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.
Jiangzi County, which belongs to Xigaze City, Tibet Autonomous region, is located in the south of Tibet, the east of Xigaze City and the upper reaches of Nianchu River. Jiangzi is not only one of the famous historical and cultural cities in China, but also a new tourist town. In 2006, the total population of Jiangzi County was 67000, and the domestic residents were mainly Tibetans, accounting for 98%. Other ethnic groups include Han nationality, Hui nationality and so on. In 2008, Jiangzi County had jurisdiction over 1 town, 18 townships, 151 villages and 3 neighborhood committees. The county government is stationed in Jiangzi town. The total area is 3771 square kilometers. In 2013, the GDP of Jiangzi County was 1.316 billion yuan, an increase of 201% over 2004. On September 25, 2018, he won the honorary title of "2018 e-commerce into rural comprehensive demonstration county" of the Ministry of Commerce.