Geomorphing Ribble Valley over 750 Million Years

If you look out of the back bedroom window of my house in Clitheroe, Lancashire, you can see Clitheroe Castle which dominates the town 100 feet up on its perch on a rocky crop of limestone. Step out of my front door and walk a few yards up the stone steps to St Mary Magdalene’s church, and up looms Pendle Hill rising 1,300 feet above its surroundings to dominate the whole of the Ribble Valley.

If you continue walking a few hundred yards through the town and up the stone steps leading to the Castle (as I try to do daily when I’m there) you can walk through the Castle Keep and up on to the ramparts to look over the town and survey the green landscape for miles around.

Image from Andy Images

And if it was possible to occupy this landscape through time and go back…

…over 350 years ago to the English Civil War and you will encounter Royalist troops who have made Clitheroe Castle their garrison. The castle is about to be taken by the Roundheads, who will later ‘decommission’ it with cannon fire; a huge hole blown out of one of its walls can still be seen today. Hang around for a couple of years and you will see a chap called George Fox struggling up to the summit of Pendle Hill; he will claim to have a vision of God there which leads him to form the Quaker Movement.

…400 years ago and you may encounter two old women and their brood roaming the footpaths of Pendle Hill – Demdike, Chattox and members of their families, who were tried and executed as witches in 1612. They will lend Pendle Hill its mythical association with witchcraft, but the fiction attached to their sad story will outweigh the fact.

…over 900 years ago and you will see the beginnings of the settlement of Clitheroe, with the building of the castle by the Normans.

3D outline image of Clitheroe Castle by Geoff Hodbod 3d-imaging.co.uk

          The original St Mary’s Church will follow a few years later as the settlement grows. The name ‘Clitheroe’ comes from the Old English for ‘Rocky Hill’ and the castle and church were each built on prominent limestone outcrops 350 yards apart, with the settlement sandwiched in between – the poor old peasants literally squeezed between church and state.

…1,000 years ago and you may witness Scandinavian travellers using the River Ribble as a highway between the Viking kingdoms of Dublin and York.

…2,000 years ago and you may see Roman soldiers passing through what will become the outskirts of Clitheroe, travelling on the Ribchester to Ilkley Roman road.

…almost 5,000 years ago and you will see Bronze Age people at the summit of Pendle Hill burying their dead.

But these are just brief flickers in the real history of this patch of country.

Go back 500 million years ago and you could have been transported to a different planet; the landscape, environment and climate would be totally unrecognisable.

          It would be very cold; you would actually be standing on a small icy landmass, Avalonia, close to the South Pole. Avalonia lies just off the super-continent of Gondwanaland and its immediate neighbour is the land comprising modern Africa and South America. It would be very lonely; there would be virtually no plant or animal life on land, except for the very early explorations of a few primitive species.

If you travel forwards again to around 360 million years ago in the Early Carboniferous period, the paleo-Ribble Valley has drifted north towards the Equator as part of a large land mass containing modern Europe and North America.

          It is around the same latitude as modern Madagascar and the climate is hot. You will need a swimming costume as the low ground is covered by a shallow sea in which coral reefs and other marine plants and animals prosper. They will go on to form the limestone base of Pendle Hill and the reef-knoll on which the centre of Clitheroe will sit, with the castle and church standing on outcrops at either end. You will also see the first animals colonising the land, having evolved from air-breathing fish.

Go forwards to 330 million years ago and the Ribble Valley is drifting over the equator. It is on a par with the area occupied by modern Kenya and the climate is tropical. You will be standing at the delta of an ancient river, which is busy laying down the river sands on top of the limestone base of the proto-Pendle Hill.

Travel forwards again to 300 million years ago in the late Carboniferous and continental drift has carried the Ribble Valley northwards across the equator, into subtropical latitudes on a par with the modern Sudan. The area is part of the super-continent of Pangea. You will see that the sea has receded and has been replaced by rainforest. The land is swampy, covered with lush vegetation and an ideal habitat for insects and early reptiles.

