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  2. Layered intrusion - Wikipedia

    en.wikipedia.org/wiki/Layered_intrusion

    A layered intrusion is a large sill -like body of igneous rock which exhibits vertical layering or differences in composition and texture. These intrusions can be many kilometres in area covering from around 100 km 2 (39 sq mi) to over 50,000 km 2 (19,000 sq mi) and several hundred metres to over one kilometre (3,300 ft) in thickness. [1]

  3. Great Dyke - Wikipedia

    en.wikipedia.org/wiki/Great_Dyke

    The Great Dyke is a strategic economic resource with significant quantities of chrome and platinum. Chromite occurs to the base of the Ultramafic Sequence and is mined throughout the dyke. [ 4 ] Below the Ultramafic-Mafic sequences' contact, and in the uppermost pyroxenite (bronzitite and websterite) units are economic concentrations of nickel ...

  4. Windimurra intrusion - Wikipedia

    en.wikipedia.org/wiki/Windimurra_intrusion

    Setting. The Windimurra Igneous Complex is part of the c. 2813 Ma Meeline Suite of mafic-ultramafic layered intrusions of the central Murchison Domain, Yilgarn Craton of Western Australia. [1] It is a conical body, approximately 7 km thick, primarily composed of layered gabbroic rocks, which intrude into c. 2820 Ma Norie Group rocks of the ...

  5. Anorthosite - Wikipedia

    en.wikipedia.org/wiki/Anorthosite

    Anorthosite (/ əˈnɔːrθəsaɪt /) is a phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal mafic component (0–10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present. Anorthosites are of enormous geologic interest, because it is ...

  6. Stillwater igneous complex - Wikipedia

    en.wikipedia.org/wiki/Stillwater_igneous_complex

    Ore grade is about 2.5 ounces of Pd-Pt per ton of rock, with a Pd-Pt ratio of about 3:1. The Stillwater igneous complex is a large layered mafic intrusion (LMI) located in southern Montana in Stillwater, Sweet Grass and Park Counties. The complex is exposed across 30 miles (48 km) of the north flank of the Beartooth Mountain Range.

  7. Dunite - Wikipedia

    en.wikipedia.org/wiki/Dunite

    Dunite (/ ˈduːnaɪt, ˈdʌnaɪt /), also known as olivinite (not to be confused with the mineral olivenite), is an intrusive igneous rock of ultramafic composition and with phaneritic (coarse-grained) texture. The mineral assemblage is greater than 90% olivine, with minor amounts of other minerals such as pyroxene, chromite, magnetite, and ...

  8. Bushveld Igneous Complex - Wikipedia

    en.wikipedia.org/wiki/Bushveld_Igneous_Complex

    The Bushveld Igneous Complex is a layered mafic intrusion (LMI) with well-defined ore bodies of stratiform chromitite layers concentrated with the so-called Critical Zone; these are referred to as reefs. The three main reef deposits are the Merensky reef, UG-2 Reef, and the Platreef.

  9. Cumulate rock - Wikipedia

    en.wikipedia.org/wiki/Cumulate_rock

    Secondly, large ultramafic intrusions are rarely sealed systems and may be subject to regular injections of fresh, primitive magma, or to loss of volume due to further upward migration of the magma (possibly to feed volcanic vents or dyke swarms). In such cases, calculating magma chemistries may resolve nothing more than the presence of these ...