Hydrogen Peroxide Formation and pH Changes at Rock-Water Interface during Stressing
Abstract
Common igneous and high-grade metamorphic rocks contain dormant defects, which become activated when stressed. They release electronic charge carriers, in particular defect electrons associated with O- states in a matrix of O2-. Known as 'positive holes' or pholes for short, the O- states can spread out of the stressed rock volume, travel along stress gradients over distances on the order of meters in the lab and probably over kilometers in the field. They carry a current, which can flow through meters of rock in the laboratory, probably tens of kilometers in the field. At rock-water interfaces the O- states turn into O radicals, which subtract H from H2O, forming OH- in the rock surface and PH radicals in the water. Two OH combine to H2O2. In the process the pH becomes more acidic. The discovery of H2O2 formation at rock-water interfaces as part of stress- activated currents on the tectonically active Earth may help us better understand the oxidation of the early Earth and the evolution of early Life.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.V13B2109X
- Keywords:
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- 1020 Composition of the continental crust;
- 1042 Mineral and crystal chemistry (3620);
- 3904 Defects;
- 4851 Oxidation/reduction reactions (0471);
- 5109 Magnetic and electrical properties (0925)