The Yangshan gold deposit is a super‐large fine‐grained disseminated gold deposit located in southern Gansu Province. Its metallogenic age has been determined by using the cathodoluminescence image and ion probe U‐Pb dating techniques. It is found that zircons from quartz veinlet of the fine‐grained disseminated gold ore show characters of magmatic origin with prism idiomorphism, oscillatory zoning and dominant Th/U ratios of 0.5–1.5. Three main populations of zircons are obtained, giving average 206Pb/238U ages of 197.6±1.7 Ma, 126.9±3.2 Ma and 51.2±1.3 Ma respectively. The first age corresponds to the K‐Ar age of the plagiogranite dike, while the latter two ages indicate that buried Cretaceous and Tertiary intrusives exist in the orefield, suggesting that the Yangshan gold deposit was genetically related to the three magmatic hydrothermal activities. By contrast, zircons from coarse gold‐bearing quartz vein in the mining area are much older than the host rock, indicating that the vein was formed earlier and was not contaminated by later magmatic fluids. It is concluded that the coupling of multiperiodic hydrothermal activities in the mining area has contributed a lot to mineralization of the Yangshan gold deposit.

The Yangshan gold deposit is a fine-grained disseminated gold deposit located in south Gansu province. The metallogenic age was determined by cathodoluminescence imaging and U-Pb SHRIMP techniques. Zircons associated with quartz veins containing finegrained disseminated gold ore have typical magmatic features including pillar idiomorphism, rhythmic zoning, and Th/U ratio of 0.5 to 1.5. Average 206 Pb/ 238 U ages of 197.6 ±1.7 Ma, 126.9±3.2 Ma, and 51.2±1.3 Ma define three primary zircon populations. The former age correlates to K-Ar ages (189.4±7.2 Ma mean) for plagiogranite dikes, while the later two ages suggest buried Cretaceous and Tertiary intrusives in or near the ore field. The Yangshan gold deposit is genetically related to the three magmatic-hydrothermal events.