zrSaturationCrisp {GCDkit}R Documentation

Zircon saturation (Crisp et al. 2022)

Description

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.

Usage

zrSaturation.Crisp(WR, P = 0, T = 0, Zr = filterOut(WR,"Zr",1), 
    H2O = filterOut(WR, "H2O.PLUS", 1))

Arguments

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. %

Details

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

Value

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

Plugin

Saturation.r

Author(s)

Jean-François Moyen jfmoyen@gmail.com

Vojtěch Janoušek, vojtech.janousek@geology.cz

References

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

See Also

zrSaturation

zrSaturation.Gervasoni

zrSaturation.Borisov

Examples

    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)

[Package GCDkit version 6.3.0 Index]