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Hello!

It was quite a struggle, but I somehow managed to run the flux melting calculations (though I have no clue how it worked!). Could you please point me towards the source of the hydrous fluid composition given in the workshop files? I checked in the manual and the workshop files but I couldn't find the reference.

Thanks again for your time and help.

I'm sorry I had posted a batch file.

hyd.melts and hyd1.melts are exactly the same with just the filenames being different. I have two different batch files referring to each of them, used separately.

Hello Paula!

Thank you for your reply!

UPDATE: I copy pasted the files into a different directory and the calculation works again! I'm not sure what was wrong with the original directory that these files were in.

Yes, I was using the exact same .melts files with the same amount of flux added in each step. I am adding the input melts files here for your convenience.

Code Select Expand

Title: Depleted MORB Mantle of Workmann & Hart 2005
Initial Composition: SiO2 44.71
Initial Composition: Al2O3 3.98
Initial Composition: Fe2O3 0.191
Initial Composition: FeO 8.008
Initial Composition: MnO 0.13
Initial Composition: MgO 38.73
Initial Composition: CaO 3.17
Initial Composition: Na2O 0.28
Initial Composition: Cr2O3 0.57
Initial Composition: TiO2 0.13
Initial Composition: NiO 0.24
Initial Trace: K 60
Initial Trace: P 20
Initial Trace: Ni 1886
Initial Trace: Cr 3900
Initial Trace: Mn 822
Initial Trace: Rb 0.050
Initial Trace: Ba 0.563
Initial Trace: Th 0.0079
Initial Trace: U 0.0032
Initial Trace: Nb 0.1485
Initial Trace: Ta 0.0096
Initial Trace: La 0.192
Initial Trace: Ce 0.550
Initial Trace: Pb 0.018
Initial Trace: Pr 0.107
Initial Trace: Nd 0.581
Initial Trace: Sr 7.664
Initial Trace: Zr 5.082
Initial Trace: Hf 0.157
Initial Trace: Sm 0.239
Initial Trace: Eu 0.096
Initial Trace: Ti 716.3
Initial Trace: Gd 0.358
Initial Trace: Tb 0.070
Initial Trace: Dy 0.505
Initial Trace: Ho 0.115
Initial Trace: Y 3.328
Initial Trace: Er 0.348
Initial Trace: Yb 0.365
Initial Trace: Lu 0.058
Initial Temperature: 1350.0
Initial Pressure: 20000
Log fO2 Path: FMQ
Log fO2 Delta: 0.0

Assimilant:

Code Select Expand

Title: hydrousfluid   
Initial Composition: SiO2 20.0
Initial Composition: TiO2 0.001
Initial Composition: Al2O3 0.001
Initial Composition: Fe2O3 0.001
Initial Composition: FeO 0.001
Initial Composition: MgO 0.001
Initial Composition: CaO 0.001
Initial Composition: Na2O 5.0
Initial Composition: K2O 2.0
Initial Composition: H2O 73.0 
Initial Mass: 0.01 
Initial Trace: La 37 
Initial Trace: Ce 80 
Initial Trace: Pr 9.7 
Initial Trace: Nd 38.5 
Initial Trace: Sm 10
Initial Trace: Eu 3
Initial Trace: Gd 7.62
Initial Trace: Tb 1.05
Initial Trace: Dy 5.6
Initial Trace: Ho 1.06
Initial Trace: Er 2.62
Initial Trace: Yb 2.16
Initial Trace: Lu 0.3
Log FO2 Path: FMQ
Log fO2 Delta: 0.0

The batch file:

Code Select Expand

1
DMM.melts
3
0
olivine
x
4
250
1
-1
hyd.melts

Thanks again for your time!

[Rank deficiency detected by HFTI, rank = 0 (12)]

Hello!

I was performing flux melting calculations using alphaMELTS 1.9 on Windows using Depleted MORB Mantle Composition of Workman & Hart 2005 and the hydrousfluid composition taken from the workshop files. It was working fine till yesterday.

