anorthosite

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anorthosite

[ə′nȯr·thə‚sīt]
(petrology)
A visibly crystalline plutonic rock composed almost entirely of plagioclase feldspar (andesine to anorthite) with minor amounts of pyroxene and olivine.
References in periodicals archive ?
the SC-95-02 showing has returned values up to 772 parts per million cobalt ("ppm Co"), 2,108 parts per million copper ("ppm Cu") and 3,907 parts per million nickel ("ppm Ni") in grab samples of pyrrhotite and chalcopyrite mineralization in anorthositic gabbro;
The silicic features we've found on the Moon are fundamentally different from the more typical basaltic mare and anorthositic highlands," said Timothy Glotch of Stony Brook University, N.
Mineral variation in anorthositic, troctolitic, and adamellitic rocks of the Barth Island Layered Structure in the Nain Anorthosite Complex, Labrador.
Those that are bright only because they contain reflective, powdery ejecta age more rapidly than rays that are also rich in anorthositic highland debris.
Coughlan (1986) recognized five units in the Staples Mountain Gabbro, designated I to V from inferred bottom to top: I--gabbro, anorthositic gabbro, and olivine gabbro; II--subophitic augite gabbro; III--interlayered norite and anortbosite; IV--unlayered augite gabbro and minor olivine gabbro; V --unlayered gabbronorite, with increased orthopyroxene and no olivine, in contrast to unit IV.
The target is entirely overburden covered and four widely spaced drill holes put down in the anomaly intersected layered gabbroic to anorthositic gabbroic rocks.
The drilling has intersected stacked packages of both cumulate and intrusive style magnetiteilmenite mineralisation intercalated with gabbroic and anorthositic country rock.
Multispectral data showed that the Inner Rook Mountains are composed of the same anorthositic rocks thought to make up much of the upper crust of the Moon.
2 Ma from one of the gabbroic plutons shows that the gabbroic plutons arc co-genetic with the dioritic to granitic plutons, although they show varied ultramafic to anorthositic and dioritic compositions as a result of crystal accumulation.
The TAZ1 zone in Hole IC-01-04 is characterized by highly variable cumulate layers, which include four olivine-bearing cycles and several anorthositic zones.
Much of the core shows extensive alteration but microprobe analyses of fresh samples revealed that the plagioclase in both anorthositic and gabbroic rocks has a fairly uniform andesine composition.
Thus, Vitello is not volcanic but rather was impact-excavated out of the anorthositic crust that formed in the early Moon's magma ocean.