TechMystery of Stonehenge. Researchers have no clue where did it come from

Mystery of Stonehenge. Researchers have no clue where did it come from

Stonehenge
Stonehenge
Images source: © Lic. CC BY-SA 4.0, Udit Kapoor, Wikimedia Commons

7:17 PM EDT, October 5, 2023

Stonehenge is one of the most famous megalithic structures in the world. Although it has long attracted the attention of researchers, it still hides unexplained mysteries. One of them was noted by scientists from Aberystwyth University. Their discovery partially questions the existing knowledge about the world-famous cromlech. What mystery has it been hiding from us until now?

Stonehenge is a cromlech - a circle made of large, vertically arranged boulders, erected in the Neolithic and Bronze Age. Located near the English city of Salisbury, it was gradually built on the site of a previous cult from around 3000 BC over the course of approximately 1400 years.

The stones from which Stonehenge was built are not uniform. There exist at least several conflicting assumptions as to the chronology, but it is believed that the outer circle of the structure, erected from stones called sarsens, was formed around 2500 BC.

Sarsen is a local building material, a hard sandstone mined about 25 km away, which was confirmed by a study conducted at the initiative of the English Heritage organization.

Inside, there is a second circle of "blue stones" – magma rocks, which take on a bluish hue when sprinkled with water. They were transported to the location from a distant excavation. They were located in the Mynydd Preseli mountain range, about 230 km from Stonehenge. However, not all the large boulders share a common origin.

Boulder 80

For many years, it was believed that the large, flat boulder placed inside the blue stones, known as the Altar Stone, originated from a rock formation known as the Old Red Sandstone (ORS). ORS extends from Norway, through Ireland and Great Britain, all the way to the eastern coast of the United States.

Altar Stone (Ołtarz)
Altar Stone (Ołtarz)© Lic. CC BY-SA 2.0, Pam Brophy, Wikimedia Commons

The altar is known to archaeologists as Boulder 80 and - when it stood upright, because it is currently overturned - was almost 5 meters high. However, new studies suggest that the origin of the Altar is different than the surrounding stones, and the path it travelled may be significantly longer.

The authors of the latest study point this out - a team from Aberystwyth University, which published the results of their work in the "Journal of Archaeological Science".

Long-distance transportation

In practice, this means searching among rocks where the barium content is significantly higher - in Northern Ireland, Northeast Wales, and parts of Northwestern England. This suggests that one of the large stones of Stonehenge traveled a much longer distance than previously thought.

Old Red Sandstone (ORS) rocks
Old Red Sandstone (ORS) rocks© Lic. CC BY-SA 2.0, Rodney Harris, Wikimedia Commons

As noted in their publication by the team from Aberystwyth University, the materials used to build megalithic structures were typically sourced locally, within a few kilometers, or even hundreds of meters from the construction site. It's these distances, over which stone blocks were transported thousands of years ago, that make Stonehenge so extraordinary.

The mystery of transporting stone blocks has been explained in various ways over the centuries, sometimes completely fantastic, like references to the magic of the wizard Merlin, the participation of giants, or the help of extraterrestrial civilizations.

14th-century depiction of a giant who helps Merlin build Stonehenge.
14th-century depiction of a giant who helps Merlin build Stonehenge.© Public domain

Closer to reality hypotheses assumed the use of boulders moved by a glacier, transportation by water using barges, rolling in massive, wicker casings, or building a road with round logs.

Lard from pork fat

Another proposal was brought by a study conducted under the Feeding Stonehenge program.

Dr. Lisa-Marie Shillito, an archaeologist from the University of Newcastle, analyzed the traces left on the remnants of vessels and places where meals were prepared. It turned out that in addition to the vessels with a mixture of fats of various origins, there were those that had contact exclusively with pork fat.

Stonehenge - bird's eye view
Stonehenge - bird's eye view© The British Academy

Traces of pigs that were roasted whole, without any signs of portion division, were also found, and the fat obtained from them was stored in containers of a different shape than those intended for food purposes.

According to Dr. Shillito, stone blocks for loading were lowered onto an earthen ramp. This was an elevation onto which a wooden structure resembling a sled could be placed. The boulder was slid onto it, and round logs were placed under the runners, functioning similarly to modern wheels. A variant of this hypothesis assumes that wooden "rails" could be placed under the logs, further reducing resistance.

Experiments have shown that such a prehistoric vehicle, burdened with a large boulder, a group of several dozen people can move at a speed of even 1.6 km per hour, and even push uphill onto an earth ramp. Another experiment, conducted in 1995 with a group of 100 people, confirmed the possibility of moving a 40-ton block a distance of almost 30 km.

This task could have been easier to perform precisely because of the animal fat that was used to grease the runners of the sled, thereby reducing friction and resistance that occurred during transport.