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.
Luo Ding, a county-level city under the jurisdiction of Guangdong Province, is hosted by Yunfu City. In ancient times, it was called Yuzhou, also known as Longxiang. Located in the west of Guangdong Province, south of the Xijiang River, it is the traffic hub of Xijiang Corridor. It has been regarded as a great defense and an important place in Fusui since ancient times. In the Ming Dynasty, it was also known as the "pivot of the whole Guangdong Province". It was once an important military town in the southwest of Shouling in the town of Guangdong. Luoding is one of the gateways for the southwest provinces to enter Guangdong, and it is also the window for Guangdong to radiate to the great southwest of China. Luoding is an important node city in the Pearl River-Xijiang Economic Belt. The central, northeastern and southern parts of Luoding City are basins and hills. Luoding Basin is the largest basin in Guangdong, with a unique basin climate, and the plain landforms of Luoding are mainly distributed here. Luoding is the first batch of famous historical and cultural cities in Guangdong Province. In 2012, Luo Ding was included in the pilot project of financial reform in counties directly under the control of Guangdong Province. two hundred and one