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.
Mount Mount Emei is located near 30 °north latitude, southwest of Sichuan Province, southwest edge of Sichuan Basin, is one of China's "four famous Buddhist mountains", steep, beautiful scenery, known as "Emei World Show", the highest on the mountain, 3099 meters above sea level, more than 2700 meters higher than the Emei Plain. "Emei County Chronicles" cloud: "Yun Ning Cui, Yi Dai remote makeup, really like the head moth eyebrows, thin and long, beautiful and gorgeous, hence the name Emei Mountain." Mount Emei is located in the confluence area of a variety of natural elements, with complex floristic composition, rich biological species and a wide variety of endemic species. it has a complete subtropical vegetation system, with more than 3200 species of plants, accounting for about 10% of the total plant species in China. Mount Emei is also home to a variety of rare animals, with 2. 5% of animal species.