Nature –
The steep valley that the Mekong River follows through the southeastern Tibetan Plateau may owe its existence to profound climate disruptions millions of years ago.
The Mekong River is one of the world’s largest rivers in terms of water volume and sediment transport, but knowledge of its geological history is patchy. Junsheng Nie at Lanzhou University in Gansu, China, and his colleagues analysed the age of minerals in samples taken from the bedrock of the upper and middle Mekong. They also modelled the history of erosion by the river.
The results suggest that the river began to cut fast and deep into the Tibetan Plateau about 17 million years ago.