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.
Huinong District, which belongs to Shizuishan City, Ningxia Hui Autonomous region, is located at the northernmost end of Ningxia, bordering the Yellow River in the east, Helan Mountain in the west and Wuhai City in Inner Mongolia in the north. It is the north gate of Ningxia, between longitude 106.70 °- 106.80 °east and latitude 39.20 °- 39.30 °north. As of August 2019, Huinong District has jurisdiction over 3 towns and 3 townships, with a total population of 200000 people and a total area of 1254 square kilometers. Huinong, derived from the name appointed by Emperor Yongzheng for Huinong Canal, contains the meaning of giving benefits to the people. Qin is under the jurisdiction of Beidi County. In April 2004, the Shizuishan District of Shizuishan City and Huinong County were abolished and Huinong District was established. The geomorphology of Huinong District is composed of three units: Helan Mountain hilly land, alluvial inclined plain and Yellow River alluvial plain. Huinong District belongs to the middle temperate zone.