porphyroblast

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Related to Porphyroblasts: Porphyroblastic Texture

por·phyr·o·blast

 (pôr-fîr′ə-blăst′)
n.
A large crystal that is surrounded by a fine-grained matrix in a metamorphic rock and forms from the recrystallization of existing mineral crystals during metamorphism.
[porphyr(y) + —blast.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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Large metamorphic minerals (e.g., porphyroblasts such as biotite, garnet, andalusite and staurolite) that contain passive inclusions are extraordinarily important because they are utilized in assessing the tectonic, metamorphic, and structural history of the mid- to deep-crustal levels of orogenic belts.
Classification, Character, and Origin of Textural Zoning in Porphyroblasts: Significance and Relation to Strain
The late schistosity in the sedimentary rocks, defined by muscovite and biotite, wraps around cordierite porphyroblasts, which contain relicts of the earlier phyllitic cleavage (Thorne and Lentz 2001; Park et al.
Geological relationships and laser ablation ICP-MS U-Pb geochronology of the Saint George Batholith, southwestern New Brunswick, Canada: implications for its tectonomagmatic evolution
Staurolite forms honey-brown large prismatic porphyroblasts which quite frequently reach up to 1.2 cm across and 12 cm in length, elongated along the schistosity and usually displaying reaction rims.
Petrologic significance of Fe-rich staurolite in pelitic schists of the Silgara Formation, Santander Massif/Significado Petrologico de Estaurolita Rica en Fe en Esquistos Peliticos de la Formacion Silgara, Macizo de Santander
The amphibolite is porphyroblastic and contains porphyroblasts of hornblende.
Facies and distribution of metamorphic rocks beneath the Muslim Bagh ophiolite (NW Pakistan): tectonic implications
Albite (Ab) and Grt2 (mineral abbreviations from Whitney and Evans, 2010) are porphyroblasts mainly syn-kinematic with the S2 and frequently helicitic, including a previous foliation (S1) (Figs.
Structure of the Andean Palaeozoic basement in the Chilean coast at 31[degrees] 30' S: geodynamic evolution of a subduction margin
The graphite occurs within "fairly homogeneous, quartz-graphite schist, incorporating minor "porphyroblasts" of muscovlte crystals and small lenses of extremely fine sillimanite".
Archer Exploration Limited (ASX:AXE) Exceptional Coarse Flake Graphite Recorded At All Of The First Three Areas Tested At Wildhorse Plains
and Speck, P.J.H.R.: 1994, The kinematic interpretation of obliquely-transected porphyroblasts: an example from the Trois Seigneurs Massif, France, J.
Microstructure of selected metamorphic rock types--application of petrographic image analysis
GROWTH OF CENTIMETER-SCALE GARNET PORPHYROBLASTS AT THE
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Andalusite, and rarely cordierite, porphyroblasts (Fig.
Great mining camps of Canada 2. The history and geology of the Anyox copper camp, British Columbia
Migmatization is widespread, resulting in the formation of plagioclase and potassium-feldspar porphyroblasts and occasionally charnockitic leucosomes, also of small granitoid veins and bodies.
Outlines of the Precambrian basement of Estonia/Eesti eelkambriumi vanusega aluskorra pohijooni

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