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.
Xiyang County, alias Leping, belongs to Jinzhong City, Shanxi Province, located in the east of Jinzhong City, the western foot of Taihang Mountain, with a total area of 1954 square kilometers. As of 2018, the total population was 238000. Under the jurisdiction of 5 towns, 7 townships and 1 management committee, the county government is located at No. 10 Yuxin Lane, Leping Town. In the early years of the great cause of the Sui Dynasty (605), it was changed to Leping County. In 34 (1945) September, Xidong and Xixi merged to form Xiyang County. On September 24, 1999, the State Council approved the abolition of Jinzhong area and the establishment of Jinzhong City at the prefecture level. Shitai Railway, Taijiu Expressway, Yangzuo Expressway, Yangzhou Railway, National Highway 207 and Provincial Highway 317 run through the whole territory of Xiyang. In 2018, the GDP of Xiyang County was 8.46 billion yuan, an increase of 7%. The added value of industries above scale