The Xing-Meng Orogenic Belt is characterized by intense and widespread Mesozoic granitic magmatism related to large-scale W mineralization. Three periods of W-mineralized granitic magmatism can be distinguished: Early Triassic, Early–Middle Jurassic, and Late Jurassic–Early Cretaceous. Early Mesozoic W-mineralized granitoids are I-type granites with metaluminous to weakly peraluminous characteristics, with higher Rb concentrations and lower K/Rb ratios than coeval W-barren granitoids. Late Mesozoic W-mineralized granitoids belong to highly fractionated A-type granites, enriched in Rb, Th, and U, and depleted in Ba, Sr, P, Ti, and Eu. They have higher Rb/Sr and U/Th ratios, and lower (La/Yb)_N, LREE/HREE, Eu/Eu*, K/Rb, Zr/Hf, Nb/Ta, and Y/Ho ratios than contemporary W-barren granitoids. Mesozoic W-mineralized granitoids mainly originated from the partial melting of juvenile lower crust, whereas Early Mesozoic W-mineralized granitoids encompassed minor reworked ancient crustal material. Triassic W-mineralized granitoids formed in a syn- and/or post-collision setting related to the closure of Paleo-Asian Ocean. Early–Middle Jurassic W-mineralized granitoids formed in a compressional setting created by the subduction of Paleo-Pacific Ocean plate in the east and the closure of Mongol-Okhotsk Ocean in the west. Late Mesozoic W-mineralized granitoids formed in a post-orogenic extensional setting controlled by the MOO and PPO tectonic regimes.

The Wulonggou Gold Field is one of the giant gold fields in the East Kunlun Orogenic Belt, northwestern China. Previous studies mainly focused on elementary mineral isotopic studies, fluid inclusions, and geological features in the Wulonggou Gold Field. In this study, we report some research on the precise age and the specific ore-forming process of the WGF: the hydrothermal monazite U–Pb ages; the way of gold precipitation; the composition, evolution, and source of ore-forming fluids of the Wulonggou Gold Field. Finally, we demonstrate a link between two-stage hydrothermal events and sequential episodes of crust-derived magmas, with implications for gold metallogeny in the East Kunlun Orogenic Belt. There are four hydrothermal stages that are recognized: a quartz–pyrite stage (stage 1), a quartz–pyrite–arsenopyrite–chalcopyrite stage (stage 2), a quartz–galena–sphalerite–pyrite stage (stage 3) and a quartz–stibnite–carbonate stage (stage 4). The monazite U–Pb ages of the Huanglonggou and Hongqigou deposits in the Wulonggou Gold Field were 422.2 ± 2.4 Ma and 236.7 ± 3.7 Ma, respectively, which support the opinion of two epochs of mineralization. Stages 1 and 2 are the main gold mineralization stages, wherein Au and As have a close genetic relationship. The Hongqigou and Huanglonggou deposits seem to have been formed in different metallogenic events due to the contrast on the trace element compositions in pyrite. The sources of the ore-forming materials and fluids of the Hongqigou and Huanglonggou deposits show apparent characteristics of orogenic gold deposit, and the magmatic events during Paleozoic and Mesozoic have an important contribution to the formation of the gold deposits. The gold deposits in the Wulonggou Gold Field can be interpreted as an orogenic gold system related to two-epoch tectonic–magmatic events.

The Wulonggou Au district in the East Kunlun Orogen is one of the most important Au producing regions in China. The Yanjingou Au deposit occurs within a shear zone in the northeastern Wulonggou Au district. Based on detailed field investigations, geochemical data for the primary halo, and in situ thermoelectric data for pyrite, the following key results were obtained: (1) the Yanjingou Au deposit has the fractured-altered-rock type gold mineralization that is arsenopyrite-rich; (2) elemental correlations and cluster analysis show that Au and As are the most diagnostic elements; (3) geochemical data for the primary halo indicate the deposit is a shallow supra-ore halo ore body; and (4) in situ pyrite thermoelectric data show that the proportion of P-type pyrite is >80% and the detachment rate is 50%, which can be inferred that the location of the ore body is shallow. Based on our data, we present a mineralization prediction model for the ore body. The Yanjingou Au deposit has a good mineralization and high prospecting potential, with at least half of the ore body being concealed at depth, which has important scientific guiding significance for the breakthrough of prospecting and exploration.