China's 'Rainbow Mountains' get their stripes from 24 million years of layered sediment
Zhangye Danxia's mountainsides show bands of red, yellow and green rock, built up as different sandstones and mineral-rich layers were laid down over some 24 million years. When the Indian and Eurasian plates collided, the once-flat layers buckled and tilted, exposing this striped cross-section at the surface. Iron oxide gives the red bands their color — the same mineral behind rust.