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 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. The red layers near the top of the sequence are Devonian sandstones formed by ancient rivers. The green layers are Silurian sandstones formed in a moderately-deep ocean. The cream-colored layers are Cambrian-Ordovician limestone formed in a shallow ocean. The Operational Land Imager (OLI) on the Landsat 8 satellite captured this view of the Keping Shan thrust belt on July 30, 2013. The ridges run northeast to southwest and stretch from Kashgar to Aksu, China. The foothills of the Tien Shan mountains are visible near the top of the image. Thrust faults formed the series of ridges seen south of these foothills. Another type of fault is visible as well. In two areas, the ridges are noticeably offset by a strike-slip or tear fault. In this image, Piqiang Fault, a northwest trending strike-slip fault, runs roughly perpendicular to the thrust faults for more than 40 miles.