Geochronology, petrogenesis, and tin-mineralization potential for the Elikendagou syenogranite in the East Elikendagou area within the Tataleng granitic batholith in the Qilian Orogen, NW China

The Elikendagou syenogranite, located within the Tataleng granitic batholith in Northwest China, hosts numerous greisen belts and significant tin mineralizations. However, there have been few investigations into these features, resulting in a limited understanding of the petrogenesis and tin-mineralization potential of the syenogranite. This study investigates the geochronology and petrogenesis of the Elikendagou syenogranite, along with ages and compositions of cassiterite from the greisen belts. Two samples of the syenogranite yielded weighted mean 206Pb/238U zircon ages of 436.0 ± 5.5 Ma and 429.3 ± 2.5 Ma, respectively, while the cassiterite yielded a lower intercept U–Pb age of 432.6 ± 2.7 Ma, all suggesting a comparable early Silurian era. Geochemically, the syenogranite is predominantly peraluminous, with high alkali contents, strongly negative Eu anomalies, high Rb/Sr and Rb/Ba ratios, and negative correlations between Rb and Th, suggesting a fractionated S-type granite. The observed low oxygen fugacities and Ce4+/Ce3+ ratios for zircon indicate that the fractionated syenogranite, which exhibits no magnetism in the field, was formed under relatively reducing conditions, demonstrating significant potential for tin mineralization. Additionally, positive correlations among specific trace elements in cassiterite suggest oxidized conditions. Overall, the redox reaction from bivalent Sn to tetravalent Sn was necessary to form greisen-type tin mineralization in this study, which may be genetically linked to the emplacement of the Elikendagou syenogranite during the early Silurian syn-collisional setting associated with the closure of the South Qilian Ocean.