setting oxygen fugacity for modelling fractional crystallisation

[Melina]

Hello everyone,

I have been trying to model the LLD for the volcanic system that I'm studying. I've been using the "MELTS v1.0.2 fractionation" Jupyter notebook on the ENKI portal sever for this and ran into a problem. I can't figure out how to change/set the oxygen fugacity? Can anyone give me a hint?

Also, I have excluded the phase sanidine from my calculations, but it is still included in my outputs? It doesn't happen with any other phase that I have excluded. Is there another way to exclude phases except with melts.set_phase_inclusion_status()?

[Paula]

Hi Melina,

I don't think there is an fO2 example in the MELTS-pMELTS directory. There is functionality like that in the newer Equilibrate package but I haven't looked at any of it lately. Your best bet might be to ask on the ENKI Slack channel (enki-portal.slack.com). It's the free version of Slack so you can't see old posts, unfortunately, but queries usually get answered by community members quickly.

Sanidine is an end member in the feldspar solid solution in (Rhyolite-)MELTS. So far as I know, you can't exclude it in Thermoengine without excluding the feldspar phase altogether, although you could might be able to  get around this by removing K2O from your bulk composition.

Paula