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.
Luxi County, located in the west of Jiangxi Province, is the east gate of Pingxiang, a municipality under the province's jurisdiction, intersects Yuanzhou District of Yichun City in the east, Anfu County and Lianhua County in the south, Anyuan District and Xiangdong District in Pingxiang City in the west, and Shangli County in the north. It covers an area of 960 square kilometers and has jurisdiction over Luxi, Shangbu, Xuanfeng, Nankeng, Yinhe 5 towns and Changfeng, Xin Quan, Zhangjiafang and Yuannan 4 townships with a population of 300000 (2011). Luxi resides at the source of Yuanshui, and the Yuanshuitou River is called Luxi in ancient times, which is the origin of the place name of Luxi County. The territory of Luxi basin covers an area of 510 square kilometers and the river is 52.8 kilometers long. Wugong Mountain is a national AAAA scenic spot. In 2016, the GDP reached 13.874 billion yuan, an increase of 10.1%. On January 25, 2019, Luxi County was selected as the national "safe Agricultural Machinery" in 2018.