Mineralogy of propilite at the large Peschanka porphyry copper deposite, Western Chykchi Penensula
The Peschanka Au–Mo–Cu porphyry deposit is located in the Egdygkych pluton (K 1). The major types of wallrock alteration are potassic, phyllic and propylitic. Amphibole of propylite has evolved from magnesiohornblende to tremolite-actinolite. In contrast to magmatic potassium feldspar, the metasomatic potassium feldspar contains up to 7,3 wt.% of BaO. Tourmaline can be classified as an intermediate member of the “oxydravite”–povondraite series. Content of Al in chlorite decreases toward the outer part of propylitic aureole testifying to decreasing temperature of crystallization.