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.
Huixian City belongs to Xinxiang City, Henan Province. Huixian City is located in the contiguous area of Henan and Jin, with Taihang in the north and the Yellow River in the south. Huixian City, with a total area of 2007 square kilometers and a population of 840000, has jurisdiction over 2 streets, 11 towns and 9 townships, with a total of 536 administrative villages. It is the first batch of pilot counties of new agricultural insurance, advanced scientific and technological progress, advanced culture and "famous green counties in China"; key counties for urbanization development, economic expansion, opening to the outside world and intellectual property pilot counties in Henan Province. the comprehensive strength of county economy ranks 28th among the top 100 counties in six provinces in central China. Huixian City is located in the northwest of Henan Province, between latitude 35 °17 "35 °50" N and longitude 113 °20 "113 °57'E. it is located at the junction of Henan and Jin provinces, Lingchuan County in the west, Linzhou City and Shanxi Province in the north.