School of Environmental Studies, China University of Geosciences, Wuhan, Hubei, China.
Ground Water. 2024 Mar-Apr;62(2):196-211. doi: 10.1111/gwat.13341. Epub 2023 Jul 12.
Structural landform evolution and hydrogeochemical analyses are crucial for understanding the characteristics of karst groundwater systems and the development of deep karst formed by complex aquifers in a tectonic collision zone. Detailed structural landform evolution analysis was carried out along the large-scale anticlinorium to investigate the temporal evolution of karst aquifer systems and karstification. Results showed that the tectonic activity included weak horizontal compression and slow vertical uplift during the Triassic to Middle Jurassic, forming a denuded clastic platform. This period was mainly preserved in the geological record as burial karst. From the Late Jurassic to the Early Cretaceous, the study area was strongly compressed by S-N-trending stress, and developed E-W-trending high-angle imbricate thrust structures, which controlled the formation of folded and fault-blocked mountains. Vertical multilayered strata underwent a strong horizontal extrusion, forming a large-scale anticlinorium with secondary folds and faults. With the exposure of carbonate rocks due to rapid crustal uplift, karst began to develop, forming a vertical multilayer karst aquifer system and controlling the distribution of karst groundwater. The Fangxian faulted basin was formed from the Late Cretaceous to the Paleogene, whereby landforms were dominated by intermountain basins. Slow crustal uplift caused the retreat of the denudation line to the east, leading to an increase in hydrodynamic conditions and karstification, and the initiation of early karst groundwater systems. Since the Neogene, intermittent and rapid crustal uplift has led to the deepening of rivers, resulting in the formation of peak clusters and canyons, the development of deep karst, and the complete formation of karst groundwater systems. Combined with hydrogeochemical and borehole data, local, intermediate, and regional karst groundwater systems were identified. It has vital significance to the geological route selection or construction of deep-buried tunnels and the utilization of karst groundwater.
构造地貌演化与水文地球化学分析对于认识构造碰撞带中复杂含水系统深部岩溶的特征及岩溶地下水系统的发育具有重要意义。本文沿大型背斜构造详细开展构造地貌演化分析，以探讨岩溶含水层系统和岩溶作用的时间演化。研究结果表明，三叠纪至中侏罗世期间，构造活动以弱水平挤压和缓慢垂向隆升为主，形成了风化碎屑岩台地，这一时期主要以埋藏岩溶的形式在地质记录中保存下来。晚侏罗世至早白垩世期间，研究区受南北向挤压应力强烈作用，发育近东西向高角度叠瓦状冲断构造，控制了褶皱断块山的形成，垂向多层地层遭受强烈的水平挤压，形成具有次级褶皱和断裂的大型背斜构造。伴随快速地壳隆升导致碳酸盐岩出露，岩溶开始发育，形成垂向多层岩溶含水层系统，并控制岩溶地下水的分布。晚白垩世至古近纪期间，发育房县断陷盆地，地貌以山间盆地为主，地壳缓慢抬升导致剥蚀基准面向东迁移，水动力条件增强，岩溶作用加强，启动早期岩溶地下水系统。新近纪以来，间歇性快速地壳隆升导致河流深切，形成峰丛峡谷，深部岩溶发育，岩溶地下水系统完全形成。结合水文地球化学和钻孔资料，识别出局部、中间和区域岩溶地下水系统。这对深埋隧道的地质选线或施工以及岩溶地下水的利用具有重要意义。
