# PTQuick

**PTQuick** is a handy ©MS Windows program for estimation of equilibrium parameters (temperatures, pressures, oxygen fugacities) for mineral parageneses using methods of classical geothermobarometry, i.e. by independent expressions and algorithms ("tools") developed by different authors.

A special attention is paid to convenience and efficiency of working, that makes obtaining final results easy and fast:

- simultaneous work with large sets of samples;

- fast "intelligent" import of tabulated data on mineral compositions from ©MS Excel or text ASCII-files with immediate calculation of formulae coefficients (by two methods);

- automatic selection of available tools based on full set of imported compositional data and on data present for separate samples;

- automatic recalculation and plotting of mineral equilibrium curves while a user navigates the table of analyses (at changes of samples) or the diagram window;

- estimation and plotting of intersection points for selected equilibria (geothermometers and geobarometers, geothermometers and oxybarometers, etc.) for all imported samples, as well as performing of "chain" calculations (estimation of P-T parameters from intersection of geothermometer and geobarometer with their following use in the expression of oxybarometer);

- plotting of different reference curves on diagrams (e.g. lines of transitions between polymorphs, conductive geotherms, etc.);

- two variants for user-specified sets of selected tools and reference lines;

- fast copy of diagrams, tables with calculated mineral analyses and tabulated results of parameters' calculations to the Windows clipboard for the following use in other programs (e.g. in ©MS Word, ©MS Excel, ©Corel Draw, etc.);

- opportunities for the program customization and more...

All the thermodynamic calculations (sensors' procedures, or tools' database) in **PTQuick** are implemented as a separate open-source module, so that you can investigate and modify their actually working algorithms: I think this idea is very important for such scientific programs.

The database of tools is implemented as a dynamically linked library (PTools.dll), i.e. correction or addition of new tools involves editing of its source text by the programmer with following compilation and linking in the ©Borland Delphi programming environment (instructions about these operations are provided in supplied sources of the library, where you can also check how all the tools are implemented).

Moreover, there is an opportunity in **PTQuick** for use of additional external tools implemented as separate small programs (executable exe-files) that communicate with the host program via small text files having very simple format.

While the current set of tools (near 150) is focused mostly on HP and UHP rocks (lower crust and upper mantle conditions) and some of them are only of historical interest, a wider range of conditions and mineral associations can be easily covered. However, addition of all known tools is not planned: I'll add new tools on your requests only.

**PTQuick** was developed in close cooperation with Sergey K. Simakov who is the author of several geothermometers, geobarometers and oxybarometers. As for the tool set and some ideas, **PTQuick** is a descendant of the >15-years old DOS-program **GEOTHERM** that was developed by Mikhail V. Ivanov and Sergey K. Simakov for geothermobarometric investigations of high-pressure and ultra-high-pressure rocks.

**List of sensors implemented in PTQuick can be viewed on (and downloaded from) Google Drive or Yandex Disk**

**How to work with PTQuick** (basic operations demo, program version 1.0):

## Comments

## Thank you for this great

Thank you for this great software!

Do you think it would be possible to add a GASP barometer to conduct thermobarometry on amphibolite-grade metapelites? According to Wu et al(Lithos 2006) those of Newton and Haselton,1981 and Holdaway (2001) are the best.

Regards,

## Hi Felix,

Hi Felix,

Sure, it's possible! I will add these calibrations for 1-2 days and let you know about it here.

P.S. However, I expect more time to implement the calibration of M. Holdaway (2001).

## Thank you very much Dmitry,

Thank you very much Dmitry, it will be extremely useful. As for Holdaway, it would ressurect the program, because it doesn't work on new Windows platforms.

## Garnet-Plagioclase-Al2SiO5

Garnet-Plagioclase-Al2SiO5-Quartz (GASP) geobarometer of R.C.Newton and H.T.Haselton (1981) has been added to the PTQuick set.

Expressions for Ky, Sil and And polymorphs are taken from the GPT MS Excel program of J.Reche & F.J.Martinez (1996).

