zrSaturationBorisov {GCDkit}R Documentation

Zircon saturation (Borisov et al. 2025)

Description

Calculates zircon saturation temperatures for the magma of the given major-element composition, Zr concentration and pressure. Alternatively, this function returns Zr saturation levels for the assumed magma temperature and pressure.

Usage

zrSaturation.Borisov(WR, P = 0, T = 0, Zr = filterOut(WR,"Zr",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

Details

Calculates Zr saturation concentration for the magma of the specified major-element composition, at assumed temperature and pressure.

Given 'T' is the estimated absolute temperature (K) of the magma, the magma chemistry has been recast to mole fractions of individual oxides (Xi) and 'P' is pressure in GPa, the Zr saturation level is given by several equations of Borisov et al. (2025). NB that all logarithms are decadic:

Equation (7)

log10(Zr.sat) = 7.47 + 3.4B - 3510BT/T - 6219/T - 0.451P + 0.156P^2

where:

B = (0.2XTiO2 + 2XAl2O3 - 3XFeO + XMgO - XCaO - 5XNa2O - 5XK2O)/XSiO2

and:

BT = (3XAl2O3 - 5XFeO + XMgO - 2.5XCaO - 9XNa2O - 9XK2O)/XSiO2

Equation (8)

log10(Zr.sat) = 8.16 + 0.557CB + 1634CBT/T - 7207/T - 0.112P

where:

CB = (XTiO2 + 8XFeO - 1.1XMgO + 1.2XCaO - 25XNa2O - 26XK2O)/XSiO2

and:

CBT = (-3XFeO + 1.8XMgO + XCaO + 16XNa2O + 16XK2O)/XSiO2

Equation (9)

log10(Zr.sat) = 7.59 + 5.535BH - 6589/T - 0.233P

where:

BH = (1.1XTiO2 + 1.3XAl2O3 + XFeO + 2.7XMgO + 4.0XCaO + 4.7XNa2O + 5.9XK2O)/XSiO2

Equation (10)

log10(Zr.sat) = 5.33 + 2.090BL - 3347/T

where:

BL = (XTiO2 - 1.2XAl2O3 + 2.4XCaO + 3.4XNa2O + 1.5XK2O)/XSiO2

On the other hand, the saturation temperature (°C) can be obtained from the observed Zr concentration and major-element composition of the magma (assuming no zircon inheritance):

Equation (7)

TZr.sat.CB25.equ7 = -(3510BT + 6219)/(log10(Zr) - 7.47 - 3.4B + 0.451*P - 0.156P^2)-273.15

Equation (10)

TZr.sat.CB25.equ10 = -3347/(log10(Zr) - 5.33 - 2.090BL)-273.15

Value

Returns a matrix 'results' with the following columns:

Zr.obs

observed Zr concentrations in ppm

Zr.sat.B25.equ7

saturation levels of Zr (ppm) at assumed T (eq. 7)

Zr.sat.B25.equ8

saturation levels of Zr (ppm) at assumed T (eq. 8)

Zr.sat.B25.equ9

saturation levels of Zr (ppm) at assumed T (eq. 9)

Zr.sat.B25.equ10

saturation levels of Zr (ppm) at assumed T (eq. 10)

T.sat.C.B25.equ7

zircon saturation temperatures (eq. 7) in °C

T.sat.C.B25.equ10

zircon saturation temperatures (eq. 10) in °C

Plugin

Saturation.r

Warning

For calculations are actually used more precise coefficients as taken from the original spreadsheet of Borisov et al. (2025).

Author(s)

Vojtěch Janoušek, vojtech.janousek@geology.cz

References

Borisov A, Aranovich L, Antoshechkina P (2025) Zircon solubility in silicate melts: New empirical models and thermodynamics. Chem Geol 679: 122682. doi: 10.1016/j.chemgeo.2025.122682

See Also

zrSaturation

zrSaturation.Crisp

zrSaturation.Gervasoni

Examples

    sampleDataset("sazava")
    zrSaturation.Borisov(WR,P=3000,T=800)
    
    # Examples from spreadsheet by Borisov et al. (2025) 
    z <- c(60.83,0.00,11.54,0.00,10.53,11.56,0.00,0.00,3757)
    names(z) <- c("SiO2","TiO2","Al2O3","FeOt","MgO",
        "CaO","Na2O","K2O","Zr") 
    zrSaturation.Borisov(z,P=0.0001,T=1408)
    
    z <- c(59.57,0.00,15.57,0.00,17.84,0.00,0.00,0.00,1131)
    names(z) <- c("SiO2","TiO2","Al2O3","FeOt","MgO",
        "CaO","Na2O","K2O","Zr") 
    zrSaturation.Borisov(z,P=0.0001,T=1501)

[Package GCDkit version 6.3.0 Index]