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.
Zuoshui County, which belongs to Shangluo City, Shaanxi Province, is located in the south of Shaanxi Province, at the southern foot of Qinling Mountains, near Xi'an, west of Shangluo, with a total area of 2332 square kilometers. The vegetation coverage of the county is as high as 78%, the forest coverage is up to 65%, and the content of negative oxygen ions is four times higher than that of Xi'an. It is known as & quot; Natural oxygen Bar, the city's lung & quot;, the famous mountain and town of quot;, the famous cave & quot;, and is known as & quot; Zhongnan Shouyi, landscape gallery & quot;. On September 25, 2018, he won the honorary title of "2018 e-commerce into rural comprehensive demonstration county" of the Ministry of Commerce. On September 26, 2018, he was awarded the establishment of "China Natural oxygen Bar" in 2018.