Calculations

Functions for calculating properties about the system and calculation types that do not necessarily have independent variables of P, T, and bulk composition (as in equilibrium_equations.py).

VolFe.calculations.P_VSA(PT, melt_wf, models, nr_step, nr_tol, Ptol)[source]

P of vapor+sulfide+anhydrite saturation for given melt composition and T.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

  • nr_step (float) – Step-size for Newton-Raphson solver

  • nr_tol (float) – Tolerance for Newton-Raphson solver

  • Ptol (float) – Tolerance for total pressure convergence

Returns:

Pressure of vapor-saturation, Concentration of melt species in weight fraction, Ratios of melt species

Return type:

tuple(float,dict,dict)

VolFe.calculations.P_sat(PT, melt_wf, models, Ptol, nr_step, nr_tol)[source]

Calculate the pressure of vapor saturation for a given P, T, and melt composition (including volatiles).

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

  • Ptol (float) – Tolerance for total pressure convergence

  • nr_step (float) – Step-size for Newton-Raphson solver

  • nr_tol (float) – Tolerance for Newton-Raphson solver

Returns:

Pressure of vapor-saturation; Concentration of melt species; Ratios of melt species

Return type:

tuple[float,dict,dict]

VolFe.calculations.P_sat_H2O_CO2(PT, melt_wf, models, Ptol, nr_step, nr_tol)[source]

Calculate the pressure of vapor saturation for a given P, T, and melt composition (including volatiles) for H2O-CO2 only.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

  • Ptol (float) – Tolerance for total pressure convergence

  • nr_step (float) – Step-size for Newton-Raphson solver

  • nr_tol (float) – Tolerance for Newton-Raphson solver

Returns:

Pressure of vapor-saturation; Gas and melt composition

Return type:

tuple(float,dict)

VolFe.calculations.P_sat_sulf_anh(PT, melt_wf, models, Ptol, nr_step, nr_tol)[source]

Calculates the conditions (P, fO2) of sulfide and anhydrite saturation (if possible) for a given melt composition (particularly S)

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

  • Ptol (float) – Tolerance for total pressure convergence

  • nr_step (float) – Step-size for Newton-Raphson solver

  • nr_tol (float) – Tolerance for Newton-Raphson solver

Returns:

Results of conditions of sulfide and anhydrite saturation

Return type:

dict

VolFe.calculations.S_given_T_P_fO2_C_H(PT, melt_wf, models, nr_step, nr_tol)[source]

Calculates the sulfur content of a melt of given CO2, H2O, P and T to cause vapor saturation (no H2S in the melt).

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

  • nr_step (float) – Step-size for Newton-Raphson solver

  • nr_tol (float) – Tolerance for Newton-Raphson solver

Returns:

Concentration of melt species, volatile ratios of melt species

Return type:

tuple(dict,dict)

VolFe.calculations.bulk_composition(run, PT, melt_wf, setup, models)[source]

Calculate bulk composition of the system from given melt composition and information about co-existing gas.

Parameters:

  • run (float) – Row number of input data

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • setup (pandas.DataFrame) – Input data

  • models (pandas.DataFrame) – Model options

Returns:

Bulk composition of the system

Return type:

dict

VolFe.calculations.calc_isobar_CO2H2O(PT, melt_wf, models)[source]

Calculates CO2-H2O isobar at given P and T assuming only CO2-H2O in the melt and vapor.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

Returns:

H2O-CO2 concentrations for vapor saturation at given P and T

Return type:

pandas.DataFrame

VolFe.calculations.calc_isopleth_CO2H2O(XH2O, PT, melt_wf, models)[source]

Calculates CO2-H2O isopleth at given XH2O and T, and up to a maximum P, assuming only CO2-H2O in the melt and vapor.

Parameters:

  • XH2O (float) – mole fraction of H2O in the vapor

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

Returns:

H2O-CO2 concentrations for vapor saturation at given P, T, and XH2O

Return type:

pandas.DataFrame

VolFe.calculations.calc_isotopes(PT, comp, R, models, nr_step, nr_tol, run=0.0)[source]

Calculates the isotope ratio for all species and melt and vapor for H, S, and C for a single melt-vapor composition.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • comp (pandas.DataFrame) – Composition of the melt and vapor by species, including weight fraction of vapor.

  • R (dict) – Bulk isotope ratio of the system.

  • models (pandas.DataFrame) – Model options

  • nr_step (float) – Step-size for Newton-Raphson solver.

  • nr_tol (float) – Tolerance for Newton-Raphson solver.

  • run (float, optional) – Row number in file to run. Defaults to 0.0.

Returns:

Isotope ratios for all species in S, C, and H. Isotope ratios for melt and vapor in S, C, and H.

Return type:

tuple(dict,dict,dict,dict,dict,dict)

VolFe.calculations.calc_pure_solubility(PT, melt_wf, models)[source]

Calculates pure solubility of H2O and CO2 at given P and T and melt composition.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

Returns:

Solubility of H2O and CO2 at given P and T

Return type:

pandas.DataFrame

VolFe.calculations.check_mass_balance(xg, melt, melt_and_gas)[source]

Checks the mass balance by comparing melt and gas composition to bulk composition given masses of the phases.

Parameters:

  • xg (dict) – Gas composition in mole fraction

  • melt (dict) – Melt composition in weight fraction

  • melt_and_gas (dict) – melt and gas composition (bulk composition)

Returns:

Mass balance for C, O, H, and S

Return type:

dict

VolFe.calculations.compositions_within_error(run, setup)[source]

Calculates a random composition within error of the given composition assuming Guassian distribution of uncertainty.

