Theriak-Domino: Pixelmaps File Names


Domino in pix X Y mode can produce a lot of files, with an array of file names that can be bewildering at first. Here is a brief, probably incomplete guide to interpreting what the names say about what is in each file.

Metadata files

First, there are three files containing metadata about the Domino/pix X Y run. These are not merged into the table by the R program.

  • datetime: Contains the date and time the run was started, and the length of time the calculation took.
  • pixa: This is a numbered list of the assemblages. The numbers correspond to those found in the assemblage file.
  • pixinfo: This file has a lot of things: The X and Y axis variables, the start and end points for each axis, the number of X- and Y-axis points in the pix grid, the Domino version number, the thermodynamic database name, the solution models used, the system composition used, and a complete list of all files saved in the _pixelmaps folder. Oh, plus a couple of other numbers that don’t mean anything to me at this point.

With each Domino run you want to keep, it’s probably a good idea to save the pixa and pixinfo files.

The other files

These contain all the thermodynamic calculation results. Until you get used to these in your project, it’s a good idea to have available a copy of the thermodynamics data file you used for the run. All these files have the same format: text only, in two columns, but having different numbers of lines. The first column has the grid calculation sequence numbers, and the second has the calculated results at the grid points. The files can be divided into groups in which the file names have 1, 2, or 3 parts, separated by “_”.

1 part file names: There is only one of these, the assemblage file. As mentioned elsewhere, it has numbers for the assemblages that occur in different parts of the pix X Y grid, which are spelled-out in the pixa metadata file.

2 and 3 part file names: These are more complicated, involving a first part, a last part, and (for 3-part names) a middle part.

  • The last part of the name is always the material. In some cases the material is the bulk or some part of the bulk system: _solids for all system solids, or _tot for total in the system. In other cases the material is a simple, single composition phase such as _ab for albite, and _q for quartz. In still other cases, those bracketed like _[abh1], are end members of solution models (look at your thermodynamic data file to see the listed end members for each solution model). For example, the PLc03 solution model (feldspar) in the mafic rock thermodynamic data file has three end members: abh1an2, and san2, for albite, anorthite, and sanidine, respectively. Domino in pix X Y mode saves the results not under the solution model name, but instead under the name of the dominant end member at that particular grid point. In little image above, used as an example, abh1 (albite) is the dominant end member in [PLc03] at there is one file that ends in _[abh1]. In another part of the grid an2 might be the most abundant, in which case there would be an _[an2] files, too. This might seem odd at first, but it makes it easy to see if a phase is simply changing composition across the grid (_[abh1] at some grid points and _[an2] at others), or if both occur on either side of a solvus (both occur at some of the same grid points). It gets somewhat more complicated to interpret more complex solution models. For example the amphibole CAMPG16 solution model has 11 possible end members. Interpretation remains the same, however: one amphibole end member like _[parg1] (pargasite) at some grid points, and _[ts1] (tschermakite) at others indicates a composition change across the grid. Two amphibole phases at the same grid points, such as _[parg1] (pargasite) and _[cumm1] (cummingtonite), indicates a solvus.
  • The middle part is present only for some solution model results, not for bulk results. If this part is _pfu, that means per formula unit, usually in the minimum oxygen formula, like the 4 oxygen formula for spinel or the 8 oxygen formula for feldspar. Otherwise, the middle part is one of the solution model end members: _abh1 for albite in feldspar, _alm for almandine in garnet, or _H2O for H2O in silicate liquid.
  • The first part refers to the characteristic in the file: G for Gibbs free energy, H for enthalpy, n for number of moles, pc for percent (I think), PV for P*V, rho for density, S for entropy, TS for T*S, V or vol for volume, wt for weight, and x for mole fraction. Some chemical characteristics also get their own files: Al for aluminum, Si for silicon, Mg# for Mg/(Mg+Fetotal).

Reading the file names, some examples

  • Al_pfu_[abh1]: Aluminum per formula unit in the feldspar PLc03 solution model, listed as_[abh1] (albite) because abh1 is the dominant end member in the solution at these grid points.
  • G_system: Sum of the Gibbs free energy of all system phases.
  • Mg#_[en]: Mg/(Mg+Fetotal) in the orthopyroxene OPXW14 solution model, listed as _[en] (enstatite) because en is the dominant end member in the solution at these grid points.
  • n_[fo]: Number of moles of the olivine OL11 solution model, listed as _[fo] (forsterite) because fo is the dominant end member in the solution at these grid points.
  • vol_[py]: Volume of garnet, as the GRTW14 solution model, listed as _[py] (pyrope) because py is the dominant end member in the solution at these grid points.
  • x_jd1_[di1]: Mole fraction of the jd1 (jadite) end member in the AUGG16 (augite) solution model, listed as _[di1] (diopside) because di1 is the dominant end member in the solution at these grid points.

Doubtless some of this is incomplete or wrong. Let me know what needs fixing.