Influence of mantle CO2 in the generation of carbonatites and kimberlites

  title={Influence of mantle CO2 in the generation of carbonatites and kimberlites},
  author={Peter John Wyllie and Wuu-Liang Huang},
THE explanation of why partial fusion of mantle peridotite sometimes yields basalts, sometimes kimberlites and sometimes carbonatites is given by the phase relationships in the system CaO–MgO–SiO2–CO2. The key is the intersection of a sub-solidus carbonation reaction with the solidus, which introduces carbonates as primary minerals alongside silicates on the surface of the liquidus. 

Links between Carbonatite and Kimberlite Melts in Chloride–Carbonate–Silicate Systems: Experiments and Application to Natural Assemblages

Recent data suggest an active role for chloride-bearing alkali carbonatitic melts in the formation and evolution of kimberlites, whereas experiments indicate that chlorides could be responsible for

Orthopyroxene survival in deep carbonatite melts: implications for kimberlites

Kimberlites are rare diamond-bearing volcanic rocks that originate as melts in the Earth’s mantle. The original composition of kimberlitic melt is poorly constrained because of mantle and crustal

Peridotite–CO2–H2O, and carbonatitic liquids in the upper asthenosphere

THE recent discovery that CO2 at upper mantle pressures has a dramatic effect on the melting temperature of peridotite (because the silicate assemblage becomes carbonated), and on the composition of

Carbon, carbides, carbonates and carbonatitic melts in the Earth's interior

  • V. Stagno
  • Geology
    Journal of the Geological Society
  • 2019
Over recent decades, many experimental studies have focused on the effect of CO2 on phase equilibria and melting behaviour of synthetic eclogites and peridotites as a function of pressure and

Effect of variable carbonate concentration on the solidus of mantle peridotite

Abstract To explore the effect of variable CO2 concentrations on the solidus of natural carbonated peridotite, we determined near-solidus phase relations of three different nominally anhydrous,

Petrogenetic grid for siliceous dolomites extended to mantle peridotite compositions and to conditions for magma generation

Decarbonation reactions in the system CaO-MgO-SiO_2-CO_2 involve calcite, dolomite, magnesite, and quartz, and the products enstatite, forsterite, diopside, and wollastonite, among others. Each

Solubility of CO2 in olivine melilitite at high pressures and role of CO2 in the earth's upper mantle

AbstractThe positions of the liquidi and the near-liquidus phases of olivine-melilitite+CO2 have been determined under MH-buffered and ‘furnace-buffered’ conditions up to 40 kb. It is found that CO2

The Transition from Carbonate to Silicate Melts in the CaO—MgO—SiO2—CO2 System

The compositions of melts in equilibrium with a lherzolite mineral INTRODUCTION assemblage were determined in the analogue system CaO– The common association of carbonatites with silicaMgO–SiO2–CO2



Experimental Evidence against the Role of Selective Volatilization on the Lunar Surface

IT has been suggested1 that the deduced sequence of crystallization and observed chemical zoning in plagioclase of a feldspar-rich lunar basalt (Fra Mauro 14310) provides evidence for selective

Low-Velocity Zone of the Earth's Mantle: Incipient Melting Caused by Water

Experimental phase diagrams for the systems gabbro-water and peridotite-water indicate that, if there is any water in the upper mantle, then traces of hydrous interstitial silicate magma will be

Fluid Precipitates in Rocks from the Earth's Mantle

Xenoliths of rocks from the Earth9s mantle are commonly included in alkalic basalt and kimberlite diatremes. The xenoliths, many of them highly deformed by plastic flow, consist primarily of olivine

A CO2 Charged Asthenosphere

Solubility considerations lead to a model of the asthenosphere which contains a CO2-rich liquid phase. The model explains variations in the asthenosphere between ocean and shield areas.

Stability of Hornblende and a Model for the Low Velocity Zone

THERE have been many discussions, but few experiments, related to the occurrence and stability of hornblende in the upper mantle1–4. We have obtained evidence relating to hornblende stability in

Electron microprobe measurement of pyroxenes coexisting with H2O-undersaturated liquid in the join CaMgSi2O6-Mg2Si2O6-H2O at 30 kilobars, with applications to geothermometry

Mixtures of synthetic crystalline enstatite and diopside were reacted with small water contents in sealed capsules in piston-cylinder apparatus at 30 kb between 1000° C and 1700° C. The compositions