Systematic variations of the mineral chemistry of ferroan anorthosite 60025, which is probably a mixture of closely related materials, suggest that lunar anorthosites formed by strong fractional crystallization and near-perfect adcumulate growth, without trapping liquid. The parent liquid for the most primitive samples was saturated with olivine, plagioclase, pigeonite, and chromite, and


Hypofysen styrer utgivelsen av endokrine hormoner, platelet fatty acid composition. Lithos , The source of Proterozoic anorthosite and rapakivi granite 

Magma compositions are the picritic Apollo 14 B green glass and an estimation of the magma parental to Mg-suite cumulate rocks. From calculated enthalpy-composition phase diagrams, assimilation of anorthite into either magma cannot produce spinel anorthosite unless the anorthite is … Bulk anorthosite compositions. Whole-rock compositions are used to determine mineral. proportions in anorthosite samples (see Electronic Annex) and will be used in the following to determine the Composition and petrogenesis of oxide-, apatite-rich gabbronorites associated with Proterozoic anorthosite massifs: examples from the Adirondack Mountains, New York 2009-11-20 Lunar anorthosite, by definition [16], is a plutonic rock with >90 vol% plagio-clase, which corresponds to about >87.5 mass%. None of the feldspathic lunar meteorites approach being “pure anorthosite” in composition. The diagonal lines are simple linear regressions to the data and the green squares (with 95% confidence limits) are This good idea needed to be tested experimentally, so Prissel and colleagues made pressed, sintered powers of calcium-rich plagioclase (a suitable lunar anorthosite analog), green glass, and magnesian suite parent, assembled experimental charges consisting of anorthosite on one side and one of the basaltic compositions on the other side, and heated them in furnaces at pressures ranging from 0 Anorthosite. Similar in composition to rocks on the moon, anorthosite is a coarse-grained, intrusive igneous rock composed almost entirely of a single mineral—plagioclase feldspar.

Anorthosite composition

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(1991) and Warren and Wasson (1980). Plagioclase (An. 95) in 67636 is up to 2 mm in size and mildly shocked. Chemistry . Warren and Wasson (1980) found that 67635, 67636 and 67637 were “chemically pristine” with relativley low content of Ir and Au (figure 4). ANORTHOSITE - Intrusive igneous, plutonic.

Y1 - 1974. N2 - Plagioclases from massif anorthosites are strongly depleted in Rb and Cs relative to those from anorthosites associated with volcanic rocks, but are enriched in K and REE. Anorthosite Similar in composition to rocks on the moon, anorthosite is a coarse-grained, intrusive igneous rock composed almost entirely of a single mineral—plagioclase feldspar.

Autochthonous Precambrian charnockite to anorthosite. 94 Shanahan, N. och Zayed, A. 2007: Cement composition and sulfate attack Part I.

E a r t h  Basalter av lunaröarna (pyroxen, plagioklas, ilmenit, olivin). KREEP-stenar (kalium, fosfor, sällsynta jordartsmetaller). ANT-stenar (norit, troktolit, anorthosite).

L’anorthosite de Chugwater ne contient pas d’olivine, en général, mais possède l’assemblage augite, pyroxène à faible teneur en Ca, ilménite et magnétite, un plagioclase iridescent de composition An50–56. Dans l’anorthosite de Snow Creek, l’olivine

Anorthosite composition

composition more close to anorthosite–mafic-leucomafic rocks.

1.2 Composition 1.2.1 Mineral Content Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene Anorthosite is usually composed of labradorite and sometimes bytownite or andesine as well (all plagioclase group minerals). Anorthosite from Finland (known also as spectrolite) showing labradorescence (blue spot).
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Anorthosite composition

It appears to consist largely of nearly pure, ferroan anorthosite (FeO < 2 wt%; Al2O3 > 33 wt%). Outcrops of pure anorthosite principally occur on the Moon in the inner rings of multiring basins, which are structurally uplifted blocks from midcrustal levels, or rarely, as central peaks in some selected craters (Alphonsus, Aristarchus). 2 dagar sedan · Apollo 16 Anorthosite. Anorthosite is an important rock type of the lunar highlands and probably formed the primitive lunar crust. This sample has been determined to be 4.19 billion years old by the Argon method of dating.

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Anorthosite /ænˈɔːrθəsaɪt/ is a phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar with a minimal mafic 

The Canadian Mineralogist, 36(1 Other researchers consider the chemical compositions of the HAOM to be the product of rapid crystallization at moderate or low pressures. Archaean anorthosite.

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The geodynamic evolution of Mesoarchean anorthosite complexes inferred from the Naajat Kuuat Complex, southern West Greenland2012Ingår i: Precambrian  Composition and texture of the industrial rocks (autoref.) P. Q.) 59: 258. — On the Chemical composition of 60: 113— 115.

Anorthite is the calcium -rich endmember of the plagioclase solid solution series, the other endmember being albite, Na AlSi 3 O 8. Anorthite also refers to plagioclase compositions with more than 90 molecular percent of the anorthite endmember. At 1 atmosphere, anorthite melts at 1553 °C.

The genesis of some pyroxenes and garnets related to Adirondack anorthosite, anortho- site-marble contact zones and their metamorphic equivalent   Jun 13, 2003 Hence, in order to determine the composition and origin of the lunar crust, Compositions ranging between noritic anorthosite and anorthositic  Jun 18, 2017 3. INTRODUCTION • Anorthosite is a phaneritic, intrusive igneous rock characterised by a predominance of plagioclase feldspar (90-100%) and a  As the composition changes through. Page 14. 0.

Compositions of individual samples are usually written as An 24 Ab 76 meaning in this case that it is 24% anorthite and 76% albite.