zrSaturationCrisp {GCDkit} | R Documentation |
Calculates zircon saturation temperatures for the magma of the given major-element composition, Zr concentration, pressure and water content. The major-element chemistry is recast to the optical density (Λ) following Lebouteiller & Courtine (1998). Alternatively, this function returns Zr saturation levels for the assumed magma temperature and pressure.
zrSaturation.Crisp(WR, P = 0, T = 0, Zr = filterOut(WR,"Zr",1), H2O = filterOut(WR, "H2O.PLUS", 1))
WR |
numeric matrix; whole-rock data in wt. % |
P |
assumed pressure in kbar (single value) |
T |
assumed magma temperature in °C (single value) |
Zr |
(optional) numeric vector with Zr contents in ppm |
H2O |
(optional) numeric vector with H2O contents in wt. % |
Calculates Zr saturation concentration for the magma of the specified major-element composition, at assumed temperature, pressure and water content.
Given 'T
' is the estimated absolute temperature (K) of the magma,
'P
' is pressure in GPa, Λ is the optical basicity of the melt and
xH2O
is the mole fraction of water in the melt, the Zr saturation level is given by equation of
Crisp et al. (2022):
log10(Zr.sat) = 0.96 - 5790/T - 1.28*P + 12.39*Λ + 0.83*xH2O + 2.06*P*Λ
On the other hand, the saturation temperature (°C) can be obtained from the observed Zr concentration and magma composition expressed by the Λ parameter (assuming no zircon inheritance):
TZr.sat.C = 5790/(0.96 - 1.28*P + 12.39*Λ + 0.83*xH2O + 2.06*P*Λ - log10(Zr)) - 273.15
Returns a matrix 'results
' with the following columns:
Zr.obs |
observed Zr concentrations in ppm |
lambda |
optical basicity (Λ) |
xH2O |
mole fraction of water in the melt (xH2O) |
Zr.sat.C22 |
saturation levels of Zr (ppm) for assumed T |
TZr.sat.C.C22 |
zircon saturation temperatures in °C |
Saturation.r
Jean-François Moyen jfmoyen@gmail.com
Vojtěch Janoušek, vojtech.janousek@geology.cz
Crisp LJ, Berry AJ (2022) A new model for zircon saturation in silicate melts. Contrib Mineral Petrol 177: 71. doi: 10.1007/s00410-022-01925-6
Lebouteiller A, Courtine P (1998) Improvement of a bulk optical basicity table for oxidic systems. Journal of Solid State Chemistry 137: 94-103. doi: 10.1006/jssc.1997.7722
sampleDataset("sazava") zrSaturation.Crisp(WR,P=3000,T=800) # Example from spreadsheet by Crisp et al. (2022) z <- c(61.26,NA,13.12,0.45,NA,1.33,NA,2.51,2.26,2.15,NA,15.00,62) names(z) <- c("SiO2","TiO2","Al2O3","MgO","MnO","FeOt","Fe2O3","CaO","Na2O","K2O", "P2O5","H2O.PLUS","Zr") zrSaturation.Crisp(z,P=2000,T=750)