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.
Minqin County is a county under the jurisdiction of Wuwei City, Gansu Province, which is located in the northeast of Hexi Corridor and the lower reaches of Shiyang River Basin. In 17 years (1928), the name was changed to "plain and mellow, the people are industrious". Minqin County is located in Wuwei in the south, Jinchang in the west, and the left and right banners of Inner Mongolia in the northeast and northwest. It is 206km long from east to west and 156km wide from north to south, with a total area of 15800 square kilometers. By the end of 2017, Minqin County had jurisdiction over 18 towns and 248 villages, with a registered population of 273700 and a resident population of 241300. In 2016, Minqin County achieved a regional GDP of 7.775 billion yuan, an increase of 8.7%. Investment in fixed assets of the whole society reached 20.876 billion yuan, an increase of 13.01%, of which more than 15.617 billion yuan was increased.