Results 121 to 130 of about 180 (171)

Magnetite-rutile-assemblages in metapelites of the Fichtelgebirge, Germany

Earth and Planetary Science Letters, 1972
Abstract Magnetite-rutile assemblages formed in the course of partial oxidation of detrital ilmenite grains during low-grade regional metamorphism of pelitic rocks. At higher grades of metamorphism magnetite + rutile reacted to produce second generation ilmenite and some hematite.
H MIELKE, W SCHREYER
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Strain localization and melt segregation in deforming metapelites

Physics of the Earth and Planetary Interiors, 2009
Abstract Crustal rocks commonly experience partial melting in deep parts of orogenic belts. Present concepts predict that the melt generation is directly related to shear localization, which also provides paths for the melt to migrate. Existing experimental studies, however, are insufficient to directly relate melt generation to deformation.
Santanu Misra, Luigi Burlini, Jean-Pierre Burg   +2 more
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Mineral assemblages of the Al2SiO5 “triple point” in metapelites

Doklady Earth Sciences, 2013
The polymorphic modifications of Al2SiO5, namely kyanite, andalusite, and sillimanite, are the most important indicators of metamorphism in rocks. Having the same chemical composition, they are characterized by different crystal structures stable at different P–T parameters.
I. I. Likhanov, V. V. Reverdatto
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Monazite–allanite phase relations in metapelites

Chemical Geology, 2010
Abstract Calculations of the transition from allanite to monazite-bearing assemblages in typical pelitic bulk compositions have been made using thermodynamic data estimated from oxide sums and inferred from natural parageneses. Calculations in the CFASHPCe and MnNCKFMASHPCe systems place the allanite to monazite transition in the middle amphibolite ...
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The metapelitic garnet–biotite–muscovite–aluminosilicate–quartz (GBMAQ) geobarometer

Lithos, 2007
Abstract In this contribution we have empirically calibrated the garnet–biotite–muscovite–aluminosilicate–quartz (GBMAQ) barometer using low- to medium–high-pressure, mid-grade metapelites. Application of the barometer suggests that the GBMAQ and GASP barometers show quite similar pressure estimates.
Wu, CM, Zhao, GC
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Petrology of metapelites in the Bugaboo aureole, British Columbia, Canada

Journal of Metamorphic Geology, 2015
AbstractContact metamorphism of greenschist facies Neoproterozoic turbidites by the Cretaceous Bugaboo Batholith in southeastern British Columbia has resulted in a well‐developed contact aureole. The aureole is about 1 km wide and can be divided into three main zones: (i) spotted phyllite zone, extending from the first appearance of spots of cordierite
D. R. M. Pattison, C. L. DeBuhr
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Metapelites: Diversity in Progressive Regional Metamorphism

1965
Metabasites are mineralogically sensitive to variations in temperature and pressure. This is the reason why Eskola (1920, 1939) based his definitions of individual metamorphic facies on the mineral assemblages of metabasites. The main characteristics are synoptically shown in table 8A–1. The mineralogical sensitivity is especially great under high rock-
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Geothermobarometry of high-grade metapelites: simultaneously operating reactions

Geological Society, London, Special Publications, 1989
Summary Experimental data on equilibria involving rock-forming minerals in high-grade metapelites (garnet, orthopyroxene, cordierite and plagioclase) have been used to derive an internally consistent system of mineralogical thermometers and barometers based on component reactions and excess mixing properties of solid solutions ...
L. Ya. Aranovich, K. K. Podlesskii
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Phase Equilibria in the Process of Anatexis in High-grade Metapelites

Earth Science Frontiers, 2007
Abstract Anatexis is a widespread phenomenon in high-grade metamorphic rocks, which has drawn considerable attention of geologists. Due to the advancements in the study of phase equilibrium since the beginning of the 1990s, the formation and fractionation of melts and relevant retrograde reactions can be quantitatively studied using the software ...
Chunjing WEI, Wei WANG
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Theoretical modeling of monazite growth in a low-Ca metapelite

Chemical Geology, 2010
Monazite growth and composition has been modeled in the system K2O–Na2O–CaO–MnO–MgO–FeO–Al2O3–SiO2–H2O–Y2O3–Ce2O3–P2O5–F and a pseudosection is presented that is contoured for monazite modal amount and YPO4 composition, garnet amount and YAG composition, and xenotime amount.
Frank S. Spear, Joseph M. Pyle
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