Archaeologists in Glasgow, Scotland, briefly excavated and then reburied a 5,000-year-old slab of stone that contains incised swirling geometric decorations.
The Cochno Stone, which measures 43 feet by 26 feet (13 by 8 meters), contains swirling decorations, also called "cup and ring marks." The stone and its decorations have been known to people in the area since at least the 19th century. Decorations similar to these swirls have been found at other prehistoric sites around the world; however, the examples incised in the Cochno Stone are considered to comprise "one of the best examples" of such art in Europe, according to a statement by the University of Glasgow, which led the new study.
The stone slab was fully unearthed in West Dunbartonshire by Rev. James Harvey in 1887. By 1965, the stone had been vandalized with graffiti and damaged by the elements, so a team of archaeologists buried it beneath the dirt in order to protect the artwork . This summer's two-week re-excavation allowed archaeologists to use modern-day surveying and photography techniques to better record the artwork. [Gallery: Aerial Photos Reveal Mysterious Stone Structures]
For instance, digital-scanning and mapping experts from the Factum Foundation used cutting-edge 3D-imaging technology to make a detailed digital record of the site, according to the university statement.
The re-excavation also revealed 19th- and 20th-century graffiti etched alongside the swirls, as well as painted lines intentionally made by an archaeologist named Ludovic Maclellan Mann, who worked at the site in 1937. Mann painted lines on the Cochno Stone to help measure the prehistoric artwork and see if there was a link to astronomical phenomena, such as eclipses.
Mann "was trying to prove that the symbols could predict eclipses and were marking movements of the sun and moon in prehistory," said Kenny Brophy, an archaeologist and senior lecturer at the University of Glasgow, in a video released by the university. He said that Mann's own data ended up disproving the archeologist's theory.
The meaning of the artwork is still unknown, said Brophy, adding that the vast amount of data gathered this summer may, in time, allow archaeologists to better understand the artifact. He said that the graffiti is also of interest and will help archaeologists better understand what people who lived in the local area thought of the artwork during the 19th and 20th centuries and how they incorporated it into their lives.
While archaeologists had to rebury the swirling prehistoric artwork in order to protect it, Brophy said he hopes that one day it will be possible to create an area where the rock art can be permanently revealed for both tourists and people in the local area to see. Funding will have to be obtained to build a protective area and visitors centre so that people can view the prehistoric artwork without damaging it.
"It is emotional when you have worked on a project such as this, touched it, walked on it and closely examined it, to then rebury it. But for now, that is what we have to do to protect it from the elements," Brophy said in the statement. "Perhaps in the future, this site could be turned into a major tourist attraction in Scotland, with a visitor center — who knows?"
