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.
Taiyuan, the capital of Shanxi Province, abbreviated as "Union ng", also known as Jinyang and Longcheng in ancient times, is an excellent tourist city in China, a famous national historical and cultural city, a national garden city, a core city in Taiyuan metropolitan area, and a political, economic, cultural, transportation and international exchange center of Shanxi Province. it is a city with a history of more than 4700 years and 2500 years. The historical capital of the city of Wuyuan. Taiyuan is surrounded by mountains on three sides, and the Fenhe River, the second largest tributary of the Yellow River, flows from north to south. It has been known as "Beautiful Taiyuan City" since ancient times. It is an important military and cultural town in northern China, a capital of Jin businessmen in the world, and one of China's energy and heavy industrial bases. The urban spirit of Taiyuan is tolerance, morality, law, integrity and excellence. Taiyuan city