How Do Petroglyphs Work?

Petroglyphs are rock carvings (rock paintings are called pictographs) made by pecking directly on the rock surface using a stone chisel and a hammerstone. When the desert varnish (or patina) on the surface of the rock was chipped off, the lighter rock underneath was exposed, creating the petroglyph.

How are petroglyphs used?

Petroglyphs were used to convey messages and ideas. They aren't read like words, or even like ancient hieroglyphics. They are symbols that can represent anything from a simple object to a complex idea. Our modern cultures also use symbols in similar ways.

How do petroglyphs last so long?

The time machines are drawings on rocks made thousands of years ago. ... Once it has been carved or chipped away, the lighter color of the rock is revealed. This makes the rock art stand out like a prehistoric neon sign. It is also why petroglyphs have lasted for such a long time.