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.


Anortosit, anorthosit eller ibland labradorsten, är en magmatisk, intrusiv djupbergart, som till mer än 90 % är uppbyggd av fältspat ().Också pyroxen samt mindre mängder av oxider som magnetit, ilmenit och olivin förekommer.

There are two The textures of plagioclase crystals within large olivine oikocrysts KEY WORDS: Ostwald ripening; CSD; plagioclase; texture preserve the sequence of the formation of anorthosite. Such textures have been quantified in a troctolite–anorthosite from the Proterozoic Lac-St-Jeananorthosite complex,Canada. Crystalsize distributions 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.

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Photograph courtesy John Myers. Winter (2001) An Introduction toIgneous and Metamorphic Petrology. Prentice Hall. Figure 20-2 Anorthosite is a white to light gray-colored intrusive igneous rock.

Primary mineralogies and textures of anorthosite in the. Texture and structure of the anorthosite are correlated with these differences in tectonic evolution. Jotunitic and mangeritic rocks envelope the dome and part of  In most of this anorthosite, andesine megacrysts with bytownite inclusions are embedded in a ghost-like, earlier fine-grained texture.

textures, developed in fine-grained to medium-grained gabbro and melagabbro layers; (4) size grading, most commonly developed in megacrystic anorthosite layers; (5) "spotted" texture in which pyroxene forms equant crystals that are more resistant to weathering than the plagioclase and, consequently, appear as "spots"; and (6) variable texture

2014-09-10 Quantitative Texture Analysis of an Anorthosite— Application to Thermal Expansion, Young's Modulus and Thermal Stresses.pdf Available via license: CC BY 3.0 Content may be subject to copyright. 2591.13 Mottled anorthosite, mottles increasing in size and frequency downwards. 2592.25 Mottled anorthosite, grading into… 2594.20 Leucogabbronorite. 2597.35 Mottled anorthosite, variable textures such as the size of mottles, orthopyroxene-clinopyroxene.

Anorthosite texture

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.

Anorthosite texture

Prentice Hall. Figure 20-1a. a. Typical texture of Archean anorthosite. From the Fiskenæsset. anorthosite (~98% plagioclase). Dixon and Papike.

Anorthosite-mangerite-charnockite-granite (AMCG) magmatism is widespread throughout the Mesoproterozoic Grenville Province (), and nowhere else on Earth are massif anorthosite complexes, which underlie approximately ∼20% of the area, so abundant (Fig. 1; Corriveau et al., 2007; Morisset et al., 2008). The Lac Rouvray anorthosite mass forms a part of the Lac St. Jean massif. Attempts to subdivide the Lac Rouvray mass into mappable types based on mafic mineral content and total rock textures failed.
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Anorthosite texture

The rock type is anorthosite, a cumulate rock made mostly of plagioclase. Cumulate rocks typically have the same minerals about the same size.

The texture has two major components, group I with ⊥(001 journal article: lunar anorthosite 15415: texture, mineralogy, and metamorphic history. Texture investigations on geological anorthosite specimens with the triclinic plagioclase-type structure have been performed by neutron diffraction po… goniometry with a position sensitive detector to anorthosite (Wenket al., 1986) has created new possibilities for the texture analysis of feldspar rocks. However, Typical texture of undeformed Archean anorthosite showing megacrysts of calcic plagioclase in a mafic groundmass, Pipestone Lake, Manitoba. From Ashwal (1993, Fig. 2.2).
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In the Adirondack Mountains, soils on anorthositic rock tend to be stony loamy sand with classic podzol profile development usually evident. In the San Gabriel 

4. 2010-01-01 2000-03-01 Quantitative texture analysis of an anorthite (polycrystalline plagioclase feldspar) has been under taken using an optical microscope equipped with a universal stage.

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Roche magmatique plutonique hololeucocrate, à texture grenue, composée de 80 à 90 % de plagioclases (andésine, labrador, bytownite) et d'un peu de  L'anorthosite est une roche magmatique de structure phanéritique, composée principalement Elles se distinguent des anorthosites protérozoïques par leur texture et leur composition minéralogique. Leur trait le plus caractéristique 7 May 1971 Nearly monomineralic anorthosite, with plagioclase Anso. This is the most common texture of the anorthosites. The homogenous crystals and  1 août 2010 textures, associated rocks and tectonic environments of anorthosites allow Primordial, Archean and Proterozoic anorthosites are distinctly  Leur texture montre que le magma dont elles proviennent a cristallisé rapidement ou assez rapidement, Roches de la série anorthosite-norite-troctolite (ANT). 10 Feb 1993 or neutron texture goniometry), crystal and spechnen sy•mnetry; but petrofabric data can be used to provide vital information about.

17 Jan 2018 Anorthosite-bearing layered intrusions are unique to the Archaean rock cumulate textures and igneous layering in the anorthosite-bearing 

1315 Ma Hosenbein massif-type anorthosite pluton (Nain, Labrador) shows complete exposure of a vertical section, described here for the first time,  28 Sep 2018 The 3000 km2 Marcy anorthosite massif dominates the Adirondack Highlands OK25 has an equigranular granoblastic texture of plagioclase,  This texture clearly suggests that the augite formed by exsolution out of the plagioclase. Apollo 12 rocldet 12037,174 is a lightly breccieted norite (average  There are two striking features of Archean anorthosites: Their texture and sills and dikes of plagioclase megacrysts of the same texture and composition as in  Such rocks are characterized by a porphyritic texture in which large crystals ( phenocrysts) of dark, iron-magnesium (mafic) minerals are enclosed in a fine- grained  Alkali suite anorthosites and norites are the second most common plutonic rock have equilibration temperatures of 950–1100 °C, relict igneous textures and,  7 grade into small bodies of leucotroctolite and olivine-bearing anorthosite towards the margin. 1 of the KIC. Cumulate textures are relatively widespread on a  Lens-shaped aggre- gates of mafic minerals, up to 10 cm in size, commonly appear as well developed corona textures. Primary olivine reacted with plagioclase,  with more homogeneous textures. oxydes et apatite peuvent adopter une texture porphyri- place d'un magma enrichi en Fe, Ti et P dans I'anorthosite. Rapakivi texture in Jack Creek rapakivi granite. Rapakivi is Finish for rotten or crumbly rock and describes the tendency of the rapakivi granite to easily weather,   The Pipestone Lake anorthosite complex (PLAC) is an ca.

Abstract. 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.