Geological history of England

This article provides a broad geological history for England. It is divided into geological Periods. For each Period the geography, environment and climate are described, key geological events are outlined and the typical rocks and landscapes we see today are highlighted.

Period name | Age
Quaternary | Present – 1.8 million years ago
Neogene | 1.8 – 24 million years ago
Palaeogene | 24 – 65 million years ago
Cretaceous | 65 – 142 million years ago
Jurassic | 142 – 205 million years ago
Triassic | 205 – 248 million years ago
Permian | 248 – 290 million years ago
Carboniferous | 290 – 354 million years ago
Devonian | 354 – 417 million years ago
Silurian | 417 – 443 million years ago
Ordovician | 443 – 495 million years ago
Cambrian | 495 – 545 million years ago
Precambrian | Prior to 545 million years ago

Quaternary Period

Age: Present – 1.8 million years ago

Geography, environment and climate

The Quaternary, also known as the Ice Age, comprises a series of periods of widespread glaciation separated by more temperate climatic conditions (interglacials). There have been at least seven glacial-interglacial cycles, although only the last three or four of these have resulted in ice sheets spreading across Britain. During the ice ages, glaciers developed in upland areas such as the Lake District, carving out U-shaped valleys and at times large ice sheets advanced over lowland Britain. Areas beyond the ice sheet margins were much like the Arctic tundra. The climate of the interglacials was temperate, similar to that of today and at times warmer.

Key Events

At the time of glacial maxima, sea-level was up to 120m lower and the English Channel and most of the North Sea were lands. As the ice melted sea-level rose, which at times would have been higher than it was today resulting in the formation of raised beaches around the coast.

During the warmer interglacials, the fauna resembled that of modern-day Africa with hippopotamus, elephant, hyena and lion being present in southern Britain. During the cold glacial episodes woolly mammoths, woolly rhinoceros and reindeer roamed over much of southern England.

Rock types and occurrence in England

Vast amounts of sediment were eroded and transported by the actions of ice, water and wind during the Quaternary. Typically, material deposited from beneath glaciers and ice sheets, known as till or boulder clay, mantles the surface rocks of much of northern England and the Midlands. Following the melting of ice sheets and glaciers, large volumes of sand and gravel were transported along river valleys or deposited along the margins of the ice bodies. In some areas large ice-dammed lakes formed in which clays and sands were laid down. In southern England, away from the main ice sheets, the processes of freezing and thawing led to the formation of dry valleys on the Chalk and limestone outcrops and the deposition of weathered material in valleys.

Neogene Period

Age: 1.8 – 24 million years ago

Geography, environment and climate

Most of Britain was land during this period although shallow seas and tidal coastal plains occupied parts of eastern and southern England. Climatic conditions were cooler than those of the Palaeogene as Britain continued its northward migration to its present-day latitude. The end of this period marked the onset of glacial conditions in the northern hemisphere.

Key Events

Southern England was affected by the collision of Africa with Europe which led to the building of the Alps. This produced a series of broad folds in the Chalk and overlying sediments, including the uplifted ridges along the flanks of these folds that now form the South Downs, the North Downs and the Chilterns.

Rock types and occurrence in England

Rocks of this age are confined to eastern England where shallow marine sands and clays belonging to the Crags form the solid geology to east Suffolk and east Norfolk. Limited evidence of terrestrial conditions is provided by small deposits of sands infilling depressions in the Carboniferous Limestone of Derbyshire.

Paleogene Period

Age: 24 – 65 million years ago

Geography, environment and climate

Southern and south-east England were occupied by a shallow sea with estuarine conditions prevailing at times. Terrestrial habitats became more prevalent as time progressed and most of the British Isles was land over this period of time. The nature of the land surface is poorly known but appears to have been subdued with wide plains and large extensive river systems.

The regional climate was warm and similar to that of the sub-tropics of Asia and was characterised by high levels of precipitation and environmental stability. Britain continued its northward migration into cooler latitudes.

Key Events

The Palaeogene period is marked by the opening of the North Atlantic, which over the next 50 million years or so had a profound effect on the climatic evolution of the British Isles.

Mammals dominated the land fauna following the extinction of the dinosaurs at the end of the Cretaceous.

Away from the shallow sea occurring over southern England, the land supported dense tropical to sub-tropical and warm-temperate forests, with mangrove swamps on the coasts. The overall character of the recorded fossil flora shows affinities with the present-day Malay Peninsula.

Rock types and occurrence in England

Rocks from this time are represented by the marine clays and sands that occupy the Hampshire Basin and the London Basin. These comprise a series of sands, clays and limestones that outcrop in East Dorset, Hampshire, the Isle of Wight, Berkshire, the wider Thames Valley, Essex and North Kent. These sediments record fluctuating environmental conditions from terrestrial/fluvial through to fully marine. Formations such as the London Clay, the Barton Clay and the Solent Group are very fossiliferous and contain the remains of many groups of animals and plants that are familiar today.

