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.
Danba County, located in the east of Ganzi Tibetan Autonomous Prefecture, is the east gate of Ganzi Prefecture, bordered by Xiaojin County, Aba Prefecture in the east, Kangding City, the state capital in the south and southeast, Daofu County in the west, and Jinchuan County in Aba Prefecture in the north and northeast. Danba County is high in the west and low in the east, with an elevation of 1700rel 5521 meters. The county seat is located in Zhanggu Town on the banks of the Dadu River, 1800 meters above sea level, 137km away from Kangding, the prefecture, and 368km away from Chengdu. By the end of 2011, Danba County had an area of 5649 square kilometers and had jurisdiction over 14 townships, 1 town and 2 streets. at the end of 2011, the total population was 60279, with a natural population growth rate of 2.05 ‰. In 2011, Danba County achieved a GDP of 852 million yuan, an increase of 15.8% over 2010. Among them, the primary industry realized an increase.