Abstarct: The closed nature of geochemical data has been referred in many studies. In order to analysis the compositional data and use standard statistical methods, firstly the data should be opened.The data might be opened by various transformations provided.One of the most popular of applied transformations is the logratio transform. To investigate the halos and concealed mineralization, data of wind blown sands related to VHMS deposit was analyzed in the form of closed and opened data. Data used in the current research was collected from the wind blown sands from the surface at defunct Areachap Cu-Zn mine from South Africa. Principal component analysis,PCA, is very popular for multivariate analysis of geochemical data. But PCA is very sensitive to outliers. Using robust methods,RPCA, could resolve this problem. For this purpose, the closed data was evaluated by PCA method and the opened data was analysed by RPCA. Later, the anomaly was separated from background on mineraised factor of PCA and RPCA by using probability-plot modelling. The results were shown that the mineralized factor of RPCA could identify the mineralized zone and PCA identify the host rock. The PCA can optimizes location of drillhole for the followup stage.