Although it is rarely seen, the remnants of a past forested landscape, where there is now sea and beach, is a very interesting feature and teaches us about past sea level rise and our recent glacial history, and makes sense of some of the archaeological remains we find around our coastline in West Wales.
At the end of the last glaciation the sea level was much lower than it is today because so much water was still locked up in the ice sheets to the north of Britain. As the climate warmed forests became established on land that had been tundra for thousands of years, and this forest extended far out beyond where sea level is today. Gradually as temperatures rose, the sea ice to the south of the arctic circle melted and sea levels rose, submerging much of the coastal forests.
In some places this action was very rapid and sand covered and then preserved the remains. After heavy storms and at very low tides, peat or the stumps of these forest trees may be seen at places along the Welsh coast, particularly, in Pembrokeshire, at Newgale and Freshwater West.
The remains of animals and Mesolithic tools have been found in these deposits. These include an Auroch, which is an ancient cow and is the ancestor of all modern cows, a pig, a roe deer, a red deer antler and a brown bear jaw.
At Lydstep Haven, a pair of broken flint microliths were found by the neck vertebrae of a pig. This pig may have been injured, but not caught by its Mesolithic hunters and subsequently died in the forest. A tree trunk fell on its remains, preserving it, and the microliths in situ. This find has been dated to about 6000 BC.
Geraldus Cambrensis (Gerald of Wales ) noted the uncovered submerged forest, during his tour of Wales in AD 1188.
‘We then passed over Newgale sands at which place a very remarkable circumstance occurred. The sandy shores of south Wales laid bare by the extraordinary violence of a storm, the surface of the earth, which had been covered for many ages, reappeared, and discovered the trunk of trees cut off, standing in the very sea itself, the strokes of the hatchet appearing as if made only yesterday. The soil was very black and the wood-like ebony. This looked like a grove cut down, perhaps at the time of the deluge, or not long after.’
We cannot be sure whether the marks he saw were made by a stone axe. It is certainly possible, since stone axes were in use before the forests were submerged between about 6000 and 5000 BC.
He made these observations 800 years ago and similar observations are the basis for medieval traditions about the Cantref Gwaelodd – ‘the lost lands of Wales.’
This is what the beautiful coastline looks like today….