Melt basics

import MagmaPandas as mp

Import some melt data from a csv file

melt_file = "./data/melts.csv"

melt = mp.read_melt(melt_file, index_col=["name"])
melt.head()

	SiO2	Al2O3	MgO	CaO	FeO	Na2O	K2O	MnO	TiO2	P2O5	CO2	H2O	F	S	Cl	total
name
PI032-04-01	49.402603	14.539062	6.509044	10.058735	9.757536	3.737374	0.697769	0.132497	2.548581	0.289823	0.628502	1.440208	0.078857	0.145452	0.033958	100
PI032-04-02	48.832207	15.116896	6.508618	9.688642	9.927146	3.564377	0.940308	0.135905	2.652552	0.336327	0.672345	1.330865	0.083879	0.165394	0.044540	100
PI041-02-02	49.124916	16.950138	4.861451	9.183852	10.238358	3.788617	1.077791	0.153258	2.804343	0.561031	0.463920	0.655494	0.047654	0.068020	0.021157	100
PI041-03-01	45.941086	15.753453	6.909844	10.996510	10.778833	3.346468	1.144852	0.112117	3.153303	0.551992	0.797715	0.293341	0.079499	0.086863	0.054123	100
PI041-03-03	45.313339	15.909531	6.831676	11.175276	10.966834	3.417548	1.167550	0.088899	3.262463	0.517891	0.821116	0.311131	0.081713	0.079495	0.055540	100

On top of the regular MagmaFrame methods, Melt has additional methods for calculating

NBO/T,
melt densities,
liquidus temperatures,
Fe3+/Fe2+ ratios,
melt FeO and Fe2O3,
olivine-melt Fe-Mg partitioning coefficients and
H2O-CO2 saturation pressures.

Let’s check the current configuration of MagmaPandas …

print(mp.configuration)

################ MagmaPandas ################
#############################################
General settings_____________________________
fO2 buffer................................QFM
ΔfO2........................................1
Melt Fe3+/Fe2+........................Sun2024
Kd Fe-Mg ol-melt.......................toplis
Melt thermometer...............putirka2008_15
Volatile solubility model......IaconoMarziano
Volatile species........................mixed
#############################################

… and calculate liquidus temperatures with a melt-only thermometer at 4 kbar. The configuration is currently set to use equation 15 from Putirka (2008).

P_bar = 4e3

temperatures = melt.temperature(P_bar=P_bar)
temperatures

name
PI032-04-01    1446.506126
PI032-04-02    1448.470282
PI041-02-02    1413.913988
PI041-03-01    1471.475055
PI041-03-03    1470.435383
PI041-05-04    1393.411880
PI041-05-06    1418.544001
PI041-07-01    1461.241836
PI041-07-02    1464.626056
PI052-01-02    1383.362277
Name: T_K, dtype: float64

We can switch to a different thermometer by changing the configuration:

mp.configuration.melt_thermometer = "putirka2008_16"

temperatures_new = melt.temperature(P_bar=P_bar)
temperatures_new

name
PI032-04-01    1441.689105
PI032-04-02    1438.624306
PI041-02-02    1395.139631
PI041-03-01    1442.485008
PI041-03-03    1441.510218
PI041-05-04    1370.343048
PI041-05-06    1399.939176
PI041-07-01    1440.598610
PI041-07-02    1439.236317
PI052-01-02    1368.655862
Name: T_K, dtype: float64

With these temperatures we can calculate melt Fe3+/Fe2+ ratios. The configuration is currently set to fO2 buffered at QFM+1 and the Borisov et al. (2018) Fe3+/Fe2+ model.

melt.head()

	SiO2	Al2O3	MgO	CaO	FeO	Na2O	K2O	MnO	TiO2	P2O5	CO2	H2O	F	S	Cl	total
name
PI032-04-01	49.402603	14.539062	6.509044	10.058735	9.757536	3.737374	0.697769	0.132497	2.548581	0.289823	0.628502	1.440208	0.078857	0.145452	0.033958	100
PI032-04-02	48.832207	15.116896	6.508618	9.688642	9.927146	3.564377	0.940308	0.135905	2.652552	0.336327	0.672345	1.330865	0.083879	0.165394	0.044540	100
PI041-02-02	49.124916	16.950138	4.861451	9.183852	10.238358	3.788617	1.077791	0.153258	2.804343	0.561031	0.463920	0.655494	0.047654	0.068020	0.021157	100
PI041-03-01	45.941086	15.753453	6.909844	10.996510	10.778833	3.346468	1.144852	0.112117	3.153303	0.551992	0.797715	0.293341	0.079499	0.086863	0.054123	100
PI041-03-03	45.313339	15.909531	6.831676	11.175276	10.966834	3.417548	1.167550	0.088899	3.262463	0.517891	0.821116	0.311131	0.081713	0.079495	0.055540	100

