Diffusion mesomatism in silica-undersaturated sapphirine-bearing granulite from Rumdoodle Peak, Framnes Mountains, east Antarctica
Article Abstract:
Consistency was noted between a modified model of diffusion metasomatism under closed system, steady state conditions and the textures and mineralogy of the reaction bands formulated between quartz veins and aluminous gneiss. Development of reaction bands can be attributed to the diffusive exchange of Si for Fe and Mg. Modelling of reaction bands' broad morphology can be effectively undertaken in terms of a single diffusing component (Si). It is also revealed that the limited diffusive exchange of Si and Al across mineral grains plays a vital role in the preservation of corona textures.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1999
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Harzburgite to lherzolite and back again: metasomatic processes in ultramafic xenoliths from the Wesselton kimberlite, Kimberley, South Africa
Article Abstract:
The presence of zoning from low-Ca harzburgitic cores and rims with lherzolitic Ca-Cr relations were observed on garnets from phlogopite harzburgite xenoliths from the Wesselton kimberlite. Such phenomenon have resulted from varying stages of a metasomatic process that transform harzburgite to lherzolite at temperatures close to 1000 degrees celsius. Some garnets composed of garnet with low Ca and Cr, but high Mg, Ti and HREE were found to have secondary replacement rims.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1999
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The crystal chemistry of romeite
Article Abstract:
The crystal chemistry of romeite minerals from Praborna, Italy; Massiac, France; and the Swiss Alps were analyzed to characterize the geological significance of pyrochlore-group minerals. The romeite minerals from the selected localities exhibited a wide range of independent and coupled substitutions. The romeite minerals from Massiac, France were also composed of H2O. Furthermore, the romeite minerals from the selected sites exhibited varied chemistry.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1997
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