Bridging the 39Ar–14C Groundwater Dating Gap: A Dual-Permeability Transport Perspective Based on Numerical Modeling and Field Data - Dataset

This dataset supports the study titled ''Bridging the 39Ar–14C Groundwater Dating Gap: A Dual-Permeability Transport Perspective Based on Numerical Modeling and Field Data'' and contains the HydroGeoSphere (HGS) input files used to simulate reactive tracer transport in a reference dual-permeability groundwater model. The model was developed to investigate mechanisms driving discrepancies between apparent groundwater ages derived from Argon-39 and Carbon-14 tracers—particularly in systems where diffusive exchange and in situ underground production significantly bias the apparent tracer ages. The domain consists of a vertical fracture embedded in a low-permeability porous matrix, explicitly representing physical processes such as advection in the fracture, diffusion into and from the matrix, longitudinal dispersion, and depth-dependent production of 39Ar. Boundary and initial conditions were configured to simulate long-term transient flow over 20,000 years, allowing tracer activity to equilibrate under realistic hydrogeological conditions. This reference model forms the basis for a broader sensitivity analysis assessing the impact of fracture aperture, porosity, diffusion coefficients, and dispersivity. The dataset supports reproducibility of key numerical results and provides a framework for future groundwater age-dating studies using HGS in complex fractured media.

本数据集支撑题为《弥合氩-39（39Ar）与碳-14（14C）地下水定年差距：基于数值模拟与野外数据的双渗流输运视角》的研究，包含用于在基准双渗流地下水模型中模拟反应性示踪剂输运的HydroGeoSphere（HGS）输入文件。该模型旨在探究氩-39与碳-14示踪剂所得表观地下水年龄出现偏差的驱动机制，尤其适用于扩散交换与地下原位生成过程会显著干扰示踪剂表观年龄的水文地质系统。研究区域由嵌入低渗透性多孔介质中的垂直裂隙构成，明确刻画了裂隙内对流、基质内外扩散、纵向弥散以及深度依赖型氩-39生成等物理过程。研究配置了边界与初始条件，以模拟20000年的长期瞬态流场，使示踪剂活度在符合实际的水文地质条件下达到平衡状态。该基准模型为更广泛的敏感性分析奠定了基础，该分析用于评估裂隙开度、孔隙度、扩散系数及弥散度的影响。本数据集可支撑关键数值结果的可重复性研究，并为未来在复杂裂隙介质中使用HGS开展地下水定年研究提供了研究框架。