Native copper in calcite crystals (late Mesoproterozoic mineralization age, 1.05-1.06 Ga; Quincy Mine, Hancock, Keweenaw Peninsula, Upper Peninsula of Michigan, USA) 4 : 無料・フリー素材/写真
Native copper in calcite crystals (late Mesoproterozoic mineralization age, 1.05-1.06 Ga; Quincy Mine, Hancock, Keweenaw Peninsula, Upper Peninsula of Michigan, 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 | Native copper (Cu) in calcite crystals from the Precambrian of northern Michigan, USA. (public display, Seaman Mineral Museum, Michigan Technological University, Houghton, Michigan, USA)The bedrock in northern Michigan's Keweenaw Peninsula area with Earth's highest concentration of elemental copper (Cu) in its native state. The copper has been extensively mined, but only one active mine remains (all the easily exploited copper is now mined out). Copper usually occurs in various late Mesoproterozoic-aged basaltic rocks and conglomerates.A beautiful and rare occurrence for native copper in northern Michigan is WITHIN other crystals. The above photo shows transparent to translucent calcite crystals having metallic orange-colored inclusions of native copper.Stratigraphy & age: derived from the upper Portage Lake Volcanic Series, upper Mesoproterozoic (1.093 Ga); copper & calcite mineralization age is late Mesoproterozoic (1.05 to 1.06 Ga).Locality: Quincy Mine, city of Hancock, north of Portage Lake, Keweenaw Peninsula, Houghton County, northwestern Upper Peninsula of Michigan, USA.-------------------Photo gallery of copper:www.mindat.org/gallery.php?min=1209 |
| 撮影日 | 2010-09-16 09:59:21 |
| 撮影者 | James St. John |
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