Liquid immiscibility between trachyte and carbonate in ash flow tuffs from Kenya
Article Abstract:
A liquid immiscibility relationship exists between trachyte and carbonate melts which is revealed by the textural, geochemical and mineralogical data in trachytic ash flow tuffs from the Suswa volcano, Kenya. A sharp, curved menisci exists between the trachyte and the carbonate, and silicate glass contains carbonate globules. Silicate glass separates fiamme rich in carbonate globules, and in the carbonate and the trachyte melts, the occurrence of phenocryst phases are alike. Silicate and carbonate-rich clasts in a carbonate matrix are a result of explosive disruption of the magma. An explosive disruption disaggregates the silicate liquid which budds off into the carbonate matrix.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1993
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Liquid immiscibility between nephelinite and carbonatite from 0.1 to 2.5 GPa compared with mantle melt compositions
Article Abstract:
The mechanisms that mediate the formation of immiscible carbonatite magmas in the lithosphere and in the earth's crust was analyzed in phasee equilibrium experiments. Phase equilibrium experiments with mixtures composed of primitive (magnesian) nephelinite (NEPH), dolomite and Na2CO3 indicated the presence of increasing miscibility gaps that correlated with reductions in pressure. Furthermore, the carbonate liquid compositions derived by partial melting of periodite intersected with the miscibility gaps.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1997
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A boundary layer-induced immiscibility in naturally re-equilibrated H(2)O-CO(2)-NaCl inclusions from metamorphic quartz (Western Carpathians, Czechoslovakia)
Article Abstract:
Naturally re-equilibrated fluid inclusions are characterized. Results show that fluid inclusions in metamorphic minerals need a re-equilibration in order to withstand the large differentials between internal inclusion pressure and confining pressure during postmetamorphic evolution of pressure-temperature conditions. Moreover, re-equilibration in metamorphic conditions leads to boundary layer-induced immiscibility of homogeneous H(2)O-CO(2)-NaCl fluids.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1992
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