NEW research has thrown serious doubt on claims that the Preseli Hills are home to a Neolithic bluestone quarry.

Archaeologists have conducted annual digs near the village of Brynberian and promoted the idea that some of the bluestones at Stonehenge were quarried in Pembrokeshire before being carried all the way to Wiltshire some 5,000 years ago.

In 2012 Professor Mike Parker Preason put forward his theory that some of the fragments of rock in the soil layers in and around Stonehenge could be matched closely to a blue rhyolite rock at Rhosyfelin.

Geologist John Downes and geomorphologists Dyfed Elis-Gruffydd and Brian John have examined the Rhosyfelin site very carefully and come to the conclusion that there are no traces of a Neolithic quarry. Instead, they interpret the rocky debris as entirely natural accumulations over a long period of time.

In their new article they also describe a number of different landforms and sediments which can be related to the events of the Ice Age, and in particular to the last glaciation of this area which occurred around 20,000 years ago. They accept that there might have been a prehistoric camp site in the sheltered valley at the foot of the Rhosyfelin rocky crag, but suggest it was used by hunters rather than by quarrymen.

Dr Brian John said: "We have no argument with the geological work that links this site with Stonehenge, but we cannot accept the idea of a Neolithic quarry here without firm evidence.

“The features referred to by the archaeologists as evidence of human quarrying activity are entirely natural. There are no artefacts, bones or tools.

“We are also increasingly convinced that the rhyolite debris at Stonehenge comes from glacial erratics which were eroded from the Rhosyfelin rocky crag almost half a million years ago by the overriding Irish Sea Glacier and then transported eastwards by ice towards Salisbury Plain.

“We are confident that radiocarbon and other dating in the future will confirm the falsehood of the Neolithic quarry theory and the essential reliability of the glacial transport theory."