| Zhaxikang district is located in Tethyan Himalaya structure and High Himalaya structure. Its northern part is located in Tethyan Himalaya structure and its southern part is located in High Himalaya structure. In regional geological survey of Tibet land resource, researchers had discovered Mazhala Sb deposit, Cheqiongzhuobu Au-Sb deposit and Xiangla Sb deposit, then they have also found Zhaxikang Pb-Zn-Sb polymetallic deposit. So Zhaxikang district displays a good prospecting future. Study area is close to the Zhaxikang Pb-Zn-Sb polymetallic deposit. The study of the Zhaxikang Pb-Zn-Sb polymetallic deposit is increasing,but the Zhaxikang district has low degree study due to traffic inconvenience and high altitude. This dissertation has summarized data about geology, stratigraphy and igneous rocks of the district, and used remote sensing to interpret the linear structure and the circular structure and information extraction, finally get the prospecting areas by analyzing the multiple source data. This dissertation has a great significance to guide the exploration in Zhaxikang area and establishes the basis for the prospecting of the subsequent work.According to the summary of the regional geological features and the deposit distribution, this paper determines the source of remote sensing and the method of data pre-processing after analyzing the spatial resolution and the spectral resolution of remote sensing data. Analyzing the spectral information of typical minerals in the study area, the dissertation extracted the mineralization alternation information and remote sensing geology information based on the characteristics of remote sensing data. The paper overlay analyzed the geologic information, the mineralization alternation information and remote sensing geologic information by Geographic Information System technology, and enclose the prospecting area. The main completed content of this dissertation as follow:(1)The dissertation decided to apply the Landsat8 OLI extract the remote sensing information and really do research the data pre-processing. According to the principle of the best combination of color bands, the paper selects OLI 752 bands to color synthesis. Through radiometric correction, atmospheric correction and digital convergence, it finally gets alteration-working map for remote sensing information extraction.(2)According to researches of the geologic basis and spectral precondition of the remote sensing information extraction, analysis the type of mineralization alternation and spectrum character of altered rock, the paper decides to choose the first PAC and the second PAC method to extract the remote sensing information after summarizing remote sensing method of the extraction. In order to classify hydroxylate anomaly levels and chalybeate anomaly levels, the paper uses the normal distribution theory.(3)Based on the established geologic interpret symbols, the paper extracts remote sensing geological information including formation lithology, linear structure, circular structure and irruptive rock body by using the Resource three satellite data and the Landsat 8 OLI data. The dissertation also analyzes the structure density and frequency of linear structures in the study area with the mathematic statistics. Finally the paper gets the map of lineament density, the map of lineaments frequency and the map of lineament and ring density.(4)Based on the comprehensive analysis of geological, remote sensing and geochemical exploration information, through GIS spatial overlay analysis, the paper views that Quzhuomu-Lamuyouta-Suolong advanced area, Ganze-Dongga-Lannizha advanced area, Nacuodong-Jisong-Nianmai-Zhagaqionggu advanced area, Jiangzhula advanced area and Kada-Xingda advanced area have a good prospecting. The paper is a useful attempt to further exploration of the prospecting in the study district. |
PDF Full Text Request