Stonehenge 'bluestones' quarried 5,000 years ago
London: The smaller 'bluestones' used to build the Stonehenge were quarried 5,000 years ago and transported over land from almost 290 kilometres away, according to scientists who have pinpointed the exact sources of the stones.
Geologists have long known that 42 of Stonehenge's smaller stones, known as 'bluestones', came from the Preseli hills in Pembrokeshire, west Wales.
A study, published in the journal Antiquity, pinpoints the exact locations of two of these quarries, and reveals when and how the stones were quarried.
"What's really exciting about these discoveries is that they take us a step closer to unlocking Stonehenge's greatest mystery — why its stones came from so far away," said Mike Parker Pearson, a professor at University College London in the UK.
"Every other Neolithic monument in Europe was built of megaliths brought from no more than 10 miles (16 kilometres) away," Parker Pearson said.
"We're now looking to find out just what was so special about the Preseli hills 5,000 years ago, and whether there were any important stone circles here, built before the bluestones were moved to Stonehenge," Parker Pearson said.
The largest quarry was found almost 290 kilometres away from Stonehenge on the outcrop of Carn Goedog, on the north slope of the Preseli hills.
"This was the dominant source of Stonehenge's spotted dolerite, so-called because it has white spots in the igneous blue rock. At least five of Stonehenge's bluestones, and probably more, came from Carn Goedog," said Richard Bevins, a geologist at National Museum of Wales.
In the valley below Carn Goedog, another outcrop at Craig Rhos-y-felin was identified by researchers as the source of one of the types of rhyolite — another type of igneous rock — found at Stonehenge.
According to the new study, the bluestone outcrops are formed of natural, vertical pillars.
These could be eased off the rock face by opening up the vertical joints between each pillar.
Unlike stone quarries in ancient Egypt, where obelisks were carved out of the solid rock, the Welsh quarries were easier to exploit.
Neolithic quarry workers needed only to insert wedges into the ready-made joints between pillars, then lower each pillar to the foot of the outcrop.
Although most of their equipment is likely to have consisted of perishable ropes and wooden wedges, mallets and levers, they left behind other tools
such as hammer stones and
stone wedges.
