Lithologic Identification And Stereoscopic Geological Mapping Based On Three-dimensional Inversion Of Gravity And Magnetic Field

Lithology identification is how to describes and understand the distribution of underground lithology,which is an important issue in geology.The lithology identification of gravity and magnetic three-dimensional inversion can greatly improve the reliability and accuracy of stereoscopic geological mapping.Especially with the development of three-dimensional physical inversion technology,both the computational power and the precision are greatly improved the three-dimensional lithology identification and mapping possible.In view of the limitation of surface geological mapping,it can only reflect the distribution of superficial lithology,and deep lithology is difficult to identify.In this paper,lithologic identification based on gravity and magnetic three-dimensional inversion were carried out in three-dimensional geological mapping of the study.Both three-dimensional model of the density and the magnetic susceptibility are obtained by inversion of gravity and magnetic force by using the same meshing,which makes the three elements of the model density and magnetic susceptibility information,and then study the differences between the physical properties of the inversion and their physical properties of the rocks.The relationship between the density,the magnetic susceptibility and the lithology is studied.The logical relationship between the physical properties and the lithology is determined.And then transform the recognition results into three-dimensional geological model,so as to realize the lithology mapping based on gravity and magnetic three-dimensional inversion.The lithology of each body voxel is carried out.Based on the conspicuous information such as geological section,drill hole and physical specimen,Encom ModelVision ProTM(MV)was used to establish the 2.5D gravity-magnetic human-vehicle interaction model of 25 sections of Tongling ore concentration area,and then the model was used as the initial.The model is introduced into UBC for three-dimensional inversion,and the lithology identification is carried out.The correction model is reconstructed by lithological identification.The shallow features of the lithology identification results are consistent with the results of surface geological mapping,and more importantly,Changes in the region and deep,make up for lacking of single-profile modeling.Finally,the modified model slices are introduced into the Geomodeller to re-splice into a three-dimensional entity with continuous integrity,and more reliable three-dimensional model is obtained,which proves the feasibility of the method.Through the three-dimensional geological mapping in the Tongling ore concentration area,revealed the 6km in shallow structure,intuitive and realistic characterizations of tectonic,strata,faults,ore controlling strata and deep magma,the internal structure and the underlying basement structure,clear structure and formation of large ore district intrusive relationship that the Tongling ore concentration area magmatite deep area development,greatly expand the space of the second prospecting The lithologic identification and three-dimensional filling of Tongling ore concentration area show that the lithology mapping based on gravity and magnetic three-dimensional inversion is the effective method to understand the characteristics of deep lithology in the ore-bearing area.With the improvement of the three-dimensional inversion method and the study of the physical-lithological relationship,the method adopted in this paper will reflect the three-dimensional distribution of the underground lithology more accurately,and provide the support for realizing the "transparency" of the ore concentration area.