Círculos en el campo y otras formaciones. Australia

At around the same time as the Bordertown circles - December 1973 - a single circle was found at another site in South Australia, in a field of wheat. The Wokurna circle was a singleton, and was investigated by Peter Horne and Stephen Bolton on December 15.

Their report is not clear on whether the circle had been visited by others prior to their arrival. They comment, "many small tracks were visible. These, however, were probably caused by curious people." However their report states elsewhere, "When we examined the marking, it had been left untouched for us by the witnesses." One of their photographs (below) shows what seems to be litter within the circle, but which is in fact their own equipment. 

Horne and Bolton took several photographs, five of which are known to us, and also drew two detailed diagrams: one an aerial view, the other a cross-section. This makes the Wokurna case among the best documented pre-1978 events. 

The swirling was confined to an anti-clockwise "rim" around the edge, inside which was a bare patch, where seed germination was in evidence (as was the case at Tooligie, two years earlier). Their diagram indicates that the demarcation between horizontal and vertical stems was extremely abrupt. They also performed a crude hardness test by dropping pliers into the soil and ascertained that it was much harder inside than out - which could be due to compaction, dehydration, or possibly some other factor.

Samples and reports were taken and sent to various bodies including scientific and research institutions. However nothing fruitful came of this and no plausible theories were proposed for the cause of the circle.