Competency contrast-driven extension veining and sequential orogenic Au-Sb mineralization: Insights from the Zaorendao deposit, China

作者：Hao‐Cheng Yu, Kunfeng Qiu, Jie Wang, Peng-Cong Zhang, Luca Smeraglia, Santiago Tassara, Jia-Dong Ma, Xian-Fa Xue, Dapeng Li, Jun Deng · 发表于：Geological Society of America Bulletin · 年份：2025 · DOI：10.1130/b38420.1 · 被引用次数：5 · 研究领域：Geological and Geochemical Analysis、Geochemistry and Geologic Mapping、Hydrocarbon exploration and reservoir analysis

Abstract The coupling between extension veining and fluid evolution in orogenic Au-Sb deposits remains poorly understood. This study presents an integrated structural, geochronological (sericite Ar-Ar, monazite U-Pb), fluid inclusion, and oxygen isotopic investigation of the Zaorendao Au-Sb deposit (China). The deposit is hosted within an Early Triassic quartz diorite stock that intrudes slate and contains two main ore types: extensional quartz-stibnite-sphalerite veins (Sb) and disseminated sulfide-hosted Au ores in the wall rocks. Structural analysis reveals that competency contrasts between a quartz diorite and slate localized tensile failure. Geochronology constrains this veining and mineralization to 231 Ma during regional NE-SW shortening. Four hydrothermal stages are identified. Stage 1 is characterized by elongated coarse quartz (Qz1) veins and disseminated Au mineralization, with chlorite geothermometry from the alteration halo of 300 ± 33 °C. Extension structure suggests high-pressure fluid under near lithostatic conditions drove continuous extension and fluid discharge into the wall rocks, leading to Au precipitation via fluid-rock interaction. Stages 2 and 3 involve microfracturing and healing of Qz1, forming quartz overgrowth rim (Qz2). Pseudo-secondary fluid inclusion assemblages (FIAs) in healed microfractures within Qz1 contain coexisting liquid-rich and vapor-rich inclusions and yield a mean homogenization temperature of 181 ± 10 °C, reflecting a significant ...