Parameters:
Returns:

Random composition within error of given composition

Return type:

dict

VolFe.calculations.conc_insolubles(PT, melt_wf, models)[source]

Calculates the concentration of H2, CO, CH4, and H2S in a melt at the given conditions and the melt species ratios.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

Returns:

Concentration of melt species, volatile ratios of melt species

Return type:

tuple(dict,dict)

VolFe.calculations.fO2_P_VSA(PT, melt_wf, models, nr_step, nr_tol, Ptol)[source]

fO2 and P of vapor+sulfide+anhydrite saturation for given melt composition and T.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

  • nr_step (float) – Step-size for Newton-Raphson solver

  • nr_tol (float) – Tolerance for Newton-Raphson solver

  • Ptol (float) – Tolerance for total pressure convergence

Results:

tuple(float,dict,dict): Pressure of vapor-saturation, Concentration of melt species in weight fraction, Ratios of melt species

VolFe.calculations.fO2_range_from_S(PT, melt_wf, models)[source]

Calculated range in fO2 assuming sulfide and anhydrite saturation (if possible) for given melt composition (particularly S).

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

Returns:

Results of range in fO2 calculation from sulfur content of melt

Return type:

dict

VolFe.calculations.fO2_silm_sulf_anh(PT, melt_wf, models)[source]

Calculates the fO2 and sulfur content for melt saturated with both sulfide and anhydrite.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

Returns:

fO2, S6+/ST, total S, SCAS, SCSS

Return type:

dict

VolFe.calculations.gas_comp_all_open(xg, xg_all, models)[source]

Cumulated gas composition during open-system degassing.

Parameters:

  • xg (dict) – Gas composition in mole fraction at given conditions

  • xg_all (dict) – Cumulative gas composition in mole fraction to this point

  • models (pandas.DataFrame) – Model options

Returns:

New cumulative gas composition in mole fraction

Return type:

dict

VolFe.calculations.graphite_saturation(PT, melt_wf, models)[source]

Evaluates if the system is graphite saturated.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

Returns:

whether or not the system is graphite saturated

Return type:

str

VolFe.calculations.mass_vol_rho(PT, melt_wf, gas_mf, bulk_wf, models)[source]

Calculates mass, volume, and density of melt, gas, and bulk system.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • gas_mf (dict) – Gas composition in molefraction

  • bulk_wf (dict) – Bulk composition in weight fraction

  • models (pandas.DataFrame) – Model options

Returns:

Melt, gas, and bulk density and volume

Return type:

dict

VolFe.calculations.melt_species_ratios(conc)[source]

Calculate ratios of melt species.

Parameters:

conc (dict) – Concentration of melt species in weight fraction

Returns:

Ratios of melt species

Return type:

dict

VolFe.calculations.mf_C_species(comp)[source]

Calculates weight fraction of C in each carbon-bearing species in the melt and vapor wrt to total carbon in the system.

Parameters:

comp (pandas.DataFrame) – Weight fraction by species in the melt and mole fraction in vapor including the wt% of vapor

Returns:

weight fraction (equivalent to mole fraction) of C in each species relative to total C

Return type:

dict

VolFe.calculations.mf_H_species(comp)[source]

Calculates weight fraction of H in each hydrogen-bearing species in the melt and vapor wrt to total hydrogen in the system.

Parameters:

comp (pandas.DataFrame) – Weight fraction by species in the melt and mole fraction in vapor including the wt% of vapor

Returns:

weight fraction (equivalent to mole fraction) of H in each species relative to total H

Return type:

dict

VolFe.calculations.mf_S_species(comp)[source]

Calculates weight fraction of S in each sulfur-bearing species in the melt and vapor wrt to total sulfur in the system.

Parameters:

comp (pandas.DataFrame) – Weight fraction by species in the melt and mole fraction in vapor including the wt% of vapor

Returns:

weight fraction (equivalent to mole fraction) of S in each species relative to total S

Return type:

dict

VolFe.calculations.mf_S_species_old(melt_wf, gas_mf)[source]

Calculates weight fraction of each sulfur species in the melt and vapor wrt to total sulfur in the system.

Parameters:

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • gas_mf (dict) – Gas composition in mole fraction

Returns:

Weight fraction of sulfur in each sulfur species

Return type:

dict

VolFe.calculations.new_bulk_regas_open(PT, melt_wf, bulk_wf, gas_mf, dwtg, models)[source]

New bulk composition of the system when regassing.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • bulk_wf (dict) – Bulk composition of the system in weight fraction

  • gas_mf (dict) – Gas composition in mole fraction

  • dwtg (float) – Weight fraction of gas to add into the system

  • models (pandas.DataFrame) – Model options

Returns:

New bulk composition of the system

Return type:

dict

VolFe.calculations.sulfur_saturation(PT, melt_wf, models)[source]

Check if melt is saturated with immiscible sulfide or anhydrite.

Parameters:

  • PT (dict) – Pressure in bars as “P” and temperature in ‘C as “T”

  • melt_wf (dict) – Melt composition (SiO2, TiO2, etc. including volatiles)

  • models (pandas.DataFrame) – Model options

Returns:

Values of SCSS, STCSS, SCAS, STCAS, ST, and whether the melt is sulfide and/or anhydrite saturated

Return type:

dict