in south-west England. The general region of Variscan folding was south of an east–west line roughly from south Pembrokeshire to Kent. Towards the end of this period granite was formed beneath the overlying rocks of Devon and Cornwall, now exposed at Dartmoor and Bodmin Moor. By the end of the Carboniferous period the various continents of the Earth had fused to form the super-continent of Pangaea. Britain was located in the interior of Pangea where it was subject to a hot arid desert climate with frequent flash floods leaving deposits that formed beds of red sedimentary rock. Mesozoic As Pangaea drifted during the Triassic, Great Britain moved away from the equator until it was between 20° and 30° north. The remnants of the Variscan uplands in France to the south were eroded down, resulting in layers of the New Red Sandstone being deposited across central England. Pangaea began to break up at the start of the Jurassic period. Sea levels rose and Britain drifted on the Eurasian Plate to between 31° and 40° north. Much of Britain was under water again, and sedimentary rocks were deposited and can now be found underlying much of England from the Cleveland Hills of Yorkshire to the Jurassic Coast in Dorset. These include sandstones, greensands, oolitic limestone of the Cotswold Hills, corallian limestone of the Vale of White Horse and the Isle of Portland. The burial of algae and bacteria below the mud of the seafloor during this time resulted in the formation of North Sea oil and natural gas The modern continents having formed, the Cretaceous saw the formation of the Atlantic Ocean, gradually separating northern Scotland from North America. The land underwent a series of uplifts to form a fertile plain. After 20 million years or so, the seas started to flood the land again until much of Britain was again below the sea, though sea levels frequently changed. Chalk and flints were deposited over much of Great Britain, now notably exposed at the White Cliffs of Dover and the Seven Sisters, and also forming Salisbury Plain. Cenozoic Between 63 and 52 Ma, the last volcanic rocks in Great Britain were formed. The major eruptions at this time produced the Antrim Plateau, the basaltic columns of the Giant's Causeway and Lundy Island in the Bristol Channel. The Alpine Orogeny that took place in Europe about 50 Ma, was responsible for the folding