北江上游浈江段河流阶地石英ESR法测年研究  

Quartz Electron Spin Resonance(ESR)Dating of River Terraces in the Zhenjiang River of the Upper Beijiang River

作　　者：程子烨 李岸莹 郑婉柔 张欣宇 刘展鹏 姬昊 唐晓春[1] Cheng Ziye;Li Anying;Zheng Wanrou;Zhang Xinyu;Liu Zhanpeng;Ji Hao;Tang Xiaochun(School of Geography and Environmental Economics,Guangdong University of Finance&Economics,Guangzhou 510320,China;State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China)

机构地区：[1]广东财经大学地理与环境经济学院,广州510320 [2]中国地震局地质研究所地震动力学国家重点实验室,北京100029

出　　处：《热带地理》2025年第3期504-513,共10页Tropical Geography

基　　金：国家自然科学基金项目(41903055);广州市科技计划项目(202002030182)。

摘　　要：河流阶地是研究河流演化过程及其气候构造响应的重要地貌标志。文章选定北江上游浈江段出露较好的河流阶地剖面为研究对象,利用电子自旋共振(ESR)测年法分析浈江河流阶地的年代。结果表明:3个剖面顶部的年龄分别为231±29、256±26、41±6 ka,底部的年龄分别为654±79、576±38、392±56 ka。通过与已有浈江和邻近流域的热释光年龄数据的对比分析,确定了北江上游浈江段左岸存在明显的两级河流阶地,T2和T1最终形成的大致时间分别为231±29、41±6 ka。浈江段二级阶地的形成主要受构造抬升运动的影响,一级阶地是在气候变化与构造活动共同作用下形成的。根据研究区T2和T1砾石层顶部的样品年龄和拔河高度,计算出对应的下切速率分别为0.056和0.524 mm/a。最后,通过与邻区其他流域河流阶地的测年数据和下切速率的对比显示,中更新世中晚期粤北主要河流具有同步演化特征,表明粤北晚更新世中期以来存在构造抬升。River terraces are important geomorphic indicators that reveal the evolution of rivers,and their climatic and tectonic responses.Dating is key to studying terrace evolution.In the past decade,electron spin resonance(ESR)dating has been widely applied in Quaternary geology and environmental research,and has solved a series of Quaternary chronology problems.This study selected well-exposed river terrace sections of the Zhenjiang River in the upper reaches of the Beijiang River as the research object and used ESR dating to analyze the ages and formation mechanisms of the terraces of the Zhenjiang River system.The experimental data show that the Ti-Li core dose-response curve of quartz in the sediment samples of the Zhenjiang River terraces fits well with the ESR signal strength,indicating that the terrace samples are stable and meet the requirements of ESR dating.Two age data were obtained from the bottom and the top of the ZJ-P1 profile,with ages of 654±79 ka and 231±29 ka respectively;three age data(576±38 ka,523±55 ka and 256±26 ka)were obtained from the bottom to the top of the ZJ-P2 profile,and three age data(392±56 ka,132±15 ka and 41±6 ka)were obtained from the bottom to the top of the ZJ-P3 profile,being respectively.These results reflect the continuous sedimentation of the strata.Through the comparative analysis with the existing thermoluminescence age data of the Zhenjiang River and adjacent basins,it is determined that there are two distinct river terraces on the left bank of the Zhenjiang River in the upper reaches of the Beijiang River,and the final formation times of T2 and T1 are approximately 231±29 and 41±6 ka,respectively.Similarly,the ages of the river terraces in the main basins of northern Guangdong obtained by different dating methods were similar,indicating that the rivers in northern Guangdong were generally incised during the Middle and Late Middle Pleistocene and that the main rivers in northern Guangdong have synchronous evolution characteristics.On the basis of sedimentary chara

关 键 词：浈江 河流阶地 ESR测年 构造活动 北江上游 

分 类 号：P931.1[天文地球—自然地理学]