The Marree Man geoglyph depicts a man holding either a throwing stick once used to disperse small flocks of birds, or a boomerang.

The lines of the figure were 20–30 cm (8–12 inches) deep at the time of discovery and up to 35 metres (114 feet) wide. The image is gradually eroding through natural processes, but because the climate is extremely dry and barren in the region, the image is still visible as of 2013.[2] While there is a layer of white chalk material slightly below the red soil, the figure was not defined to this depth.

http://en.wikipedia.org/wiki/Marree_Man