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.
Liaoyang County, which belongs to Liaoyang City, Liaoning Province, is one of the open counties in Liaodong Peninsula. It is located in the middle of Liaodong Peninsula, with a total area of 2511 square kilometers. It has jurisdiction over 15 townships (12 towns, 1 township and 2 nationality townships) and 199 villages with a population of 500000. Liaoyang County has a temperate continental monsoon climate, with an average annual temperature of 7.1-9.5 ℃ and an average annual precipitation of 730.6 mm. It belongs to national commercial grain base county and provincial commercial fish base county. Mineral deposits include oil, copper, iron, lead, placer gold, silica, rare earth and so on. Changchun-Dalian (Lian) railway and Shen-Da highway transit. In 2010, the GDP of Liaoyang County reached 20.52 billion yuan. The main scenic spots are Huhuogou Natural Scenic spot, Bahui Tongming Mountain Scenic spot and Xiaotun Wild Cat Cave Scenic spot.