Cretaceous Period

Age: 65 – 142 million years ago

Geography, environment and climate

The Cretaceous in England can be divided into two parts. In the Early Cretaceous, much of Britain was above sea-level and in southern England, the earliest Cretaceous strata were deposited under continental lagoonal, lake, and fluvial conditions. Further north, the Lower Cretaceous is entirely marine in character. However, only a few millions of years into the Cretaceous, there was a global rise in sea-level and the sea rose over most of Britain, thereby flooding most of the early Cretaceous landmass. Marine conditions then prevailed until the Palaeogene.

Warm, tropical conditions prevailed throughout the Cretaceous.

Key Events

Reptiles were the main large predators and herbivores of the Cretaceous world and dominated both terrestrial and marine habitats. Many species of dinosaurs occurred and their remains are commonly found in the Lower Cretaceous river deposits of the Weald Group.

The Chalk is mostly made of the remains of microscopic plankton called coccoliths but the fossils of sea-urchins (echinoderms), belemnites, ammonites and bivalves are also found in the Chalk. Large marine reptiles such as ichthyosaurs, crocodiles and mosasaurs were the top marine predators.

The end of the Cretaceous was marked by a global catastrophic event, probably a large meteorite impact, which contributed to the extinction of the dinosaurs, marine reptiles, ammonites and many species of plants.

Rock types and occurrence in England

During the Lower Cretaceous thick deposits of fluvial and lacustrine muds and sands accumulated in southern England (the Wealden Group), which now outcrop in Sussex, the Isle of Wight and east Dorset. These are succeeded by marine sands and clays (the Greensand and Gault Clay) associated with the rise in sea-level and establishment of marine conditions over much of Britain. Deepening of the sea in the later Cretaceous marked the onset of the deposition of large amounts of calcareous ooze on the sea-floor. These deposits later formed the Chalk, which originally covered much of Britain, but now outcrops in eastern and southern England.

Jurassic Period

Age: 142 – 205 million years ago

Geography, environment and climate

The British Isles continued its northwards drift. As global sea-level began to rise in the Early Jurassic the consequent marine transgression replaced the low-lying desert plains and marginal seas by more permanent, warm, shallow shelf-seas, which occupied much of Britain. However, only southern and eastern England remained submerged throughout the Jurassic, with the south-west and northern England, Scotland, Wales emerging as land areas from the Lower Jurassic onwards. An isolated island, the Anglo-Brabant landmass, occupied the area around London.

Key Events

The warm, tropical Jurassic sea teemed with life including marine reptiles such as plesiosaurs and relatives of squids known as ammonites and belemnites. Reptiles also flourished on land and evolved into many forms including the dinosaurs and birds.

Rock types and occurrence in England

Marine Jurassic rocks comprising mudstones, limestones and sands run right across the country from Dorset to North Yorkshire. Lower Jurassic rocks are superbly exposed on the Dorset and North Yorkshire coasts, while Middle Jurassic oolitic limestones deposited in warm shallow seas and over tidal flats now form the broad ridges of the Cotswolds and their continuation through Northamptonshire and into Lincolnshire.

Triassic Period

Age: 205 – 248 million years ago

Geography, environment and climate

During the Triassic, the ‘British Isles’ formed part of the supercontinent known as Pangea. The area that now constitutes the British Isles drifted northwards as Pangea rotated, to a latitude of ~10o – 20o N, equivalent to the latitude of the present day Saharan desert.

Sediments (dune sands and shallow lake mudstones) accumulated in a number of large, shallow basins. Large braided rivers crossed the desert plains which were punctuated by more mountainous areas formed by the older rocks of Dartmoor, the Mendips and the Malverns.

Towards the end of the Triassic, sea-level started to rise and a warm, shallow sea developed over what is now southern England.

Key Events

The Triassic marked a new beginning for life on Earth following the mass extinction at the end of the Permian. Forests of conifers and cycads dominated the land flora replacing earlier plant forms, such as ferns, and the reptiles started to attain dominance, with the first dinosaurs evolving in the late Triassic. Many new species of marine life evolved to fill the vacant space left by the demise of the groups that had dominated the Palaeozoic seas.

Rock types and occurrence in England

Triassic rocks are widespread throughout England outcropping either side of the Pennines, the Midlands, Gloucestershire, Somerset and east Devon. The rocks are relatively soft and have been weathered and eroded to form the lower lying ground of much of Worcestershire, Cheshire and Nottinghamshire. Triassic river deposits occur along the south coast between Exmouth and Sidmouth. Further north, Triassic sandstones form the red sandstone cliffs at St. Bees Head in Cumbria.

