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.
Xiao County, a county under the jurisdiction of Suzhou City, Anhui Province, is located at the north gate of Anhui Province, at the junction of Jiangsu, Shandong, Henan and Anhui provinces, at the center of Huaihai Economic Zone, Xuzhou metropolitan area and the southeast edge of North China Plain. Known as the "thoroughfare of the four provinces", it is the node of the national implementation of overall strategies such as "Belt and Road Initiative" and "Central Plains Economic Zone" and the implementation of regional strategies such as "eastward development" and "revitalization of northern Anhui" in Anhui Province. It is bordered by Xuzhou in the east, Huaibei in the south, Lianfeng County in the north, Yongcheng and Dangshan in the northwest, Heze in Shandong Province, and Hanqiao District in Suzhou in the southeast, covering an area of 1885.3 square kilometers. Xiao County, known as Xiao Guo in ancient times, has a history of more than 6000 years of civilization and more than 3100 years of history of building the city. It is the birthplace of Han culture and filial piety culture. There are Jinzhai cultural sites, Huajia Temple sites and other Neolithic sites.