Petroglyph Rock Art Symbols

Symbols for Communication
Petroglyphs are images incised in rock, usually by prehistoric, especially Neolithic, peoples. They were an important form of pre-writing symbols, used in communication from approximately 10,000 B.C.E. to modern times, depending on culture and location.

The word comes from the Greek words petros meaning "stone" and glyphein meaning "to carve" . The term 'petroglyph' should not be confused with pictograph, which is an image drawn or painted on a rock face, both of which contribute to the wider and more general category of rock art. Petroforms, or patterns and shapes made by many large rocks and boulders in rows over the ground, are also quite different.


Interpretation of Symbols on Rocks
These images probably had deep cultural and religious significance for the societies that created them. Many petroglyphs are thought to represent some kind of not-yet-fully understood symbolic or ritual language. Later glyphs from the Nordic Bronze Age in Scandinavia seem to refer to some form of territorial boundary between tribes, in addition to possible religious meanings.

Some researchers have noticed the resemblance of different styles of petroglyphs across different continents; while it is expected that all people would be inspired by their surroundings, it is harder to explain the common styles. In 1853 George Tate read a paper to the Berwick Naturalists' Club at which a Mr John Collingwood Bruce agreed that the carvings had '.. a common origin, and indicate a symbolic meaning, representing some popular thought.' In his cataloguing of Scottish rock art, Ronald Morris summarised 104 different theories on their interpretation.

Similarity of Petroglyphs
Other, more controversial, explanations are that the similarity of petroglyphs (and other atavistic or archetypal symbols) from different cultures and continents is a result of the genetically inherited structure of the human brain. Other theories suggest that petroglyphs were made by shamans in an altered state of consciousness, perhaps induced by the use of natural hallucinogens. Many of the geometric patterns (known as form constants) which recur in petroglyphs and cave paintings have been shown to be "hard-wired" into the human brain; they frequently occur in visual disturbances and hallucinations brought on by drugs, migraine and other stimuli.

Present-day links between shamanism and rock-art amongst the San people of the Kalahari desert have been studied by the Rock Art Research Institute (RARI) of the University of the Witwatersrand. Though the San people's artworks are predominantly paintings, the beliefs behind them can perhaps be used as a basis for understanding other types of rock art, including petroglyphs.