Low tides reveal a prehistoric landscape on the sand
Winter storms have revealed astonishing relics of the past on a Welsh beach. On one part of the shoreline at a private beach below a luxury holiday park on the Llŷn Peninsula, was the spectral outline of a wooden vessel, on another was the eerie remnants of a submerged forest.
The discoveries in 2013 soon disappeared back into the sand at Warren beach, Abersoch. After more winter scouring in 2018, a team of researchers returned to find the site was even more astounding than first supposed.
At the water’s edge was peat “pavement”, heavily ridged and peppered with prehistoric animal hoof prints. Some had been left by roe deer or sheep, other appeared to be the imprints of aurochs, an extinct cattle species.
Here and there, time-blackened tree stumps poked up from the mud between fallen trunks and branches. Also discovered were the possible remains of wattle hurdles, perhaps laid down to form an ancient trackway across the peat.
In places, there were clear signs of peat cutting using spades, similar to rectangular marks preserved on Tywyn beach further south. This activity was thought to be more recent, carried out mere centuries ago.
In a place where the wealthy now come to sunbathe and watch yachts glide across Tremadog Bay, a wooded habitat once existed around 7,700 years ago. Where there are now sandbanks, bass and dolphins, there were rivers, marshes and forests full of deer, pigs and even wolves.
Abersoch’s research was carried out by the CHERISH scheme, a six-year European-funded Ireland-Wales project. It reported: “Radiocarbon dating revealed that trees grew once again on the foreshore at Abersoch around 4,300 years ago, while at Borth and Ynyslas (in Ceredigion) they flourished between 6,200 and 4,300years ago.
“At both sites, peat formation replaced the woodland habitat as the sea continued its inexorable rise, which finally submerged the wetland and formed the current shoreline.
“It’s intriguing to imagine the habitats that would have supported wild boar, Eurasian aurochs, bear, lynx and wolf that would have been hunted by the Mesolithic inhabitants. It seems plausible they would have witnessed the encroaching sea and loss of landscape…. unaware of the causes and helpless to influence them.”
Warren Beach is far from unique. Around the Welsh coastline, scores of ancient ghost forests lie beneath the waters, the legacy of retreating ice sheets.
Thousands of years ago, Wales was a much bigger place. It’s estimated sea levels may have been more than 75 metres lower than they are today. Yet much of Cardigan Bay lies less than 50 metres below its current level. This area alone equates to 4,400 sq km – equivalent to a fifth of the total area of present-day Wales.
The CHERISH team speculated that, as sea levels rose, woodlands now on Warren beach were probably drowned by rising ground water and were replaced by peat bogs. Further sea advances may also have stopped rivers like the Afon Soch from draining out.
Its academics found a parallel example on Anglesey, discovering that the sea reached Llyn Maelog near Rhosneigr around 7,000 years ago. What was previously a freshwater lake became a marine inlet. It was subsequently marooned and has long since reverted.
Once, the submerged forests were called “Noah’s Trees”, supposedly evidence of the biblical flood. Over the centuries they have inspired numerous myths and tales of drowned settlements, most famously the legendary Cantre’r Gwaelod (Lowland Hundred) sunken kingdom of Cardigan Bay.
On Anglesey alone, at least 16 drowned woodlands have been recorded, some becoming more visible in recent years as sandbanks shift in winter storms.
In 1893, hundreds of people flocked to Splash Point, Rhyl, when its submerged forest was revealed by the tide for the first time in 80 years. Stone Age axe heads have been found here, along with a deer antler dated at 2,000-5,000 years-old.
CHERISH added: “It is perhaps little comfort that our prehistoric ancestors had to contend with the same threats that we are facing today. The trajectory for future sea levels means that further loss and environmental change are inevitable.”
Every so often, the stumps and peat pavements on Warren beach are revealed by a low tide, as they were this week. So too is the mysterious wreck, a 64ft trading vessel whose hull was fastened with wooden tree nails and was once repaired with copper binding.
A lack of barnacles on the timbers indicates it’s only rarely exposed to the air. Littered around are broken slates, its former cargo.
Records show a ship named the Maria of Aberystwyth was grounded here in 1872. However the favoured candidate is the Fosil, driven ashore in 1889. Officially, the wreck is still classed as “unidentified”.
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