Structural Controls and Primary Geochemical Halo of the Mailong–Walega Orogenic Gold Field, East Kunlun, China

More than 40 tons of cumulative gold resources have been identified in the Mailong–Walega gold field, East Kunlun Orogenic Belt (EKO). However, further exploration has been limited by the unclear mineralization prospectivity in depth. This study integrates field structural analysis with primary geochemical halo data to address this issue. Three deformation events are recognized: pre-mineralization N–S compression (D1) producing E–W folds and cleavage; syn-mineralization NNW–SSE compression (D2) generating NNE- to NW-trending conjugate faults hosting gold ore bodies; post-mineralization N–S extension (D3) forming W–E-trending brittle normal faults. The sinistral-normal nature of the major syn-mineralization NNE-trending faults indicates that ore bodies therein should plunge toward the north. Primary geochemical halo analysis of the Au VIII ore body in the Mailong segment reveals a well-developed axial zoning sequence of Cu–W–Sn–Hg–As–Ag–Sb–Au–Pb–Mo–Zn. The superposition of deep-level frontal and rear halos, and an increasing ratio of low- to high-temperature elements, suggest concealed mineralization at depth. The structural and geochemical data collectively indicate that the area north of exploration line 76, at an elevation of approximately 3600 m, is another potential mineralization center of the Au VIII ore body.