Multi-mineralization Information Analysis And Metallogenic Prediction In Shiquanhe Area,Tibet

The Shiquanhe area is located at the intersection of the Bangong Co-Nujiang Suture Zone and the Gangdese tectonic-magmatic arc zone.The regional magmatism is frequent and the structure is developed.Taking advantage of remote sensing technology,this paper takes the Shiquanhe area as the research object,and focuses on extracting and analyzing the structural information and mineralization alteration information in the area,and combining the geological and geochemical data to analyze the metallogenic elements of the known ore(mineralization)points.19 ore-seeking factors such as geology,geochemical exploration,tectonic and remote sensing alteration were selected and divided into 456 grid units.The prospecting model for multi-mineralization information was established by expert evidence weighting method and BP neural network method,and 6 metallogenic prospects have been circled by this model.Field verification shows that the prediction results have certain reliability and provide an important basis for guiding the next geological prospecting in the area.The main research results obtained in this paper are as follows:(1)Comprehensively collect and analyze regional geological and geochemical data,study the characteristics of metallogenic regularity of known ore(mineralization)points,summarize the ore-forming elements in the area,and determine the ore-bearing lithology factors and the geochemical exploraction factors of regional mineralization.(2)The OLI data and ZY-1 02 C data were used for image fusion,and the study area construction interpretation marks were established.A total of 186 linear structures were interpreted.The total length of the linear structure was 714 km,and 62 ring structures were interpreted.On the basis of interpretation,quantitative analysis of the density,frequency and anomalous orientation of geological structures in the study area reveals the spatial distribution characteristics of structural information.At the same time,the relationship between the structure and the ore(mineralization)point is discussed.The analysis suggests that the geological structure is developed and the intersection area has a large metallogenic potential.(3)Using ASETR data as the data source,the extraction of altered minerals such as Al-OH alteration,carbonate lithification,barley lithology and iron-dye series in the study area was carried out by using the band ratio method,principal component analysis method,combined analysis method and end-spectrum spectral mineral mapping method,The advantages and disadvantages of the four alteration methods were summarized from the method treatment and the distribution of alteration information.Finally,the selected end-spectrum mineral mapping method was used in this study and the extraction of the area is the best.At the same time,the content of SiO2 in the study area is calculated and inversion.The inversion results can locate the medium-acid rocks in the area,which has an important indication for the skarn type deposits related to the search for medium-acid rocks.(4)Based on the regional metallogenic theory and laws,a Multi-information prospecting model for the Shiquanhe area was established.By extracting 19 predictive variables such as geological,geochemical,structural and remote sensing alterations,two models of evidence weight and BP neural network were used to predict mineralization and define the prospecting area of the Shiquanhe area.Field verification shows that there is a certain mineralization phenomenon in the verification area,indicating that the prospective area defined by the prediction model has certain reliability.