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.
Hot Spring County, which belongs to Bortala Autonomous Prefecture of Xinjiang Uygur Autonomous region, is located in the northwest of Xinjiang, the upper reaches of Bortala River, the northern foot of the western part of Tianshan and the western margin of Junggar Basin. It is bordered by Bole to the east, Zhentao Mountain to the south and Huocheng County to the south, and Kazakhstan to the west and north to Kongguoro Obo Mountain and the western part of Alatao Mountain respectively. The county is 139.4 km long from east to west and 64.8km wide from north to south. The area of arable land is 490000 mu, the area of grassland is 6.19 million mu and the forest is 551000 mu. The climate here is warm in winter and cool in summer, with an annual average temperature of 3.6 degrees Celsius. The total annual diameter of surface water is 800 million cubic meters, the groundwater reserves are 310 million cubic meters, and the theoretical water energy reserves are 279000 kilowatts. The population in 2012 was 74600. 2018