Porphyry copper deposits are one of the main sources of copper in the world and are usually associated with intrusive complexes of calc-alkaline composition formed in subduction-related geodynamic settings. Eastern Kazakhstan is characterized by the presence of a number of large porphyry copper-molybdenum deposits, but the metallogenic potential of many intrusive complexes in the region remains insufficiently studied. This paper presents new geological, mineralogical, and geochemical data on the Bala-Urpek deposit, located within the Sarykol intrusive complex (Eastern Kazakhstan), aimed at identifying diagnostic criteria for porphyry copper mineralization. The present study is based on field geological observations, petrographic analysis, and whole-rock geochemical data obtained by XRF and ICP-MS. Intrusive ore-bearing rocks are mainly represented by granitoids of the calc-alkaline series with I-type geochemical characteristics. Mineralogical studies have revealed veinlet-disseminated sulphide mineralisation, represented mainly by chalcopyrite and pyrite, as well as the development of hydrothermal alteration associations typical of porphyry systems. The geochemical characteristics of the rocks, including enrichment with large-ion lithophile elements and depletion with high-charge elements, indicate the subduction nature of magmatism. The combination of the data obtained allows us to identify geological, mineralogical and geochemical criteria characteristic of copper-porphyry systems and indicates the potential of the Bala-Urpek deposit area and the associated apophyses of the Sarykol complex for further exploration and prospecting.

Rare-metal pegmatites of the Kalba–Narym belt (Eastern Kazakhstan) represent an important source of Li, Cs, Ta, Nb, Be, and associated critical metals. Despite extensive geological investigations, the relationships between granites, pegmatites, and late-stage alteration products within the Central Kalba ore district remain insufficiently constrained. This study integrates whole-rock geochemistry and muscovite trace-element data to evaluate regional fractionation trends and rare-metal enrichment within the granite–pegmatite system. The dataset comprises 29 whole-rock samples, including Phase I and Phase II granites, pegmatites, greisens, and hornfels, together with 11 muscovite separates from the Akhmetkino, Yubileynoye, Bakennoye, and Asubulak ore fields. Geochemical evolution was assessed using granite-normalized multi-element patterns and the Cs–Rb, K/Rb–Cs, Li–Rb, Li–Cs, Rb/Sr–Cs, and Ta–Cs relationships. Muscovite compositions were additionally compared with published datasets from the Totoral (Argentina) and Gatumba (Rwanda) pegmatite districts. The results reveal systematic enrichment in Li, Rb, Cs, Nb, and Ta accompanied by depletion in Sr and Ba from granites to the most evolved pegmatites. The strongest geochemical relationship is recorded by the Rb/Sr–Cs system (R² = 0.805), whereas Ta and Cs show only weak correlation (R² = 0.062). Muscovite compositions display decreasing K/Rb and K/Cs ratios and increasing Rb and Cs concentrations from Akhmetkino through Yubileynoye and Bakennoye to Asubulak, defining a regional fractionation sequence consistent with whole-rock geochemistry. The most evolved muscovites overlap compositional fields characteristic of highly fractionated LCT pegmatites. The geochemical patterns identified in both whole-rock and muscovite datasets indicate progressive melt evolution across the Central Kalba district. Late-stage alteration and volatile-rich mineral assemblages record additional fluid-related processes, although their quantitative contribution to rare-metal redistribution remains uncertain. The results identify Cs, Rb/Sr, K/Rb, and K/Cs as useful indicators of relative pegmatite evolution and provide new constraints on the development of rare-metal granite–pegmatite systems in Eastern Kazakhstan.