The Formation of the East-flowing Yangtze Three Gorges:Time,Evidence and Controversy
The Yangtze River is the largest river system in Asia,and its formation and evolution are of great significance for understanding the topography,climate change,biological evolution,and material cycles of East Asia.The Three Gorges lie in the central Yangtze Block,and its formation connects the drainage in the Sichuan Basin and the Jianghan Basin;therefore,it is regarded as one of the most critical events in the history of the Yangtze River.However,the debate over how and when the Three Gorges were formed has been ongoing for over a century.This study reviews the century-long debate,especially regarding the formation mechanism and age of the Three Gorges,to clarify the formation of the Yangtze Three Gorges.A comparison highlighted a conflict between the erosion time of the Three Gorges and the provenance analysis in the downstream basin,stemming from limitations in research ideas,objects,and methods.Determining the formation time of the Three Gorges necessitates a comprehensive approach that integrates gorge erosion and provenance analysis in the Jianghan Basin.Methods such as monazite fission track,cosmogenic nuclide dating,and geochemical analysis of single-grain minerals offer precise constraints on gorge erosion and aid in establishing a source-sink system between the Jianghan Basin and Sichuan Basin.Drawing on the principles of Earth system science and source-sink systems,this study proposes an analysis of tectonics,landforms,and climatic evolution to understand the evolution of large drainage systems such as the Yangtze River.In particular,a comprehensive analysis of the geochemical characteristics and exhumation histories of the Qinghai-Xizang Plateau,basin development,and geochemical characteristics of detritus minerals is required to investigate the evolutionary processes of large rivers such as the Yangtze River.
Yangzte Three GorgesDebatesDrainage evolutionFormation time
NETL
NSTL
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