Application Of Gravity Data Processing And Interpretation Technology In Geological Structure Interpretation And Mineral Prediction In Southern Tibet

The complex geological structure has bred rich metal mineral resources in southern Tibet.However,it is very hard to carry out area high-precision geological and geophysical survy because of the extreme natural environment and traffic conditions.It affects exploration and development of mineral resources in this area.In this paper,we take the advantages of gravity and magnetic data in geophysical interpretation in the large area.In the process of interpretation,geology,minerals,geophysics,geochemistry and other data of southern Tibet are used.We research the deep structural information,and infer the rock masses and faults in the study area.The main research results are as follows.1.The most accurate gravity data in the study area was collected.Using the 1/1000000 gravity data as the expanding edge data and 1/500000 gravity data as the constraining data,the latest and most accurate gravity data was formed.A large amount of physical property data was measured.The physical properties of the strata and rocks in the study area were scientifically summarized,which provided a scientific basis for this geological interpretation.2.Aiming at the unique high-altitude terrain characteristics of the study area,the " isostatic gravity anomaly fitting method " was adopted to obtain a more accurate Moho depth and the resulting gravity field,which effectively achieves the division of the density interface.This method has theoretical and practical significance and was recommended for use in high altitude areas.3.The potential field transformation method and parameters were reasonably selected.21 important ore-controlling faults were newly inferred,and the location,scale,and rock-controlling and ore-controlling characteristics of the important faults were studied,providing an important basis for the establishment of a ore-controlling framework.Constrained by quantitative interpretation,qualitative interpretation and inference of rock masses were carried out,and 23 concealed and semi-concealed rock masses were delineated,two of which have been verified.The combination of 2.5D and 3D inversion was used to obtain the basement distribution characteristics in the study area,which provided a geophysical basis for basic geological research and structural evolution.4.Combining gravity anomalies,aeromagnetic anomalies,geochemical prospecting anomalies and the distribution of known mineralization(chemical)points,five mineralization prospects were delineated,providing reliable new clues for future prospecting of mineral resources in this area.The source-storage-cap conditions of hot dry rocks in the area were summarized.Based on the basement characteristics,terrestrial heat flow characteristics and geological characteristics,two prospective areas of hot dry rock resources wre delineated,providing an important basis for the development and utilization of new energy in the region.This research work provided high-quality regional gravity data for further mineral resources surveys and utilization,basic geological research and related field applications in this study area.