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.
Zhaohua District is a municipal district under the jurisdiction of Guangyuan City, Sichuan Province. it is located in the north of Sichuan Basin and in the middle of Guangyuan City, with a total area of 1434.71 square kilometers and 11 towns, 17 townships and 1 street. By the end of 2016, there were 76150 households and 233008 people. During the warring States period, it was the territory of Shu, and Qin destroyed the State of Wei after it was located in Qimeng County. In the five years of Kaibao of the Northern Song Dynasty (AD 972), Qin, the emperor of the Song Dynasty, was changed to Zhaohua County with the meaning of "showing the grace of the emperor and transforming the people". The name Zhaohua got its name from this. Yuanba District was bought in 1989 and renamed Zhaohua District in March 2013. In 2016, the gross domestic product of Zhaohua District reached 4.49605 billion yuan, and the per capita disposable income of residents was 14531 yuan, of which the per capita disposable income of urban residents was 25580 yuan.