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.
Wensheng District, Liaoyang District, Liaoning Province, is located in the east of Liaoyang City in the central part of Liaoning Province, the middle of the Great Shenyang Economic Circle and the economic belly of Shenyang Liaoan, 42 kilometers away from Shenyang Taoxian Airport, 120 kilometers from Yingkou Port and 315 kilometers from Dalian Port. As of 2013, Wensheng District has a total area of 305sq km and a total population of 136800. As of 2013, Wensheng District has jurisdiction over 3 streets and 2 towns. In 2013, the total output value of Wensheng District was 6.3 billion yuan, the industrial added value was 1.72 billion yuan, the public budget income was 919 million yuan, the investment in fixed assets was 11.5 billion yuan, the total retail sales of consumer goods was 880 million yuan, the disposable income of urban residents was 20300 yuan, the per capita net income of farmers was 12400 yuan, and foreign trade.