地质科学2026，Vol.61Issue(2)：540-556,17.DOI:10.12017/dzkx.2026.037
断层阀与模式切换模型的时序耦合:胶东金矿成矿机制新见解
Temporal coupling of fault valve and pattern switching model:New insights into the gold mineralization mechanism in the Jiaodong gold deposit
摘要
Abstract
Many mesothermal gold-quartz vein systems are controlled by high-angle reverse faults.However,this observation presents a classic"structural paradox":in a regional compressional setting,such high-angle reverse faults not only contradict Anderson's fault theory,but also fail to serve as effective fluid conduits due to their friction-locking effect.Currently,there are two main explanatory mechanisms:the fault-valve model suggests that pre-existing high-angle fractures periodically reactivate during tectonic activity,driving the accumulation and release of fluid overpressure through seismic pumping,thereby promoting mineralization.The mode-switching model,based on the"capped"yield surface theory,proposes that high-angle reverse faults can spontaneously form under chem-mechanical feedback,accompanied by fluid pressure oscillations and rupture mode transitions,leading to mineralization through dissolution-precipitation processes.This paper compares the theoretical foundations and geological applicability of the two mechanisms and uses field and core observations from the Jiaodong gold deposits as an example for analysis.Two types of structural associations were identified in the cores:one is a high-angle reverse fault with ductile-brittle deformation prior to mineralization,which is consistent with the"cap-end"failure behavior under low fluid pressure and high differential stress conditions;the other is a near-horizontal tensional vein that cuts through early structures.The study indicates that during the formation of the Jiaodong gold deposits,the fault-valve and mode-switching models correspond to different evolutionary stages of the Jiaodong mineralization system:the early stage(＞135 Ma)was dominated by the mode-switching model in a compressional setting,forming high-angle reverse faults;the main mineralization stage(～120 Ma)showed a tectonic regime shift to extension,with the fault-valve model controlling the periodic reactivation of pre-existing fractures and large-scale gold precipitation;and the late stage(～115 Ma)during stress relaxation may have reverted to the mode-switching model.The transition and coupling of the two mechanisms are jointly controlled by regional stress state,pre-existing structures,and fluid pressure,shaping the unique mineralization structure and timing in the Jiaodong region.This study provides a new temporal framework and mechanistic explanation for understanding the coupling processes of tectonics-fluids-reactions in hydrothermal mineralization systems.关键词
断层阀/模式切换模型/中温热液金矿/盖帽屈服面/构造—流体—成矿耦合/胶东金矿Key words
Fault valve/Mode-switching model/Mesothermal gold deposit/Capped yield surface/Tectonic-fluid-mineralization coupling/Jiaodong gold deposit分类
天文与地球科学引用本文复制引用
陈国明,田忠华..断层阀与模式切换模型的时序耦合:胶东金矿成矿机制新见解[J].地质科学,2026,61(2):540-556,17.基金项目
国家重点研发计划项目(编号:2023YFC2906900)、国家自然科学基金项目(编号:42172222)和中国地质科学院基本业务费项目(编号:JB2304)资助 （编号:2023YFC2906900）
