A mesa is an isolated, flat-topped elevation, ridge or hill, which is bounded from all sides by steep escarpments and stands distinctly above a surrounding plain. Mesas characteristically consist of flat-lying soft sedimentary rocks capped by a more resistant layer or layers of harder rock, e.g. shales overlain by sandstones. The resistant layer acts as a caprock that forms the flat summit of a mesa. The caprock can consist of either sedimentary rocks such as sandstone and limestone; dissected lava flows; or a deeply eroded duricrust. Unlike plateau, whose usage does not imply horizontal layers of bedrock, e.g. Tibetan Plateau, the term mesa applies exclusively to the landforms built of flat-lying strata. Instead, flat-topped plateaus are specifically known as tablelands.
Qinghe County, which belongs to the Altay region of Xinjiang, is located in the northeast of Xinjiang Uygur Autonomous region, Fuyun County to the west, Qitai County to the south, Mongolia to the east and north, and the boundary line is 280 km long. The longest is 258km from north to south and 110km from east to west, with a total area of 15579.5 square kilometers (2013). There are 16 ethnic groups in Qinghe County, including Kazak, Han, Mongolian, Hui, Uygur and so on. Among them, Kazak accounted for 76.46%, Han nationality accounted for 18.55%, and other ethnic minorities accounted for 4.99%. Qinghe, Mongolian "Qinggli", means "beautiful and clear river". Qinghe County has a continental north temperate arid climate, with high mountains and cold mountains, no obvious changes in the four seasons, dry air, long and cold winters, strong winds and cool summers. Qinghe County 2