Prospecting Application Of Soil Geochemical Measurement In The Area Of Shiquanhe Power Station,Tibet

The area of Shiquanhe power station is located in the border of Tibet.The administrative division is divided into the Ali area of Tibet,under the jurisdiction of Gaer County and Ritu County.The geological structure of the study area is extremely complex,forming a complex tectonic pattern with different scales,different levels,different periods and different genesis.The previous work level of the study area is mainly based on small-scale regionalization.Based on the prospecting area of 1:50000 water sediment measurement,this paper uses the theory,method and norm of exploration geochemistry to carry out the key areas 1:10000 soil geochemical measurements and system sampling.ICP-MS and ICP-OES were used to detect the content of six elements such as Au,Bi,Cu,Mo,Sn and W.The data was processed to calculate the Clark value and coefficient of variation of the sample content.Parameters such as kurtosis and other factors analyze the trend of element enrichment,dispersion and normal distribution.The correlation analysis,R-type cluster analysis and factor analysis method were used to study the symbiotic combination characteristics of the elements,and three groups of symbiotic combinations were divided:(1)Au-Bi element group(2)W-Sn element group(3)Cu-Mo element group,and extract two main factors:(1)F1: Cu,Au,Bi,Mo;(2)F2:W,Sn.Through the traditional statistical methods(iterative method),EDA technology(box and whisker method),85% cumulative frequency method and content arrangement method,the data processing comparison study,the values obtained by several methods are relatively close,but numerically,there are still differences.When the box-and-whisker method(EDA)determines the abnormal lower limit of the element,there is almost no requirement for the data,that is,the geochemical data does not need to conform to the normal distribution or the lognormal distribution.Finally,this paper picks the use of the box and whisker method to determine the abnormal lower limit of the element.After determining the lower limit of the elemental anomaly,the abnormality is divided into the outer,middle and inner concentration bands by using the one times,double and quadruple abnormal lower limit,and the single element anomaly map is produced and evaluated according to the abnormal lower limit and the third-order concentration.On this basis,combined with the geological background of the study area,a total of four comprehensive anomalies were identified,which are close to the distribution of known ore points,providing practical and credible information for further prospecting.On the basis of the comprehensive anomaly,a B-level metallogenic prospecting area was delineated in combination with the ore-forming geological conditions of the study area.The sandstone of the middle-upper Jurassic Lagongtang Formation in the area was discovered through a survey of the comprehensive anomalies in the prospect area.There are a large number of quartz veins in the slate,accompanied by the development of muscovite.There are two long granites in the east.The quartz-tourmaline veins are developed.The porphyry is developed on the contact zone between the rock mass and the sandstone.The potential can be used as a key area for the search for tungsten-tin-bismuth ore.