Zn-Rich VMS Metallogeny of the Rudny Altai Belt: Metal Dis-tribution, Stratigraphic Relationships and Felsic Volcanic Associations

The Rudny Altai belt of Kazakhstan, Russia, and China is a major volcanogenic massive sulfide (VMS) province of the Central Asian Orogenic Belt, hosting numerous Zn–Pb–Cu deposits within Devonian volcanic and volcano-sedimentary successions. This study in-tegrates geological and metallogenic data from 29 VMS deposits to quantify regional metal specialization and evaluate its relationships with stratigraphy and volcanic setting. Indi-vidual Zn/(Zn+Pb) values range from 0.56 to 0.93, whereas district means vary from 0.663 to 0.803, indicating a persistent regional Zn-rich tendency superimposed on substantial deposit-scale variability. Stratigraphic analysis demonstrates that mineralization occurs at several discrete Devonian lithochronological levels rather than along a single continuous ore-bearing horizon. Major deposits are commonly associated with felsic volcanic and volcano-sedimentary successions; however, variations in Cu/(Cu+Zn) and compiled δ³⁴S data demonstrate substantial deposit-scale variability in metal distribution. Comparison with major VMS provinces shows that Rudny Altai district-scale Zn/(Zn+Pb) values over-lap with reference values for the Bathurst district and Green Tuff Belt. The results define the Rudny Altai as a Zn–Pb–Cu-dominated VMS province characterized by a regional as-sociation between mineralization and felsic-bearing Devonian successions rather than a simple direct control of felsic magma composition on Zn enrichment. The proposed prov-ince-scale framework provides a quantitative basis for metallogenic comparison and iden-tification of favourable stratigraphic intervals for VMS exploration.