Chinese researchers say they've found evidence that a flood submerged a vast swath of the country almost 4,000 years ago, possibly offering evidence that China's legendary first dynasty did in fact exist.

The researchers say in an article in this week's edition of the journal Science that radiocarbon dating of soil samples along the Yellow River show an earthquake triggered a huge landslide that dammed the waterway in 1920 B.C.

Water that built up behind the wall of rock and earth flooded the North China Plain, which is considered the cradle of Chinese civilization.

Historical texts from about 1,000 B.C. mention a legendary ruler, Yu, who devised a system to tame a great flood, winning him acclaim leading to the establishment of the Xia dynasty.