List of files to be replaced:

P.S. I think this geobarometer has historical interest only. E.g. it uses the problematic volumetric data for Grs-Alm and Grs-Prp garnets from Cressey et al. (1978), you can read critique in Berman (1990).

## Historical interest .... but

Historical interest .... but it is the GASP barometer that yielded the best results after Holdaway, according to Wu and Cheng, 2006

http://www.sciencedirect.com/science/article/pii/S0024493705001982

## Unfortunately, these tests

Unfortunately, these tests doesn't include GASP (+GB thermometer) calculations by programs like TWQ or Thermocalc+AX (avPT) with updated thermodynamic databases (more modern than Berman 1992). BTW I think that Holdaway's barometer can also be easily implemented directly in TWQ (all what we need is to replace Hf and Sf parameters of grossular in the database B92.dat and to add the alternative set of garnet Margules parameters to the B92.sln file). I'll try...

## Garnet-Plagioclase-Al2SiO5

Garnet-Plagioclase-Al2SiO5-Quartz (GASP) geobarometer of M.Holdaway (2001) has been added to the PTQuick set. The most recommended "AVF" version (averaged garnet Margules parameters and plagioclase model of M.Fuhrman & D.Lindsley (1988)) is used. GASP with andalusite is also implemented. The procedure automatically detects the correct alpha/beta quartz polymorph.

~~The only difference is that fixed Fe~~though the procedure is sensitive to Fe^{3+}can not be set via the program interface yet,^{3+}/Fe^{2+}ratio estimated by the charge disbalance method (BTW you can clear the "Use Fe[3+]" checkbox to assign all Fe to Fe^{2+}or set variable "Fe3=N" for the barometers in the Tools.dat file).List of files to be replaced:

The "DLL Source" folder is also updated, this GASP barometer is placed starting from the line

~~6963~~in PTools.dpr...There is also the Excel version of this barometer designed for one sample per time calculations. It's good for testing/educational purposes or just to check how it works, I've commented most important details there. This Excel version can be downloaded from my Google Drive or Yandex Disk.

P.S. I've added a new optional variable "Fe3%=" that can be used in Minerals.dat file for fixed mol.% of Fe

^{3+}in desired minerals. E.g. you can add the lineFe3%=3

to the garnet description and

Fe3%=11.6

to the biotite description. This setting affects only the calculations by cationic method and supersedes the calculations of Fe

^{3+}by charge disbalance and from measured contents of Fe_{2}O_{3}.Therefore, PTQuick.exe with help-files (*.chm) are also updated!

## Grt-Bt geothermometer of M

Grt-Bt geothermometer of M.Holdaway (2000) has been added to the PTQuick set. The most recommended 5AVE model (consistent with the "AVF" version of GASP geobarometer from Holdaway, 2001) is used. List of files to be replaced:

## Grt-Bt-Pl-Qtz geobarometers

Grt-Bt-Pl-Qtz geobarometers from (Wu, Zhang & Ren, 2004) have been added, expressions equivalent to the Excel variants are used (however, expressions of activity coefficients are replaced by general equation). These Mg and Fe barometers are almost consistent with GB thermometer and GASP barometer of M.Holdaway (2000, 2001). W

^{H}_{CaK}and W^{H}_{KCa}for Pl are swapped (vs. original paper) due to missed typo in the Fuhrman & Lindsley (1988) paper (though, this error has negligible effect). Fe3%=3 in the garnet description and Fe3%=11.6 (assemblages with ilmenite) or Fe3%=20 (assemblages with magnetite) for the biotite description are recommended in Minerals.dat. Check "Use Fe[3+]" option for correct Bt recalculation. NB: Fe and Mg GBPQ lines are crossed at T ≠ T_{Grt-Bt}(Holdaway, 2000), a little.## Dear Sir

Dear Sir

I am trying to calculated PT condition for my samples which consist of garnet, muscovite, chlorite, plagioclase and quartz so it would be great help if you add garnet-muscovite geothermometer and garnet-muscovite-plagioclase-quartz geobarometer. According to Wu et al(Lithos 2006).

