Generation of Methane in the Earth's Mantle: In situ High Pressure-Temperature Measurements of Carbonate Reduction

We present in situ observations of hydrocarbon formation via carbonate reduction at upper mantle pressures and temperatures. Methane was formed from FeO, CaCO3-calcite, and water at pressures between 5 and 11 GPa and temperatures ranging from 500°C to 1,500°C. The results are shown to be consistent...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 2004-09, Vol.101 (39), p.14023-14026
Main Authors: Scott, Henry P., Hemley, Russell J., Mao, Ho-kwang, Herschbach, Dudley R., Fried, Laurence E., Howard, W. Michael, Bastea, Sorin
Format: Article
Language:English
Subjects:
Calcite
Carbon dioxide
Earth mantle
Fluids
Gaskets
Geology
High pressure
High temperature
Hydrocarbons
Laser heating
Methane
Physical Sciences
Raman scattering
Temperature measurement
Upper mantle
Vibration
Water pressure
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present in situ observations of hydrocarbon formation via carbonate reduction at upper mantle pressures and temperatures. Methane was formed from FeO, CaCO3-calcite, and water at pressures between 5 and 11 GPa and temperatures ranging from 500°C to 1,500°C. The results are shown to be consistent with multiphase thermodynamic calculations based on the statistical mechanics of soft particle mixtures. The study demonstrates the existence of abiogenic pathways for the formation of hydrocarbons in the Earth's interior and suggests that the hydrocarbon budget of the bulk Earth may be larger than conventionally assumed.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.0405930101