Weathering of petroglyphs: Direct assessment and implications for dating methods

Petroglyphs weather at varying rates, compared to the unengraved host rock into which they are carved. Most petroglyphs are significantly harder or si gnificantly softer than surrounding rock, depending on the nature of weathe ring. Variability and intensity of weathering probably introduces error int o radiocarbon, rock varnish and microerosion dating methods.