Results 171 to 180 of about 10,884 (225)

OXYGEN ISOTOPIC STUDIES OF AMPHIBOLITES

Canadian Journal of Earth Sciences, 1965
The whole-rock oxygen isotope ratios of amphibolites from a variety of localities have been studied in an attempt to distinguish para-amphibolites from ortho-amphibolites. If para-amphibolites were derived from a pelite–carbonate mixture or any carbonate-bearing sedimentary rock, they should be enriched in18O relative to basaltic parents. Exchange with
H. P. Schwarcz, R. N. Clayton
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Amphibolitization of calc-silicate metasedimentary rocks

Contributions to Mineralogy and Petrology, 1971
Diopside granofels layers are associated with other metasedimentary rocks and gneisses near McMurdo Sound, Antarctica. Disrupted diopside granofels layers form tectonic inclusions which may have reaction rims of amphibolite. This amphibolite may either be a typical hornblende-plagioclase amphiholite or a hornblende-quartz amphibolite according to the ...
Smithson, Scott, Fikkan, Philip, Houston, Robert S.   +2 more
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Amphibolite-granulite facies charnockites

Proceedings of the Indian Academy of Sciences - Section A, 1953
The Cheri Hill in the Madras type area of charnockites, shows on careful mapping the folding of bands of leptynite and basic charnockites. The mineralogy of the basic types gives striking evidences of the metamorphic origin of charnockites. The rocks have been subjected to some little retrograde metamorphism and are ascribed to the almandine-diopside ...
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Amphibolites of the Cartersville District, Georgia

Geological Society of America Bulletin, 1971
The Cartersville district, which is bisected by the boundary between the Valley and Ridge and Piedmont provinces, contains thick lenses of thinly bedded, greenschist facies amphibolite in the southeastern (Piedmont) part that appear to correlate with lenses of carbonate-rich sedimentary rock in the Lower Cambrian Rome Formation to the northwest ...
THOMAS L. KESLER, STEPHEN E. KESLER
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Eclogitic amphibolites from the Grampian Moines

Mineralogical Magazine, 1986
AbstractAmphibolites from the Grampian Moines of Scotland contain clinopyroxene-plagioclase symplectites and plagioclase-hornblende coronas around garnet. The clinopyroxene-plagioclase symplectites are interpreted as former omphacites. It is inferred that an eclogitic garne-tomphacite-quartz assemblage once existed, but has since undergone partial ...
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Amphibolitization of mafic crust: mechanism and time scales

Goldschmidt2025 abstracts
Fluid–rock interactions play a key role in the formation, evolution and recycling of the Earth’s crust. For fluids to infiltrate rocks and enable and sustain fluid-mediated mineral transformations, fluid pathways are required. Time scales of fluid-mediated rock transformations cover a wide range from several million years to several
Timm John, Saskia Grund, Johannes Vrijmoed   +2 more
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Water-induced Weakening of Hornblende and Amphibolite

Nature, 1969
THE disparity between the great laboratory strength of silicate rocks and their apparent weakness in nature, suggested by stress drops associated with earthquakes, remains a persistent problem in tectonics. The strength disparity sometimes approaches three orders of magnitude.
ROBERT E. RIECKER, THOMAS P. ROONEY
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The Amphibolite of Doir'a'Chatha (Durcha), Sutherland

Geological Magazine, 1958
AbstractThe amphibolite at Durcha passes from a dark, hornblende-rich rock, through every gradation of delicate striping and banding by quartzo-feldspathic material out into psammitic Moine schist, within a few metres. Irregular cross-cutting bands of quartz and feldspar which seem to “ feed ” the delicate stripes can be seen and there are intergrown ...
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Eclogitic and glaucophane amphibolites in Venezuela

Eos, Transactions American Geophysical Union, 1950
Several occurrences of amphibolites with sodic pyroxenes and am phiboles are found in association with garnet amphibolites within the metamorphosed sedimentary rocks of northern Venezuela. They are interpreted as having been, originally, shallow basic intrusive rocks and perhaps tuffaceous sediments.
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Plagioclase porphyroblasts from an amphibolite paleozome

Lithos, 1972
Abstract Plagioclase porphyroblasts from the amphibolite paleozome of the Valle granite, Setesdal in South Norway have been studied in detail petrographically. Each porphyroblast is composed of a mosaic of nearly one thousand plagioclase grains with interstitial quartz and some microline.
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