Table 2 |
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|
Rates of olivine dissolution and CH4 accumulation |
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|
pH |
Initial fluid composition |
Grain size (m) |
Temp (°C) |
Duration of dissolution (days) |
Dissolution rate based on Si (Mg) (mol/m2/s) |
Accumulation rate of CH4 (mol/m2/s) |
|
|
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|
8.72 |
2.2 mM HCO-3 |
2.5E-4 to 1E-4 |
30 |
295 |
8.10E-12 (7.28E-12) |
2.70E-11 |
|
8.74 |
2.2 mM HCO-3 |
2.5E-4 to 1E-4 |
50 |
295 |
1.81E-11 (4.68E-12) |
3.21E-11 |
|
8.57 |
2.2 mM HCO-3 |
2.5E-4 to 1E-4 |
70 |
295 |
5.12E-11 (1.91E-12) |
7.31E-11 |
|
9.05 |
H2O (Milli-Q) |
2.5E-4 to 1E-4 |
30 |
295 |
6.35E-12 (5.46E-12) |
2.73E-11 |
|
9.01 |
H2O (Milli-Q) |
2.5E-4 to 1E-4 |
50 |
295 |
1.46E-11 (7.41E-12) |
3.12E-11 |
|
9.09 |
H2O (Milli-Q) |
2.5E-4 to 1E-4 |
70 |
295 |
6.39E-11 (1.79E-12) |
5.39E-11 |
|
|
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|
Rates of dissolution calculated from the release of Si and Mg into solution and from the accumulation of CH4 into the headspace of the experiment bottles after 295 days of dissolution. The CH4 rate is calculated from the net accumulation of CH4 into the headspace of the bottles, i.e. with the control values subtracted from the analyzed values. The pH is changing between the buffered and non-buffered groups but not remarkably within the groups. |
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|
Neubeck et al. Geochemical Transactions 2011 12:6 doi:10.1186/1467-4866-12-6 |
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