Time-travelling by train - Carlisle to Newcastle - Part 1

Our journey starts in Carlisle and heads east. In a nutshell in terms of bedrock geology we begin on rock that is around 250 million years old from the Triassic period and as we head eastward travel over progressively older rocks crossing into 330 million year old Carboniferous strata around Brampton Station. 

Then we are on Carboniferous all the way to Newcastle – and once we get past Ovingham we start to cross younger Carboniferous rocks with many coal seams. That’s the bedrock geology – and natural rock outcrops are something we will rarely see – the biggest impact on the landscape we will travel through and most other northern landscapes are much younger deposits from the last glacial period 20000 years ago and the even younger river deposits that cover the glacial debris in the valleys. But that is more than enough of a preamble – time to head into Carlisle Citadel Station.

Transcript

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Series 5, Episode 2. Time Travelling by Train Carlisle to Newcastle Part 1 These podcasts have rocks as their focus, and it wasn't difficult to make connections to geology along this railway line. There is the landscape and its evolution of course, but as with the majority of old railways, this one owes much of its origin to rocks, disjointed mineral railway lines, wagonways serviced by horses. They were its precursors. And long before the first coast to coast railway in Britain received royal assent in 1829, coal wagons were working on Lord Carlisle's Brampton line, and lead was being hauled on wagonways down from the North Pennines. The Tyne Valley Line, formerly opened to passengers on the 18th of June 1838, reaching Newcastle Central Station in 1851. The route could have been an even bigger and more expensive engineering feat. In 1794, a man called Ralph Dodd had proposed linking the east and west coast by canal. The estimated cost of building this railway, one of the earliest in the world, was£250,000. That was a quarter of the cost of the canal. Like the last train journey to settle, the Tyne Valley Line and I go back a long way. I remember hauling a trunk with all my books and belongings back and forth to university in the late 60s, and fifteen years later using it to commute to work from Hexham. Now we live beside it again, and I'm a regular east and west traveller from Barden Mills tiny station. But despite all those journeys along it, I thought I'd better make sure my recollections recollections of the landscape the Carlisle to Newcastle line passes through were accurate. So the other day I rode the line both ways, just to do that. There's a lot to see and a lot I'd like to tell you about this journey, so it's going to take at least two episodes. Our journey starts in Carlisle and heads east. In a nutshell, in terms of bedrock geology, we begin on rock that is around 250 million years old from the Triassic period, and as we head eastward, travel over progressively older rocks, crossing into 335 million year old Carboniferous strata around Brampton Station. Then we're on Carboniferous all the way to Newcastle, and once we get past Ovingham, we start to cross younger Carboniferous rocks with many coal seams. That's the bedrock geology done, and natural rock outcrops are something we will rarely see. The biggest impact on the landscape we will travel through, and most other northern landscapes, are much younger deposits from the last glacial period twenty thousand years ago, and the even younger river deposits that cover the glacial debris in the valleys. But that's more than enough of a preamble. Let's head into Carlisle Citadel Station. You might not see much natural bedrock in Carlisle or in many British towns, but what you do notice, well at least us nerdy geologists do, are that the local stones their buildings are made from. In Carlisle, as you can see from its famous castle and cathedral and the formidable Citadel, a former courthouse, standing just outside the station, these are all made of red St. B's sandstone, once sand in a hot Triassic desert which had transient lakes at rivers that would frequently flood. It's called the St. Bees Sandstone because it's the cliffs at St. B's Head where it's the thickest and the best seen. But the bits of the Carlisle railway station you can see are not built of this same red stone. The architect who designed and built it in 1847, William Tite, chose to use a buff pale brown sandstone. I'm trying to find out exactly what stone it was and where it was quarried, but the best answer I have right now is it was a rock called the calciferous sandstone. That's a Carboniferous rock from Scotland, interpreted as being deposited in a shallow coastal