A huge spiral carved into the ground in India covers almost 100,000 square metres, dwarfing other individual geoglyphs like those in the Nazca desert in Peru.
The spiral is in a small cluster of geoglyphs discovered by father-and-son researchers Carlo and Yohann Oetheimer, who are based in Luriecq, France. Carlo searched Google Earth images of the Thar desert in India and identified eight sites with possible geoglyphs. In 2016, they flew a drone over them and found that four were furrows dug for failed tree plantations.
One site was near the village of Boha. Using the drone there, the Oetheimers identified four distinct symbols, which they then visited. Each line in the geoglyphs is 20 to 50 centimetres wide and was made by scraping away sand and silt.
The central symbol is a roughly oval spiral that is 724 metres long and 201 metres wide, made of a single 12-kilometre line. To the immediate south-west, there is a second line that repeatedly bends back on itself, forming a grid of parallel lines. There are also two smaller geoglyphs to the north and south-west that are heavily eroded.
“The report is convincing,” says Daniela Valenzuela at the University of Tarapacá in Arica, Chile.
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The spiral dwarfs all other known geoglyphs. Peru’s Nazca Lines cover a much wider area, but none of that site’s figures are especially large: one bird figure is 300 metres long and a shape thought to be a labyrinth is made up of one 4.4-kilometre line.
The Oetheimers suspect the Boha geoglyphs are at least 150 years old because they have been eroded by wind, and plants have grown on them in places. But they have no further evidence to shed light on their age, meaning or purpose.
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It may be significant that they can’t be seen from the ground, says Valenzuela. This may imply that their significance stemmed from the act of creating them, not from later viewings. She says that some Aboriginal communities in Australia are known to do sand drawings and then erase them immediately. Alternatively, the intention may have been that people experience the geoglyphs by walking through them, rather than by looking at them.
Journal reference: Archaeological Research in Asia, DOI: 10.1016/j.ara.2021.100290