TWQ202 (version 2.02b) ------ -------- ----- The TWQ package (version 2.02) uses the same executables as version 2.01, together with new thermodynamic data described below. Latest revision (TWQ202a; October, 1996): small changes to CMP.EXE Latest revision (TWQ202b; March, 1997): small bug fixed in INTERSX.EXE CMP.EXE fixed to recognize CORD as cordierite BA96a.SLN: corrected (site multiplicity of ilmenite=1, not 2) added binary Fe-Mg spinel solution properties Overview -------- This file describes changes to TWQ (version 1), and is intended as an add-on to the documentation of programs found in the file TWQ.DOC. The main changes to this version of TWQ are in the database described below and in a new option implemented in TWQ201 that allows only selected equilibria to be calculated rather than all possible equilibria. To access this option, type TWQ/S. After selecting endmembers for the calculation, the program will show tables of all possible equilibria and ask you to select the numbers of those you wish the program to compute. This option is useful if there are more than 3 independent equilibria and you wish to see the positions of the most robust ones without the clutter of the others. Beware that at the present time, the program will not perform properly on a PC if too many equilibria are possible. Thermodynamic Data: BA96a.DAT, BA96A.SLN, RECIP.SLN: Uses Berman (1988) thermodynamic data for minerals & fluids for K-Na-CASH phases, along data for the following minerals that have been derived by MAP analysis of relevant experimental data discussed in detail in the references below:: 1. anthophyllite, talc, rutile, as well as components of the following solid solutions: olivine (fo, fa), orthopyroxene (en, fs, al-opx), cordierite (Mg-, Fe-; both of which are assumed to follow the same hydration energetics), garnet (alm, py), ilmenite (Fe-, gk) (Berman & Aranovich,1996, CMP, 126,1-24) 2. hedenbergite and Mg-Fe-Al (M1) clinopyroxene mixing properties (Berman et al., 1995, Contrib Mineral Petrol 119:30-42) 3. provisional properties for biotite (phl, annite, siderophyllite, eastonite), and Mg-Fe spinel, based on unpublished data of Berman & Aranovich (1997). Please note the new formats for opx, cpx, and biotite solutions in BA96a.sln. These formats can be generated with the CMP program described briefly below. Note also that because some Mg endmembers have changed (fo, en, cd, py, sp), you cannot use other Mg-, CaMg, or MgAl phases from Berman (1988) with the current data set. Calculations are currently in progress to rectify this situation. If you need to use phases that are not included in the present database (e.g. most amphibole endmembers, CaMg phases, some MgAl phases), you will have to perform these calculations with the earlier database provided in TWQ version 1.02. Lastly, note that thermodynamic data in this version of TWQ are NOT identical to the data in the above references or in TWQ2.01 because this version is based on simultaneous analysis of ALL data, whereas the earlier works considered each set separately. ------------------------------------------------------------------------------ CMP (version 2.01) CREATING MINERAL COMPOSITION FILES MINERAL COMPOSITIONS For each set of thermobarometric calculations, you must provide a file that contains mineral compositions used by TWQ to compute displaced equilibria. This file can have any name you like and must be edited by you so that it contains all appropriate information about mineral compositions in one rock or `equilibrium assemblage'. The expected compositional terms relate to the sites that are defined in the SOLID.SLN (or BA96a.SLN) file that is described in the TWQ.DOC file. The following is a list of the CMPTEST.CMP file that can be used as a template for making other CMP files. PLAG [-An-][-Ab-][-Or-] PLAG .3537 .6300 .0163 OPX [xMg-][xFe-][xAl2] Fe3 used-calc: .00-.08 OPX .4899 .4492 .0608 GARN [-Gr-][-Py-][-Alm][-Sp-] cFe3+ used-calc: .00-.07 GARN .0288 .3183 .6353 .0175 AMPH [NaA ][K A ][v A ][MgM2][FeM2][AlM2][Fe3M][TiM2][CaM4][MgM4][FeM4][MnM4][MgM1][FeM1][MnM1][SiT1][AlT1][O O3][OHO3][F O3] AMPH .3885 .2907 .3208 .2849 .2704 .1978 .1613 .0857 .9480 .0015 .0505 .0000 .2394 .7565 .0041 0.6079.3921 .0857 .9143 .0000 BIOT [xMg-][xFe-][F3M2][MgM1][FeM1][TiM2][AlM1][F3M1][-vM1][Al4-][-Si4][-xK-][-xOH] BIOT .6619 .3381 .0000 .4375 .2235 .1358 .2032 .0000 .0000 .2937 .7063 0.90341.0000 CORD [xMg-][xFe-] CORD .6743 .3232 CPX [MgM1][FeM1][AlM1][TiM1][CaM2][MgM2][FeM2][NaM2] - Fe3 cations = .00 CPX .1830 .0877 .7274 .0020 .0000 .6747 .3234 .0000 Abbreviations for each mineral composition must match those used to define the solution phase in the file SOLID.SLN (or BA96a.SLN). The order and number of entries for each phase corresponds to the number of components and number of sites upon which mixing takes place in the solution phase defined in SOLID.SLN. All compositions are input as mole fractions, which can be up to 6 digits