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.
Hejing County belongs to Bayingol Mongolia Autonomous Prefecture of Xinjiang. Located in central Xinjiang, northwest of Bayingoleng Mongolia Autonomous Prefecture, with beautiful mountains and rivers, Qifeng stacked on top of each other and pleasant climate, it is a populous county of Bayingol Mongolia Autonomous Prefecture. Hetong County was established in 1939 and changed to Hejing County in August of the same year. In 1965, under the care of Premier Zhou Enlai, Hejing County was changed to Hejing County. Hejing has a long history and culture. From 3000 years ago, ancient humans lived and propagated from the Western Zhou Dynasty to the Spring and Autumn period. In 1771, the Mongolian Turhute completed the last national migration in human history-to settle down and settle down from the Volga River Valley in Russia, and the culture of returning to the east has been inherited and developed by the Mongolian people from generation to generation. Hejing County is also an important place for the spread of the Mongolian "Jianger" epic.