| 广西凌云天坑群特征及成因分析 |
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| 关键词:tiankeng cluster genesis analysis evolution model Lingyun County Guangxi |
| 基金项目:本文由中国地质调查局地质调查项目“渝东南地区岩溶地貌地质遗迹立典调查评价”(编号: DD20242325)和中国地质科学院岩溶地质研究所基本科研业务费项目“重庆金佛洞望天宫冰洞成景机制研究”(编号: 2023005)联合资助。 |
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| Features and Genesis of the Lingyun Tiankeng Cluster, Guangxi |
| The Lingyun tiankeng cluster in Guangxi is a high-density assemblage of collapse-type tiankengs situated within a small-scale underground river system of the Chengbi River Basin. It consists of 19 tiankengs, accompanied by a variety of karst landforms including canyons, lakes, skylights (tianchuang), dolines, peak clusters, depressions, valleys, caves, and underground rivers. Its distinctive evolutionary pattern exemplifies unique karst processes on isolated carbonate platforms and offers key insights into the landscape evolution of karst regions in Southwest China. Based on field investigations and laboratory analyses, this study systematically examines the formation conditions and evolutionary mechanisms of the tiankeng cluster. The key findings are as follows: (1) The exceptionally thick, pure, and continuously deposited Devonian to Permian carbonate rocks provide an optimal material foundation for tiankeng development. NE- and NW-trending faults and steeply dipping joint zones control the spatial pattern of karstification. The hot and humid subtropical monsoon climate, coupled with substantial recharge from allogenic water sourced from surrounding clastic rock areas, serves as the critical external dynamic mechanism for the formation of the tiankeng cluster. (2) Chronological analyses, including optically stimulated luminescence (OSL), radiocarbon (14C), and uranium-thorium dating of paleo-underground river passages indicate that tectonic uplift during the late Middle Pleistocene enhanced river incision in the region, which promoted chamber collapse and tiankeng formation. (3) The Lingyun tiankeng cluster exhibits a unique “evolutionary model of karst tiankengs fed by allogenic water”, demonstrating a complete developmental sequence from underground river → cave chamber → tiankeng → composite tiankeng → peak-cluster valley. This study provides a significant case and theoretical basis for understanding the genesis of high-density tiankeng clusters in small-scale underground river basins. |
| PAN Tianwang,SHI Wenqiang,LI Chengzhan,CHEN Weihai,TANG Liangliang,CHEN Zhiqiang.2026.Features and Genesis of the Lingyun Tiankeng Cluster, Guangxi[J].Acta Geoscientica Sinica,47(3):688-702. |
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