Microdiamondiferous ultrapotassic minette (Akluilâk Dike System, Paleoproterozoic, 1.832 Ga; Gibson Lake area, Central Churchill Province, northern Canada) 2 : 無料・フリー素材/写真
Microdiamondiferous ultrapotassic minette (Akluilâk Dike System, Paleoproterozoic, 1.832 Ga; Gibson Lake area, Central Churchill Province, northern Canada) 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 | Minette from the Precambrian of Canada. (4.2 centimeters across at its widest)This is an ultrapotassic minette, a rare intrusive igneous rock. Minettes are potassic mica lamprophyres. The dark crystals are biotite mica. The light-colored crystals are orthoclase feldspar. This particular minette is microdiamondiferous, and comes from the Akluilâk Dike System of the Central Churchill Province, northern Canada. The Akluilâk Dikes were intruded during the late Paleoproterozoic, at about 1.832 billion years ago. Microdiamonds found in these rocks are ~2 billion years old.Locality: Gibson Lake area, Gibson-MacQuoid Lake Belt, ~120 km northwest of Rankin Inlet, District of Keewatin, Northwest Territories (sensu lato) (“Nunavut”), northern Canada (approximately 63º 35’ North latitude, 93º 30’ West longitude)------------------See MacRae et al. (1996) for more info.:MacRae, N.D., A.E. Armitage, A.R. Miller, J.C. Roddick, A.L. Jones & M.P. Mudry. 1996. The diamondiferous Akluilâk lamprophyre dyke, Gison Lake area, N.W.T. in Searching for diamonds in Canada. Geological Survey of Canada Open File 3228: 101-107. |
撮影日 | 2020-05-27 15:32:43 |
撮影者 | James St. John |
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