Scientists in South Africa have discovered 8,000-year-old carvings made by a group of humans inside the world's biggest meteorite impact crater. The carvings—of animals—were discovered in the 'Rain Snake' dyke of the Vredefort structure, and are believed to have had spiritual significance relating to rain making.
At 190 miles wide, the Vredefort structure is the largest verified impact crater on Earth. It was made by an asteroid between six and nine miles wide and was traveling at almost 43,500 miles per hour when it hit, over two billion years ago.
In the century since the discovery of the impact site, there have been many studies looking at its structure—however, little research has been done into some of the more unusual features of the crater, including its "Granophyre Dykes"—long, narrow structures that can be six miles long and 16 feet wide. These dykes are known to have formed during the impact, but how the molten material the rocks were made from were transported to the surface is unclear.
While investigating these strange rock formations, researchers discovered a set of ancient carvings at the site that were unknown to archaeologists.
Matthew Huber, of South Africa's University of the Free State, told Newsweek that planetary scientists and geologists working at the site had known about the rock art for many years. "Once we learned that the archaeological and anthropological communities did not know about the site, we immediately began to seek out assistance in studying these features further," he said.
The carvings, which include what appears to be of a hippo, horse and rhino, were made 8,000 years ago by the Khoi-San—known as South Africa's 'First Peoples.' "As scientists, we recognize the special nature of the impact crater, but it was also recognized by ancient inhabitants of the area," Huber said.
"The area around these dykes is littered with artifacts and carvings from the Khoi-San people. Obviously, they also recognized the significance of the site. What is amazing is that the same dykes that we recognize to have the most geological significance also had the most spiritual significance for these early inhabitants. Our anthropological studies are focused on trying to uncover exactly what was done at these sites and how it influenced the people that were there."
Researchers noticed that one of the dykes resembles the shape of the "Rain Snake"—an important deity at the time. Archaeologists Shiona Moodley and Jens Kriek, who worked at the site note that San mythology is split into a three-tiered universe. Above is occupied by god and spirits of the dead, the middle is the material world, while below is associated with the dead and shamanistic travel. Snakes, they said, were found on all three tiers, and they were thought of as creatures of "rain."
In their report of the site, they said: "Kaggen, uppermost deity of the IXam, could transform himself into a snake. In this form he had the power to flood the countryside. If a man wished to become a shaman, he had to plunge into a deep pool and come out with a large snake. If the snake did not struggle as he came out, he was destined to become a shaman. He then had to kill it and perform a public dance with the skin tied around his forehead, the rest of the snake's body streaming behind him."
Huber believes the Khoi-San used the snake-shaped dyke as a "rain-making site." He said that while some of the art styles and carvings had changed over time, there is a constant connection to rain. "The dyke is positioned near the Vaal river—a body of water—and is on top of a hill. As a high point, it would have attracted lightning strikes. The animals carved into the dyke are all associated with the rain-making mythology of the San. All of these features point towards the site being used for making rain."
Huber said work at the site is ongoing and the team is about to go on another trip to the crater: "We will be generating lots of data on the dykes as well as the carvings. This will include making a 3D model of the dykes, and we will be making reference points for all of the locations of the carvings that we locate...we will also be visiting some new sites that we have never been to before, and we don't know what we will discover."