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Triple oxygen isotope values of carbonates

Source: R/d17O.R
d17O_c.Rd

d17O_c() calculates the equilibrium d18O, d17O, and D17O values of a calcite grown at a given temperature.

Usage

d17O_c(
  temp,
  d18O_H2O_VSMOW,
  D17O_H2O = 0,
  min = "calcite",
  eq18 = "Daeron19",
  lambda = 0.528
)

Arguments

temp

Calcite growth temperature (°C).

d18O_H2O_VSMOW

Water d18O value expressed on the VSMOW scale (‰).

D17O_H2O

D17O value of ambient water calculated using a lambda of 0.528. Default 0.

min

Mineralogy. Options are "calcite" (default), "aragonite", apatite, siderite, and "dolomite".

eq18

Equation used to calculate the 18O/16O fractionation factor between calcite and water. Options are like in a18_c_H2O(). Default "Daeron19".

lambda

Triple oxygen isotope reference slope. Default 0.528.

Value

Returns a data frame:

  1. d18O value of the carbonate expressed on the VSMOW scale (‰).

  2. d17O value of the carbonate expressed on the VSMOW scale (‰).

  3. D17O value of the carbonate expressed on the VSMOW scale (‰).

Details

$$\theta_{A/B} = \frac{\alpha^{17}_{A/B}}{\alpha^{18}_{A/B}}$$

$$ \delta'^{17}O_{H2O,VSMOW} = \beta \times \delta'^{18}O_{H2O,VSMOW} + \gamma \textrm{ , where } \beta=0.528 \textrm{ and } \gamma = 0 $$

$$\Delta^{17}O_{CaCO3,VSMOW} = \delta'^{17}O_{CaCO3,VSMOW} - \lambda \times \delta'^{18}O_{CaCO3,VSMOW} $$

NOTE: Due to a lack of experimental and theoretical data, the theta values for all carbonate mineralogies - except aragonite - are calculated with the calcite equitation from Guo & Zhou (2019):

$$\theta_{aragonite/water} = \frac{78.1173}{T^{2}} - \frac{1.5152}{T} + 0.5299$$

$$\theta_{calcite/water} = \frac{59.1047}{T^{2}} - \frac{1.4089}{T} + 0.5297$$

References

Guo, W., & Zhou, C. (2019). Triple oxygen isotope fractionation in the DIC-H2O-CO2 system: A numerical framework and its implications. Geochimica et Cosmochimica Acta, 246, 541-564. doi:10.1016/j.gca.2018.11.018

See also

Other equilibrium_carbonate: D47(), D48(), d18O_c()

Examples

d17O_c(temp = 10, d18O_H2O_VSMOW = -1) # Returns the data frame (length = 3)
#>     d18O_c   d17O_c      D17O_c
#> 1 32.43637 16.91235 -0.08357564
prime(d17O_c(temp = 10, d18O_H2O_VSMOW = -1)[, 2]) # Returns the d'17O value
#> [1] 16.77093
d17O_c(temp = 10, d18O_H2O_VSMOW = -1)[, 3] # Returns the D17O value
#> [1] -0.08357564