Extraction And Evaluation Of Geochemical Abnormal Information In Xiongmei Area,Shenzha County,Tibet

The Xiongmei area is located in the south of the Bangong-Nujiang suture zone in Tibet.Its geological evolution is very complicated and its mineralization conditions are superior.In recent years,several areas of copper(polymetallic)have been found in the skarn type and porphyry type,indicating that the prospecting potential of this area is considerable.The contents of 14 elements such as Cu,Pb,Zn,Ni,Co,Sb,As,Hg,W,Mo,Bi,Sn,Ag and Au in the sediments of the study area were statistically analyzed.Compared with the sediments of the national and alpine mountainous areas,the elements in the low background field(such as Cu)form a point in this area,indicating that the geochemical background of the region is not directly related to mineralization.According to the factors such as the bedrock environment,topography and geomorphic conditions and the number of samples,the study area is divided into 20 geological units.The background value and the abnormal limit of the elements in different geological units are quite different.And the ratio between the maximum value and the minimum value is between 1.5 and 116(most of 2 to 18),and the ratio between the maximum value and the minimum value is between 1.8 and 113(most of 2 to 13).Therefore,the delineation of geochemical anomalies must take full account of the geological background.The geochemical anomalies of the elements were extracted by the traditional method(mean value plus standard deviation method)and sub-region anomaly limit lining filter method respectively.It was found that the traditional method could not overcome the disturbance of geological background in the area,The background area is circled into the patch,and the sub-region anomaly limit lining filter method is better to solve the problem of abnormal extraction under different geological background conditions.Based on the results of correlation analysis and cluster analysis and the combination of common metallogenic types,the Cu-Mo-Au combination of porphyry copper deposits and the Pb-Zn-Ag combination with lead-zinc deposits It is found that the combination of the combination of the threshold to extract the combination of a large degree of weakening some of the abnormal strength is weak,was decentralized state,and mine-independent anomalies,and makes the single element lining value is higher,different elements of the combination is better,An abnormality associated with a certain mineralization type is highlighted.According to the abnormal element combination,abnormal area,abnormal intensity and the existence of ore and other factors,in the study area were conquered a class A comprehensive anomaly 5,B class comprehensive abnormalities 13,C class comprehensive abnormalities 12,these abnormalities basically reflect the research District of the future focus of the prospecting.