Norite


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Related to Norite: pyroxenite, granophyre, anorthosite, Troctolite

norite

[′nȯ‚rīt]
(petrology)
A coarse-grained plutonic rock composed principally of basic plagioclase with orthopyroxene (hypersthene) as the dominant mafic material. Also known as hypersthenfels.

Norite

 

(Norwegian norit, from Norge, “Norway”), a rock of basic composition in the gabbro group. It differs from gabbro in that it contains a rhombic pyroxene, usually bronzite but sometimes enstatite and hypersthene. When both pyroxenes are present the rock is called gabbro-norite. The remaining minerals are those in gabbro. Plagioclase with more than 50 percent anorthite predominates; olivine is often present; and various ore minerals such as magnetite, titanmagnetite, and sulfides occur as insignificant impurities. Norite typically has a low SiO2 content (45–55 percent), significant amounts of Mg and Ca (10–20 percent), and a negligible alkali content (rarely more than 2–3 percent). It is used as a building material.

References in periodicals archive ?
The gabbro body in the vicinity of the Woodland Dump was described by Ludman and Hill (1990) to consist of olivine norite.
Stephen Gabbro consists of complexly intermingled olivine gabbro, olivine gabbronorite, and olivine norite, with less abundant gabbro, gabbronorite, norite, troctolite, anorthosite, and dunite.
Ore hosted in a norite body within a large unexplored anorthosite complex.
5 kilometres as a funnel shaped embayment from the base of the norite at the south central footwall contact of the Sudbury Irruptive and thins to a vertical or steeply dipping dyke averaging 40 metres in width and extending 19 kilometres to the south ("Copper Cliff Offset").
Pyroxenite and norite above the peridotite contain disseminated sulphides.
Two 45 degree angled drill holes on a SE bearing returned core lengths of 53m and 90m respectively of anorthosite and norite breccia with massive ilmenite matrix.
harzburgite, olivine pyroxenite, and norite rock types.
This ground covers an unexplored part of the Sudbury Igneous Complex (SIC) contact just west of Falconbridge's Roland Lake Deposit, as well as a highly prospective and distinctive protuberance of SIC norite that extends over 200 metres into the footwall and is associated with zones of well-defined Late Granite Breccia and Sudbury Breccia.
No mineralization was intercepted and the resistivity low was attributed to norite with talc alteration.
This ground covers an unexplored part of the Sudbury Igneous Complex (SIC) contact south of the Foy Offset Dyke as well as a highly prospective and distinctive protuberance of the main SIC norite into the footwall rocks.
The hole was collared on Norite and intersected the contact between the Norite and Bronzite - the geologic contact commonly located near the VEZ.