Results 171 to 180 of about 12,234 (224)

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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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 Scourian granulites

Scottish Journal of Geology, 1974
Synopsis Scourian granulite-facies gneisses from north-west Scotland occur as relict masses surrounded by amphibolitized granulites. During amphibolitization the gneisses suffered both deformation and metamorphism. Ortho- and clinopyroxenes were replaced by hornblende and hornblende-quartz intergrowths forming corona textures.
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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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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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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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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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Microstructure in hornblende of a mylonitic amphibolite

Geological Society, London, Special Publications, 1990
Abstract The microstructure in a dynamically recrystallized amphibolite of a deep crustal shear zone from the Ivrea Zone, NW Italy, has been investigated by conventional and high resolution transmission electron microscopy. The microstructure in the amphibole phase consists of recrystallized grains, subgrains, free dislocations and various ...
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The geochemistry of the Strathconon amphibolites, Northern Scotland

Scottish Journal of Geology, 1984
Synopsis The Strathconon ortho-amphibolites were intruded into Glenfinnan and Loch Eil Division metasediments of the Moine Assemblage before the area was deformed in late Precambrian time. A chemical study has indicated that they consist of a single suite of variously fractionated tholeiitic sills and dykes which can be distinguished ...
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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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