Study On Remote Sensing Extraction Method And Its Application Of Mineralization And Weak Information In Yunnan Pulang Porphyry Copper Mine Area

Yunnan Pulang porphyry copper area is located in the southeast of the Yidun Island Arc of the central south section of the southwest Sanjiang of China,which is China’s important copper polymetallic metallogenic belt,in which pulang Copper has reached large scale, Songnuo and Di Suga copper polymetallic ore has reached more than a small scale. With the Pulang porphyry copper mineral exploration in depth, such as the genesis and evolution of geological research work has been deepened.While Pulang mine has a higer elevation (3000-4800m),large relative elevation, complex geological setting,lush vegetation long time snowing,poor traffic conditions,which limiting traditional geological measurement and test analysis, and seriously affecting the mineral exploration progress of this area.Due to mineralization alteration abnormal information is weak, relatively low, which often mixed or added together with background interference information, in the previous early stage of the information extraction of remote sensing data processing of the refined extraction of remote sensing mineralization alteration are removed as interference information,such as vegetation, shadow, snow and water,making many low and weak alteration anomalies is also a masked,to a certain extent affect the integrity of the remote sensing alteration anomaly information extraction and accuracy; In addition, previous studies more focus on the hydroxyl, iron and other types of alteration extraction, in view of the porphyry type porphyry copper ore, silica, potassium-lithification-propylitization zoning ore-prospecting criteria such as diagnostic spectral characteristic analysis and its refinement extract less involved.To compensate the insufficient in previous studies that the refined extraction of remote sensing mineralization alteration is not very high and the supporting roll for advancing prospecting and exploration of Southwest Sanjiang deep porphyry copper is limited, aimed at the characteristics of zoning of mineralization alteration of Pulang porphyry copper ore, the authors analyzed the features of the characteristic minerals, the diagnostic spectrum and ASTER remote sensing spectral response of the porphyry copper mineralization and alteration zonation. With the multifractal theory of "generalized self similarity" and "singularity" and the method of concentration area (C-A), it explored the enhancement and extraction methods for the weak information of the characteristic minerals of porphyry copper alteration mineral zonation under the condition of complex geological background, including the propylitization (chlorite and epidote), lithification (quartz and sericite), potassium (potassium feldspar) and silica (quartz).Through the field test for the remote sensing alteration zoning results and mineral identification, the reliability of the methods of enhancement and extraction of the remote sensing abnormal information for the porphyry copper ore alteration zoning was confirmed.