Metasomatic zoning and features of mineralization of porphyry copper deposits of the North-Eastern Balkhash region

Abstract

The study is devoted to the analysis of metasomatic zoning and features of mineralization of porphyry copper deposits of the North-Eastern Balkhash region, comparing them with other analogs around the world. Based on geological, mineralogical, and hydrothermal changes, the key characteristics of the Aktogay, Aidarly and Kyzylkiya fields were identified. Methods included rock and mineral analysis, geochemical studies, and comparative analysis with global deposits. The results showed the uniqueness of Kazakhstan deposits in terms of mineral composition and zoning structure. The conclusion emphasizes the importance of these deposits for understanding the formation of porphyry copper systems and the potential for further research in this direction. The copper ore deposit of North-Eastern Balkhash region is located 450 km northeast of Almaty, within the Balkhash-Ili suite of the Central Asian Orogenic Belt, an orogenic structure over 800 million years old. The porphyry formations are found within the Koldar plutonic massif, which dates from the Late Devonian to the Early Carboniferous period. Laccolith intrusions of diorite-granodiorites extend 17 km in an east-west direction here. The Koldar plutonic massif includes plates of volcanogenic sedimentary rocks consisting of Carboniferous andesites and dacite-rhyolites. The Aktogay deposit occupies the central plate, composed of volcanic rocks and bounded by magmatic formations. The stocks of porphyritic granodiorites that intrude into the volcanic layers date from the Middle Carboniferous period.