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.
Lintan County belongs to Gannan Tibetan Autonomous Prefecture, which is called Taozhou in ancient times. It is located in the south of Gansu Province and in the east of Gannan Tibetan Autonomous Prefecture. It is located on the northeast edge of the Qinghai-Tibet Plateau. It is the combination of agricultural and pastoral areas, Tibetan and Han areas. Lintan County, with a total area of 1557.68 square kilometers, is an alpine and hilly area, with an average elevation of 2825 meters, with an elevation of 2209, 3926 meters. The county has jurisdiction over 16 townships (towns) and 141 administrative villages, with a total population of 150000 (2011). There are 10 ethnic groups, including Han, Hui, Tibetan and Mongolian, with ethnic minorities accounting for 26% of the total population. Lintan County has National AAAA Scenic spot Yeliguan, Huangjianzi National Forest Park, Lianhuashan National Nature Reserve and Provincial Geopark. Total output value of Lintan County in 2011 (