kinetic isotopic exchange

[p.m.berger]

Is there a way to do kinetic isotopic exchange as in Druhan et al. GCA 2013? I have a system that recrystallizes calcite due to hot fluid circulation and I've read some papers that look at closure temperatures for isotopes. Currently I have a kinetic transformation from a (segregated) low ordered to a (unsegregated) hydrothermal calcite. I was just wondering if there was a cleaner way. Crunchflow, as used in the original paper, doesn't do heat flow for some reason and so isn't an option.

Thanks,

Peter

[Jia Wang]

Hello Peter,

Apologies for the delayed response.

The GWB can account for equilibrium fractionation of stable isotopes as described in the Geochemical and Biogeochemical Reaction modeling text section 19. You can use the ‘segregated’ mineral option so that only minerals precipitated and dissolved are in isotopic equilibrium of the changing system. Any mineral present at the start of the time step is unaffected. Kinetic minerals are automatically considered fully isotopically segregated since they exist outside of the equilibrium system. You can set up kinetic minerals to dissolve and precipitate using rate constants and surface area. From your brief description above, your input file setup seems to be pretty efficiently setup. If you would like someone to take a closer look, please attach the file below. The GWB does not incorporate isotope fractionation kinetically as Druhan et al., 2013.

Hope this helps.

Best regards,

Jia Wang