Thank you very much

## Hello,

Hello,

I was planning to add these geothermometer and geobarometer, I'll do it next week!

## I am very happy to know that.

I am very happy to know that. Hope to get your updated version after next week

## I'll echo the above comments,

I'll echo the above comments, very handy piece of software, Dimitry. Could you add the Spear (1993) and Bhattacharya et al.(Contrib. min. pet., 1992) garnet-biotite thermometers as well?

Cheers!

## OK! I'll add these historical

OK! I'll add these thermometers tomorrow, together with equations of Wu et al. Do you mean the simple Grt-Bt expression from the Spear's 1993 book, chapter 15?

## Wonderful, yes that would be

Wonderful, yes that would be great. Thanks so much!

## I've updated the main

I've updated the main executable PTQuick.exe ("Fe3%=" option in Minerals.dat now affects the both two re-calculation methods) and added muscovite to Minerals.dat.

Several new geothermometers and geobarometers appeared in PTools.dll (+ Tools.dat & Sets.dat):

1. Grt-Mu geothermometer (Wu & Zhao, 2006)

2. Grt-Mu-Pl(+Qtz) geobarometers (Wu & Zhao, 2006), Mg & Fe reactions

3. Grt-Bt-Mu-Pl geobarometers (Wu, 2015), Mg & Fe reactions

Historical Grt-Bt thermometers:

4. Grt-Bt geothermometer (Spear, 1993)

5. Grt-Bt geothermometers (Bhattacharya et al., 1992), HW & GS versions

Some notes on the tools of Wu et al.:

1. Don't forget to set "Fe3%=3" for garnets and "Fe3%=11.6" for biotites in Minerals.dat (just type "=" in these lines)

2. You may notice very small differences in pressures between PTQuick vs. Wu's Excel workbooks (several bars lower in PTQuick). This is mainly due to W

^{H}_{CaK}/W^{H}_{KCa}plagioclase Margules parameters erroneously swapped in original paper (Fuhrman & Lindsley, 1988) with used felspar model. This typo has been corrected by M. Holdaway (2001) in his GB.EXE, GASP.EXE and GBGASP.EXE programs (supplementary letter) but not in feldspar expressions of Wu et al. (Fc=W^{H}). I decided to use the same corrected feldspar expressions in PTQuick for all these tools (following M. Holdaway). BTW, I prefer to use the general RTlnγ expression in PTools.dll with immediate W values rather than re-arranged expressions from the papers of Wu et al. (which are great for Excel spreadsheets but too awkward in conventional programs).## Thanks Dmitry for this

Thanks Dmitry for this software! It works very well and is way more convenient than dealing with the equations in different spreadsheets. Thanks also for your great work on TC_Comb!

Would it be possible to add the following barometer for metapelites with Ca-poor garnet or plagioclase?

Garnet-biotite-muscovite-aluminosilicate-quartz barometer (Wu and Zhao, 2007, Lithos)

http://www.sciencedirect.com/science/article/pii/S0024493707000047

It would also be neat to have the following thermometers added as well. Although the equations are easy to calculate, they are pressure dependent and PTQuick would work nicely to display them along with other reactions.

Ti-in-biotite thermometer (Wu and Chen, 2015, Science Bulletin)

http://link.springer.com/article/10.1007%2Fs11434-014-0674-y

Ti-in-muscovite thermometer (Wu and Chen, 2015, Lithos)

http://www.sciencedirect.com/science/article/pii/S0024493714003995

Your dedication to ameliorate the software is truly appreciated!

Regards,

Renaud

## Thank you Renaud for the kind

Thank you Renaud for the kind words! I'll add these barometer and thermometers as soon as possible, but not earlier than beginning of the next week (when I can get all required Wu's Excel tables with calculation examples for testing).

I regard Excel spreadsheets from supplementary materials as open-source working examples of presented methods. IMHO, they are great for educational and testing purposes and for small tasks, but poorly suitable for voluminous regular works. I've tried once to write a serious program in Excel (after closer look at Isoplot), but abandoned this project despite its success: a) it works too slow with large data volumes, b) Excel puts too many limitations for programming (especially for interface, user-program interaction).