Surprisingly, today I encountered the Rank deficiency detected by HFTI, rank = 0 (12) with a THE QUADRATIC MINIMIZATION ALGORITHM HAS FAILED TO CONVERGE error. The initial subsolidus calculation using Option 3 was fine. The output was as follows:

Initial alphaMELTS calculation at: P 10000.000000, T 1200.000000
olivine: 56.637167 g, composition (Ca0.00Mg0.89Fe''0.10Mn0.00Co0.00Ni0.00)2SiO4
orthopyroxene: 24.202071 g, composition opx Na0.01Ca0.05Fe''0.18Mg1.67Fe'''0.01Ti0.01Al0.16Si1.92O6
clinopyroxene: 15.707648 g, composition cpx Na0.10Ca0.66Fe''0.11Mg0.91Fe'''0.01Ti0.01Al0.31Si1.88O6
spinel: 3.592112 g, composition Fe''0.16Mg0.85Fe'''0.04Al1.62Cr0.33Ti0.01O4

Selecting option 4 and then trying to run the calculation gives the Rank Deficiency error. I had tried to run the calculation on the WSL version of alphaMELTS 1.9 with the same input files and got the same (which was working fine till last week!). For your reference, I am attaching the settings file and the input files here. 

Any leads on how to solve this issue would be much appreciated.

Thank you!

Hello all!

I am trying to model crystallization of arc magmas at pressures (1GPa - 0.1GPa) using MELTS v1.2.0 with two objectives:

1. Effect of P and initial H2O on the amphibole crystallization and composition
2. Crystallization of An rich (An98) plagioclase

However, amphibole is never found as a crystallizing phase no matter the initial H2O content or the pressure. Increasing H2O content would lead to water being present as a separate fluid phase, and hence never triggers amphibole due to a decrease in magma's water contents or An rich plagioclase crystallization.

Any leads on solving this?

The primary magma composition is as follows:

Initial Composition: SiO2 49.0555
Initial Composition: TiO2 0.4904
Initial Composition: Al2O3 16.3157
Initial Composition: Fe2O3 1.3472
Initial Composition: Cr2O3: 0.033
Initial Composition: FeO 8.4557
Initial Composition: MgO 9.7423
Initial Composition: CaO 10.2108
Initial Composition: Na2O 1.3813
Initial Composition: K2O 0.0100
Initial Composition: H2O 2.9910
Initial Temperature: 1383
Increment Temperature: -10.00
Mode: Fractionate Solids

Thanks in advance!

[Fs = Cli-En + Hd - 2Di]

Hi all,

I am trying to calculate the molefractions of Ferrosilite (Fs) and Wollastonite (Wo) from the given mole fractions of Diopside (Di), Hedenbergite (Hd) and Clinoenstatite (Cli-En) so that I can plot the compositional variation of pyroxenes during fractional crystallization in the pyroxene quadrilateral diagram of Morimoto, 1988.

Like you have mentioned, I have used the relation: Fs = Cli-En  + Hd - 2Di and
similarly, I have used the relation: 2Di = 2Wo + Cli-En to calculate the mole fraction of Wollastonite, but ended up with a negative value for Wo. As pyroxene quadrilateral is a ternary diagram, negative values do not plot within the ternary.

Is there a mistake in my approach? Any leads would be highly appreciated.

Dear Asimow,

Thank you for your elaborate reply! I will surely try it this way and let you know of any developments.

I have not put any constraint on the fo2, but I did distribute the Fe between the two oxides. The buffer is off.

Hi,
I am trying to understand the possibility of a silicate-silicate liquid immiscibility in the Skaergard intrusion. I'd like to begin with a melt of basaltic composition and fractionate olivine, clinopyroxene and plagioclase (Ã,±orthopyroxene) till the residual liquid has 10% of the initial mass. I would like to then simulate a liquid immiscibility leading to a SiO2 enriched melt and a ferrobasalt. I tried doing it by using both rhyoliteMELTS and pMELTS, at 2-5kbar pressures. I end up with a quadratic convergence failure error every time.

Any leads would be highly appreciated.

Thank you for your reply, Paula. I would try to get the composition of the olivine to recheck if the equilibrium exists and let you know if that helps.
Thanks again!

Hi,
I am trying to crystallize a gabbro from a primitive basaltic melt and I would like to put a constraint on the amount of Olivine that can crystallize out of the melt. The amount of Olivine crystallized from the melt exceeds 15% but I have made a thin section of the gabbro that I want to model and Olivine doesn't exceed 5%. Is there a way to do put a check on the amount of olivine crystallizing from the melt?