Memories of aurochs and oaks: the re-emergence of the submerged forest

“Mr Cash went to Beckfoot … the submerged forest was not visible and I regret to say the residents he inquired from had not even heard of it”. So wrote Brian Blake in his 1955 book The Solway Firth, which is illustrated by black-and-white photographs taken by J. Allen Cash. Fortunately, Mr Blake himself did find the forest later, and was “delighted with [his] luck” when he walked South along the Cumberland coast from Silloth.

I first went to look for the forest back in 2004, and found the stumps and roots of the ancient trees on the shore near Beckfoot; I continued to find them in roughly the same area for the next 10-12 years, and they became part of the ‘itinerary’ of my guided low-tide shorewalks. It was not just the trees that made this forest area special. As I wrote elsewhere back in 2004:

“the patches of black are like shadows along the sharp edges of channels in the sand. Walk down towards them, and the shadows resolve themselves into banks of peat. Poke them with your toe and feel how dense and sodden they are, smoothed by the friction of waves and sand. Walk on them and feel their sponginess. And gradually you will become aware that the dark organic mass is not only peat, but supports here a horizontal tree-trunk, or there a stump that radiates roots. Wander around and you will find trunks and branches, single and entangled, embedded in the peat and sand; and erect stumps, 20-30 cms high, their tops flattened as though cut by a chainsaw. The wood is still fibrous, soft and dark; you can crumble it and tease it apart, as though it were any rotting log in a woodland. But the difference is that this woodland thrived about 8000 years ago.”

Then, a few years ago during a sequence of winter storms, the peat was thrashed and fragmented by the waves, the wet and fragile wood vanished, and nothing remained visible of the woodland and grassy plain that had once covered part of the modern bed of the Solway Firth.

Shingle, sand-waves and a distant rocky scaur

Yet that patch had been just a small area: underneath the new and ever-changing profile of the mid-shore near Beckfoot, where shingle was swept away, rocky scaurs – relics of glacial deposits – were exposed, and sand was piled in sessile waves and tiny ripples, the time-horizon containing the forest and peat and clay would still exist. It was a comfort to know that this evidence of the formation and changing development of the turbulent Solway Firth was still there – but hidden, from sight and perhaps from memory.

So this month, after weeks of strong north-westerly winds and storm surges and Spring tides, I went down to Beckfoot again – wondering, hoping, that the secret of the submerged trees might once more have been revealed. The shore looked so different from back in the autumn that I was failing to find my usual ‘markers. The cloud was low and the air was grey, and across the Firth Scotland had (very sensibly) taken leave of the Union and was no longer to be seen. A mixed flock of gulls sat and preened near the water, keeping a silent watch on my movements, and I apologised as thirty or more oystercatchers failed to hold their nerve and rose up in a flock, trilling with indignation.

I zig-zagged between the tidelines, hoping to find ‘treasures’ like goose barnacles attached to flotsam, but the long mounds of tangled wrack and twigs were too tightly woven together by the waves. Dark shapes ahead were merely small boulders and rounded pebbles of a newly-exposed scaur.

Looking up to watch a curlew come gliding over the dunes, its outspread wings motionless as it let itself be carried on the wind towards its friends by the distant water, I suddenly saw that, higher up the shore towards the battered dune faces, there were smooth dark plates of – something.

They were not peat, as I had expected when I went to look, but sheets of heart-stoppingly slippery, grey clay: the same type of clay that had lain beneath the peat layer that had preserved the forest. Its surface was speckled with embedded fragments of wood – and over there, there was a tree-stump with radiating roots; some fallen branches or perhaps more roots, half-buried in the clay. And more stumps, sticking up defiantly.

Had the peat been broken up and washed away, or was this one of those places where salt- or fresh-water had temporarily inundated the peat bog? Perhaps there had been a meeting of sea and river water, where the suspended sediment had flocculated and fallen – or perhaps the sea had broken through a barrier and washed out clay that had been deposited at the bottom of a still, small lake? For we know that the margins of the post-glacial Firth were always changing, as sea-level varied relative to the land. Finally the trees had died, their roots waterlogged as by a beaver-dam, their bodies gradually preserved as the sphagnum mosses grew ever upwards and compressed into layers of acidic, anaerobic peat.

There was another puzzle too, for the surface of the clay was pock-marked with tiny holes, the entrances to burrows. I broke off a piece and found the burrows had been filled in with yellowish sand. What creatures had lived in this clay, and when? I had previously found peat that was riddled with the burrows of piddocks, bivalved molluscs that usually bored their homes in rock, which showed that the peat must have been exposed to the sea before it was buried, and later un-buried, by the sand. But these burrows were smaller and regularly spaced, and clay is a firm, dense substance that would not be easily penetrated…

Here were the lost stories of the inhabitants of land and water – aurochs and oaks, bog-plants and bivalves. Here on the Solway’s malleable edges, focus always switches between the geological past and the passing of a few tidal cycles; between the landscape-scale of scattered woodland to the microscopic archive of peat and clay.

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