sea and estuaries. The stone was probably chosen not only for its colour, but all for its ability to be finely cut and carved. You can see what are called Ashlar blocks with their tight joints on the station facade, and the quality of the carvings in the fireplaces of the recently renovated first class lounge. That's become a magnificent bar, and if you can be tempted to visit, you'll see many of the clocks on the wall are all set to the time of 1847, the date the station was first built. But beneath the pale brown older stone is a younger red variety. It's visible below the platforms and in the undercroft of the station. Back to the fine pale brown sandstone for a moment. You'll see from the facade that while it may have been good to shape and carve, it hasn't endured the Cumbrian weather very well. Many of its blocks are eroding, spalling, and have done for decades, as the failed attempts to disguise that by rendering now show. I guess if I'd been around in 1847 and there'd been a public consultation, both of those are fantasies, I would have been an objector to the use of the imported stone. Why didn't Mr Tite use the local red sandstone that gives Carlisle in this part of Cumbria so much of its character? It's also the stone that's used in so many of the structures on the Tyne Valley line. After all, we object to introducing alien plant and animal species, so why do we have to tolerate alien stones? What's wrong with the vernacular? Enough, grumpy old geologist. There's not a lot of geology, well geology that's obvious anyway, in the first mile or so, and like all towns, Carlisle and so and its suburbs has a veneer of man-made fill, from Roman settlements, cemeteries and metalworking shops to twentieth century rubble. The topography, as we head out of the city, is flat at first. This is the Carlisle Plain, after all, part of the Solway Plain. It was covered by a thick ice sheet, think one thousand meters of ice, and when that wasted away between eighteen thousand and fifteen thousand years ago, there was at least one, if not several, large glacial lakes covering this area. So pretty flat. Meltwater brought mud and silt into the lakes, and they were laid down as fine layers. Laminated, geologists would say. Before we go under the M six and leave the perimeter of Carlisle's newly built housing estates behind, we passed through the old, now birch sapling covered, extensive rail sidings at Botchibi. A hundred years ago you'd have been able to see large clay pits near here, extracting those glacially laminated stone free clays to make bricks. Intergreen pastures now with sheep and cows. But where there is ploughed land, you'll see the colour of the soil is red brown, like the bedrock and the glacial deposits below them. Now and again to the east and the south we get a glimpse of the northern end of the Pennine Hills in the distance. Maybe if your eyes are sharp enough, you will see a large cairn and bronze aged tombless on top of Cardonough Pike, which sits above Castle Carrack. The steep slope that separates the Pennine Hills in the east from the lowlands of the Eden Vale in the west is a huge geological fault, one that still moves now and again. It's not long until we reach Weatherell. The land has gone from flat to gently undulating, and the older houses often as not have red sandstone coins, if not whole walls. The churches certainly do. Immediately after the station we cross Weatherill Viaduct, an impressive structure designed and built, like many other structures on this line, by Francis Giles. It's almost 300 metres long and 30 metres above the river Eden. It's built of red sent beast sandstone too, and the big facing blocks are said to come from a quarry near Newbigan, south of Castle Carrack. The sandstone infill is from quarries in the same rock at Corby Hill and Wetherill itself. If you visit Weatherill, take a walk south along the River Eden. In the woodland there you will see quarries in the red stone, and lower down, nearer the river, there are Roman inscriptions, the work of Condraus Sisius, a soldier of the twentieth Legion Valeria Victrix. There are also some caves carved in the cliffs. They're known as Constantine's Caves. They were once used as a refuge from the border reavers. After Weatherall, the landscape becomes a lot more hummocky. We've entered a huge area of sand and gravel, silt and clay, forty-four square kilometres of it. Fifteen thousand years ago, rivers and lakes draining England's last stagnating ice sheet deposited one of the largest areas of glacial meltwater sediments anywhere in the UK. Only a few thousand years earlier, an ice sheet over 1,000 meters thick had advanced down the Irish Sea, crossed the Solway Plain, joining with ice from the Lake