The CAOB stretches from the Ural Mountains to the Pacific Ocean, occupying an area of about 5.3 million square kilometers, about 11% of the Asian surface area. It is bounded on the north by the Siberian craton and on the south by the North China craton and the Tarim craton, which provides substrate for the Tarim Basin. The CAOB encompasses parts of six nations: China, Mongolia, Russia, Kazakhstan, Kyrgyzstan, and Uzbekistan. It includes mountain ranges north of Tibet, including the Tian Shan (Chinese for heavenly mountains) where a good example of Paleozoic arc accretion is exposed. The Altai Mountains of Russia, Kazakhstan, northwest China and western Mongolia also expose a complex accretionary terrane. CAOB rocks are also well exposed in Kazakhstan, the South Gobi Range of southern Mongolia, the Beishan and Inner Mongolia of northern China, the Sayan Mountains of southern Siberia just north of Mongolia, the ranges of Buryatia in southern Siberia south of Lake Baikal, and in the Far East of China and Russia.