June 20, 2014

The sounds of celebrations welcoming the summer solstice at Stonehenge in England thousands of years ago might have included rock music. If so, the music made from striking the huge stones used to construct the monument might explain why ancient Britons went so far afield to find the stones. People who gather at the valued World Heritage site for the arrival of the summer solstice tomorrow, however, will almost certainly have to content themselves with beating drums and singing.

The ancient ruin of Stonehenge, which lies on the Salisbury Plain in Wiltshire, consists of huge, rough-cut stones set in a circle. Archaeologists think that ancient Britons constructed the site as a gathering place and religious center, particularly for ceremonies linked to the solstices, the times of the year that mark the beginning of summer and winter. In fact, the paved avenue at Stonehenge lines up with the sunrise on the summer solstice. Thousands of people continue to gather at the site twice a year to celebrate the solstices.

Stonehenge was probably used as a tribal gathering place and a religious center by ancient inhabitants of England. It was built between about 2800 and 1500 B.C. The drawing shows what scholars believe was the original arrangement of the monument's huge stones. (Aerofilms)

One of the many mysteries of Stonehenge is why its ancient builders used rocks from hundreds of miles away for the inner ring–despite the presence of rock deposits much closer. Stonehenge’s inner stones, called bluestones, were quarried some 245 miles (395 kilometers) away in the Preseli Mountains of Pembrokeshire in southern Wales. After quarrying, the stones were dragged to the sea, loaded onto barges, and floated up Hampshire’s River Avon to near Stonehenge. For the ancient Britons, this was no small effort. The bluestones are massive, with some weighing up to 4 tons (3.6 metric tons).

Now researchers from the Royal College of Art in London have suggested an answer: The rocks were chosen for the bell-like sounds they produce when struck. Such sounding stones, also called lithophones, are often associated with healing rituals and can be found throughout the world. In the United States, Ringing Rock State Park in Pennsylvania is known for the chime-like qualities of its ancient boulders. Stonehenge’s bluestones, like the Pennsyvania boulders, are diabase rocks, dense, fine-grained igneous rocks with deposits of iron and magnesium. The volcanic rocks spent some 170 million years cooling below ground, explained geologist Lawrence L. Makinconico of Lafayette College in Pennsylvania. “When they cool, it’s something like forging a cast-iron bell,” he told The New York Times.

Additonal World Book articles:

• Avebury
• Megalithic monuments
• History of the United Kingdom (Prehistoric Britain)
• Archaeology (1966) (a Back in Time article)
• Cahokia: Mysteries in the Mounds (a Special Report)
• Reading the Sky: Early Places of Astronomy (a Special Report)

To hear sounds made by rocks in the Preseli Mountains, where Stonehenge’s bluestones were quarried, go to:

http://www.landscape-perception.com/acoustic_mapping/