## New expressions added to

New expressions added to PTools.dll (+ Tools.dat & Sets.dat):

1. Grt-Bt-Mu-Als-Qtz geobarometers (Wu & Zhao, 2007, Lithos), Ky, Sil & And versions

2. Ti-in-Bt geothermometer (Wu & Chen, 2015, Science Bulletin)

3. Ti-in-Mu geothermometer (Wu & Chen, 2015, Lithos)

However, the last two thermometers are imprecize tools which can be used only for rough estimations. You can read also: Chambers J.A. & Kohn M.J., 2012. Titanium in muscovite, biotite, and hornblende: modeling, thermometry, and rutile activities of metapelites and amphibolites // American Mineralogist, v. 97, p.543-555.

## Thanks a lot Dmitry for

Thanks a lot Dmitry for adding these tools! It's much easier now to visualize and compare them with other thermobarometers.

However, I noticed that the Ti-in-Ms thermometer line disappear below 10 kbar, even if the range of applicability is 1-14 kbar. This issue occurred with all the samples I tested. Do you know why this happens?

## This may occur at

This may occur at inappropriate settings for axes due to ln(P) term in the expression of the thermometer. Only positive input pressures are valid, therefore if P-increment is too large and if Pmin ≤ 0, at least one line node (Pmin) can not be calculated. Try to decrease "Step" (increment) value in the "Parameters" window (tab "Calculations"), or uncheck "Step" and increase number of steps in the counter under this checkbox. I guess you have Step=10 in your settings.

## Yes, this is exactly what

Yes, this is exactly what happens and both suggestions solved the problem. Thanks again!

## Dear Dmitry,

Dear Dmitry,

Thank you for this great piece of software. I appear to be having some trouble however when calculating P-T ranges for multiple minerals i.e. Grt Bio, etc. It may be the way my data is formatted however data analyses for single minerals such as garnet, biotite and muscovite all work perfectly.

If you have any insight into my problem I would be grateful.

Thanks

## Dear Sean,

Dear Sean,

The format of PTQuick input files (or data tables copied from MS Excel) is like this, in general:

Values in rows should be separated by TAB symbols, order of columns is not important.

The optional column "Area" (or "Field", "View", etc, look in PTQuick.ini its possible headers) can be treated as "sub-sample", i.e. as suffix for Sample ID: the program takes it into account to decide which analyses should be used for calculations when you select analysis in the table or press the "Report" button. So, you can regard this example as the set of 3 samples:

Smp1_A,Smp1_BandSmp2_A.PTQuick doesn't generate permutations of analyses by itself (as TC_Comb and TWQ_Comb do). If all data rows in this table are checked in PTQuick and some minerals have two or more analyses, the program takes only first appropriate analyses of each mineral (i.e. combinations Grt

_{1r}+Bt_{3}+Mu_{5}+Pl_{6}forSmp1_A, Grt_{7r}+Bt_{8}forSmp1_Band Grt_{2r}+Bt_{1}forSmp2_A). You should uncheck Grt-1r and Bt-3 rows to see the combination Grt_{2c}+Bt_{4}+Mu_{5}+Pl_{6}ofSmp1_A.If you wish to process all possible combinations of analyses simultaneously, use the supplementary program

PTQ_Comb: this program generates expanded tables for PTQuick. For example, this table will be represented as the set of samplesSmp1_A_00,Smp1_A_01,Smp1_A_02,Smp1_A_03,Smp1_B_00,Smp1_B_01andSmp2_A, where separate combinations are marked by additional numerical suffixes (00, 01, etc.).Then you have to select desired thermometers and barometers in the window "Tools". PTQuick shows there sets of sensors on the basis of the whole set of minerals in the table. If curve of some sensor doesn't appear on the diagram while the selected sample contains analyses of all required minerals, you can press the "Table" button under the diagram: the program writes there notifications about possible errors like division by zero, invalid negative values, etc.

