MELTS Software Users

MELTS for Excel, rhyolite-MELTS (GUI) and alphaMELTS => The MELTS family of algorithms, and scientific discussion => Topic started by: Melina on May 21, 2024, 05:49:04 AM

Title: setting oxygen fugacity for modelling fractional crystallisation
Post by: Melina on May 21, 2024, 05:49:04 AM
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()?
Title: Re: setting oxygen fugacity for modelling fractional crystallisation
Post by: Paula on May 23, 2024, 03:38:36 PM
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
Title: Re: setting oxygen fugacity for modelling fractional crystallisation
Post by: LeaOst on December 13, 2024, 01:21:41 AM
Dear Melina,

I have the same question regarding the LLD for a volcanic system that I'm studying. I've also been using the "MELTS v1.0.2 fractionation" Jupyter notebook on the ENKI portal server for this and I wanted to know if you figured out how to change/set the oxygen fugacity? (can't access the Slack channel as my email address is not recognized).

Thank you very much in advance for your answer,

Best regards.

Lea Ostorero
Title: Re: setting oxygen fugacity for modelling fractional crystallisation
Post by: Paula on December 13, 2024, 11:41:35 AM
I just tried to invite you both on Slack, though I am not sure it will work (seemed to want an @caltech.edu email address). If not, try emailing Mark Ghiorso (ghiorso AT ofm-research.org) and he can add you.