Research On Comprehensive Information Prospecting Of GIS Technology In Tangjia Minerals Model

Tangjia area is located in the south of Nyainqentanglha,the eastern section of the Gangdise metallogenic belt,and its geological conditions for mineralization are excellent.In this paper,based on the in-depth understanding of the Bangpu copper-molybdenum deposit,the Nabuding zinc deposit,and the Cuoga lead-zinc deposit in the area,the metallogenic geological background was used to analyze the metallogenic regularity and a mineral descriptive model was established.Focusing on remote sensing mineral alteration anomalies and structural information in this area.On this basis,the GIS comprehensive information model was established and metallogenic predictions were made in the study area by using the evidence weight method.The main achievements and understandings of this paper are as follows:(1)Analyzed and field surveyed the Bangpu copper-molybdenum deposit,the Nabuding zinc deposit,and the Cuoga lead-zinc deposit in the study area.Combined with the collected geological data,The basic rules of mineralization in the area have been determined and the GIS comprehensive information model for the study area was established.(2)The ASTER data was selected and the iron-stained,Al-OH,Mg-OH and carbonate alteration anomaly information extraction studies were performed by ratio method and principal component analysis method.By comparing the traditional thresholding method determined by the lower limit of abnormality and the fractal dimension method of the new fractal theory,it was found that the fractal dimension method eliminates human factors interference,the extracted lower limit of abnormal value is higher,and the alteration information is more accurate.(3)Using the merged high-resolution data,the structural information in the study area was translated through image enhancement techniques and texture analysis.There are a total of 102 linear structures and 11 circular structures are interpreted.The main structures of the study area are in the northwest direction and near the east-west direction,and the ore points are located in the vicinity of the line and loop structure and are affected by the structure.Through analysis,the central and southern regions of the study area are complex in structure and have large potential for mineralization.(4)Using comprehensive Information Model Based on GIS Analysis Method and combining with the digital mapping system,18 evidence layers were selected to conduct the evidence weight method to obtain the metallogenic favorableness of each evidence layer,and the metallogenic prediction was conducted through the posterior probability to divide the Bangpu(Level 1),Nabuding-Cuoga(Level 2),Wuluzan(Level 3),and Budingga(Level 3)four metallogenic prediction areas.It has been verified that the metallogenic prediction of this model using the weight of evidence method has achieved good results and new mineralization trails have been discovered.