## Hi Dima -- I was just about

Hi Dima -- I was just about to bother you with another email but thought I'd scour the discussion board for answers first. And voila, here is an exactly perfect answer to my questions already!

## Thank you Dmitry,

Thank you Dmitry,

Excel sheet was reformatted, the problem is fixed and tools are all working perfectly.

I appreciate your help.

With gratitude,

Sean

## New expressions added to

New expressions added to PTools.dll (+ Tools.dat & Sets.dat):

It is also important that while PTQuick takes amphibole formula coefficients recalculated by the method suggested in the article, you can not see these specific values in the compositional table (where results of standard calculations may only appear)!

## Hello Dima,

Hello Dima,

I've yet to try this out (got to get onto a PC), but before I do I am wondering, have you included Auzanneau et al.'s (2009) Ti-in-phengite geobarometer in your program?

Thanks,

Luke

## Dear Luke,

Dear Luke,

Unfortunately, Ti-in-phengite geobarometer from Auzanneau et al. (2010) is not implemented yet. Though, I can add this barometer over the next few days, depending on its complexity. I've just read this article quickly and have not yet understood where is geobarometer expression itself... :))) Is it that Fig.7 on page 16 with the PressION(GPa)-Temperature(°C)/logTi(Zrc)-Ti[Phengite] diagram? If it is, I should just approximate these curves by some polynomial.

BTW, no any Ti-in-Zircon geothermometers in PTQuick yet, too((( It seems that I should add them! ;-)

P.S. However, isoplethes on Fig.7 are getting too irregular at high Ti contents, this may prevent a simple polynomial fitting(((. So, the best way is more difficult: as the article is not completed (IMHO), readers/users have to write the full ΔG expression for MgCel+Rt=TiP+SiO2 reaction and solve it somehow (e.g. iteratively) relative to P at given T and mica composition.

## Thanks for your quick

Thanks for your quick response!

I am having the same problem with that paper -- I can find various expressions but nothing that appears to be in the final, ready-to-use format. I am supposing that is might require rearranging the equations in the appendix, which I haven't done yet myself. (I was hoping it was in PTQuick!)

I tend to agree about the article -- it is difficult enough to get at the working expression that it is a huge barrier to use of the barometer. Which is too bad, because it otherwise seems like a really nice paper. Given how user unfriendly the article is, however, I am a little surprised it has so many citations.

Thanks again for your quickness. Also, this website of yours is a really good resource for others. It makes thermobarometry more accessible and less arduous.

-Luke

## Dear Luke,

Dear Luke,

I've looked several articles (having promising titles))) which cite Auzanneau et al. (2010): their authors just use this mica solution model for calculation of pseudosections, e.g. in Perplex. I suspect that you can find similar usage in all other articles. So, they don't use Ti-in-phengite geobarometer itself.

Expressions in the appendix are not required: these have been used by authors only for derivation of unknown thermodynamic properties of Ti-phengite. All what we need is to expand expression for ΔG(reaction)=0 (on p. 15) accurately using all relating expressions and data. Some of calculations readers must repeat on their own, e.g. derivation of Cp function for Ti-phengite (fortunately, this calculation is very simple).

I think the only problem with this very good article is its misleading title ("...geobarometer...", even not "potential"). In my opinion, to make true geobarometer, authors should derive the direct expression, including its simplifying with elimination of data having negligible effect on calculated pressures.

I will try to add this geobarometer to PTQuick.

## You are a saint. -L

You are a saint.

-L

## I forgot to mention, I had

I forgot to mention, I had also looked at some of the citing papers and found the same thing -- no reference to the geobarometer itself, just use of the solution model.

## Dear Luke,

Dear Luke,

I've prepared the evaluation version of this

Ti-in-Phengite geobarometerin the MS Excel format. I usually write such kind of documents for complicated tools (just to test all expressions before adding to PTQuick). It seems that Excel version works as expected. You can download fileAuzanneau et al 2010.xlsmfrom my GoogleDrive or YandexDisk folder, look how geobarometer is implemented (I decided to leave the full version) and try some of your own samples.I'm planning to add this geobarometer to PTQuick in the next few days. I'll also replace the method of setting Fe

^{3+}% values in PTQuick.exe by the more correct one.## New expressions

New expressions added to PTools.dll (+ Tools.dat & Sets.dat):

PTQuick.exe has also been updated: more correct method is now used for recalculation of minerals having variable "Fe3%=" in Minerals.dat. Though, this fix should not seriously affect the results in most cases.