print(mp.configuration)
mp.configuration.dfO2 = 2

################ MagmaPandas ################
#############################################
General settings_____________________________
fO2 buffer................................QFM
ΔfO2........................................1
Melt Fe3+/Fe2+........................Sun2024
Kd Fe-Mg ol-melt.......................toplis
Melt thermometer...............putirka2008_16
Volatile solubility model......IaconoMarziano
Volatile species........................mixed
#############################################

moles = melt.moles()

moles.FeO_Fe2O3_calc(0.33, wtpc=False)

	SiO2	Al2O3	MgO	CaO	FeO	Na2O	K2O	MnO	TiO2	P2O5	CO2	H2O	F	S	Cl	total	Fe2O3
name
PI032-04-01	0.498648	0.086478	0.097943	0.108783	0.061930	0.036570	0.004492	0.001133	0.019353	0.001238	0.008661	0.048484	0.002517	0.002751	0.000581	0.989782	0.010218
PI032-04-02	0.496051	0.090491	0.098564	0.105452	0.063410	0.035101	0.006093	0.001169	0.020272	0.001446	0.009325	0.045090	0.002695	0.003148	0.000767	0.989537	0.010463
PI041-02-02	0.518555	0.105437	0.076501	0.103871	0.067958	0.038769	0.007257	0.001370	0.022270	0.002507	0.006686	0.023077	0.001591	0.001345	0.000378	0.988787	0.011213
PI041-03-01	0.480702	0.097135	0.107784	0.123283	0.070919	0.033945	0.007641	0.000994	0.024822	0.002445	0.011396	0.010237	0.002631	0.001703	0.000960	0.988298	0.011702
PI041-03-03	0.474557	0.098185	0.106660	0.125399	0.072220	0.034697	0.007800	0.000789	0.025705	0.002296	0.011741	0.010868	0.002706	0.001560	0.000986	0.988084	0.011916
PI041-05-04	0.512278	0.117337	0.061949	0.107859	0.064936	0.047763	0.010978	0.001253	0.020040	0.003742	0.007460	0.016494	0.002973	0.002438	0.001071	0.989286	0.010714
PI041-05-06	0.492420	0.106249	0.075050	0.101574	0.077597	0.041217	0.009602	0.001508	0.029047	0.002786	0.009285	0.020756	0.003609	0.002551	0.001141	0.987197	0.012803
PI041-07-01	0.473225	0.094020	0.103617	0.108615	0.074906	0.031789	0.008501	0.001267	0.027836	0.002460	0.006689	0.035661	0.002488	0.003207	0.001000	0.987641	0.012359
PI041-07-02	0.479135	0.096393	0.103903	0.113359	0.075639	0.032479	0.009113	0.001195	0.027930	0.002739	0.005337	0.021588	0.002444	0.002763	0.001021	0.987519	0.012481
PI052-01-02	0.515492	0.105613	0.058860	0.117128	0.055223	0.050291	0.010295	0.002089	0.013974	0.003052	0.004143	0.039428	0.002737	0.002494	0.000958	0.990888	0.009112

mp.configuration.Fe3Fe2_model = "borisov"
Fe3Fe2_QFM1 = melt.Fe3Fe2(T_K=temperatures, P_bar=P_bar)
Fe3Fe2_QFM1

name
PI032-04-01    0.501960
PI032-04-02    0.497872
PI041-02-02    0.455355
PI041-03-01    0.507279
PI041-03-03    0.517809
PI041-05-04    0.477988
PI041-05-06    0.492887
PI041-07-01    0.512346
PI041-07-02    0.504972
PI052-01-02    0.511342
dtype: float64

Changing the fO2 buffer to lower log offset values reduces the amount of Fe3+

mp.configuration.dfO2 = 0

melt.Fe3Fe2(T_K=temperatures, P_bar=P_bar)

name
PI032-04-01    0.193495
PI032-04-02    0.191919
PI041-02-02    0.175530
PI041-03-01    0.195545
PI041-03-03    0.199604
PI041-05-04    0.184254
PI041-05-06    0.189997
PI041-07-01    0.197498
PI041-07-02    0.194656
PI052-01-02    0.197111
dtype: float64

With our Fe3+/Fe2+ ratios we can calculate melt FeO and Fe2O3 contents

melt.FeO_Fe2O3_calc(Fe3Fe2=Fe3Fe2_QFM1)

