Image: Indian petroglyphs (~100 B.C. to ~1540 A.D.) (Newspaper Rock, southeastern Utah, USA) 19 (22693596040)

Description: Human footprints & animal - Indian petroglyphs (~100 B.C. to ~1540 A.D.) on desert varnish-covered quartzose sandstone (Wingate Sandstone, Lower Jurassic) in Utah. This is part of a fantastic panel of prehistoric and historic petroglyphs that was carved by several groups - Archaic Indians, the Anasazi, Fremont, Navajo, Pueblo, and Ute. The dark coloration of the rock is desert varnish - a mineral-encrusted rock surface that is common in many desert settings. Desert varnish is composed of clay minerals, brick red-colored hematite, and/or black-colored manganese oxide minerals (for example, birnessite - www.mindat.org/min-680.html). Scraping or hammering away at the desert varnish exposes the light-colored sandstone. The oldest petroglyphs are identified by the partial development of another layer of desert varnish - they are dark-colored than younger petroglyphs. Locality: Newspaper Rock, Newspaper Rock State Historic Monument, southeastern Utah, USA
Title: Indian petroglyphs (~100 B.C. to ~1540 A.D.) (Newspaper Rock, southeastern Utah, USA) 19 (22693596040)
Credit: Indian petroglyphs (~100 B.C. to ~1540 A.D.) (Newspaper Rock, southeastern Utah, USA) 19
Author: James St. John
Usage Terms: Creative Commons Attribution 2.0
License: CC BY 2.0
License Link: https://creativecommons.org/licenses/by/2.0
Attribution Required?: Yes