Geophysicists offer explanation for Andes formation (Mar 15)
http://physicsweb.org/article/news/11/3/10

Geophysicists in Australia think they may have solved the long-standing
enigma of how the Andes mountain range was formed. Using computer
simulations that model the fluid dynamics and mechanics of tectonic
plates, they reckon that the Andes were formed when one tectonic plate
in the Pacific slides or "subducts" under a neighbouring plate beneath
South America in an uneven fashion. The existence of the Andes has
baffled researchers because most other large mountain ranges, such as
the Himalayas, have emerged where two plates collide head-on (Nature 446
308).