People, not glaciers, brought the iconic stones to England’s Stonehenge, a new peer-reviewed study published in Communications Earth & Environment at the end of January confirmed.

The study, “Detrital zircon–apatite fingerprinting challenges glacial transport of Stonehenge’s megaliths,” refutes an idea known as the “glacial transport theory,” which suggests that Stonehenge’s bluestones and Altar Stone were brought to Salisbury Plain in Southern England by glaciers during the last ice age.

For decades, scientists have believed that the 5,000-year-old monument’s iconography originated in Wales and Scotland, but there has been debate about how it actually reached southern England.

Now, an analysis of microscopic mineral grains from rivers around Stonehenge revealed that glaciers never reached Salisbury Plain, so the stones must have been intentionally brought by people to build the monument.

“While previous research had cast doubt on the glacial transport theory, our study goes further and applies cutting-edge mineral fingerprinting to trace the stones' true origins," said study authors Anthony Clarke and Christopher Kirkland.

Stonehenge’s bluestones are from the Preseli Hills in Western Wales, meaning they were dragged approximately 225km to the site of the monument. 

Even more impressively, the Altar Stone at the center of Stonehenge’s middle circle came from Northern England or even Scotland, at least 500km from Salisbury Plain.

The glacial transport theory is a counterproposal to the idea that the stones were intentionally moved, suggesting instead that they were already in the area.

However, for many years, archaeologists have argued that the rocks show no signs of glacial transport, and they have been uncertain about how far into southern England the glaciers reached.

In this study, the researchers used radioactive decay rates to date tiny particles of zircon and apatite left over from ancient rocks in river sediments around Stonehenge, revealing the age of the rocks that once existed in the region and providing insight into where they came from.

If the rocks were dragged across the land to Stonehenge by glaciers, they would have left traces.

After analysing over 700 zircon and apatite grains, they found no significant match for rocks in either Scotland or Wales.

They found that glaciers likely didn’t reach parts of England as far south as Salisbury Plain during the last ice age, disproving the theory that the stones were transported there by glaciers.

"This gives us further evidence that the monument's most exotic stones did not arrive by chance but were instead deliberately selected and transported," the researchers wrote.