Carbon compounds under the conditions of the upper mantle
Abstract
The abundances and the forms of carbon present in the upper mantle material are discussed on the basis of data on oxygen fugacities, which were estimated from the equilibria of spinels and sulfides with the silicate minerals of mantle rocks. It is shown that the fluids in mantle fractions are represented in the majority of cases by aqueous phases of high alkalinity and are likely to carry carbon in the form of carbonate complexes. The appearance of diamond in deeper regions may be explained as due to the reduction of the carbonate forms or to the displacement of equilibria with rock minerals under conditions of increasing pressure.
- Publication:
-
Geokhimiia
- Pub Date:
- November 1988
- Bibcode:
- 1988Geokh.....1539R
- Keywords:
-
- Carbon Compounds;
- Earth Mantle;
- Spinel;
- Sulfides