## Sad mistake is fixed

Outdated *.lng-files appeared in the distributive, causing incorrect text messages and values (e.g. absence of "T,°C" for the "Axis" drop-down lists) and, finally, crushes of the program. Files replaced by their actual versions, now everything should work as expected.

## Pseudo-sensors T(file), P(file) and lgfO2(file)

New pseudo-sensors added: T(file), P(file) and lgfO2(file), you can find them in "Default" sections of Thermometers, Barometers and Oxybarometers. You can use them to assign separate T(°C), P(kbar) and/or lg(fO2) values for each sample in the loaded table with mineral analyses, e.g. to calculate temperatures at experimental pressures, or to use constant parameters calculated by another sensors which I can not implement in PTQuick yet (like Ti-in-Zircon thermometer).

You must prepare additional file(s) (FileName.T, FileName.P, FileName.O) and place them to the folder of the main file with analyses (FileName.TAB). The program reads these files automatically after loading of FileName.TAB.

Files should contain simple tables (without headers), with 2-3 TAB-delimited values in each line: Sample ID, Field ID (if required) and T(°C), P(kbar) or lg(

fO_{2}) value.Previous versions of PTools.dll (1.3.x.x) are incompatible with this version of PTQuick.exe due to small changes of interface between EXE and DLL programs, so you have to upgrade also PTools.dll (1.4.x.x is required).

## Grt-Phe geobaramoter

Hi Dmitry,

Any chance that a Grt-Phe geobaramoter of Green and Hellman (1982) is gonna be used in PTQuick? It seems reasonable to have this calibration, since even some fresher thermobarometers for phengite (e.g., that of Auzanneau, 2010) are present already.

## Grt-Phe geobaramoter

Hi Sergey,

Yes, incorporation of this old Grt-Phe geo

thermometermay be useful: it is directly based on unique high-PT experimental Fe-Mg exchange data, expressions are very simple. However, these 3 calibrations are strongly limited to experimental bulk compositions. So, I should also add more recent calibrations which take into account various modern data and avoid strong compositional restrictions, e.g. from Coggon & Holland (2002, JMG, 20, 683–696).## Grt-Phe geothermometer

Garnet-Phengite geothermometer close to Coggon & Holland (2002) is added to PTools.dll. Grt model is taken from Dale, Holland and Powell (2000, CMP, v.140, p.353-362). This geothermometer is extremely sensitive to Fe

^{+3}estimations in Mu, use reasonable value of Fe3% variable in Minerals.dat for this mineral.## Two-feldspar thermometers

New expressions added to PTools.dll (+ Tools.dat & Sets.dat):

Two-feldspar thermometers (albite, anorthite and orthoclase equations) according to the most popular ternary feldspar model of Fuhrman & Lindsley (1988). However, they deal only with original compositions of minerals: tricks with re-equilibrations etc. are not performed (as they described in FL88 paper, Kroll, Evangelakakis & Voll, 1993, Wen & Nekvasil, 1994) because current version of PTQuick unable to report original and adjusted mole fractions, leaving these important information hidden from users. You have to use programs like SolvCalc, MTHERM.BAS, F/L/E-THERM.BAS or MATHEMATICA/Excel tools (from Benisek, Kroll & Cemić, 2004) for more sophisticated works.