District, before flowing southwards and eastwards through the Eden and Tyne valleys. As the climate warmed, the ice progressively wasted and receded southwards and westwards, and the meltwater transported and sorted the debris the ice had carried. The debris, and thus the soil is red, because the ice sheets had eroded and turned the local red sandstone into clay, silt and sand. Before we reach Brampton Station, look out for the rail line going through a long, deep cutting. It's called the Cowran Cut, one of the deepest in the country at the time. It was originally planned as a tunnel, but the engineering problems caused by the glacial geology and the water were too great. Think of the huge amount of effort this must have taken to dig a million cubic yards of sand and clay without machines in the eighteen thirties. You may already have noticed a few, but along the Tyne Valley, in fact all along the line, you will see rock blankets, spreads of broken rock placed on the slopes to reduce the risk of landslips. It's a function of the geology and steep slopes the railway encounters and the route line the engineers chose. There's always a price to pay for reducing ups and downs on any transport route, but more on this later when we guess past Hexham. Soon after we cross another impressive viaduct over the river Gelt. Below us, on the northern side, are quarries in the St. B's sandstone that used to supply stone for the bridges, buildings, and walls along this line. And a little further downstream on the Gelt, the Romans were quarrying here too 2,000 years ago. There are at least two Roman quarries on the sides of the gorge. One is called the Written Rock of Gelt. This red sandstone is easily shaped and carved, and as well as for building Hadrian's wall, may well have been used for monuments and architectural purposes. The soldiers who worked the quarries left many wonderful carvings here that are visible from the path, letters and names, and even caricatures of their officers. Kilometre further east along the line we cross another gorge, Hellbeck. It's got a gruesome history. In the 16th century there was a bloody battle here between the armies of Elizabeth I and Leonard Daker, a local rebel lord. Nearby, at Cape Entree, six of Bonnie Prince Charlie's men were hanged after the 1745 rebellion. That turmoil is in the past. Today the gorge is a beautiful place to walk. The river Gelt has cut winding channels, chutes and potholes in the sandstone, and Gelt Woods is one of the few surviving ancient woodlands in East Cumbria. Even though the canopy trees are much altered by human activity, the shade and humidity provide ideal conditions for mosses, ferns, fungi, and a variety of ground flora. Next time you're in the area, park at Low Gelt Bridge and see some of this for yourself. And so we've reached Brampton. Well, Brampton Station. It's a mile and a half from Brampton. It used to be known as Brampton Junction. It's the place where the original Brampton Railway or Lord Carlisle's Railway crosses or used to cross. Lord Carlisle's Railway started out in 1776 as a wooden wagonway using horses to carry coal down from Tyndall Fell Collieries. It actually did reach Brampton Town. In 1836 it was realigned and joined to the Carlisle Newcastle Railway. Believe it or not, the rocket, one of the first steam engines, and the template for all those engines that came after, was the locomotive that used to haul traffic on this railway back then. This line was also one of the first, if not the first, to use wrought iron rails. Quite the history for a place few will have heard of or realized as they speed by. But in reminiscing about railways, I've forgotten a pretty important geological point. Just before Brampton Station, we crossed over from the Triassic to the Carboniferous. There's a divide here, a geological boundary that separates western red from eastern grey brown bedrock. Unlike a bit further south, where the Pennines start near Castlecarrick, this is not a fault. It's what geologists called an unconformity. A fault is a tectonic fracture of the rocks. An unconformity is a gap in the rock record. This unconformity is where water depositing the Permian and Triassic sediments encroach progressively eastwards on the eroded surface of Carboniferous rocks around 270 million years ago. That geological boundary is a good place to pause this episode. We'll resume next time with Carboniferous rocks beneath us, and for the rest of the way to Newcastle. Just don't expect to see much of them. They are mostly hidden beneath glacial and more recent deposits, a landscape less than 20,000 years old that will dominate our journey. But don't be deceived, these very young bits of geology have an awful lot of stories to tell.