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.
Dushanzi District, Karamay City, Xinjiang is located at the northern foot of Tianshan Mountain, southwest edge of Junggar Basin, Nanping Tianshan Mountain, adjacent to Kuitun City by National Highway 312 in the north, Wusu City in the west and Shawan County in the east. It is 250 kilometers away from Urumqi, the capital of the autonomous region, and 150 kilometers away from the central city of Karamay. The place name of Dushanzi comes from Dushan in the district. Dushan is in the shape of "one" from east to west, which gets its name because it is not connected with other mountains and independent of the Gobi. In Uygur and Kazakh languages, Dushanzi is called "Mayitak" and "Mayi set", meaning "Youshan". In 2015, Dushanzi District has a total area of 448 square kilometers and a built-up area of 26 square kilometers with a total population of more than 90, 000, including more than 57000 registered residents, including Han, Uygur, Kazakh, Mongolian, Xibo,