A mafic intrusive igneous rock composed largely of the calcium rich plagioclase feldspar labradorite together with orthopyroxene and olivine, also known as orthopyroxene gabbro because it is distinguished from ordinary gabbro chiefly by its pyroxene: norite contains orthopyroxenes such as enstatite or hypersthene, while gabbro contains clinopyroxenes, typically augite. Its name comes from Norge, the Norwegian word for Norway. Norite forms in layered igneous intrusions alongside gabbro and other mafic to ultramafic rocks, with major deposits found in platinum associated formations including the Bushveld Igneous Complex in South Africa, the Skaergaard intrusion in Greenland and the Stillwater complex in Montana, and it also forms the basal rock of the Sudbury Basin in Ontario, the site of an ancient comet impact and the world's second largest nickel mining region. Norite is also common among lunar samples returned by the Apollo missions, and on Earth it occurs in smaller localized deposits such as the Gombak norite in Bukit Batok, Singapore, and the Sokndal intrusion area of Norway, which contains titanium deposits.
Facts
Formation ClassIgneous, intrusive (mafic plutonic) 1 Classification
Classification Connections
Associated With
Norite intrusions such as Sudbury and the Bushveld Complex are classic hosts of magmatic sulfide mineralization including pyrite.
Classified As
In Discipline
Sources
1. Norite (Wikipedia)
Lead section, opening sentence
Norite is a mafic intrusive igneous rock composed largely of the calcium-rich plagioclase labradorite, orthopyroxene, and olivine.
Lead section, opening sentence (formation clause)
Norite is a mafic intrusive igneous rock composed largely of the calcium-rich plagioclase labradorite, orthopyroxene, and olivine.
Lead section
Norite is a mafic intrusive igneous rock composed largely of the calcium-rich plagioclase labradorite, orthopyroxene, and olivine.
View the SourceWikidata: Norite
Wikidata Q1468713
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