Crop circle found in Mount Delaney, Australia

On 1st September 2014, on morning, an Australian has discovered possible UFO landings marks in the area of Mount Delaney, in the State of Queensland (Australia). What is it?

Witness statement:

At approximately 8 am, I was walking to the stables to feed chickens, and noticed a large circle on the lawn about 10 feet across.

This was outlined in white which appeared to be an ice-like material, even though the temperature was about 12 degrees C. The material disappeared touched.

Upon closer inspection, there were 4 circles, the larger then decreasing in size to the smallest approximately 2 feet across. I proceeded to take photographs.

In the afternoon I went back to the area and the lawn is discolored, and the clear outline is still evident. I have no explanation for what caused this.

Photographs taken with Sony ILCE-7