Configuration

Start by importing MagmaPEC

import MagmaPEC as mpc

MagmaPEC is based on MagmaPandas and uses the same global configuration. MagmaPEC comes preloaded with the MagmaPandas configuration class, which is accesssible in MagmaPEC via model_configuration:

print(mpc.model_configuration)

################## MagmaPandas ###################
##################################################
General settings__________________________________
fO2 buffer.....................................QFM
ΔfO2.............................................1
Melt Fe3+/Fe2+.............................sun2024
Kd Fe-Mg ol-melt........................toplis2005
Melt thermometer....................putirka2008_15
Volatile solubility model.......iaconomarziano2012
Volatile species.............................mixed
##################################################

Change models for fO2 buffers, melt Fe3/Fe2, ol-melt Fe-Mg Kd, or melt thermometer by accessing their attributes: Fe3Fe2_model , Kd_model, or melt_thermometer

mpc.model_configuration.Fe3Fe2_model = "armstrong2019"
mpc.model_configuration.Kd_model = "blundy2020"
mpc.model_configuration.melt_thermometer = "shea2022"

print(mpc.model_configuration)

################## MagmaPandas ###################
##################################################
General settings__________________________________
fO2 buffer.....................................QFM
ΔfO2.............................................1
Melt Fe3+/Fe2+.......................armstrong2019
Kd Fe-Mg ol-melt........................blundy2020
Melt thermometer..........................shea2022
Volatile solubility model.......iaconomarziano2012
Volatile species.............................mixed
##################################################

Kd and melt Fe3Fe2 can also be set to fixed values, but inputting (“fixed”, value, error). For example, (“fixed”, 0.2, 0.05) for a fixed Fe3Fe2 of 0.2, with an error of 0.05

mpc.model_configuration.Fe3Fe2_model = ("fixed", 0.2, 0.05)

print(mpc.model_configuration)

################## MagmaPandas ###################
##################################################
General settings__________________________________
fO2 buffer.....................................QFM
ΔfO2.............................................1
Melt Fe3+/Fe2+.....................fixed 0.20±0.05
Kd Fe-Mg ol-melt........................blundy2020
Melt thermometer..........................shea2022
Volatile solubility model.......iaconomarziano2012
Volatile species.............................mixed
##################################################

Please see the MagmaPandas documentation for more detailed information on how to change these settings.

Settings specific to the post-entrapment crystallisation (PEC) correction model are stored in the PEC_configuration class:

print(mpc.PEC_configuration)

############ Post-entrapment crystallisation ############
################### correction model ####################
Settings_________________________________________________
Fe2+ behaviour...................................buffered
Stepsize equilibration (moles)...................0.002
Stepsize crystallisation (moles).................0.05
Decrease factor..................................5
FeO convergence (wt. %)..........................0.05
Kd convergence...................................0.005
#########################################################

The following settings are available:

• Fe2_behaviour:

  Determines how melt inclusion Fe2+ and Fe3+ are calculated. Currently, buffered is the only option, where Fe2+ and Fe3+ are buffered by external melts and their concentrations are recalculated at each model increment, according to the Fe3Fe2 model set in the MagmaPandas configuration.

• stepsize_equilibration:

  The stepsize in moles of Fe-Mg cation exchange in the equilibration phase

• stepsize_crystallisation

  The stepsize in moles of olivine crystallisation or melting in the crystallisation phase

• decrease_factor

  Factor by which stepsize_equilibration and stepsize_crystallisation get decreased after overstepping of convergence values for Kd and FeO respectively.

• FeO_converge

  Value in wt.% within which melt inclusion FeO and initial FeO are considered the same

• Kd_converge

  Value within which modelled and observed olivine-melt Fe-Mg Kd are considered the same

You change these settings via their attributes:

mpc.PEC_configuration.stepsize_equilibration = 0.001
mpc.PEC_configuration.stepsize_crystallisation = 0.02
mpc.PEC_configuration.decrease_factor = 2
mpc.PEC_configuration.FeO_converge = 0.01
mpc.PEC_configuration.Kd_converge = 0.001

print(mpc.PEC_configuration)

############ Post-entrapment crystallisation ############
################### correction model ####################
Settings_________________________________________________
Fe2+ behaviour...................................buffered
Stepsize equilibration (moles)...................0.001
Stepsize crystallisation (moles).................0.02
Decrease factor..................................2
FeO convergence (wt. %)..........................0.01
Kd convergence...................................0.001
#########################################################

When you input a value outside the expected range, MagmaPEC raises an error and displays the minimum and maximum allowed values

mpc.PEC_configuration.stepsize_crystallisation = 5

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
Cell In[5], line 1
----> 1 mpc.PEC_configuration.stepsize_crystallisation = 5

File ~/Dropbox/research/python/packages/MagmaPandas/src/MagmaPandas/parse_io/validate.py:55, in _check_setter.<locals>.decorator.<locals>.wrapper(*args)
     53     min, max = allowed_values
     54     if not (min < var < max):
---> 55         raise ValueError(
     56             f"value: {var}, outside allowed range: {*allowed_values,}"
     57         )
     58 elif isinstance(var, str):
     59     if var not in allowed_values:

ValueError: value: 5, outside allowed range: (0.0, 1.0)

The reset method resets everything to default values:

mpc.PEC_configuration.reset()
print(mpc.PEC_configuration)

############ Post-entrapment crystallisation ############
################### correction model ####################
Settings_________________________________________________
Fe2+ behaviour...................................buffered
Stepsize equilibration (moles)...................0.002
Stepsize crystallisation (moles).................0.05
Decrease factor..................................5
FeO convergence (wt. %)..........................0.05
Kd convergence...................................0.005
#########################################################