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An igneous rock consisting almost entirely of plagioclase feldspar, especially the labradorite variety.

[French anorthose, a kind of feldspar (Greek an-, not; see a-1 + Greek orthos, straight) + -ite.]

an·or′tho·sit′ic (-sĭt′ĭk) adj.


resembling or consisting of anorthosite
References in periodicals archive ?
The Property is underlain primarily by gabbroic to anorthositic rocks belonging to the Morin Intrusive Suite; lesser quartzite is also present.
From this evidence and from looking at the highlands' topography and density, scientists concluded that the early Moon must have been nearly totally molten, covered by an ocean of magma in which low-density minerals floated to the top (forming an anorthositic crust) while denser, iron-rich minerals such as olivine sank to the bottom, ultimately becoming the mantle.
Lunar geology can be roughly broken down into two categories-the anorthositic highlands, rich in calcium and aluminum, and the basaltic "maria," giant impact basins filled with solidified lava flows that are abundant in iron and magnesium.
The drilling has intersected packages of both cumulate and intrusive style magnetite-ilmenite mineralisation intercalated with gabbroic and anorthositic country rock.
In some stocks (Playa Matapalito), the elongated crystals of plagioclase display planar textures and anorthositic layers parallel to the planes suggest differentiation processes in dynamic conditions.
1977, Regional geobarometry in the contact aureoles of the anorthositic Nain Complex, Labrador, Jour.
The complex contains many individual mafic layered intrusions of tholeiitic affinity and structurally complex coeval anorthositic and felsic instrusions.
In addition, the overlying anorthositic, Middle Unit (MU) contains three PGE enriched zones and hole RP03-01 on the southern boundary of Rooipoort contains the best PGE values in one of these zones intersected to date (Table: 1).
Samples from the Apollo missions revealed that the maria are basaltic lava flows that include an abundance of the dark minerals rich in iron and titanium, whereas the highlands are rich in bright, aluminum-rich anorthositic rocks.