Cracking the Mystery of the Andes Mountains' Formation.

Researchers at the University of Copenhagen have developed a new method to estimate how Earth's tectonic plates changed speed over the past millions of years. Using this method, they found that the South American plate suddenly and spectacularly shifted gears and slowed on two significant occasions over the past 15 million years, which may have contributed to the widening of the Andes mountain range. The researchers' hypothesis is that the interaction between the expansion of the mountains and the lower speed of the plate was due to a phenomenon called delamination.