Experimental reconstruction of sodic dolomitic carbonatite melts from metasomatised lithosphere

Article Abstract:

A series of high pressure experiments reveal a significant role for ephemeral, sodic dolomitic melts in producing metasomatic changes in the lithosphere. The study involves the experimental reversal of the decarbonation produced by the reaction between sodic dolomitic carbonatitic melt and lherzolite at pressures around two GPa. The wehrlites are made to react with CO2 at 900 to 1150 degrees celsius. The equilibrated carbonatite melt and lherzolite residue allow for the estimation of natural phase compositions. The open system behavior of metasomatism is discussed.

Observations, Metasomatism (Mineralogy), Metasomatism, Carbonatites, Dolomite

---

A close look at dihedral angles and melt geometry in olivine-basalt aggregates: a TEM study

Article Abstract:

Olivine-basalt aggregates were sintered at high pressure and temperature for long periods to examine their melt geometry. A transmission electron microscope was used to analyze the dihedral angle concept. Results indicate that the olivine crystal structure and orientation rather than the surface area minimization control the melt distribution in crystals with F-faces. Moreover, the melt distribution in olivine aggregates with F-faces cannot be sufficiently characterized by the dihedral angles.

Usage, Transmission electron microscopes, Olivine

---

Internally consistent gahnitic spinel-cordierite-garnet equilibria in the FMASHZn system: geothermobarometry and applications

Article Abstract:

An analysis describing gahnitic spinel equilibria in an FMASHZn system is presented. The analysis involves the calibration of the equilibrium (MG, FE, ZN)3Al2Si3O12 and 2Al2SiO5 equals 3(Mg, Fe, Zn)Al2O4 and 5SiO2 garnet and sillimanite/kyanite equals spinel and quartz in a pistol-cylinder apparatus set at 11 and 30 kbar. The process leads to the development of a model depicting Fe-Mg-Zn symmetric mixing for aluminous spinels in an equilibrium with garnet.

Spinel, Spinel group

Similar abstracts:

• Abstracts: Some thermomechanical aspects of the subduction of continental lithosphere
• Abstracts: Late orogenic extension of the Betic Cordillera and the Alboran Domain: a lithospheric view. Comment on "Alternating contractional and extensional events in the Alpujarride nappes of the Alboran Domain (Betics, Gibraltar Arc)" by Juan C. Balanya et al
• Abstracts: Crustal structure and evolution of the Trans-Hudson orogen: results from seismic reflection profiling
• Abstracts: Geochemical evolution of Jurassic diorites from the Bristol Lake region, California, USA, and the role of assimilation
• Abstracts: The causes and petrological significance of cathodoluminescence emissions from alkali feldspars. Origin of mantled (rapakivi) feldspars: experimental evidence of a dissolution- and diffusion-controlled mechanism

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.