Results 151 to 160 of about 3,223 (190)

Mafic Phyllosilicates in Low-Grade Metabasites. Characterization Using Deconvolution Analysis

Clay Minerals, 1994
AbstractThe <2 µm clay fractions from low-grade metabasalts of eastern North Greenland are mixtures of mafic phyllosilicates and celadonite that show complex X-ray diffraction (XRD) patterns. Interpretation of such patterns is difficult and subjective using only visual examination of peak positions and shapes.
Robinson, D, Bevins, RE
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Lawsonite-bearing eclogitic metabasites in the Cazadero area, northern California

Mineralogy and Petrology, 1997
In the Cazadero area, northern California, Lawsonite-bearing eclogitic metabasites occur in association with glaucophane schists. Lawsonite-bearing eclogitic metabasites are coarse-grained, and characteristically lack albite. Representative mineral assemblages are; (1) garnet + omphacite + Lawsonite + epidote + glaucophane + chlorite + quartz, (2 ...
H. Shibakusa, H. Maekawa
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Geochemistry and petrogenesis of metabasites from the KTB ultradeep borehole, Germany

Geologische Rundschau: Zeitschrift Fur Allgemeine Geologie, 1997
The metabasites from the KTB pilot and main drill holes can be divided into two major associations. The first is the metagabbro-amphibolite suite which is composed principally of metagabbros, basalts, and basaltic andesites with tholeiitic P-MORB affinities.
Harms, U., Cameron, K., Simon, K., Brätz, H.   +3 more
exaly   +5 more sources

Metabasites: Progressive Mineral Changes

1965
The chlorites of metabasites show a limited range of the \(Si(Mg,F{e^{2 + }}) \rightleftharpoons AlAl\) substitution, just like those of metapelites (§7B-6). The number of Si atoms on the basis of 18(O, OH) is in the range 2 5–3 O. Hence, the same formula (Mg, Fe)4.5Al3Si2.5O10(OH)8 may be used for both metabasite and metapelite chlorites. The Fe2+/(Mg
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Sodic pyroxenes from metabasites in the eastern mediterranean

Contributions to Mineralogy and Petrology, 1978
The compositions of sodic pyroxenes from blueschist metabasites in Northwest Turkey were investigated by electronprobe microanalysis. These are compared with sodic pyroxenes from high-grade blueschist terrains and eclogites with special reference to the island of Syros in Greece.
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Phase equilibria and mixed parageneses of metabasites in lowgrade metamorphism

Mineralogical Magazine, 1985
AbstractThe system Na2O-CaO-MgO Al2O3-SiO2-H2O is proposed to model phase equilibria and mineral parageneses for low-temperature metamorphism of basaltic rocks. Univariant reactions marking the transitions between various sub-greenschist facies are identified and some have been experimentally determined.
J. G. Liou, S. Maruyama, M. Cho
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Chemographic analysis of metabasite assemblages from c central Scottish Highlands

Lithos, 1981
Abstract From the observed textures and mineral associations, chemographic relations have been derived in isobaric T-X CO 2 space for the minerals actinolite, ankerite, calcite, chlorine, epidote, and hornblende in Scottish Dalradian metabasites from Central Perthshire.
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Metabasites with eclogite facies relics from Variscides in Sardinia, Italy: a review

International Journal of Earth Sciences, 2006
Metabasites with eclogite facies relics occur in northern Sardinia as massive to strongly foliated lenses or boudins embedded within low- to medium-grade rocks (Anglona) and migmatites (NE Sardinia). U–Pb zircon dating yielded 453 ± 14, 457 ± 2  and 460 ± 5 Ma as the protolith ages; 400 ± 10 and 403 ± 4 Ma have been interpreted as the ages of the HP ...
FRANCESCHELLI, MARCELLO, PUXEDDU M, CRUCIANI, GABRIELE, UTZERI D.   +3 more
openaire   +4 more sources

Metabasite parageneses in south-west England.

1994
Metabasites with diagnostic chlorite ± pumpellyite ± actinolite assemblages are sporadically developed in the Variscan belt of south- England. Consideration of these phases in the NCFMASH system [SiO2-(Al2O3+Fe2O3)-FeO-MgO-CaO-Na2O-H2O], using the epidote projection, shows in most cases sub-parallel tielines between coexisting chlorite - pumpellyite ...
ROBINSON D., MAZZOLI, CLAUDIO, PRIMMER T. J.   +2 more
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Upper amphibolite- and granulite-facies metabasites: the natural record

Upper amphibolite- and granulite-facies metabasites, ubiquitous in Archaean and Proterozoic terranes, represent a critical source of information on the lower continental crust. Elucidating the metamorphism of these rocks provides insights into the processes occurring at depth throughout Earth&#8217;s history.
Jacob Forshaw, Eleanor Green, Pierre Lanari   +2 more
openaire   +1 more source