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.
Jinkou River District is a municipal district of Leshan City, Sichuan Province, which is located in the southwest of Sichuan Province and in the middle of Xiaoliang Mountains. Jinkou River Industrial and Agricultural District at county level was established from Ebian County in 1978 and changed to Jinkou River District of Leshan City in 1985. As of 2014, it covers an area of 598 square kilometers and has jurisdiction over 2 townships, 2 ethnic townships and 2 towns, with a registered population of 52722. Jinkou Grand Canyon is known as the Kingdom of Animals and plants and the Geological Museum. It was awarded as the National Geopark by the Ministry of Land and Resources in 2001 and one of the ten most beautiful canyons in China by China National Geographic in October 2005. Dawashan National Wetland Park is called "the most charming natural park in the world" by American natural scientist Berber. In 2014, Jinkou District realized GDP2980 million yuan.