Cornwall Cornwall Cornwall (; ) is a county in South West England in the United Kingdom. The county is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar which forms most of the border between them. Cornwall forms the westernmost part of the South West Peninsula of the island of Great Britain. The furthest southwestern point of the island is Land's End; the southernmost point is Lizard Point. Cornwall has a population of and covers an area of . The
Lower Dicker affinity) and are considered to reflect the effects of tectonic uplift in nearby areas feeding sediment into the area. The mineralogy of these sandstones reflects their provenance and they are therefore of great importance for understanding the changes which took place in the palaeogeography of the Weald. Upper Dicker provides the most southerly exposure of any of the Weald Clay sand members in Britain. It is also important for marking the furthest known extension eastwards of Cornubian (what is today Devon and Cornwall) debris (pieces of rock incorporated into the sandstones and clays), indicating the presence of a river system