Anorthosite texture

L'anorthosite a communément une texture grenue, souvent pegmatitique. Some of the rock at this location remains strong and competent, but much of it has a brittle crumbly or chalky texture as weathering has begun the process of breaking it down into clay. Many of the anorthosite samples returned by astronauts from the Moon have a similar crumbly texture, not because of weathering by water but due to impact shock and shattering by meteorite bombardment. Media in category "Anorthosite textures" The following 5 files are in this category, out of 5 total. Feldspar (in anorthosite) Some varieties of gabbro have few dark minerals, and are made almost entirely of plagioclase feldspar.

Anorthosite texture

Anorthosite is by definition an igneous rock consisting of 90-100% plagioclase feldspar. When the amount of mafic minerals exceeds 10 % the name leucogabbro or anorthositic gabbro (alternatively -norite) is commonly used, depending on the nature of the pyroxene. Lunar anorthosite 15415 consists almost entirely of anorthite (homogeneous anorthite 96.6 molecule percent), with accessory diopsidic augite and traces of hypersthene, ilmenite, and a silica mineral. Silicate textures and compositions and metal-silicate relationships. Geochimica et Cosmochimica Acta 35(1): 5-34. (Jan 1971); Weigand, P. W. (1975) Pyroxenes in the Patwar mesosiderite: Meteoritics 10(4): 341-351. 2010-01-01 · Massive anorthosite has adcumulate texture comprising tightly packed cumulus plagioclase with accessory (<10 vol%) abundances of intercumulus pyroxene and Fe-Ti oxide.

I14-05 – Andesite porphyry – you manner in the liquid state and produced anorthosite magma. Now we must realize, and face having a "suggestion of a schistose texture."2 Observations such. Apr 23, 2013 Copper and nickel are two metals modern society cannot get enough of, but there is not enough to go around, says Rick Mills, publisher of Ahead Aug 23, 2019 Igneous textures and composition are variable at the mesoscale, and due to the scarcity of meter-scale structural mapping across much of the Sep 8, 2020 the radial texture) reflected the change in the undercooling state of the magma.

TEXTURE • Anorthosite are leucocratic, coarse- grained and hypidiomorphic. Some crystals have euhedral form, some have poorly developed faces and others have no crystal form at all.

osti.gov journal article: lunar anorthosite 15415: texture, mineralogy, and metamorphic history. blastoporphyritic texture deﬁned by antiperthitic plagioclase phenocrysts set in a well recrystallized ﬁne-grained mosaic of Fe-rich orthopyroxene Fe-rich clinopyroxene, ilmenite with or without fay-alitic olivine. The proportion of ferromagnesian minerals increases from anorthosite to ferrodiorite through leuconorites L'anorthosite est une roche ignée intrusive formée de 90% ou plus de feldspath plagioclase et 10% ou moins de minéraux mafiques comme le pyroxène, l'olivine, l'ilménite et la magnétite.

1980-01-01 Such textures have been quantified in a troctolite-anorthosite from the Proterozoic Lac-St-Jean anorthosite complex, Canada. Crystal size distributions (CSDs) indicate that initially plagioclase nucleated and grew in an INTRODUCTIONenvironment of linearly increasing undercooling, producing a straight-The textures of plutonic rocks are one of their most line CSD. 1994-07-01 The textures of plagioclase crystals within large olivine oikocrysts preserve the sequence of the formation of anorthosite. Such textures have been quantified in a troctolite-anorthosite from the 2004-05-01 1994-07-01 Inequigranular anorthosite. Ths rock has a continuum of grain sizes, from very small to quite large. It does not have a phenocrystic texture, having larger crystals set in a much finer-grained matrix. The rock type is anorthosite, a cumulate rock made mostly of plagioclase. Cumulate rocks typically have the same minerals about the same size.
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In the San Gabriel Author(s): Gómez Barreiro, J; Wenk, HR; Vogel, S | Abstract: A sample of anorthosite from the granulite facies Morin Shear Zone (Quebec, Canada) was DESCRIPTIONS OF ANORTHOSITES The anorthositic rocks (Fig. la) differ from the dark, Ti-rich lunar basalts in composition, density, and texture. They are In the other trend, the rocks are norites, troctolites, dunite, spinel anorthosites, The 62237 troctolitic anorthosite clast has a clear igneous texture; if this rock can Dec 1, 2010 individual anorthosite plutons and between anorthosites and adjacent rocks is due to overprinting of primary igneous textures and boundary In low-strain areas, igneous textures, involving plagioclase, olivine and/or pyroxene (ortho- or clinopyroxene) may be preserved and igneous crystals up to. 30 cm The Laramie anorthosite complex includes three anorthositic plutons: the Poe Mountain, Chugwater, in zones of intense alteration, a texture suggesting that.

An information card with details on the rock formation, mineral content, characteristics, and uses is included.
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Mottled leucotroctolite pockets are commonly found in coarse-grained anorthosite. Coronitic textures are developed in Ol- and Pl-bearing rocks. These textures are formed by a core of Ol, which is separated from Pl by an inner rim of Opx and an outer rim of amphibole-spinel symplectite.

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Lunar anorthosite 15415 consists almost entirely of anorthite (homogeneous anorthite 96.6 molecule percent), with accessory diopsidic augite and traces of hypersthene, ilmenite, and a silica mineral. The rock has had a complex metamorphic history. The texture reflects at least two episodes of shearing (followed by intense and partial recrystallization, respectively), one episode of cataclastic deformation, and one or more episodes of shattering and fragmentation. = Mafics). The name is from anorthose, an old name for triclinic feldspars.

Small anhedral grains of plagioclase have smooth boundaries and meet in Sep 13, 2014 Many lunar meteorites contain anorthositic clasts that may be The texture of the section of Dho 081 we studied (BM2004, M5) is that of a Winter (2001) An Introduction toIgneous and. Metamorphic Petrology.

Commonly, anorthosites form at the tops of modally graded layers on the scale of several meters up to 100 meters or more. Grain size (typically <1 cm) is characteristically smaller than the massif-type or Archean anorthosites, and textures vary from orthocumulates with tabular crysts of plagioclase to adcumulates having equant polygonal grains. Lunar anorthosite 15415 consists almost entirely of anorthite (homogeneous anorthite 96.6 molecule percent), with accessory diopsidic augite and traces of hypersthene, ilmenite, and a silica mineral. Here you can know more about texture of Gneiss and Anorthosite. Texture of Gneiss is Banded, Foliated, Platy whereas that of Anorthosite is Foliated, Glassy. Based on the texture of rocks, they are used for various purposes.