Go forward to 280 million years ago in the Early Permian and the Ribble Valley has continued to drift northwards away from the equator towards the latitude of modern southern Libya. It is an arid desert environment which will persist for the next 30 million years. The reddish tinge to the landscape is caused by iron oxides, the result of intense heating by the sun on a surface devoid of vegetation cover. Many older types of plants and animals die out.

Forward again to 250 million years ago in the late Permian, and the Ribble Valley is still within desert latitudes on a par with modern Tunisia. You will find that a shallow sea has encroached on the area once again. If the area seems lifeless it is because the most extensive extinction event recorded in paleontology has slowly killed off up to 95% of all marine species and 70% of all land organisms. It will take the Ribble Valley’s ecosystem at least another 30 million years to recover.

So let’s fast forward to 65 million years ago and the late Cretaceous. The Ribble Valley has drifted further north in line with the northern tip of present-day Spain. The climate is still sub-tropical. There is no ice at the Earth’s poles and world sea levels have risen to the extent that only the top of Pendle Hill is visible – ‘Pendle Island’ would be more apt. Clitheroe is deep beneath the sea all around you and home to turtles and sharks, as well as big marine reptiles such as ichthyosaurs. Although land-dwelling dinosaurs rule the world, you will be unlikely to find any on Pendle Island; it is cut off from its neighbouring landmasses of Europe and North America by the sea. The timing of your arrival is bad. A few minutes ago a 6 mile wide asteroid hit the sea off the Yucatán Peninsula in southeastern Mexico. Material ejected by the enormous blast is billowing into the upper atmosphere to the extent that it will plunge the planet into a long dark winter for years to come, killing off those dinosaurs and many other species that have managed to survive the initial global shock wave. The megatsunami generated by the blast, which created a wave a mile high at the impact site, is still 100 feet high after crossing the short Atlantic Ocean; it’s about to crash into Pendle Island, so it’s time to get out of there.

Fast forward again to 125,000 years ago and the Ribble Valley is in its current geographic position in the North Atlantic, but enjoying a warm climate similar to the African savannah. This is reflected in the animals that you can see roaming at the foot of Pendle Hill: lions and elephants, as well as rhinoceroses, hyenas, hippopotami.

Travel forwards to 15,000 years ago and you will find Clitheroe under ice. The ‘last glacial maximum’ has passed and the ice sheets are finally starting to retreat after their 50,000 year occupation of the landscape. The climate varies between conditions seen today in Scandinavia  and the Arctic. Mammoths roam the area and will soon be hunted to extinction by modern humans who will begin to arrive as the ice falls further back.

As you head back to today, you will notice the effects of glaciation on Pendle Hill and the surrounding countryside. Deposits of boulder clay left by the glaciers have created the familiar rolling landscape within the Ribble Valley and have padded out the lower slopes of Pendle Hill, moulding it into its distinctive elongated whale-shape. Clitheroe sits on the triangle of land between the River Ribble and Mearley Brook and since the industrial revolution it has expanded well beyond the reef-knoll upon which the Castle, old town centre and Church sit.

…And finally, you can leap forward 250 million years into the future to see what’s become of the Ribble Valley.

Dig out your winter woollies because it has drifted in a northeasterly direction into the Arctic Circle. It now sits above where Siberia is today and lies off the northernmost tip of the supercontinent Pangea Ultima. The endless cycle of glaciation, rising seas, forest and desert has now added enough material to Pendle Hill to rechristen it Mount Pendle. However, you will see that the area is now a polar desert and whatever remains of Clitheroe and its inhabitants is fossilised and buried deep beneath the ice.

So before that happens, visit the Ribble Valley and go to Clitheroe Castle. You can learn more about the history and geology of the area in the Castle Museum. And you can view the landscape from the ramparts for yourself –you might just see it a bit differently.

Further Reading:

Further Viewing: