Fixed some typos and incorrect statements (e.g. olivine is not necessary in a norite; the pyroxene composition is more variable than the text implied; Pt mineralization is not that common in magic layered intrusions).
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Norite occurs with gabbro and other mafic to [[ultramafic]] rocks in [[layered intrusion]]s which are often associated with [[platinum]] [[ore]]bodies such as in the Bushveld Igneous Complex in [[South Africa]], the [[Skaergaard intrusion|Skaergaard igneous complex]] of [[Greenland]], and the [[Stillwater igneous complex]] in [[Montana]]. Norite is also the basal igneous rock of the [[Sudbury Basin]] complex in [[Ontario]], which is the site of a [[impact event|comet impact]] and the world's second-largest [[nickel]] mining region. |
Norite occurs with gabbro and other mafic to [[ultramafic]] rocks in [[layered intrusion]]s which are often associated with [[platinum]] [[ore]]bodies such as in the Bushveld Igneous Complex in [[South Africa]], the [[Skaergaard intrusion|Skaergaard igneous complex]] of [[Greenland]], and the [[Stillwater igneous complex]] in [[Montana]]. Norite is also the basal igneous rock of the [[Sudbury Basin]] complex in [[Ontario]], which is the site of a [[impact event|comet impact]] and the world's second-largest [[nickel]] mining region. |
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<ref>{{citation| last=Petrus| first = Joseph A.|last2= Ames | first2= Doreen E. | last3 = Kamber |first3= Balz S.| journal= Terra Nova| date= October 18, 2014| doi= 10.1111/ter.12125| title=On the track of the elusive sudbury impact: geochemical evidence for a chondrite or comet bolide (accepted for publication)}}</ref> <ref>{{cite web|url = http://www.largeigneousprovinces.org/sites/default/files/BushveldLIP.pdf|title=The Bushveld Large Igneous Province |publisher = School of Geosciences, University of the Witwatersrand |author= Judith A.Kinnaird |accessdate= March 1, 2018}}</ref> |
<ref>{{citation| last=Petrus| first = Joseph A.|last2= Ames | first2= Doreen E. | last3 = Kamber |first3= Balz S.| journal= Terra Nova| date= October 18, 2014| doi= 10.1111/ter.12125| title=On the track of the elusive sudbury impact: geochemical evidence for a chondrite or comet bolide (accepted for publication)| doi-access= free}}</ref> <ref>{{cite web|url = http://www.largeigneousprovinces.org/sites/default/files/BushveldLIP.pdf|title=The Bushveld Large Igneous Province |publisher = School of Geosciences, University of the Witwatersrand |author= Judith A.Kinnaird |accessdate= March 1, 2018}}</ref> |
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<ref>{{cite web|url = https://academic.oup.com/petrology/article/45/3/507/1396172 |title= The Shape and Volume of the Skaergaard Intrusion, Greenland: Implications for Mass Balance and Bulk Composition |
<ref>{{cite web|url = https://academic.oup.com/petrology/article/45/3/507/1396172 |title= The Shape and Volume of the Skaergaard Intrusion, Greenland: Implications for Mass Balance and Bulk Composition |
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|publisher = Journal of Petrology, Volume 45, Issue 3, 1 March 2004, Pages 507–530|author= Troels F. D. Nielsen|accessdate= March 1, 2018}}</ref><ref>{{cite web|url = http://www.d.umn.edu/~mille066/Teaching/5100/Articles/McCallum.Stillwater.pdf|title= The Stillwater Complex: A review of the geology|publisher = University of Washington|author= I. S. McCallum|accessdate= March 1, 2018}}</ref> |
|publisher = Journal of Petrology, Volume 45, Issue 3, 1 March 2004, Pages 507–530|author= Troels F. D. Nielsen|accessdate= March 1, 2018}}</ref><ref>{{cite web|url = http://www.d.umn.edu/~mille066/Teaching/5100/Articles/McCallum.Stillwater.pdf|title= The Stillwater Complex: A review of the geology|publisher = University of Washington|author= I. S. McCallum|accessdate= March 1, 2018}}</ref> |
Norite is a mafic intrusive igneous rock composed largely of the calcium-rich plagioclase labradorite, orthopyroxene, and olivine. The name norite is derived from Norge, the Norwegian name for Norway.[1]
Norite also known as orthopyroxene gabbro. Norite may be essentially indistinguishable from gabbro without thin section study under the petrographic microscope. The principal difference between norite and gabbro is the type of pyroxene of which it is composed. Norite is predominantly composed of orthopyroxenes, largely high magnesian enstatite or an iron bearing intermediate hypersthene. The principal pyroxenes in gabbro are clinopyroxenes, generally medially iron-rich augites.[2][3]
Norite occurs with gabbro and other mafic to ultramafic rocks in layered intrusions which are often associated with platinum orebodies such as in the Bushveld Igneous Complex in South Africa, the Skaergaard igneous complexofGreenland, and the Stillwater igneous complexinMontana. Norite is also the basal igneous rock of the Sudbury Basin complex in Ontario, which is the site of a comet impact and the world's second-largest nickel mining region. [4] [5] [6][7] [8]
Norite is a common rock type of the Apollo samples. On a smaller scale, norite can be found in small localized intrusions such as the Gombak noriteinBukit Batok, Singapore. It is also plentiful in the Egersund intrusion area of southwestern Norway, with titanium deposits to the east.[9]