By Sid Perkins
Grains of silt embedded in thick sediments in China may settle a debate about the age of a nearby desert, scientists say.
The Taklimakan Desert of northwestern China covers nearly 337,000 square kilometers, about 85 percent of which consists of shifting sand dunes that support little or no vegetation. Previous estimates of the desert’s age range from about 1 million to 3.5 million years, says Jimin Sun, a geologist at the Chinese Academy of Sciences in Beijing. The estimates vary widely because scientists hadn’t found sediment layers that could be accurately dated, he notes.