Abstract
Porphyry copper deposits are the source of most of the world's copper, molybdenum and significant amounts of gold. This makes them a major focus of scientific research due to their economic significance. The article is devoted to the study of the geochemistry of host rocks and copper-porphyry ores at the Nurkazgan deposit. It identifies geochemical criteria for the distribution of gold in copper‑porphyry systems, as well as refines ore formation mechanisms in order to improve predictive criteria. The results were obtained by interpreting analytical data obtained using the ICP-OES (ICP-AES) method and the geostatistical method. Based on this research, key factors have been identified that determine the distribution of element content. As a result of studying the distribution of REEs in the host rocks, conditions for ore formation were established: the deposit has an igneous origin with signs of prolonged fractionation of the magma; a negative Eu anomaly confirms the involvement of plagioclase fractionation typical of medium and acidic magmas; LREE enrichment indicates an evolved magma involving the continental crust, while moderate depletion of HREE indicates a deep source of magmatism with residual garnet involvement. The established strong positive correlation between REES indicates a single geochemical process and reflects the primary magmatic identity. A porphyry system with a deep magmatic source has been revealed, where ore fluids are separated from the residual melt, which is already depleted in Eu but enriched in LREEs and metals.