Collaborative Image's Establishment And Application Of Lithology's Enhancement And Extraction In Magmatic Rocks Zone

The Sanfeng mountain in Pobei area of Xinjiang is located in the northeastern margin of Lop Nor in the North Mountain metallogenic belt.Magmatite in the region is mainly Variscan intrusive rocks,quartz diorite in the northwest,diorite and granodiorite in Sanfeng mountain northeast side of the area.The inner vein rocks are mainly based on the base and acidity,and some of them intruded into the Carboniferous strata.The basic vein rocks are mainly diabase,which are distributed on the north side of the region.The acid veins are mainly quartz veins,and some quartz veins contain trace gold.The ground rock outcropping is good in the study area,which is the superior area of remote sensing rock and mineral work.On the basis of analysis of the Sanfeng mountain area magmatite typical lithologic spectral features,combined with the characteristic bands of different lithology,Co WorldView-3 data high resolution image with ASTER medium resolution multi spectral images to construct magmatite region collaborative image.And enhanced the characteristic wave band ratios of diorite,granodiorite,quartz diorite and ]monzonitic granite in the magmatic area by collaborative image.The collaborative image bands covers the VNIR,SWIR and TIR range.Cooperative data not only reflect the high resolution advantage of WorldView-3data,but also make up for the shortcomings of WorldView-3 partial shortwave infrared band missing and setting,and the absence of thermal infrared band.Compared with the ASTER images,the collaborative data not only enrich the spectral information of the VNIR band,but also effectively improve the spatial resolution of the data in SWIR and TIR band.In the study area different lithologic rock units due to the different proportion of iron content of plagioclase and K-feldspar in trivalent mixed have absorption characteristic in the spectrum of visible light of 0.45?m and 0.7?m.Dark minerals and iron content increase,will cause the 1.0?m absorption peak depth increases,the collaborative image band ratio B2/B1 would reflect the iron content of plagioclase and K-feldspar;Secondly,according to the absorption peak depth affected by dark minerals and ferrous iron content of 1.0um,the collaborative image band ratio B2/B4 would distinguish the difference of iron content in dark mineral;And according to the spectral absorption characteristics of biotite and hornblende,which are affected by hydroxyl ions at 2.2?m,2.3?m,and 2.4?m,we can get grayscale images using collaborative image band ratio B8/B9.Finally,the above three ratio factors are applied to the false color image synthesis.This enhanced images can effectively identify lithology and improve the image interpretation ability in magmatic area.