Differential exhumation of giant lode gold deposits in the Jiaodong Peninsula, eastern China

The Jiaodong Peninsula is China’s premier gold province, containing 5500 t of gold reserves, and exhibits pronounced spatial variation in lode gold mineralization. This variation is especially evident along the Jiaojia fault zone, where the northern segment hosts 90% of the gold endowment, while the southern segment is only sparsely mineralized. To understand this pattern, we integrate new apatite (U-Th)/He (AHe; n = 48 single-grain ages from eight samples, 50.1 ± 9.6 Ma to 2.8 ± 0.7 Ma) and zircon (U-Th)/He (ZHe; n = 40 single-grain ages from eight samples, 133.8 ± 6.1 Ma to 106.8 ± 5.0 Ma) ages obtained from a vertical drill-core profile (Dayinjia ZK32-1; surface to −1492 m depth) in the southern Jiaojia fault zone with a comprehensive low-temperature thermochronologic database (70 zircon fission-track ZFT, 164 apatite fission-track AFT, 84 ZHe, and 52 AHe). Thermal modeling reveals five distinct exhumation phases (120−95 Ma, 95−60 Ma, 60−45 Ma, 45−15 Ma, and 15 Ma to present) occurring in the southern segment. Regional analysis reveals substantially less post-mineralization exhumation along the southern Jiaojia fault zone relative to the northern segment. This disparity is likely responsible for the lower gold endowment found in the south. Regionally, two major post-mineralization exhumation episodes (110−70 Ma and 50−30 Ma) in the Jiaodong Peninsula reflect tectonic transitions driven by evolving subduction dynamics. These episodes indicate elevated exhumation rates and greater cumulative denudation in the eastern peninsula. This likely limited ore preservation, contributing to the heterogeneous distribution of gold resources across the peninsula. Notably, the older thermochronologic ages at the low elevations of key gold districts, such as Sanshandao, Jiaojia, and Linglong, suggest limited post-mineralization exhumation, which has contributed to the preservation of these ore deposits. These findings underscore the critical relationship between exhumation processes and the spatial variation in gold mineralization and demonstrate that low-temperature thermochronology is an effective tool for guiding the exploration of deep-lying lode gold deposits.