Stratigraphic data pinpoint prehistoric Chinese flood

BBC : According to legend, some four millennia ago China’s Emperor Yu tamed the so-called Great Flood on the Yellow River. After more than a decade of work to build canals and drain the water out to sea, Yu founded the Xia dynasty, which according to Chinese history was the first one. Until now the exact dates of the flood and the start of the Xia dynasty were unknown. By studying sediments washed about 25 km downriver to an abandoned prehistoric site called Lajia, Wu Qinglong of Nanjing Normal University and colleagues have managed to trace the legendary sequence of events. Lajia’s cave dwellings and cultural artifacts had been buried the year before the flood by a major earthquake, which the researchers say could have also caused a landslide farther upstream that dammed up the Yellow River. The bursting of that dam some six to nine months later created the cataclysmic flooding event. Because of Lajia, known as the Pompeii of China, the researchers have been able to determine that the flood occurred around 1922 BC, and hence that the Xia dynasty was founded around 1900 BC, which is 200–300 years later than had been previously thought.