1) Ancient rock engraving 2) French word used in English 
Petroglyphs (also called rock engravings) are pictogram and logogram images created by removing part of a rock surface by incising, picking, carving, and abrading. Outside North America, scholars often use terms such as `carving`, `engraving`, or other descriptions of the technique to refer to such images. Petroglyphs are found world-wide, and...
(from the article `pictography`) ...of all details not necessary for the expression of the communication. (Pictographs that are drawn or painted on rocks are known as petrograms; ... [9 related articles]
an image carved or pecked into a rock face using tone tools. 
petroglyph, petroglyphic A rock-carving (usually prehistoric).