When was the Yellow River Formed?

Rivers are one of the important geological forces that shape the land surface. Understanding the development history of big rivers is helpful for us to improve the efficiency of using big rivers, so as to promote the development of human society. The Yellow River is the mother river of China. Researchers have conducted extensive research on it in the past hundred years, however, there is no clear answer to the question of when it was formed and the specific evolution process. In view of this, on the basis of our previous research results, this paper extensively collected and collated the data published by domestic and foreign researchers to reconstruct the evolution process of the Yellow River during the Cenozoic era. The results show that: The proto-Yellow River, which flowed along the plateau boundary, developed in the northeastern part of the Tibetan Plateau in the Paleogene. In the Miocene, the eastern Qilian Mountains developed parallel rivers flowing into the depocenter of Longxi basin, and large rivers with different flow directions appeared in the north and south parts of the Jinshan Gorge. The Yellow River had not yet appeared in the Bohai Bay Basin and the South Yellow Sea Basin during the Miocene. The Yellow River entered the stage of segmental evolution in this time. In Pliocene, the Yellow River had already connected Xining basin, Lanzhou basin, Yinchuan Basin and Hetao basin, while Guide basin and Gonghe basin still had internal flow system. At this time, the upper reaches of the Yellow River had not penetrated into the deeper hinterland of the northeast section of the Tibetan Plateau. The Jinshan Gorge still has the Yellow River flowing south into Weihe basin and north into Hetao basin, respectively. The Sanmenxia basin is still occupied by large ancient lakes, and the Yellow River material does not appear in the Bohai Bay basin and the South Yellow Sea basin. Pliocene is an important turning stage for the Yellow River to complete its final connection. In the early Pleistocene, the Yellow River connected the upper, middle and lower reaches, similar to the current connection between the Tibetan Plateau, the Loess Plateau and the North China Plain. The Yellow River flowing east to the sea was formed at this time. In the Late Pleistocene, under the influence of climate change, all sections of the Yellow River entered a new stage of evolution, and some of the river channels were occupied by ancient lakes again. In the period of abundant precipitation, the river channels were connected again. The combination of structure and climate has an important influence on the development of the Yellow River. The maintenance of the high landform in the hinterland of river system is one of the preconditions for the development of river system. In particular, the uplift of the eastern Qilian Mountains in Miocene and Pliocene shaped the basic form of the Yellow River on the interior of the Tibetan Plateau. The uplifting of the Helan, Yin and Qinling Mountains around the Ordos Plateau have shaped the deep graben of Yinchuan, Hetao and Weihe River, which has become an important factor limiting the full transmission of the Yellow River in dry weather periods. The Quaternary is a period of frequent climate change in East Asia, and the final connection of the Yellow River is closely related to the process of climate change. Conversely, the study on the formation and evolution of the Yellow River can effectively reveal the tectonic evolution and climate change of the Cenozoic in North China.