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.
Tujia Autonomous County along the River, Tongren City, Guizhou Province, is located in the northeast corner of Guizhou Province, the north of Tongren Prefecture and the lower reaches of the Wujiang River. located in the northeast edge of Guizhou Plateau slope, Dalou Mountains and Wuling Mountains crisscross, warm and humid climate, water and heat synchronization, light and temperature synchronization; the county area of 2468.8 square kilometers, jurisdiction over 4 streets, 17 towns, 2 townships; 2018 registered population of 690800. Along the river Tujia culture, red culture, Wujiang culture reflect. The Wujiang River flows 132 kilometers along the river and is known as the "Wujiang hundred Li Gallery". It is a national scenic spot and water conservancy scenic spot. The Mayang River Black Leaf Monkey Reserve is the habitat of the national first-class protected animal black leaf monkey and a treasure house of many rare animals and plants. It is the largest distribution of black leaf monkey population in the world and is a national nature reserve.