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.
Qinghai Province, referred to as "Qing", is the provincial administrative region of the people's Republic of China and the capital of Xining. Located in the inland of northwest China, Qinghai is bounded by 31 °36 degrees north latitude, 39 °19 degrees north latitude, 89 °35 degrees east longitude, 103 °04 degrees east longitude, Gansu in the north and east, Xinjiang in the northwest, Tibet in the south and southwest, and Sichuan in the southeast. The overall topography of Qinghai Province is high in the west and low in the east, high in the north and south, low in the middle, high and steep in the west, tilting to the east, showing a ladder-shaped decline, and the eastern region is a transitional zone from the Qinghai-Tibet Plateau to the Loess Plateau, with complex topography and diverse landforms. The landforms of Qinghai Province are complex and diverse. More than 4/5 of the areas are plateaus, mountainous in the east and plateaus and basins in the west, with three landforms of the Qinghai-Tibet Plateau, inland arid basins and the Loess Plateau.