	SiO2	Al2O3	MgO	CaO	FeO	Na2O	K2O	MnO	TiO2	P2O5	CO2	H2O	F	S	Cl	Fe2O3	total
name
PI032-04-01	49.223872	14.486461	6.485495	10.022344	6.473030	3.723852	0.695245	0.132018	2.539361	0.288775	0.626228	1.434998	0.078572	0.144926	0.033835	3.610989	100.0
PI032-04-02	48.653453	15.061559	6.484793	9.653176	6.603239	3.551329	0.936866	0.135407	2.642842	0.335096	0.669884	1.325994	0.083572	0.164789	0.044377	3.653623	100.0
PI041-02-02	48.950318	16.889894	4.844172	9.151211	7.009950	3.775152	1.073961	0.152713	2.794376	0.559037	0.462271	0.653164	0.047484	0.067778	0.021082	3.547435	100.0
PI041-03-01	45.756266	15.690078	6.882046	10.952271	7.122418	3.333006	1.140246	0.111666	3.140617	0.549772	0.794506	0.292161	0.079179	0.086514	0.053905	4.015349	100.0
PI041-03-03	45.125352	15.843528	6.803334	11.128914	7.195461	3.403370	1.162706	0.088530	3.248928	0.515743	0.817709	0.309840	0.081374	0.079165	0.055309	4.140735	100.0
PI041-05-04	47.550926	18.482696	3.857219	9.344093	6.485652	4.573285	1.597563	0.137275	2.472596	0.820543	0.507178	0.459036	0.087262	0.120753	0.058686	3.445239	100.0
PI041-05-06	46.169509	16.905232	4.720217	8.888523	7.750329	3.986434	1.411383	0.166960	3.620062	0.617108	0.637611	0.583491	0.107004	0.127627	0.063132	4.245378	100.0
PI041-07-01	45.661478	15.395014	6.706579	9.781336	7.600286	3.164057	1.285957	0.144360	3.570197	0.560783	0.472711	1.031699	0.075901	0.165164	0.056926	4.327553	100.0
PI041-07-02	45.674476	15.593199	6.644080	10.085505	7.619363	3.193726	1.361936	0.134466	3.539037	0.616858	0.372665	0.617027	0.073670	0.140577	0.057439	4.275978	100.0
PI052-01-02	49.163316	17.092713	3.765547	10.425720	5.541869	4.947634	1.539288	0.235204	1.771429	0.687744	0.289378	1.127454	0.082551	0.126918	0.053913	3.149322	100.0

Our melts also contain H2O and CO2, so let’s calculate volatile saturation pressures. In the configuration we see that we’re currently using the Iacono-Marziano et al. (2012) model with mixed CO2-H2O fluids:

print(mp.configuration)

################ MagmaPandas ################
#############################################
General settings_____________________________
fO2 buffer................................QFM
ΔfO2........................................0
Melt Fe3+/Fe2+........................borisov
Kd Fe-Mg ol-melt.......................toplis
Melt thermometer...............putirka2008_16
Volatile solubility model......IaconoMarziano
Volatile species........................mixed
#############################################

pressures_IM2012 = melt.volatile_saturation_pressure(T_K=temperatures)
pressures_IM2012

Saturation pressure...    |█████████████████████████| 100% [10/10] in 1.0s (5.59

name
PI032-04-01    5859.560466
PI032-04-02    6071.786862
PI041-02-02    4791.149912
PI041-03-01    6461.985990
PI041-03-03    6339.842577
PI041-05-04    4118.352036
PI041-05-06    5170.724099
PI041-07-01    4504.675250
PI041-07-02    3819.965205
PI052-01-02    2590.928144
dtype: float64

Lets change the volatile solubility model to Allison et al. (2022):

mp.configuration.volatile_solubility = 'Allison2022'
print(mp.configuration)

################ MagmaPandas ################
#############################################
General settings_____________________________
fO2 buffer................................QFM
ΔfO2........................................0
Melt Fe3+/Fe2+........................borisov
Kd Fe-Mg ol-melt.......................toplis
Melt thermometer...............putirka2008_16
Volatile solubility model.........Allison2022
Volatile species........................mixed
#############################################

pressures_A22 = melt.volatile_saturation_pressure(T_K=temperatures)
pressures_A22

Saturation pressure...    |█████████████████████████| 100% [10/10] in 0.6s (15.7

name
PI032-04-01    4762.967014
PI032-04-02    5382.216127
PI041-02-02    4898.391782
PI041-03-01    5839.864575
PI041-03-03    6016.042165
PI041-05-04    5258.315488
PI041-05-06    5827.032917
PI041-07-01    4519.918367
PI041-07-02    3925.172944
PI052-01-02    2597.606572
dtype: float64