中文摘要：

加速器质谱技术（AMS）是一种高灵敏的核素分析技术。本文利用加速器质谱技术测定岩石中原地宇生放射性核素^36Cl含量来研究广西乐业大石围天坑的暴露年龄，实现了对广西大石围天坑的定年。研究结果表明，大石围天坑的最低暴露年龄为10-20万年。该研究为喀斯特地貌及演化提供重要参考价值。

英文摘要：

Accelerate mass spectrometry is a nuclide analysis technique with high sensitivity. In this paper, accelerator mass spectrometry is used to measure the content of radionuclide ^36 Cl in the rocks to study the exposure age of Dashiwei Tiankeng, Leye County of Guangxi, and realize the dating of Dashiwei Tiankeng in Guangxi. The results show that the exposure age of Dashiwei Tiankeng is at least 100-200 thousands years. The study intends to provide a significant reference value for the study of karst relief areas and its evolution.