MELTS Software Users

MELTS for Excel, rhyolite-MELTS (GUI) and alphaMELTS => Interactive operation => Magma chamber processes => Topic started by: azarbron on July 07, 2010, 08:25:18 AM

Title: Assimilation followed by fractional crystallization
Post by: azarbron on July 07, 2010, 08:25:18 AM
Hello, I've been attempting to model assimilation of iron-rich metasediments by a komatiitic magma. To do so I set the program to isenthalpic mode and added assimilant with deltaT and deltaP set to 0. Afterwards, I took the assimilated data and made it into a MELTS file to run fractional crystallization on it with deltaT -10. When I attempt to use this new data created by melts at an imposed fO2 at FMQ, I receive an error that a buffer overrun was detected. Any ideas on how to avoid this problem? Is there a way to fractionally crystallize isenthalpically without constant addition of assimilant?
Thank you, Bronwyn
Title: Re: Assimilation followed by fractional crystallization
Post by: Paula on July 07, 2010, 11:01:06 AM
Hi Bronwyn,

Sorry you have been having problems. Without trying your actual files it's hard to know exactly where the buffer overrun is happening.  Mark Ghiorso and I fixed a bunch of buffer overruns recently but I haven't had a chance to post the new versions of adiabat_1ph (lots of odds and ends to tidy up first). So you can either e-mail me the files and I'll test it and / or let me know what operating system you are on (Windows?) and I'll let you have the new version to see if you still get problems.

There's nothing to stop you doing a fractional crystallisation run in isenthalpic mode but it won't actually do much. After the first crystallisation step (which will be isothermal unless you set the total enthalpy) and fractionation, the system will be in equilibrium.  You need to change the temperature and / or composition...

Cheers,
Paula