Indian petroglyphs (~100 B.C. to ~1540 A.D.) (Newspaper Rock, southeastern Utah, USA) 2 : 無料・フリー素材/写真
Indian petroglyphs (~100 B.C. to ~1540 A.D.) (Newspaper Rock, southeastern Utah, USA) 2 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | Anthropomorphs & animals (buffalo and horses, etc.) & footprints & abstract figures - 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.The petroglyphs at Newspaper Rock have been chemically restored, in response to vandalism by tourists in the past.Locality: Newspaper Rock, Newspaper Rock State Historic Monument, southeastern Utah, USA |
| 撮影日 | 2011-09-04 11:43:31 |
| 撮影者 | James St. John |
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