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.
Macheng, directly under the jurisdiction of Hubei Province, is hosted by Huanggang City. It is located in the northeast of Hubei Province, the north of Huanggang City, the southern foot of the Dabie Mountains on the north bank of the middle reaches of the Yangtze River, and the junction of Hubei, Henan and Anhui provinces. Wuhan City Circle has a total area of 3747 square kilometers and a population of 1.26 million. By 2018, Macheng has jurisdiction over 3 streets, 15 towns and 1 township municipal government in Longchi Street. Macheng has a long history, named after Magu, the "longevity fairy"; Sui Kai Huang 18 years (AD 598), set up Macheng County, 1986, withdraw the county to set up the city. The whole landscape of Macheng is horseshoe-shaped, with high mountains in the east and northeast and low in the southwest, tilting from east to southwest; the territory belongs to subtropical continental humid monsoon climate and Jianghuai microclimate zone. Four distinct seasons, plenty of light and heat