Geological Survey of Jiangsu Province
Key Laboratory of Earth Fissures Geological Disaster, Ministry of Land and Resources
Jiangsu Earthquake Agency
Geophysical Exploration Center, China Earthquake Administration

溧阳−南渡断裂是中国东部长三角地区一条重要的近EW向隐伏断裂，位于中国人口、经济和城镇密度最高区域之一苏南现代化建设示范区中部，是一条重要的区域地貌和新构造分区界线。溧阳−南渡断裂尚未见系统研究，其最新活动时代尚不明确。为此，采用纵横波联合地震勘探和钻孔联合地质剖面探测等方法研究溧阳−南渡断裂空间展布及第四纪活动性，并对其构造多期活动及地震活动性进行探讨。结果表明：断裂西段倾向向北；中东段倾向向南，具正断性质，倾角为64°~84°；断裂向上明显切错地表以下约70 m层位，垂直差异活动影响至地表以下36~45 m，综合分析认为应属第四纪早−中更新世断裂，最新活动时间在距今(310±54) ka之后、晚更新世之前。断裂具多期活动：印支期到燕山早期为逆断裂，燕山晚期以来为正断裂控制新生代盆地和火山岩发育。研究成果为苏南乃至长三角地区防震减灾、重大工程建设、城市规划及土地利用等提供科学依据。

Located in the central part of the Sunan Modernization Construction Demonstration Area—one of the areas with the densest population and urban areas and the most developed economy in China, the Liyang-Nandu fault is an important concealed fault with a nearly E-W strike in the Yangtze River Delta in eastern China. This fault serves as an important regional geomorphic and neotectonic boundary. However, there is a lack of systematic research on this fault, and its latest activity era is yet to be ascertained. Using seismic exploration P-waves and S-waves and cross-well stratigraphic correlation, this study investigated the spatial distribution and Quaternary activity of the Liyang-Nandu fault and explored its multiphase tectonic activity and seismicity. The results are as follows: (1) The western and central-eastern segments of the Liyang-Nandu fault have dip directions of north and south, respectively, suggesting the nature of a normal fault. Their dip angles range from 64° to 84°. (2) This fault evidently offsets the intervals above at burial depths of approximately 70 m, with vertical activity difference affecting the parts at depths of about 36-45 m underground. The comprehensive analysis revealed that this fault should be a Quaternary Early-Middle Pleistocene fault, with the latest activity occurring after approximately 310±54 ka, predating the Late Pleistocene. (3) This fault has undergone multi-stage activity. From the Indosinian to the Early Yanshanian, it was present as a reverse fault. Since the Late Yanshanian, it has been a normal fault, controlling the development of Cenozoic basins and volcanic rocks. These results will provide a scientific basis for the prevention and reduction of earthquake-induced hazards, major engineering construction, urban planning, and land use in southern Jiangsu and even the broader Yangtze River Delta.

苏南现代化建设示范区综合地质调查项目

张硕，张平，陈火根，等. 苏南溧阳−南渡断裂活动性研究[J]. 煤田地质与勘探，2023，51(12)：47−56.

ZHANG Shuo，ZHANG Ping，CHEN Huogen，et al. Activity of the Liyang-Nandu fault in Southern Jiangsu[J]. Coal Geology & Exploration，2023，51(12)：47−56.