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.
"Delinha" means "Golden World" in Mongolian. Delingha City, founded in 1988, is the capital of Haixi Mongolian-Tibetan Autonomous Prefecture of Qinghai Province. It is the center of politics, education, science and technology, and culture of the whole prefecture. It is also the center of the eastern economic zone of Hercynian. Delingha City has jurisdiction over three streets, three towns and one township with a total area of 27700 square kilometers, with an elevation of 2980 meters above sea level in the urban area. by 2012, it has a population of nearly 100000. There are 19 ethnic groups, including Mongolia, Tibet, Hui, Sala, Tu and Han, with Mongolians as the main ethnic minorities. There are 16 kinds of mineral resources and 65 mineral deposits found in Delingha City, of which the proven limestone reserves are more than 700 million tons, which is of high utilization value. Gahai Lake, 30 kilometers south of the city, is rich in natural Artemia resources. two