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.
Hengshui, a prefecture-level city of Hebei Province, is located in the southeast of Hebei Province, between longitude 115o10mm UV 116o 34km east and latitude 37 °03qq. it is adjacent to Cangzhou City and Dezhou City, Shandong Province in the east, Shijiazhuang City in the west, Xingtai City in the south, Baoding City and Cangzhou City in the north, with a total area of 8815 square kilometers. Hengshui City is located in Hebei alluvial plain, the terrain slowly tilts from southwest to northeast, 12 meters ~ 30 meters above sea level. It belongs to the continental monsoon climate zone, which is warm and semi-arid. It is an important processing and supply base for agricultural products in Beijing and Tianjin. Hengshui belongs to the "1th 93rd" plan of the Bohai Rim Economic Circle and the Capital Economic Circle. It is a member city of the Joint Conference of Mayors of Regional Cooperation around the Bohai Sea. It is called the "Golden Cross" by Fei Xiaotong.