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.
Linzhou County, which belongs to Lhasa City, Tibet, is located in the Penbo River Basin in central Tibet and the upper reaches of the Lhasa River. The county is 65 kilometers away from Lhasa. In 2013, Linzhou County had a total population of 70,000, including Han, Miao, Hui and other ethnic minorities. The main mineral resources in Linzhou County are lead, zinc, barite, coal, gypsum and so on. Linzhou County has Lhasa River, Tanggula Mountain and other tourist attractions. In Linzhou County, there are pots, card pads, brazier, flowerpots, oil pots, wine kettles and so on. In 2013, the GDP of Linzhou County reached 839 million yuan, with an average annual growth rate of 15.5%. The fiscal revenue reached 26.9 million yuan, exceeding 10 million yuan in a row, 6.73 times that of 2012, with an average annual growth rate of 46.4%. Investment in social fixed assets reached 450 million yuan, an increase of 4.63 times over 2012