No explanations for 'fairy circles'

Scientists in South Africa are baffled by Namibia's 'fairy circles.'

The circles comprise innumerable discs of completely bare sandy soil, ranging from two to 10 metres across, found in grass on Namibia's coastal fringe.

Scientists looked at three explanations: the milkbush, termites and radioactive soil. All of them have been discarded.

Lead scientist Gretel van Rooyen, a botanist at the University of Pretoria, is now exploring the theory that, somehow, toxic elements are deposited in the shape of the circle, making it impossible for plant life to get established there.
"But even if we find them, how they came there is the next problem," New Scientist quotes her as saying in next Saturday's issue.
For the moment, she admits wryly, "we're left with the fairies".