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.
Taiqian County, under the jurisdiction of Puyang City, Henan Province, is located in the northeast of Henan Province, at the junction of Henan and Shandong provinces, with a total area of 454 square kilometers. It now has jurisdiction over 6 towns, 3 townships, 372 administrative villages, 376400 people and 270000 mu of arable land. Taiqian County is an old revolutionary base, a national key county for poverty alleviation and development, and an important part of the Pufantai comprehensive experimental area for poverty alleviation and development in the Central Plains Economic Zone. In 2012, it was named "the hometown of China's down". The geographical location is special. Taiqian County is bordered by or across the river from six counties in Shandong Province (Shenxian, Yanggu, Dongping, Liangshan, Yuncheng and Juancheng). It is 40.4 km long from east to west and 15.5 km wide from north to south. It is the northeast gateway of Henan Province. Connected to the Central Plains Economic Zone in the west and the Bohai Economic Circle in the east, Henan Province is away from Tianjin Port, Qingdao Port and Lianyun.