Scientists have discovered the source of miniature bluestones that surround Stonehenge, bringing the archaeological world one step closer to cracking the mystery of how the ancient structure was created, Live Science reported.
Stonehenge, located in Wiltshire, England, is comprised of massive, 30-ton sarsen stones made of sandstone, and smaller bluestones. The smaller rocks were named bluestones due to their blue tinge when wet.
By studying the bluestones' composition, scientists found they originated from an outcropping not far from Stonehenge. The outcropping is also 1.8 miles from another site that was originally thought to be the source of the bluestones almost 100 years ago, Live Science reported.
The discovery "locates the exact sources of the stones, which highlight areas where archaeologists can search for evidence of the human working of the stones," said National Museum of Wales geologist Richard Bevins, who co-authored the study, Live Science reported.
The discovery was published in the February issue of the Journal of Archaeological Science.
Stonehenge is a prehistoric structure that dates back to 5,000 years ago. Construction of the structure, a large circle of vertical stones with horizontal stones on top, was altered by several ancient civilizations over the course of 1,000 years, Live Science reported.
The reason for the structure, or how the stones were raised, is still unknown.
Though the discovery may make solving the mystery easier, it still raises new questions about how they got there in the first place.
Scientists hope that finding out where the rocks originated will lead to evidence humans left behind in the area, Bevins said, Live Science reported. The evidence left by humans could then confirm or deny other theories of how the stones were moved. One theory says that glaciers transported the bluestones to the Stonehenge location during an ancient ice age, Live Science reported.
"For example, if we could determine with confidence that the stones had been worked by humans in Neolithic times, then the ice-transport theory would be refuted," Bevins said, according to Live Science.
