Formation of H2 and CH4by weathering of olivine at temperatures between 30 and 70°C

Geochemical Transactions

Research Article

Nguyen Thanh Duc¹  Nils G Holm¹  Patrick Crill¹  Anna Neubeck¹  David Bastviken² 

[1] Department of Geological Sciences, Stockholm University, Sweden;Department of Thematic Studies-Water and Environmental Studies, Linköping University, Sweden;

关键词: Olivine;    Fluid Inclusion;    Chromite;    Martian Atmosphere;    FeCr2O4;   

DOI  :  10.1186/1467-4866-12-6

 received in 2010-12-15, accepted in 2011-06-27,  发布年份 2011

来源: Springer

【 摘 要 】

Hydrocarbons such as CH4 are known to be formed through the Fischer-Tropsch or Sabatier type reactions in hydrothermal systems usually at temperatures above 100°C. Weathering of olivine is sometimes suggested to account for abiotic formation of CH4 through its redox lowering and water splitting properties. Knowledge about the CH4 and H2 formation processes at low temperatures is important for the research about the origin and cause of early Earth and Martian CH4 and for CO2 sequestration. We have conducted a series of low temperature, long-term weathering experiments in which we have tested the CH4 and H2 formation potential of forsteritic olivine.The results show low temperature CH4 production that is probably influenced by chromite and magnetite as catalysts. Extensive analyses of a potential CH4 source trapped in the crystal structure of the olivine showed no signs of incorporated CH4. Also, the available sources of organic carbon were not enough to support the total amount of CH4 detected in our experiments. There was also a linear relationship between silica release into solution and the net CH4 accumulation into the incubation bottle headspaces suggesting that CH4 formation under these conditions could be a qualitative indicator of olivine dissolution.It is likely that minerals such as magnetite, chromite and other metal-rich minerals found on the olivine surface catalyze the formation of CH4, because of the low temperature of the system. This may expand the range of environments plausible for abiotic CH4 formation both on Earth and on other terrestrial bodies.

【 授权许可】

CC BY   
© Neubeck et al; licensee Chemistry Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.