This is one of the most moving sights I know. Like the Malverns, which I wrote about a couple of weeks ago, it relates to this extraordinary geological subconscious, the pre-Cambrian basement: the truly, truly ancient rocks which (probably) underpin the entire island, but which — apart from a long sliver of north-west Scotland that forms one of the most remarkable landscapes on the planet — rarely appear above the surface.
We are on the edge of Charnwood forest, just north-west of Leicester. It’s a little-known landscape outside the immediate area, and the last thing one expects in what is otherwise a mixture of Midlands towns and low, easy, farming country. But Charnwood is a Place with a capital ‘P’. If the Malverns are a mini-mountain range, a spine, a totemic border heralding the English far west, then Charnwood is a landscape in and of itself: an island, a world apart. And parts of it have been ravaged by industry. It thus stands in for two of the most contradictory and vital aspects of man’s relationship with stones: their role in making places of dreaming, freedom and danger (the more visible the stones beneath the surface are, the more likely it is that one is in relative highland and relative wilderness) — and their usefulness as a resource, excavated from the earth and re-arranged to make everything from cathedrals to motorways.
The Malvern slice of ancient basement made its way to the surface partly thanks to the existence of an ancient scar in the earth’s crust. Charnwood may be on another one of these, but here the story is much more one of the greatest shaper of Places of all, which is not the orogenies of mountain-building — but their wearing away, by erosion.
Perhaps 575 Million years ago, then, these rocks came to the surface in a dramatic series of volcanic eruptions. Some erupted beneath an ocean, others on islands; some came out fast, others came out slow. The result is a range of igneous rocks of different appearances and propensities — and all of them very hard. There are 3.5 kilometres of them lying beneath the surface.
These volcanoes were then built up and ground down again in several cycles of mountain-building and mountain-erosion: and by the Triassic era, about 250 million years ago, they were again at the surface, where they formed low rocky barren granite hills, set in a desert as large as a small continent. Where the dry rock-covered wadis then filled with sand; and that sand was then compacted by more sand until it too became rock.
Today, much of that rock, the New Red Sandstone, has been stripped away, and the tips of these buried hills have appeared above the surface, forming a sudden moorland in the middle of Leicestershire. It is this last process which formed the Charnwood we see today.
It is truly a place apart, Charnwood forest. Though only six to eight miles across, in the middle of it one could be forgiven for thinking one was on the edge of Snowdonia or the Lakes. Forest, rough grazing, drystone walls. Little houses made of a jumble of hard, shiny stones: tones of brown, grey and black in an east Midlands ocean of red brick and green fields. Sudden dramatic frost-shattered tors. As one explores the landscape one discovers shallow gorges, cut by rivers that worked their way down through soft sandstone, washing it away as they did so, and then found themselves cutting steeply into something harder. At Bradgate Park the medieval hunting forest is preserved, with ancient oaks scattered among the rocks of the mini-gorge romantically called Little Matlock. At Mount St Bernard C19 Cistercians re-occupied a ‘desert fastness’ last inhabited by monks (the Augustinians had a house a few miles to the east) at the Dissolution. And throughout, one is dimly aware of the edges: that surrounding this rocky island is a sea of low farmland (and, to the south-west, coalfields). Less visible are the precious fossils: shallow fan-like patterns on exposed surfaces, which in the 1950s first proved that there had been complex life, albeit not yet with a skeleton, in the distant pre-Cambrian.
Humans discovered the potential of this landscape early. Roman Leicester was partly built of it: at Swithland, the rocks split easily into slabs thin and impermeable enough to make roofs, and Swithland ‘Slates’ as they are called have roofed everything from Roman villas to twentieth-century Midlands cottages. And here, at Bardon Hill quarry, the demand for rocks for aggregate: principally, rocks strong enough to take wheeled traffic, skyrocketed with the invention of Tarmac and the Industrial Revolution, and shows no sign of abating.
Climb Bardon Hill, then and one is in for a shock. Firstly, the outline of a tor, a communications mast and an Ordnance Survey triangulation point become visible. Then, just yards from the trig point: a cliff, and one realises the rest of the hill has been cut away. Peer over the edge, and you are looking into a quarry that supplies about a tenth (32 million tonnes) of the aggregates and other such products mined in Britain. A quarry that is also a cross-section of the ancient geologies beneath our feet.
Look again at this view. First notice how big this hole is: those giant-tyred lorries look
like toys. Then look at the land-surface that stretches around it: one can see the housing estates on the edges of Coalville; the fields of rural Leicestershire. To look at this is as undramatic and unremarkable a landcape as any in England. Then look at the side of the quarry itself, and behold a cross-section of what lies beneath.
A great lateral divided crosses the image: below is hard grey, above is soft reddish-orange. This is the line of the hill we are standing on, the pre-Cambrian basement which we have just climbed continuing on underground towards its customary deeply-buried home. The slope is the lost hillside of a Pangean desert. And the redness above is the New Red Sandstone which is the remnant of that desert, and is otherwise the usual rock one finds lying beneath the English midlands. It is like being tipped back in time; and like all tips-back-in-time, even those that are the side-products of Extractive Industry, it is very moving: a series of lost landscapes, past places, vertiginous sequences of time, jammed together; the undercarriage on which we live exposed.
Even more remarkably, you probably drove over chippings of these ancient rocks last time you hit your local motorway.