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.
Puge County, which belongs to Liangshan Yi Autonomous Prefecture of Sichuan Province, is located in the east of Liangshan Yi Autonomous Prefecture, located between 27 °13 & #39;-27 °30 & #39; in north latitude and 102 °26 & #39;-102 °46 & #39; in east longitude. Butuo County, Ningnan County, Dechang County, Xichang City and Zhaojue County are bordered to the east, south, west, northwest and north respectively. Puji Town, the county seat, is 74 kilometers north from Xichang, the state capital. Located in the southwest of Sichuan Province and southeast of Liangshan Prefecture, it covers an area of 1918 square kilometers and has jurisdiction over 34 townships, 153 administrative villages and 8 neighborhood committees. Puge County, which has 21 ethnic groups, including Yi, Han and Hui, is the birthplace of the Yi Torch Festival. It is an ethnic minority county with Yi as the main body and approved by the State Council.