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.
Nanxun District, which belongs to Huzhou City, Zhejiang Province, is an emerging city in Shanghai Metropolitan Circle and Hangzhou Metropolitan Circle. It is located in the north of Hangjiahu Plain, the center of Shanghai, Suzhou and Hangzhou in the Yangtze River Delta, Hangzhou, the provincial capital in the south, Taihu Lake in the north, Suzhou and Shanghai in the east, and Nanjing in the west. Nanxun is an area under the jurisdiction of Huzhou City, which was established in January 2003, formerly known as Dongqian County, which was founded in the Western Jin Dynasty. As of 2013, Nanxun District has jurisdiction over nine towns, one provincial economic development zone and one international tourist resort, covering an area of 702.17 square kilometers. On January 25, 2019, he was selected as the national "Ping an Agricultural Machinery" demonstration county in 2018. In July 2019, it was listed as a national intellectual property rights strong county project demonstration county (district). In October 2019, it was named as the top 100 green development area in 2019. Enter