Geochemical Characteristics And Ore Finding Prediction Of The Stream Sediment In The Chachaka Area Of Tibet

The tectonic position of Chachaka area is located in the southern part of the Bangonghu-Nujiang suture zone western margin and the northern part of Gandise–Nyainqêntanglha landmass,belonging to a first order tectonic unit of Tibet-Sanjiang orogenic and crossing two secondary order tectonic units: the Island-Lake systems of southern part of Bangonghu-Nujiang suture zone and Gangdese-nyainqentanglha microcontinent.I take advantage of previous geological studies and geological features of study area in order to circle and identify the most favorable exploration area,finding out the most powerful mineralizing prospect area and summarizing its geochemical characteristics,which provides the strongest evidence and prospecting direction for the next step exploration.First of all,I summarize the geological background of Chachaka area and make statistics and analysis of the geochemical characteristics of the geochemical elements in drainage sediments,such as the Clark value,the coefficient of variation of the elements and so on.Through the geochemical data analysis,it is concluded that the element content of the drainage sediments in the measurement area is higher than that of the Clark value,which is As,Pb,Sb,Bi,W,and Sn;Compared with the background values,the contents of Au,As,Sb,Bi,W,Sn and other elements measured in sediments are higher;The contents of Cu,Ag,and Pb have a certain enrichment trend compared to the national background value,at the same time,the content of Au,As,Cu,Pb and Zn change greatly;The contents of Ni,Cr,CO show that Au,Cu is the main concern of ore-forming elements,related to ophiolite mafic ultramafic intrusive rocks,and Ni,CO elements also have certain metallogenic potential.Secondly,by way of data spatial filtering-neutrino zone method,according to conventional methods of geochemical characteristic value calculation,we circle all kinds of various types of 47 comprehensive anomalies.In order to determine the combination anomaly,I use the methods of correlation analysis,cluster analysis and factor analysis to comprehensive analysis of the elements Au,Ag,Hg,as,Sb,Bi,Ba,Co,Cu,Ni,Pb,Zn,Sn,W and Mo in stream sediments of the study area.In single element geochemical anomaly map based,abnormal elements into four kinds of combination of abnormal,which represent high,middle and low hydrothermal elements and iron group elements,namely W-Sn-Bi-Mo,Cu-Pb-Zn-Ag,Au-As-Sb,Ni-Gr-Co.This paper lists 5 anomalies which are representative and has a certain guiding significance to the ore prospecting evaluation work: Hs47,Hs25,Hs39,Hs20,Hs16,and deduces and translates the five anomalies.Finally,according to the similar mineralization,we use local ore controlling factors and geochemical anomalies to determine prospecting area.The study area was divided into two V-grade prospect areas,namely: Buqule-Xiangqu metallogenic area of copper and gold(?-1),Chalangle-Yazhuo metallogenic area of copper and gold(?-2).According to the principle and classification of the prospecting area and the prospecting target,the two V-grade prospect areas can be further divided into 8 prospecting targets,in which there are three A-class targets and five B-class targets,namely: V-1(1)Number 2 Buqule copper target(A);(2)Number 1 Buqule gold target(A);(3)Jiangmengale copper target(B);(4)Xiangqu copper target(B);(5)Number 3 Buqule copper target(B);V-2(6)Zhuoya copper target(A);(7)Number 2 Gunong gold target(B);(8)Chalangle-Chabudibo copper target(B).