• Mesa
  • Qilian County

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.

Qilian County, which belongs to Haibei Tibetan Autonomous Prefecture of Qinghai Province, gets its name because it is located in the hinterland of the middle part of Qilian Mountains. It is adjacent to the Gansu Hexi Corridor, the primary passage of the ancient Silk Road, to the north, so it is known as the "north gate" of Qinghai. Qilian County covers an area of 14000 square kilometers, accounting for 41% of the total land area of the whole state. It has jurisdiction over 45 administrative villages in 4 townships and 3 towns, with a total population of 50,000 as of 2013, with 15 ethnic groups, including Han, Tibetan, Mongolian and Hui, with ethnic minorities accounting for 79.2% of the population. The average elevation in the territory is 3169 meters, the county seat is 2787 meters above sea level, the annual average temperature is 1 ℃, and the annual precipitation is about 420mm, which is a typical plateau continental climate. Qilian is an important resource-rich area in Qinghai Province. A variety of mineral resources, known as "China's Ural", is a key county in the development of resources in the province. "Qilian" system
Travel Notes In Qilian County