobaoshan-Daxintun metallogenic sub-belt.The recent discovery of Zhengguang gold（Au）,Tongshan copper（Cu）,and Xiaoduobaoshan Fe-Cu deposits highlighted the prospectivity of this area to host deep-seated gold mineralization.Therefore,in this study,we apply the3D weight of evidence（3D WofE）modeling,involving the integration and combination of multisource geoscientific data to construct a 3D mineral prospectivity model that delineates targets for future prospecting of concealed gold mineralization in the Sanhetun area of Heilongjiang Province,China.The framework of 3D WofE modeling mainly involves three steps:（1）Integrating and combining multisource geoscientific data with 3D geological modeling technology to construct 3D geological,geophysical,and geochemical models（e.g.,relative density,relative magnetic susceptibility,apparent resistivity,geochemical indictors,fault system,lithostratigraphic,and volcanic basin models）using explicit 3D geological modelling in GOCAD^TM software;（2）Converting geological,geophysical,and geochemical models into 3D prospecting evidences with positive and negative parts,including fault distance field,crater distance field,contact surface of the Early Carboniferous granite complex distance field,apparent resistivity field,relative density field,relative magnetic susceptibility field,contact zone of the low and gentle positive and negative resistivity field,contact zone of the low and gentle positive and negative magnetic field,and abnormal soil geochemical anomalies of Au and Ag elements,using 3D spatial analysis methods（e.g.,spatial distance,interpolation,overlay,and statistical analysis）;（3）Calculating positive and negative weights for each prospecting evidence and the 3D posterior probability of mineralization of each grid cell in 3D space.The resulting prospectivity model reflects the functional relationship between the mineralization and prospecting evidence models and identifies five highly gold prospective targets for future prospecting.In summary,the 3D geological modeling,3D spatial analysis,and 3D WofE modeling showcased within this study indicate that combining legacy available multisource geoscientific data are beneficial in identifying controls on mineralization.The 3D WofE-based mineral prospectivity modeling approach provides an efficient way for optimizing the process of selecting new drilling locations and planning the exploitation of gold orebodies in the Sanhetun area of Heilongjiang Province,China,and is potentially applicable to other same geological environments worldwide.Figures 34,Table 6,References 145...