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.
Dongxiang District, which belongs to Fuzhou City, Jiangxi Province, is located in the eastern part of Jiangxi Province. It is located in the transitional zone between the hills of eastern Jiangxi and the Poyang Lake Plain. Dongxiang District, known as the Gandong Portal, was founded in the seventh year of Zhengde in the Ming Dynasty (1512). In 2018, it has jurisdiction over 1 street, 9 towns, 4 townships, 3 reclamation farms, 1 forest farm and 1 provincial economic development zone. The total area of the district is 1196 square kilometers, with a total population of 452000, of which the urban population is 220000. Dongxiang District is an important settlement and breeding place of the Jiangyou people. Because most of the area is in the east of Linchuan, it is named Dongxiang. Dongxiang District is 40 kilometers away from Linchuan District of Fuzhou and 96 kilometers away from Nanchang, Shanghai-Kunming Railway, Shanghai-Kunming Expressway, Dongchang Expressway, 320 National Highway and 236 National Highway.