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.
The word Tori comes from Mongolian, which means "Mirror Spring". Because there is a prosperous spring in the city, the spring is clear and sweet, and Yuanwang is like a mirror, so it gets its name. Tuoli County is located in Tacheng area of Xinjiang Uygur Autonomous region, the northwest margin of Junggar Basin, Tacheng in the east, Yumin County in the west, Wusu County in the south, the Republic of Kazakhstan in the southwest and Emin County in the north. it is located between longitude 82 °28km east and latitude 44 °58km north, with a total area of 21300 square kilometers. Toli County is high in the middle and low in the edge. There are Dalbutt River, Urschelt River, Chalegai River, Suwur River and other rivers. It is a temperate continental semi-arid climate with cool summer and windy and snowy winter. two