## For eclogites with phengite and/or Ky+Qtz/Coe

New expressions added to PTools.dll (+ Tools.dat & Sets.dat):

System of 2 barometers and 1 thermometer for eclogites with phengite and/or Ky+Qtz/Coe from Ravna & Terry (2004). Barometers can also be combined with Grt-Cpx thermometer from Ravna (2000). This thermometer has been renamed (was

Krogh, 2000).Recommendations for different assemblages:

- Grt+Cpx+Mu+Ky+Qtz/Coe: P(RT04a) + T(RT04c)

- Grt+Cpx+Mu: P(RT04a) + T(R00)

- Grt+Cpx+Ky+Qtz/Coe: P(RT04b) + T(R00)

NB! Don't forget to~~delete "Fe3%" fixation for muscovite in Minerals.dat and~~set "Use Fe[3+]" option ON.P.S. However, compare results with Thermocalc avPT ("old style") calculations (using TC_Comb) to check bias even if 3 linearly independent equilibria (incl. Grt-Cpx Fe

^{2+}/Mg exchange thermometer) intersect almost at the same PT point for both two methods. If PT parameters are shifted along Cpx-free reaction py+3mu+4coe=3cel+4ky, this bias occurs almost only due to different activities of Cpx components (Di). Elongation of uncertainty ellipse in TC_Comb also corresponds to this bias.## Thermobarometer for Mafic Granulites

Hi Mr Dima,

Thank you for developing such a beautiful programme. Can you please add the following geothermobarometers to PT Quick? It will be a great help.

1) grt-opx-pl-qtz barometers (Perkins and Chipera, 1985)

2) grt-opx thermometer (Ganguly et al., 1996)

3) grt-opx thermobarometer (Pattison et al., 2003)

References-

1) Perkins, D., Chipera, S.J., 1985. Errata. Garnet-orthopyroxene-plagioclase-quartz geobarometry: refinements and application to the English River subprovince and the

Minnesota River Valley. Contrib. Mineral. Petrol. 90, 410.

2) Ganguly, J., Cheng, W., Tirone, M., 1996. Thermodynamics of aluminosilicate garnet and solid solution: new experimental data, an optimized model, and thermometric applications. Contrib. Mineral. Petrol. 86, 359-373.

3) Pattison, D.R., Chacko, T., Farquhar, J., Mcfarlane, C.R., 2003. Temperatures of granulite facies metamorphism: constraints from experimental phase equilibria and thermobarometry corrected for retrograde exchange. J. Petrol. 44, 867-900.

Thanks

## Thermobarometer for Mafic Granulites

Hi,

I will try to add these expressions next week. However, the iterative Grt-Opx thermobarometer with retrograde exchange correction may require some more time for investigations.

## Thanks for your quick

Thanks for your quick response.

Regards

Sadiq

## Thermobarometer for Mafic Granulites

New expressions added to PTools.dll (+ Tools.dat & Sets.dat):

^{H}_{CaMn}=W^{H}_{MnCa}=618 J/mole, W^{S}=W^{V}=0. Small uderestimation (ca. 2-3°) vs. GTPX-TEM.exe program of J. Ganguly (Windows 7 version) is unclear for me.## Thanks a ton Mr Dima for your

Thanks a ton Mr Dima for your help.

## About Pattison et al., 2003

Unfortunately, I can not add Grt-Opx-Pl-(Crd-Bt) geothermobarometer to PTQuick because it requires some additional input data (modes of minerals in each sample and some other options) and produces additional important output. However, I will try to modify the program RCLC.BAS (and complile for 64-bit Windows) to make it more convenient, so that you will be able to process many samples at once and load results to Excel.

## You have developed an

You have developed an excellent software which saves lot of time. Thanks for timely efforts and update on PTQuick.

## RCLC2_FB

RCLC2_FB is a modified version of the RCLC program of Dave Pattison, Thomas Chacko, James Farquhar and Christopher McFarlane:

Pattison, D.R.M, Chacko, T., Farquhar, J. & McFarlane, C.R.M. 2003. Temperatures of granulite-facies metamorphism: constraints from experimental phase equilibria and thermobarometry corrected for retrograde exchange // Journal of Petrology, v. 44(5), p. 867-900. https://doi.org/10.1093/petrology/44.5.867

I've made it compatible with FreeBasic dialect and compiled to EXE-file. Workflow is changed: you have to prepare input table(s) with recalculated mineral analyses in Excel and edit very simple file RCLC.INI, then run RCLC2_FB.EXE. For example, you can take tables with recalculated analyses from PTQuick and modify them in Excel. Output files can also be directly loaded to Excel.