The rocks of this period are characteristically red in colour due to the oxidation of iron-rich minerals in the sediments under the arid conditions. The arid conditions led to extensive evaporation and thick deposits of salt accumulated in some of the desert basins, notably in the area that is now Cheshire.

Permian Period

Age: 248 – 290 million years ago

Geography, environment and climate

Britain formed part of Pangea, a landmass comprising all of the major continents. Desert conditions prevailed over much of Pangea, which lay near the Equator. An inland sea (the Zechstein Sea) occupied much of the area that is now the North Sea.

Key Events

At the end of the Permian, a mass extinction took place when three-quarters of known species of land animals and 96% of marine animals became extinct. Groups such as the trilobites disappeared forever.

Rock types and occurrence in England

Sandstones formed from desert sand dunes can be found across England from Dawlish in south Devon to County Durham. Erosion of the uplifted mountain areas (e.g. Dartmoor) led to the deposition of thick fans of sediment along their flanks. This material now forms the cemented breccias of East Devon and Worcestershire.

Shallow marine limestones and associated evaporites (salts) deposited in the Zechstein Sea now form the Magnesian Limestone. This outcrops in a narrow band from Nottinghamshire, through central England to the Durham coast.

Carboniferous Period

Age: 290 – 354 million years ago

Geography, environment and climate

The start of the Carboniferous was marked by a major rise in sea-level which covered almost all of England and Wales. A gradual shallowing of the sea and the formation of extensive deltas feeding from a landmass to the north (Scotland) led to the establishment of terrestrial conditions by the end of the Period.

A tropical climate predominated with the British Isles occupying an equatorial location.

Key Events

The shallow tropical seas of the Lower Carboniferous were rich in marine life, particularly corals, brachiopods and trilobites. On land dense forests of ferns and horsetails grew on low-lying deltas during the Upper Carboniferous. The buried remains of these forests now form the coal beds found in the Coal Measures of the midlands and northern England.

Towards the end of this period the coming together of tectonic plates to form a supercontinent known as Pangea led to a major phase of mountain building (the Variscan Orogeny). The main mountains were formed in Europe, but southern Britain felt the force of the collision, which produced spectacular folds in the Devonian and Carboniferous rocks along the north Devon coast at Hartland Quay. The deformative pressure reduced northwards and more gentle folds formed the Mendip Hills. Associated with this period of mountain-building was the intrusion of the granites found in south-west England and the attachment of the serpentinite of the Lizard Peninsula, a small piece of ocean crust which was pushed up and ‘welded’ onto the continental landmass.

Rock types and occurrence in England

Marine limestones (the Carboniferous Limestone) deposited during the Lower Carboniferous now outcrop widely forming the Mendip Hills, Avon Gorge, Derbyshire Peak District, the Yorkshire and Northumberland Dales. The overlying Millstone Grit forms upland areas in the Midlands and northern England (Peak District, Pennines, Forest of Bowland) while the Upper Carboniferous Coal Measures outcrops adjacent to the Millstone Grit, but forming lower-lying land, from Bristol, northwards to Cumbria and across to County Durham.

Devonian Period

Age: 354 – 417 million years ago

Geography, environment and climate

During the Devonian, much of Britain formed part of a large continental landmass that included Greenland, Scandinavia and north-east Canada. In the area occupied by southern England and the Midlands large rivers flowed across an extensive coastal plain transporting large amounts of sediment derived from erosion of mountains to the north and west. The most southerly part of England was occupied by a shelf sea which deepened rapidly to the south.

The climate was semi-arid and the part of the landmass incorporating the British Isles lay to the south of the Equator.

Key Events

The Devonian seas were home to many species of fish, shelled relatives of the squid (nautiloids), corals, brachiopods and trilobites. The Devonian continent supported freshwater lakes and rivers with many fish species, the first higher plants, insects and amphibians.

Rock types and occurrence in England

Rocks of the marine Lower and Middle Devonian outcrop in Devon and Cornwall, with warm-water reef limestones predominating in south Devon, deeper water shales and mudstone in Cornwall and shallow water sandstones in North Devon. To the north, sandstones and mudstones of fluvial origin outcrop in the Forest of Dean, Herefordshire and Shropshire.

Silurian Period

Age:417 – 443 million years ago

Geography, environment and climate

The time period covered by the Silurian documents the assembly of two continental elements and closure of the Iapetus Ocean to form the continental landmass from which the British Isles were later formed. England lay on the southern landmass (Avalonia). During the Lower Silurian the land of central and south-eastern England gave way to a shallow shelf sea along its margins. This sea deepened to the north so that the area now occupied by the Lake District was a deep-water basin. The Middle Silurian was marked by marine incursion across much of England and the Upper Silurian by the closure of the Iapetus Ocean, establishment of terrestrial conditions in the north and rapid shallowing of the shelf sea in the Midlands, Welsh Borders and southern England.

