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.
Batang County is located in the west of Ganzi Prefecture and belongs to Ganzi Tibetan Autonomous Prefecture. Latitude 28 °46-30 °38'N, longitude 98 °58 mi 99 °45 'east. It is about 260 kilometers from north to south and 45 kilometers from east to west. It covers an area of 8186 square kilometers (2013). It is bounded by Township City and Litang County to the east, Delong County to the south, Mangkang County, Yanjing County, Gongjue County in Tibet and Deqin County in Yunnan Province to the west, and Baiyu County to the north. In 2006, the income of urban and rural people in Batang County was 8000 yuan. The per capita net income of farmers and herdsmen is 1396 yuan. In 2006, the local financial revenue of Batang County reached 9.71 million yuan. The balance of deposits in financial institutions totaled 417.86 million yuan, an increase of 173.11 percent. The balance of various loans totaled 109.83 million yuan, an increase of 41.9%. twenty