Download RCLC2_FB from Google Drive or Yandex Disk.

Use this method with caution, as there may be more interpretations for displacement of equilibria than just late Fe-Mg exchange.

P.S. I've added also RCLC2_QB64.BAS which is the version for QB64 BASIC dialect (https://www.qb64.org/portal/). While it produces huge executables (> 2 Mb for Windows OS!), you can compile this program also for Mac OS (not tested, though).

## Si in phengite geobarometer

Dear Dmitry,

I wonder if there is a possibility to include in your nice tool expressions for Si in phengite geobarometry in calibration by Caddick and Thomson (Contrib Mineral Petrol 2008 156:177–195) and Kamzolkin Geology of Ore Deposits (2016, Vol. 58, No. 8, pp. 613–622)? That would be really nice.

All the best

Jacek

## Si in phengite geobarometer

Dear Jacek,

These geobarometers appear to be rather simple, I will add them in the next few days.

## Si in phengite geobarometer

Dear Dima,

you are extremely fast. Thank you very much.

All the best

Jacek

## Si in phengite geobarometer

New expressions added to PTools.dll (+ Tools.dat & Sets.dat):

## Si in phengite geobarometer

Dear Deim,

Thanks a lot!

Jacek

## Si in phengite geobarometer

I just want to note that I have not yet verified the correctness of the first expression from Kamzolkin et al. (2016), because operator between Si and Fe+Mg terms is missed in the paper. So far I have used "+" and must test it using analyses from the paper.

## Si in phengite geobarometer

OK. I tried to use this geobarometer and I put there a multiplication sign. However, I didn't test the expression using analyses from the paper.

## Si in phengite geobarometer

I decided that operator "+" or "-" is missing (typo) because there are also two constants in both terms (1.76 and 12.89) that produce 22.6864 after simplification if multiplication is used. Though, they leave division by 10 to convert kbars to GPa, that also should be simplified in the final expression...)))

## Si in phengite geobarometer

You are right. Using two different constants does not have a sense in that case. So, it should be a - or + sign.

## Si in phengite geobarometer

I've checked this expression with different operators using analyses from the paper. It seems that with "+" pressures are closest to authors' results. However, I noticed also numerous irregular (+/-) differences in calculated formulae and, somewhere, in pressures. Most of them lie within 0.5 kbars, but several analyses demonstrate deviations even >7 kbars. These differences doesn't look like obvious typos (which are present in analytical data in the majority of publications).

## Si in phengite geobarometer

Dimitry,

this does not sound good. Do you think that this geobarometer is reliable?

Jacek

## Si in phengite geobarometer

I suspect that the authors didn’t complete something in the article and that there are differences between the descriptions in the article and the calculations that they actually made, apart from the usual typos (which are also there for sure). For example, the article might include the results of earlier versions of calculations. I will try also to calculate their data directly in Excel and then communicate with Alexandr Konilov (I suspect he is the first author of this barometer).

P.S. I've analysed data and results in the paper: expressions are correct (and yes, "+" is missing). However, many formulae of phengites (apfu) in the paper are strange (at least) and not fully correspond to their Wt% of oxides. Though, pressures in the paper are calculated using these doubtful formulae. This is the source of these large differences. So, I think that expressions are reliable, or more prudent: work as intended.

I remember only one case where the large set of garnet analyses has been recalculated by irreproducible method (or mixed up) in one publication and these unverified formulae (in mole fractions of components) where then used in testing of thermobarometric expression by another authors. And another case where one K-free analysis of "biotite" has been used in derivation of Grt-Bt expression. Fortunately, these mistakes didn't affect expressions dramatically.

## Si in phengite geobarometer

Thank you for your explanation. I agree that there are in the paper some typos like for example in the Caddic and Thomsnom formulae of Si in phengite geobarometer. The recalculation from oC to K is wrong.