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.
Linxia Hui Autonomous Prefecture (Linxia Prefecture for short) is one of the two major Hui Autonomous prefectures in China, which was established in November 1956. Linxia Hui Autonomous Prefecture is located in the southwest of central Gansu Province, the upper reaches of the Yellow River. It is bordered by Lanzhou to the north, Lintao River to the east and Dingxi City to the east, Jishi Mountain to the west and Haidong area of Qinghai Province to the west, and Taizi Mountain to the south to Gannan Tibetan Autonomous Prefecture. The total area is 8169 square kilometers. The resident population is 2.0441 million (2017). It has jurisdiction over 1 county-level city, 5 counties and 2 autonomous counties. In 2017, Linxia State achieved a GDP of 23.884 billion yuan, of which the added value of the primary industry was 3.889 billion yuan, the secondary industry was 4.318 billion yuan, and the tertiary industry was 15.677 billion yuan.