Grounds of the Orphan Boy Mine (Butte, Montana, USA) 4 : 無料・フリー素材/写真
Grounds of the Orphan Boy Mine (Butte, Montana, USA) 4 / 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 | The town of Butte, Montana is known as the “Richest Hill on Earth” and "The Mining City". The Butte Mining District has produced gold, silver, copper, molybdenum, manganese, and other metals.The area's bedrock consists of the Butte Quartz Monzonite (a.k.a. Butte Pluton), which is part of the Boulder Batholith. The Butte Quartz Monzonite ("BQM") formed 76.3 million years ago, during the mid-Campanian Stage in the Late Cretaceous. BQM rocks have been intruded and altered by hydrothermal veins containing valuable metallic minerals - principally copper sulfides. The copper mineralization has been dated to 62-66 million years ago, during the latest Maastrichtian Stage (latest Cretaceous) and Danian Stage (Early Paleocene). In the supergene enrichment zone of the area, the original sulfide mineralogy has been altered.Seen here is the grounds of the former Orphan Boy Mine in Butte. Hydrothermal veins in this area are part of the lead-zinc-gold zone. Copper occurs in Butte's central zone. Mining at this site used to be for manganese (Mn), which was concentrated in the uppermost supergene enrichment cap. Dark manganese oxide-stained rocks are common close to the veins.Locality: grounds of the Orphan Boy Mine, western side of the town of Butte, southwestern Montana, USA (vicinity of 46° 00' 42.36" North latitude, 112° 34' 05.50" West longitude) |
| 撮影日 | 2010-08-09 13:48:36 |
| 撮影者 | James St. John |
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