Anomaly Analysis Of Multi-source Remote Sensing Prospecting In Jiajika Pegmatite-type Lithium Deposit In Western Sichuan

Lithium,as an important strategic energy source of the country,is highly commercial and widely used for civilian use,and permeates into all aspects of life.Nowadays,the role of lithium resources has become increasingly prominent,which has attracted wide attention from all walks of life.However,the supply of lithium resources in China is insufficient,and there is a greater security implication in the supply system.As the largest lithium resource deposit in the world,the study of Jiajika deposit's resource content is of great significance for reducing imports.However,the average altitude of the Jiajika area is over 4500 m,the weather is bad,the traffic is inconvenient,and the field geological survey is difficult to implement.The rapid development of remote sensing technology can make up for the shortcomings of traditional geological work and provide a new technical means for remote sensing geological survey in Jiajika special geological and geomorphological area.Based on ENVI 5.3 and ARCGIS 10.1 platforms,using Landsat 8,Geoeye-1optical data and Palsar-2,Radatsat-2 radar data and other multi-source remote sensing data,this paper extracts ore-controlling information such as structure and pegmatite outcrop aggregation area in Western Sichuan,and carries out exploration of remote sensing prospecting methods in the Jiajika area combined with relevant geological data to delineate anomalies in prospecting prospect area,thus providing technical support for prospecting.The main results are as follows:(1)Using Landsat8 optical data to extract alteration information based on spectral curves of cordierite and tourmaline mineralized surrounding rocks in the area,it is impossible to carry out accurate prospecting and prediction in the Jiajika area.(2)Based on the object-oriented classification method,using high-score Geoeye-1 data to select appropriate segmentation and merging scales,pegmatite outcrop can be extracted based on the peculiar spectral characteristics of the ground features of pegmatite.(3)Based on the hue and texture features,it can extract the linear anomaly in the region by filtering the radar data.(4)Based on the information of outcrop and structure extracted from optical data and radar data,the anomalous areas of prospecting for pegmatite rock mass and dike are delineated by comprehensive analysis.Four anomalous areas of prospecting area are determined.By comparing with the existing geological data,the distribution of rock mass and dike is found near the area.The results show that it is feasible to use pegmatite outcrop as indirect prospecting indicator for lithium ore prospecting in Western Sichuan area when alteration information of mineralized wall rock is not available and the effect is ideal to some degree.