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.
Chaoan (TeoAnn/ChaoAn), under the jurisdiction of Chaozhou City, is located in the eastern part of Guangdong Province, in the middle and lower reaches of the Hanjiang River, which runs 96 kilometers from north to south, and connects to the Shantou Special Economic Zone in the south. It is located in the "Golden Triangle" zone of Shantou, Chaozhou and Jieyang. Chaoan District has jurisdiction over 16 towns and 1 state-run forest farm, including 313000 mu of arable land and 1.1 million mu of mountainous and hilly areas, with a total area of 1065.92 square kilometers and 28 community neighborhood committees, with a total population of 1.004 million in 2013. Chaoan is a famous hometown of overseas Chinese, with 700000 Chaoan ethnic Chinese, overseas Chinese and compatriots from Hong Kong, Macao and Taiwan living overseas. Chaoan was founded in the sixth year of Xianhe in the Eastern Jin Dynasty (AD 331).