OSL Dating of the River Terraces in Upper Jinjiang River around Fuxi, Northern Guangdong Province
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摘要: 南岭是我国重要的自然地理分界线和东亚季风环流屏障，第四纪期间粤北山地发育的多级河流阶地是研究南岭构造运动与气候变化的良好地质载体。粤北锦江扶溪段保留了5级阶地，运用光释光（OSL）技术对T2到T5级阶地的砾石层进行了测年，并从气候和构造角度分析了阶地成因。结果显示：T3形成于67 ka，对应于深海氧同位素的MIS4阶段；T2形成于51 ka，对应于MIS3b阶段；阶地沉积层堆积于冷期，气候变化影响着河流的侧蚀、堆积和下切作用交替进行，而新构造运动的构造抬升发动了足够的下切量使锦江扶溪段依次下切17 m、19 m、12 m和10 m形成T5、T4、T3和T2；南岸的河谷下切速率为0.3 mm/a，大于2倍的流域现代侵蚀速率，地貌发育符合年轻山地的抬升-下切-侵蚀模式。
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关键词:
- 河谷下切速率
Abstract: The Nanling Mountain is an important physical geographic dividing line and a barrier for the monsoonal circulation. The remarkable river terraces recorded paleoclimatology and tectonic movement information during Quartenary. There are five river terraces in upper Jinjiang river around Fuxi, Northern Guangdong Province, OSL techniques was used to date sediments from the four higher terraces(T5~T2), The evolution processes of the four terraces were analyzed on the basis of the dating results and the geomorphological and sedimentological characteristics. It was showed that T3 and T2 were formed at 67 ka and 51 ka, corresponding to the early period of marine isotope stage 4 and 3b, respectively. The sediments on the straths deposited during cold periods. The incisions began at the cold-warm transitions. Climate change influenced the alternation of fluvial lateral erosion, deposition and incision processes, but the adequate incision amount was droven by tectonic uplifting. The valley incision ratio of Jinjiang river is 0.267 mm/a, which is more about twofold of the erosion ratio. It is implied that the Nanling Mountain was response to an uplift-incision-erosion mechanism that generally occurs in a young mountain.-
Keywords:
- valley incision ratio
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期刊类型引用(3)
1. 程子烨，李岸莹，郑婉柔，张欣宇，刘展鹏，姬昊，唐晓春. 北江上游浈江段河流阶地石英ESR法测年研究. 热带地理. 2025(03): 504-513 . 
百度学术
2. 翟天成. 郎溪剖面石英粒度和沉积物粒度特征对比与意义分析. 科技和产业. 2023(01): 255-266 . 百度学术
3. 饶峥，刘晓东，刘帅，龚志军. 塔木素预选区第四纪构造活动性的光释光测年分析. 科学技术与工程. 2020(25): 10170-10176 . 百度学术
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