“United Kingdom” Geography Quiz

Geology of the United Kingdom

• The UK's geology is varied and complex, shaped by a combination of tectonic forces and climate change
• The oldest rocks in the British Isles are the Lewisian gneisses, metamorphic rocks found in the far north-west of Scotland and in the Hebrides, dating back to at least 2,700 million years ago

Precambrian Era

• Around 1,000 million years ago, the North West Highlands and Grampian Highlands in Scotland were formed through the folding of sedimentary rocks
• At the same time, England and Wales were largely submerged under a shallow sea studded with volcanic islands

Palaeozoic Era

• Around 520 million years ago, what is now Great Britain was split between two continents: Laurentia and Gondwana
• England and Wales were largely submerged under a shallow sea, with volcanic islands that later formed part of the landscape
• The remains of these volcanoes can still be seen in central England
• Avalonia broke away from Gondwana and drifted towards Laurentia, eventually colliding and forming a mountain range in north and west Britain

Caledonian Orogeny

• The Caledonian Orogeny occurred around 425-400 million years ago, resulting from the collision of continents and the formation of mountains in north and west Britain
• The resulting erosion deposited numerous sedimentary rock layers in lowlands and seas
• The Old Red Sandstone and contemporary volcanics and marine sediments found in Devon originated from these processes

Carboniferous Period

• Around 360 million years ago, Great Britain was lying at the equator, covered by warm shallow waters of the Rheic Ocean
• During this time, the Carboniferous Limestone was deposited, as found in the Mendip Hills and the Peak District of Derbyshire
• River deltas formed and the sediments deposited were colonized by swamps and rainforests
• The Coal Measures were formed during this period, which are the source of the majority of Britain's extensive coal reserves

Variscan Orogeny

• Around 280 million years ago, the Variscan orogeny mountain-building period occurred, resulting in deformation in south-west England
• Granite was formed beneath the overlying rocks of Devon and Cornwall, now exposed at Dartmoor and Bodmin Moor

Mesozoic Era

• During the Triassic period, Great Britain moved away from the equator and became a hot, arid desert climate with frequent flash floods
• The remnants of the Variscan uplands in France to the south were eroded, 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, 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

Cenozoic Era

• Between 63 and 52 million years ago, the last volcanic rocks in Great Britain were formed
• The seas started to flood the land again, and chalk and flints were deposited over much of Great Britain