This topic will show you how to work through one page of the (old) MELTS tutorial, using the current downloadable rhyolite-MELTS software:
Testing MELTS installation using the sample input file - Try this firstThe page is part of the 'Getting Started: Testing and Examples' section of the
MELTS manual, written by Mark Ghiorso for the original graphical-user-interface (GUI) version. The idea of this topic is to show how the GUI has evolved since its original release and as a comparison with the
alphaMELTS and
other versions of the same tutorial. This post is for rhyolite-MELTS 1.0.2, 1.1.0, 1.2.0 / pMELTS version 5.6.1 (updated from rhyolite-MELTS version 1.0.1 / pMELTS version 5.0.0).
The software can be downloaded from the
MELTS website. This
links page summarizes the download options and installation procedures for various flavors of Mac and Linux, and for MELTS versus rhyolite-MELTS. The screen output in this particular example is from a rhyolite-MELTS run on the
Windows Subsystem for Linux but almost all the information applies to Mac and Linux users too.
This example uses an input file that has been modified from the
Morb.melts file used in the original tutorial. The modifications simply bring it up to date with the latest GUI versions of MELTS and do not affect software results. Early versions of the MELTS software used a 'Mode: Fractionation' line in the input file to to select fractional crystallization, whereas in later versions this is replaced by 'Mode: Fractionate Solids'. Also some phases were suppressed in the original tutorial because the solid solution models were still being developed / tested. None of the phases are stable for the run conditions of the tutorial example, so suppressing these phases has no effect. However, the 'Suppress: ' lines can cause read errors as the names of some phases have changed slightly since (see
here).
If you have downloaded and installed
alphaMELTS then the modified Morb.melts file will be in the installation folder and you can copy it from there. Otherwise, copy the contents of the file from the
reply below and save it as 'Morb.melts'. Note that the version of
Morb.melts available on the
MAGMA Source server is the same except that it has Windows line endings but the
morb.melts version linked on the
Mac OS X download site differs slightly in Cr
2O
3 content and in the
P-T conditions.
When the original tutorial was written there was only one liquid calibration (i.e. MELTS) and so the software could be started by double-clicking it. Now it must be opened in a Terminal program and a choice between rhyolite-MELTS, with or without the mixed H
2O-CO
2 fluid, and pMELTS made before the user interface is initialized. In MacOS the Terminal program may be used and is found using Finder in Applications/Utilities. Depending on the exact flavor of Linux being run, a Terminal program may be located in a submenu of the Applications menu, or accessible via a Desktop launcher or context menu (mouse right click). In VM alphaMELTS the LXTerminal icon is located next to the start menu. On Windows 10 with the Windows Subsystem for Linux (WSL), open the ubuntu command line app and start the X11 server (Xming or X410).
Navigate to the folder where you want the output files to be written. If this is the same folder where the rhyolite-MELTS executable is located then type './Melts-rhyolite-public'. If the rhyolite-MELTS executable is located elsewhere you may need to type the path, either absolute or relative. Alternatively, if the rhyolite-MELTS executable is located in a folder that appears in your PATH variable (try typing 'echo $PATH' at the terminal command line) then you can just type 'Melts-rhyolite', or similar, without the './' beforehand (replace 'Melts-rhyolite' with whatever the executable, or link to it, is actually called). You will be presented a choice that looks something like this:
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
rhyolite-MELTS (1.0.2, 1.1.0, 1.2.0) pMELTS (5.6.1) - (Aug 16 2018 - 13:50:34)
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
---> Reading environment variables...
<><> There are three releases of rhyolite-MELTS and a version of pMELTS included in this package:
(*) rhyolite-MELTS v. 1.0.2 (original version, with corrections) - old H2O model, no mixed fluids.
(*) rhyolite-MELTS v, 1.1.0 (mixed fluid version that perserves the ternary minimum) - old H2O model.
(*) rhyolite-MELTS v. 1.2.0 (mixed fluid version optimal for mafic and alkalic melts) - new H2O model.
(*) pMELTS v. 5.6.1 (original version, with corrections) - - old H2O model, no mixed fluids.
<><> Visit the website melts.ofm-research.org for information on which version to use for your application.
---> Default calculation mode is rhyolite-MELTS (v. 1.0.2). Change this? (y or n):
There is more explanation of the various MELTS versions in the
MELTS decision tree. However, rhyolite-MELTS 1.0.2 should give identical results to the original MELTS model for the bulk composition used here. So, choose 'n' and press enter, which should start up a graphical user interface that looks something like the screenshot below. If the graphical user interface does not open, then check the
alphaMELTS links page and
operating system-specific boards here for troubleshooting hints.
The first thing you will notice is that the great big AFM plot shown in the
original screentshot is missing. Don't get your hopes up with the 'Graphics Display Window' button either - depending which MELTS executable you have, you may find that the
Melts Graphics Output Window is inactive or you may be able to open the window, and the 'Graphics Options Dialog', but when you go to plot something you will get a message like 'Selected option has not yet been implemented'. In fact, the graphics are disabled in all current GUI versions of MELTS and rhyolite-MELTS (including
CORBA MELTS). Many more plotting tools are widely available now, than when MELTS was first released, so that it is not a worthwhile use of time to keep the MELTS plotting routines up to date as the underlying graphics software (Grace) changes. The other Icons don't do much either, unfortunately, but you can find links to the Supplemental Calculator (a.k.a the Phase Properties calculator)
here and tools for processing the output files
here.
O.K. that's all the bad news over, it should be plain sailing from now on!
Follow the instructions in the original tutorial to open the Morb.melts file. The only minor difference will be that the 'Execution Mode' option will be disabled (it's supposed to be grayed out like that; that it wasn't at first was a bug).
By default the program looks for .melts files, so if your input file is called, say, 'Morb.txt' then change '*.melts' to '*.txt' in the Filter box and then press the Filter button. You can also change the folder name in the Filter box and / or navigate around folders by double-clicking them under 'Directories', where '.' is the current folder and '..' is one level up in the folder hierarchy. If you get an error message during the file read then you probably have an incompatible Morb.melts file (e.g. it has Windows line endings and / or an outdated 'Mode: Fractionation' line); in many cases, the bulk composition will still be read in correctly but you will need to switch fractional crystallization on manually by selecting 'Fractionate Solids' under the 'Options' menu. If you see no changes to the Bulk System panel then make sure to select the Morb.melts / Morb.txt file (even if it's the only one in the folder) before clicking the 'OK' button in the 'Open...' pop-up dialogue.
Although the front-end program looks a little different to the one in the
original tutorial, the settings for the underlying MELTS algorithm should now the same as described in the 'Four things have been accomplished:' list there. You can verify that the
P-T conditions are set correctly by selecting 'Intensive Variables', then 'T, P ...'.
The remaining steps in the tutorial can be followed as is. If you get a message like 'Error in SILMIN file output procedure. Cannot open file: ' then either some other program is accessing the file or, more likely, you started the MELTS executable in a folder that you do not have write access to (e.g. /Applications when running as a non-Administrator on Mac). When it is finished the program window will look like this:
As with the
alphaMELTS run there will be slight discrepancies between the newly generated melts.out file and the
original output file. The most striking differences are the addition of Mn, Co and Ni to the olivine solid solution model, though none of these components are in the Morb.melts bulk composition, and splitting of the pyroxene phase into separate clinopyroxene and orthopyroxene phases (see
here). The phase compositions are essentially the same though and differences in the phase masses are a few hundredths of a gram, at most.
If there are any problems or feedback about this post then please let me know.
Cheers!
Paula