including the decimal point. They must by aligned within the square brackets of the appropriate component on the preceding line. Note: the plot file generated by TWQ will contain labels giving the name of the file from which mineral compositions were read, as well as the solution model used for each mineral. For convenience in some situations, you can also put in fixed activities for any phase component that overide fixed activities specified during interactive input or in the restart file. These fixed activities are input in the compositional file by typing lines as follows (capital letters must be used): FIXED ACTIVITY SILLIMANITE=0.9 ORTHOENSTATITE=.5 ENDFIX The phase names must match exactly those used in the thermodynamic data file. If the activities are less than 0, they are assumed to be natural log activities. Any activities input in this way are applied during the calculation, even if activities are further reduced based on mineral compositions that may be present in this file. CMP.EXE provides an easy way to make a CMP file for biotite or any other of the above solid solutions. Type in your oxides as shown in the sample file CMPTEST.OXI - the order of oxides is not important as long as the order is specified on the second line. The program scans the first part of each line for key letters that identify which mineral the analysis corresponds to: b=biotite, p=plag, o=opx, g=garnet, c=cpx, a=amph, cd=cord, i = ilmenite THe file CMP.FIG lets you control whether there is a header line with comments that precede the oxide list line and also the starting position of each data line from which to search for the mineral abbreviation. The default is having a comment line and searching from position 1. If, e.g., you don't have a comment line and wish to search from position 7, the CMP.FIG should read 07 instead of the default 11 The program assumes the input file has the .OXI extension, and output is directed to a file with the .CMP extension. Additional graphics file output is sent to XXXX.p (XXXX is garn, plag, opx, cpx, amph, cord, biot depending on which minerals are in your input file. Use TWQ's PLOT.EXE to view this file on screen, or DXF to convert it to a DXF file that can be imported into a number of different graphics packages. Summary of site fraction calculations: For gt, bi, and pyroxenes, Fe3+ can be calculated by stoichiometry, but in general this is not recommended due the extreme sensitivity to probe errors. Below are the mole fractions for specific phases that need to be defined for each solution phase. Opx: 1-site model with En-Fs-Ok (orthocorundum) endmembers. The following mole fractions must be defined: M(1):xEn,xFs,xOk where, for a 6-oxygen formula, xOk = Al/2 xFs = Fe/2 xEn = Mg/2 Nonideal Mg-Fe-Al interactions are given by Berman & Aranovich (1996) Cpx: 2-site model with equal partitioning of Fe-Mg between sites, octahedral Al assumed to be tshcermakitic, except for jadeite component (=Na) The following mole fractions must be defined: M1(1):Mg,Fe,Al,Ti-M2(1):Ca,Mg,Fe,Na Na = Na - Fe3 (acmite) AlM1 = Na + (Al-Na)/2 (increase AlM1 by jadeitic Al) mgfe = Mg/(Mg+Fe2) sum1 = 1-Ti-AlM1-Fe3 FeM1 = (1-mgfe)*(sum1) MgM1 = (mgfe)*(sum1) Sum2 = 1 - Na - Ca - Mn FeM2 = (1-mgfe) * sum2 MgM2 = (mgfe) * sum2 Nonideal Mg-Fe-Al interactions are given by Berman & Aranovich (1996a) Biotite: 3-site model assuming Al, Ti on 1 M1 site (Circone & Navrotsky, 1993). M2(2):Mg,Fe,F3-M1(1):Mg,Fe,Ti,Al,F3,v-T(4):Al,Si Nonideal Mg-Fe-Ti-Al mixing corrections are given by Berman & Aranovich (1996a) Garnet C(3):Ca,Mg,Fe,Mn Nonideal Mg-Fe-Ca-Mn interactions are given by Berman & Aranovich (1996a) Cordierite M1(2):Mg,Fe Nonideal Mg-Fe interactions are given by Berman & Aranovich (1996) Olivine M(2):Mg,Fe Nonideal Mg-Fe interactions are given by Berman & Aranovich (1996) Ilmenite M(1):Mg,Fe Nonideal Mg-Fe interactions are given by Berman & Aranovich (1996) Mica A(1):K,Na-M(2):Al-H(2):OH Nonideal mixing corrections for K-Na are available from Chatterjee & Froese (1975). Plagioclase I(1):Ca,Na,K Nonideal Ca-Na-K interactions are given by Fuhrman & Lindsley (1988). Spinel X(1):Mg,Fe-Y(2):Al Nonideal Mg-Fe interactions are given by Berman & Aranovich (1996) ------------------------------------------------------------------------------ DXF.EXE (version 2.01) To convert Ascii PLOT.DAT files to DXF files read by AUTOCAD,CORELDRW, etc. Type DXF and answer the program queries: Name of file: plot.dat Plot points: 1 Scale factor: 1.0 (100.0 if a T-X diagram) Shape: 0 (=square, 1 or more = progressively thinner rectangle) Offset: 1 (normal position, 0 = Y position shifted down, 1 or more = Y position shifted up progressively) Note: the shape and offset can be used together to make connecting plots E.g. if shape = 3 then 3 plot files will fill the space normally filled by one if offset = 0 for the first plot file, 1 for the second, and 2 for the third plot file, then the 3 files will plot together in the same order