| 广州礌岗断裂的晚第四纪活动证据 |
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| 引用本文：宋毅盛,陈文彬,尤惠川,唐方头,李金臣.2026.广州礌岗断裂的晚第四纪活动证据[J].地球学报,47(3):480-492. |
| DOI：10.3975/cagsb.2025.093021 |
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| 基金项目:本文由城市活断层探测与地震危险性评价项目“礌岗断裂稳定性及其对佛山市南海区城市建设的影响评价项目”(编号：NHZJ20170419G0334)和中国地震局地球物理研究所自主立项“重大工程项目地震安全性评价中隐伏活动断裂研究”(编号：JY2023Z18)联合资助。 |
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| 中文摘要:礌岗断裂为广州—从化断裂带南段的一支, 位于珠江三角洲断陷盆地中心、多组NE向和NW向构造交汇的特殊部位。现有证据表明, 珠江三角洲断陷盆地内NW向断裂多为晚更新世活动断裂, 而与之共轭的NE向断裂晚更新世以来是否活动, 已成为一个正确认识本区晚第四纪构造活动格局、动力学环境的科学问题, 也影响对珠三角地区地震危险性的科学评估。在佛山市南海区针对礌岗断裂的探测过程中, 在浅层地震勘探的基础上, 实施了多组详细的钻探调查。结果表明, 礌岗断裂在第四组、第三组和第二组等3组钻孔联合剖面中均断错了晚更新世地层, 断错的最新地层测年介于40~50 ka之间, 时代为晚更新世早中期, 活动性质为逆右旋, 最大垂直位错量为0.9~2.3 m, 估算晚更新世早中期以来的平均垂直滑动速率为0.02~0.06 mm/a。虽然礌岗断裂滑动速率较低, 但其属晚更新世活动断裂, 有必要防范其未来发生6级左右地震的可能性。 |
| 中文关键词:珠江三角洲 断陷盆地 礌岗断裂 断裂活动性 晚更新世 |
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| Evidence of Late Quaternary Activity of the Leigang Fault in Guangzhou |
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| Abstract:The Leigang Fault is a branch of the southern section of the Guangzhou–Conghua fault zone, which is located in the center of the Pearl River Delta fault basin, a special tectonic position where several groups of NE- and NW-trending structures meet. Existing evidence shows that most of the NW-trending faults in the Pearl River Delta fault basin are Late Pleistocene active faults, and whether the conjugate NE-trending faults have been active since the Late Pleistocene has become a scientific problem to correctly elucidate the Late Quaternary tectonic activity pattern and dynamic environment in the region and also affects the scientific assessment of seismic risk in the Pearl River Delta. During the exploration of the Leigang Fault in Nanhai District, Foshan City, multiple detailed drilling surveys were conducted based on shallow seismic exploration. The Leigang Fault faulted the Late Pleistocene strata in the joint profiles of the fourth, third, and second drilling groups. The latest stratigraphic age of the faulted strata is between 40 ka and 50 ka, belonging to the early and middle stages of the Late Pleistocene. The nature of Leigang Fault is reverse and right-lateral, and the maximum vertical displacement is 0.9–2.3 m. The estimated average vertical sliding rate since the early and middle stages of the Late Pleistocene is 0.02–0.06 mm/a. Although the sliding rate of the Leigang Fault is relatively low, it belongs to the Late Pleistocene active fault, and it is necessary to keep aware of the possibility of future earthquakes with magnitude of 6. |
| keywords:Zhujiang river delta fault basin Leigang Fault fault activity Late Pleistocene |
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