Results 131 to 140 of about 603 (179)

LIGHT ELEMENT METASOMATISM OF THE CONTINENTAL MANTLE: THE EVIDENCE AND THE CONSEQUENCES

Physics and Chemistry of the Earth, 1975
Abstract The highly potassic volcanics of South West Uganda and the sodi-potassic volcanics of the West Eifel, Germany, represent two distinctive aspects of the highly alkaline volcanism characteristic of uplifted and rifted continental cratons. The sparse lavas are feldspathoidal clinopyroxenites and the associated explosive volcanism provides ...
F.E. Lloyd, D.K. Bailey
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The influence of mantle metasomatism on the oxidation state of the lithospheric mantle

2009
The oxidation state, reflected in the oxygen fugacity (fO2), of the lithospheric mantle is both laterally and vertically heterogeneous. Depth-fO2 profiles from kimberlite-borne peridotitic mantle xenoliths from the Bultfontein kimberlite, Kimberley, South Africa and the A154-N and A154-S kimberlites of the Diavik Mine, NWT, Canada were constructed by ...
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An experimental replication of upper-mantle metasomatism

Nature, 1995
INTERACTION of melts ascending from the asthenosphere with the lithospheric mantle through which they pass is widely accepted to be a significant process by which the lithosphere can acquire distinctive trace-element and isotopic signatures1–3. Despite the importance of this process in the genesis of the lithosphere, the nature of these 'metasomatic ...
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Metasomatic mineral titanate complexing in the upper mantle

Nature, 1986
The extent and expression of metasomatism in the upper mantle are contentious issues1,2, although the process has gained widespread acceptance to account for the subsequent enrichment of previously depleted lithosphere3,4. Uncertainties exist in the origin and precise compositions of the fluids involved, as well as in the total inventory of introduced ...
Stephen E. Haggerty, A. J. Erlank, Ian E. Grey   +2 more
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Sulfide metasomatism and the mobility of gold in the lithospheric mantle

Chemical Geology, 2015
Abstract Gold is a strongly chalcophile element and its concentration and behaviour in the mantle are intimately connected to the nature, abundance and mobility of sulfide phases. In this study Au has been analysed together with a suite of chalcophile and siderophile elements in sulfides hosted in 31 mantle-derived xenoliths from Spitsbergen in the ...
J. Edward Saunders, N.J. Pearson, Suzanne Y. O'Reilly, W.L. Griffin   +3 more
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Fluid Transport and Metasomatic Storage in the Mantle

1987
Alkaline intra-plate magmatism ranges from felsic to ultramafic, with the latter melts showing extremely low SiO2 activity, carbonatite being associated throughout, and all having mantle signatures. In all its forms this magmatism shows evidence of enhanced volatile activity, ranging from the chemistry of the melts through to the style of eruption ...
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Mantle metasomatism—precursor to continental alkaline volcanism

Geochimica et Cosmochimica Acta, 1980
REE distributions of an unusual suite of mantle-derived amphibole/apatite rich xenoliths have very steep, LREE-enriched chondrite-normalised patterns with no Eu anomalies. These are closely analogous to REE distributions of carbonatitic and kimberlitic rocks.
Suzanne Y. Wass, N.W. Roge
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Contrasting Types of Upper-Mantle Metasomatism?

1984
Abstract Metasomatism is now well-recognized in upper-mantle peridotite xenoliths in kimberlites and basalts. It is patent when petrographically recognizable by development of hydrous phases rich in incompatible elements, usually by replacement of anhydrous phases and sometimes associated with injection of fluids into channel ways.
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Stable Zirconium Isotopic Compositions of the Metasomatized Mantle

Journal of Geophysical Research: Solid Earth
AbstractMantle metasomatism, which affects the geochemical and lithological properties of the Earth, is crucial to the evolution and modification of the Earth's interior. Variations in chemical proxy of metasomatism, including high‐field strength elements (HFSE, e.g., Zr‐Ti isotopes and isovalent Zr‐Hf), have been commonly utilized as a tool to unravel
Zongqi Zou, Yi‐Gang Xu, Zaicong Wang, Chuyu Hu, Lanping Feng, Jing‐Liang Guo, Wen Zhang, Liang Ma, Zhaochu Hu, Yongsheng Liu   +9 more
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MANTLE METASOMATISM

Annual Review of Earth and Planetary Sciences, 1985
Michael F. Roden, V. Rama Murthy
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