The British Isles lay at about 20-30° south of the Equator and the climate was tropical to sub-tropical.

Key Events

At the end of the Silurian, the Iapetus Ocean closed, and England and Scotland were joined together. This formed part of a wider series of collisions between the North American continent, southern Britain, the Baltic continent and various island arcs within the Iapetus Ocean during the late Ordovician and Silurian. These collisions resulted in a series of episodes of mountain building, which together are known as the Caledonian Orogeny. The resultant mountains, collectively known as the Caledonides, ran along the eastern side of North America, through Newfoundland, Scotland, Greenland and Scandinavia. The collision generated the folding, faulting and metamorphism (heat and pressure) of the affected rock successions. In Britain, all that remains of the Iapetus Ocean is a thick pile of deformed Ordovician and Silurian deep-sea sediments which now form the Southern Uplands of Scotland.

Rock types and occurrence in England

Deep-sea sandstones and mudstones outcrop in the southern Lake District. Along the Welsh borders, the sea was shallower and limestones and mudstones were deposited. These outcrop in Shropshire around Shelve, along Wenlock Edge to the Ludlow area and as small inliers scattered across the West Midlands, Worcestershire, Herefordshire, and Gloucestershire.

Ordovician Period

Age: 443 – 495 million years ago

Geography, environment and climate

At the beginning of the Ordovician, the part of the continental plate that is now England lay about 600 S and formed part of the supercontinent of Gondwana. Following break-up of Gondwana this part of the plate (known as Avalonia) gradually moved northwards to about 350 S by the end of the Period. England was occupied by shallow shelf seas, with the deeper water of the Iapetus Ocean being present to the north over the area of the Lake District. Arcs of volcanic islands formed on the northern edge of Avalonia as the microplate drifted northwards.

Climate was cool at the beginning of the Ordovician and gradually became warmer as Avalonia drifted northwards.

Key Events

The Iapetus Ocean reached its greatest width during this period. Trilobites, brachiopods and graptolites dominated the marine fauna, while there was a significant increase in the overall diversity of marine life. Mountain building began at the end of the Ordovician, associated with the beginning of collision between the separate plates carrying what are now England and Scotland.

There is evidence of a widespread and major phase of glaciation at the end of the Ordovician which caused a major fall in sea-level and the extinction of marine organisms.

Rock types and occurrence in England

Huge thicknesses of muddy sediments accumulated on the margins of the Iapetus Ocean and these now form the Skiddaw Slates of the northern Lake District. Extensive volcanic activity in the Upper Ordovician led to the formation of islands on the edge of the Iapetus Ocean, the remnants of which now form the Borrowdale Volcanics of the High Fells of the Lake District.

Cambrian Period

Age: 495 – 545 million years ago

Geography, environment and climate

England and Wales were a long way south (approximately 800 S), and part of a different continent (Gondwana) to Scotland that lay much further to the north forming part of the North American continent. As a consequence of its polar location, the climate would have been relatively cold. Most of England was occupied by a shelf sea which deepened to the north, while southern England was probably land.

Key Events

The Cambrian sees the first appearance of animals with shells, including trilobites, a now extinct group of arthropods, graptolites and squid-like nautiloids and other types of mollusc.

Rock types and occurrence in England

Rocks of this period in England are relatively rare and outcrops are confined to central Shropshire, the Malvern Hills and Warwickshire. These comprise shales and sandstones deposited in relatively shallow water.

Precambrian Period

Age: Prior to 545 million years ago

Geography, environment and climate

There was no Atlantic Ocean at this time and England and Scotland lay on separate continental plates. Most of England was occupied by a sea in which thick sequences of muds, sands and conglomerates were deposited. Volcanic activity was widespread.

Key Events

Several major phases of mountain-building occurred during the hundreds of millions of years represented by this period.

The Precambrian seas were populated by a range of soft-bodied organisms, some of which were related to modern-day life forms. At Charnwood, Leicestershire, the rocks contain an early fossil called Charnia which might be related to modern sea-pens but may not have any living relatives.

Rock types and occurrence in England

Due to subsequent erosion and earth movements, only small outcrops of Precambrian rocks now occur in the Country. Sedimentary and volcanic rocks of this age (approximately 600 million years old) are found in Shropshire (the Long Mynd and the Wrekin) the Malvern Hills in Worcestershire and Herefordshire and the Midlands (Charnwood and Hartshill).