Sydney Rock Engravings - How Were They Made?

How Were They Made?

Examination of the grooves shows that they were made in several stages as follows:

• Presumably, a sketched outline was scratched on to the surface of the rock.

• Then a series of holes was drilled along the line, using a pointed stone or shell, which is possible because the Sydney Basin sandstone is relatively soft.

• Finally, the holes were joined by rubbing a sharp stone along the line.

This results in a U-shaped groove which is typically about 2 centimetres deep and 2 centimetres wide. It is easily distinguished from natural grooves in the sandstone, which are usually V-shaped, modern grooves made with steel tools, which are usually narrower and deeper, or those made by bulldozers, which usually have a square section.

The grooves were often maintained by "re-grooving" during ceremonies, which complicates attempts at dating them.