Mass of Assimilated

[pmmx]

Hi Paula

I'm trying to evaluate processes of  isoenthalpic assimilation of mafic cumulates in Stromboli magmas.  I would like to understand the meaning of some parameters that Adiabat ask during the interactive operations.

In particular if at the question

How many AFC iterations to perform?
I answer

10

and after

Superliquidus (1) or subsolidus (0) initial guess ? 1
Initial Adiabat_1ph calculation at: P 3000.000000, T 1200.000000
liquid: 101.908 g 48.34 0.88 17.14 2.34 5.66 0.15 6.19 11.45 2.42 1.95 0.53 2.94
Activity of H2O = 0.490408  Melt fraction = 1
Setting reference Enthalpy to current enthalpy = -1.24561e+06
Assimilant file is text (1) or binary (0)? 0
Assimilant filename: /Users/max/Dropbox/elabostrparox/AssimilazioneMAfic/adiabatfiles/gabbro_1000res
Trace and major (1) or trace only (0): 1
Mass of enriching agent added per cycle (in grams): 5

I'm expecting the an increase of the mass of 5 grams per cycle and a total of 50 g at the end
On the contrary I see an increase of mass (only liquid in this case) that is much more smaller (about 0.121 g) Why ???
Same figures appears as mass in Liq_tbl files
How can I evaluate tha mass of assimilated material ?
Thanks in advance (also for this wonderful code)

Best regards

Massimo



Adiabat_1ph at: P 3000.000000, T 1199.785314
liquid: 102.029 g 48.34 0.89 17.13 2.34 5.65 0.15 6.19 11.45 2.42 1.96 0.54 2.94
Activity of H2O = 0.489565  Melt fraction = 1
Adiabat_1ph at: P 3000.000000, T 1199.571114
liquid: 102.150 g 48.35 0.89 17.12 2.34 5.65 0.16 6.18 11.46 2.42 1.96 0.55 2.94
Activity of H2O = 0.488723  Melt fraction = 1
Adiabat_1ph at: P 3000.000000, T 1199.357399
liquid: 102.271 g 48.36 0.89 17.11 2.34 5.64 0.16 6.17 11.46 2.42 1.96 0.55 2.93
Activity of H2O = 0.487884  Melt fraction = 1
Adiabat_1ph at: P 3000.000000, T 1199.144167
liquid: 102.392 g 48.36 0.90 17.10 2.34 5.64 0.17 6.17 11.46 2.42 1.96 0.56 2.93
Activity of H2O = 0.487047  Melt fraction = 1
Adiabat_1ph at: P 3000.000000, T 1198.931415
liquid: 102.513 g 48.37 0.90 17.09 2.33 5.63 0.17 6.16 11.46 2.42 1.96 0.57 2.93
Activity of H2O = 0.486212  Melt fraction = 1
Adiabat_1ph at: P 3000.000000, T 1198.719144
liquid: 102.634 g 48.37 0.90 17.08 2.33 5.63 0.18 6.15 11.46 2.42 1.97 0.58 2.92
Activity of H2O = 0.485379  Melt fraction = 1
Adiabat_1ph at: P 3000.000000, T 1198.507350
liquid: 102.755 g 48.38 0.91 17.07 2.33 5.62 0.18 6.15 11.47 2.42 1.97 0.59 2.92
Activity of H2O = 0.484549  Melt fraction = 1
Adiabat_1ph at: P 3000.000000, T 1198.296032
liquid: 102.876 g 48.38 0.91 17.06 2.33 5.62 0.19 6.14 11.47 2.42 1.97 0.59 2.92
Activity of H2O = 0.483721  Melt fraction = 1
Adiabat_1ph at: P 3000.000000, T 1198.085189
liquid: 102.997 g 48.39 0.91 17.05 2.33 5.61 0.19 6.13 11.47 2.42 1.97 0.60 2.91
Activity of H2O = 0.482895  Melt fraction = 1

[Paula]

Hi Massimo,

Please could you post (or e-mail) your settings and I'll have a look into it. In particular, are you doing batch or fractional crystallisation? If the latter then what is ADIABAT_MASSIN set to? Do you know what the liquidus temperature of the starting composition is? Also what temperature was the assimilant at when you wrote out the binary file before?

Thanks!
Paula

[Paula]

Hi Massimo,

Thanks for sending the various files and sorry it has taken so long to get back to you. I am still having problems reading in the original binary restart file - for some reason it reads in fine with the public version of the code but not with the debugging version. I need to work out why that is happening but in the meantime I made a new restart file following your instructions and found the problem with your assimilation runs.

So there is a bug in the assimilation routine when it uses binary files. It's to do with picking up the wrong mass (the initial mass from the routine where you made the assimilant, i.e. ~97 grams instead of the final one, i.e. ~3 grams), which means it adds the wrong number of moles of assimilant. I will fix this but in the meantime you can work around the problem. When you do the run that generates the assimilant, write out the bulk composition as a melts file. Then immediately read in the same file, before writing out the binary restart file. This move resets what the system believes the initial mass to be (to the ~3 gram value in this case) so that when you use the restart file later everything will be scaled properly.

Apologies again for the delay,
Paula

[pmmx]

Hi Paula

thanks for your suggestions.
However
<. When you do the run that generates the assimilant, write out the bulk composition as a melts file. Then immediately read in the same file, before writing out the binary restart file. >
I did, but now I got a format  error (something like "unxpected ? character" )when i try to read the binary restart file.
To resolve this problem I tried to use the bulk composition (as melts text file, instead of binary ) generated starting from the assimilant. It works, the mass added it's correct temperature is realistic, but I got unrealistic concentrations for Sr86 and Sr87 (> 10000 each) when Sr concentration is less than 800 ppm. Is this another possible bug ???

Thanks again in advance for any suggestion

regards

Massimo

[Paula]

Hi Massimo,

Sorry - somehow I missed your reply when you posted it. For the melts_file style assimilant, the isotope problem you have is probably due to this bug. I just realised yesterday that I forgot to fix that bug in Adiabat_1ph 3. Ironically enough, it was because I was searching the forum for that old thread that I saw your new reply...

The 'mass of assimilant' problem is fixed in 3.0, which allows the user to choose what to do with the mass when you read in a restart_file (whether to update the system or as an assimilant). E.g. you can set it to a given value, such as 100 grams, or to the current solid+liquid mass. Update 3.0.1 has the fix for writing out isotope compositions to a melts_file. So that you can continue to use the 'mass of assimilant' workaround described above in Adiabat_1ph 2.X, I have included the isotope melts_file fix in update 2.0.2 also.

I'm still looking into the restart_file issues. I think I've found why I couldn't read in your file originally but I don't know about the unexpected character error you are getting. More on that soon.

Best wishes,
Paula