Data Processing In Geochemical Exploration And Metallogenic Prognosis Of Gold And Copper Ore

Geochemical exploration data processing is an essential part of exploration geochemistry,which may affect the geochemical exploration effects and efficiency directly. It is to extractinformation from the original data by using the mathematical methods and computer technology,to indicate the interrelationship between chemical elements and geological phenomena whichprovides clues for geochemical prospecting. How to extract geochemical anomaly scientificallyand efficiently, and then to select and evaluate them quickly and precisely, to identify theprospect area and improve the probability of ore, is the key for the exploration effects andeconomic benefit.This paper analyzes the1:10000soil geochemical data in the northern margin of theQaidam Basin Qaidam Mountain Chaoliben Tavan Tolgoi area, by using traditional statisticalmethod, fractal theory (fractal content-area method and fractal content-grads method),multivariate statistical analysis method (cluster analysis and factor analysis), and metallogenicenergy method. It delineates the ore-forming prospective areas based on the geologicalbackground of study area, which provides beneficial basis for future prospecting work.Research shows that the distribution characteristics of geochemical elements data is notfollowed by the normal distribution and lognormal distribution simply, but show thecharacteristics of high cluster fractal distribution. So, we adopt fractal theory to analyze the soilgeochemical data in this paper. use the fractal content-area method to determine single-elementgeochemistry of the anomaly lower limit, re-use concentration gradient method of fractal todelineate abnormal concentration center and then to determine the abnormal zonation.Compared with the anomalies that delineate by the traditional statistical method, the areadelineate by fractal content-area method is bigger. It is better coincidence with themineralization-concentrated areas. The abnormal zonation that delineate by fractalcontent-grads method is more obvious, which can describe the elements spatial distributioncharacteristics clearly and reflect the concentration pattern of elements.By using cluster analysis and factor analysis to determine the mineral assemblages, the6elements are divided into two groups, namely Au-As-Sb and Cu-Pb-Zn. According to the two groups, make the elements assembled anomaly maps. Anomalies of Au-As-Sb, namely factor2,are distributing in the Permian strata that is the main stratum of gold deposit. The distributionsof Au, As, Sb are quite similar in many areas and Au and As set better relatively. Anomalies ofCu-Pb-Zn, namely factor1, are distributing in the Silurian strata that is the main stratum ofcopper deposit. The distributions of Cu、Pb、Zn in the study area have both commonness anddifference. The higher background areas and high background areas of Cu and Zn are large andthey overlap roughly. By comparison, the elements assembled anomalies calculated by usingmultivariate statistical analysis method, distributes more collective relatively, with clearconcentration heart and regular shape. These anomalies which may match with some otherssterically are more meaningful than single element anomaly, and meanwhile assembledanomaly is better in accordance with the geological characteristics of element association inmineralization and hydatogenesis, which has important significance in ore prospecting.In this paper, adopting metallogenic energy method extracts composite anomaly and makea comprehensive analysis in combination with geological conditions in this region to delineatethe ore-forming prospective areas. E2area can be the main prospecting target of Hydrothermalcopper polymetallic ore. E11area can be priority prospect area to search the gold polymetallicore.