Application of Discriminant Analysis for Alteration Separation; Sungun Copper Deposit, East Azerbaijan, Iran

The Sungun porphyry copper deposit that intruded Eocene volcano sedimentary and Cretaceous carbonate rocks hosted by a diorite/granodioritic to quartz- monzonitic stock. Copper mineralization is essentially associated more with potassic and less phyllic alteration. Therefore separating these two kinds of alteration is so important. In this paper, by applying the discriminant, it was attempt to separate the alteration zones "as well as" possible and discriminate as various mineralogical compositions. The principal component analysis method is actually based on the visual value, visual vector and the trajectory with the maximum changeability and discriminant analysis consists of finding a transform which gives the maximum ratio of the difference between two group multivariate means to the multivariate variance within the two groups. In this method, 24 electron microprobe element analysis related to the rock samples were used as the input data to identify the rock classification and separation the variety of alterations. Therefore, to aim this goal, the discriminate analysis method was applied within the Sungun deposit. First, the discriminate analysis method was applied to separate them effectively. In this method, for each of the variables (elements) their specific scores were obtained and finally the critical value (R„) for separation was obtained to be -73.1603. By comparing this value (R„) with the elements (R) the alteration class would be determined. One of this method advantages is to introduce the transition zone. This zone is known as a boundary in which potassic changes to phyllic alteration gradually. Since it is very hard to separate the samples microscopically, this method could be able to separate them more effectively. Based on this method, the discriminate analysis could verify the exact boundary between the two well-known alteration zones (potassic and phyllic)