古地理学报2024，Vol.26Issue(1)：208-229,22.DOI:10.7605/gdlxb.2023.06.071
长江三峡贯通过程的动态古地貌重建
Dynamic paleo-landscape reconstruction revealing incision process of Three Gorges of Yangtze River
摘要
Abstract
The Yangtze River,Asia's largest river,represents a significant geomorphological event within the integrated tectonics-climate-landscape system of the Cenozoic era in China.A key point of de-bate in understanding its formation is the timing of the incision of the Three Gorges,situated between the Sichuan and Jianghan basins,which marked the emergence of the modern Yangtze River.Despite abun-dant geological data,there remains controversy over when exactly the Three Gorges were formed or in-cised.Previous studies usually focused on isolated factor affecting the river development,e.g.,tectonic movements,sedimentology,paleo-climate and sea level changes,to resolve this key issue.In contrast,our study utilizes Badlands,a software for simulating paleo-landscape,to integrate these key factors quantitatively.Focusing on the area east of the"first bend"(Shigu Town in Yunnan Province)of the Yangtze River,we used Badlands to reconstruct the paleo-landscape and river system evolution process since the Late Cretaceous(80 Ma).We further validated our model results using seismic data from the Si-chuan and Jianghan basins.The results revealed that the river flow direction in the Sichuan Basin was re-versed to drain northwards due to the Late Eocene-Oligocene uplift in the eastern Tibet and the south-western Upper Yangtze Plate.The Jianghan Basin maintained a consistently low base level during the early Paleogene,influenced by the continental rifting environment in eastern China.The reversal of the drainage direction in the Sichuan Basin and the long-lasting low base level in the Jianghan Basin eventually made the Three Gorges to be incised at the latest Oligocene.We propose that the reversal and subsequent capture of the Upper Yangtze River's flow by the middle Yangtze River played a crucial role in the incision mecha-nism of the Three Gorges.关键词
古地貌重建/长江三峡贯通/晚渐新世/四川盆地/江汉盆地/水系反转Key words
paleo-landscape reconstruction/Three Gorges incision/Late Oligocene/Sichuan Ba-sin/Jianghan Basin/drainage inversion分类
天文与地球科学引用本文复制引用
田子晗,索艳慧,李三忠,丁雪松,韩续,宋双双,付新建..长江三峡贯通过程的动态古地貌重建[J].古地理学报,2024,26(1):208-229,22.基金项目
青岛海洋科学与技术国家实验室山东省专项经费(编号:2022QNLM05032)、国家自然科学基金项目(编号:42121005,91958214)、山东省自然科学基金项目(编号:ZR2021YQ25)和中央高校基本科研业务费专项(编号:202172003)联合资助.Co-funded by the Marine S & T Fund of Shandong Province for National Laboratory for Marine Science and Technology(Qingdao)(No.2022QNLM05032),the National Natural Science Foundation of China(Nos.42121005,91958214),the Natural Science Foundation of Shandong Province of China(No.ZR2021YQ25)and the Fundamental Research Funds for the Central Universities(No.202172003) （编号:2022QNLM05032）
