Abstract

Scattered throughout the Great Basin and the drainages of the upper Colorado and Rio Grande Rivers is a legacy of prehistoric and historic (i.e., post-Spanish contact) Indian rock art that represents a several-thousand year old tradition of creating culturally meaningful images on stone. Depending on the nature of the stone surface, and also on the intent of the "artist", the images were either pecked, scratched or abraded into the stone, or painted on suitably smooth and protected cliff walls. The terms petroglyph and pictograph are respectively applied to these two basic techniques. Petroglyphs typically were pecked through the dark patina coating, which slowly develops on many rock surfaces in the desert environment, to disclose the lighter colored rock beneath, whereas mineral-based pigments were employed in making pictographs. Among the inventory of images are human-like (anthropomorphic) and animal (zoomorphic) forms, as well as a large variety of abstract elements and more esoteric designs that are subject to various interpretations. With time, the rock art of the Great Basin area generally evolved from the abstract to the more representational, although many abstract designs remained popular (i.e., meaningful) throughout the area's long history.

© 1990 Optical Society of America