Colliding continents and cracks in the Earth’s crust make for some remarkable scenery in western China.
Just south of the Tien Shan mountains, in northwestern Xinjiang province, a remarkable series of ridges dominate the landscape. The highest hills rise up to 1,200 meters (3,900 feet) above the adjacent basins, and they are decorated with distinctive red, green, and cream-colored sedimentary rock layers. The colors reflect rocks that formed at different times and in different environments. When land masses collide, the pressure can create what geologists call “fold and thrust belts.” Slabs of sedimentary rock that were laid down horizontally can be squeezed into wavy anticlines and synclines.
The ridge is noticeably offset by a strike-slip or “tear” fault in the image showing the Piqiang Fault, a northwest trending strike-slip fault that runs roughly perpendicular to the thrust faults for more than 70 kilometers (40 miles). The colored sedimentary rock layers are offset by about 3 kilometers (2 miles) in this area.