Tools for Stable Isotope Geochemistry
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isogeochem makes working with stable oxygen, carbon, and
clumped isotope data straightforward and reproducible. It offers tools
to quickly calculate:
The list of available proxy–temperature calibrations is growing with each new released version. Please get in touch if you have suggestions to include!
Install the released version of isogeochem from
CRAN.
install.packages("isogeochem")Install the development version of isogeochem from
GitHub.
if (!require("devtools")) install.packages("devtools")
if (!require("rmarkdown")) install.packages("rmarkdown")
devtools::install_github("davidbajnai/isogeochem", build_vignettes = TRUE)Case studies demonstrating the use and scope of the functions in
isogeochem are available as vignettes.
browseVignettes("isogeochem")Use D47() and D48() to calculate
equilibrium carbonate clumped isotope values (∆47,
∆48) for a given temperature.
temp_D47() calculates carbonate growth temperatures from
∆47 values, while temp_D48() calculates
growth temperature corrected for kinetic effects considering both the
∆47 and the ∆48 value.
if (!require("shades")) install.packages("shades")
# Model equilibrium carbonate ∆47 and ∆48 values
temp = seq(0, 100, 10) # temperature range: 0—100 °C
D47eq = D47(temp, eq = "Fiebig21")
D48eq = D48(temp, eq = "Fiebig21")
# Sample data
D47_coral = 0.617; D47_coral_err = 0.006
D48_coral = 0.139; D48_coral_err = 0.022
D47_speleo = 0.546; D47_speleo_err = 0.007
D48_speleo = 0.277; D48_speleo_err = 0.029
## Plot in ∆47 vs ∆48 space ##
plot(0, type = "l", axes = TRUE, ylim = c(0.4, 0.7), xlim = c(0.1, 0.3),
ylab = expression(Delta[47] * " (CDES90, ‰)"),
xlab = expression(Delta[48] * " (CDES90, ‰)"),
lty = 0, font = 1, cex.lab = 1, las = 1)
# Plot the equilibrium curve and points
lines (D48eq, D47eq, col = "purple", lwd = 2)
points(D48eq, D47eq, col = shades::gradient(c("blue", "red"), length(temp)),
pch = 19, cex = 1.2)
# Plot the sample data,
# ... the kinetic slopes,
# ... and calculate growth temperatures corrected for kinetic effects
# ... using a single function!
temp_D48(D47_coral, D48_coral, D47_coral_err, D48_coral_err, ks = -0.6,
add = TRUE, col = "seagreen", pch = 15)
#> temp temp_err
#> 1 38 6
temp_D48(D47_speleo, D48_speleo, D47_speleo_err, D48_speleo_err, ks = -1,
add = TRUE, col = "darkorange", pch = 17)
#> temp temp_err
#> 1 30 9
# Add labels to the plot
text(D48(temp, eq = "Fiebig21"), D47(temp, eq = "Fiebig21"), paste(temp, "°C"),
col = shades::gradient(c("blue", "red"), length(temp)), pos = 4, cex = 0.8)
d17O_c() calculates equilibrium carbonate oxygen isotope
values (δ18O, δ17O,
∆17O) for a given temperature and ambient water
composition. Use the mix_d17O() function to calculate
mixing curves in triple oxygen isotope space, e.g., for modeling
diagenesis.
if (!require("shades")) install.packages("shades")
# Model equilibrium *calcite* precipitating from seawater
temp_sw = seq(0, 50, 10) # temperature range: 0—50 °C
d18O_sw = 0 # d18O value of seawater
D17O_sw = -0.004 # D17O value of seawater
d18Op = prime(d17O_c(temp_sw, d18O_sw, D17O_sw, eq18 = "Daeron19")[, 1])
D17O = d17O_c(temp_sw, d18O_sw, D17O_sw, eq17 = "Wostbrock20", eq18 = "Daeron19")[, 3]
# Model progressing meteoric diagenetic alteration
d18O_ds = -8 # d18O value of diagenetic fluid
D17O_ds = 0.020 # D17O value of diagenetic fluid
em_equi = d17O_c(temp = 10, d18O_H2O = d18O_sw, D17O_H2O = D17O_sw,
eq17 = "Wostbrock20", eq18 = "Daeron19") # equilibrium endmember
em_diag = d17O_c(temp = 80, d18O_H2O = d18O_ds, D17O_H2O = D17O_ds,
eq17 = "Wostbrock20", eq18 = "Daeron19") # diagenetic endmember
mix = mix_d17O(d18O_A = em_equi[1], d17O_A = em_equi[2],
d18O_B = em_diag[1], d17O_B = em_diag[2], step = 25)
## Plot in ∆17O vs d'18O space ##
plot(0, type = "l", ylim = c(-0.1, 0.05), xlim = c(-10, 40),
xlab = expression(delta * "'" ^ 18 * "O (‰, VSMOW)"),
ylab = expression(Delta ^ 17 * "O (‰, VSMOW)"),
lty = 0, font = 1, cex.lab = 1, las = 1)
# Plot meteoric waters from the build-in dataset
points(prime(meteoric_water$d18O), D17O(meteoric_water$d18O, meteoric_water$d17O),
col = "lightblue1", pch = 20)
text(-4, 0.05, "meteoric water", pos = 4, col = "lightblue1")
# Plot the composition of the fluids
points(prime(d18O_sw), D17O_sw, col = "darkmagenta", pch = 8) # seawater
text(prime(d18O_sw), D17O_sw, "seawater", pos = 4, col = "darkmagenta")
points(prime(d18O_ds), D17O_ds, col = "deeppink", pch = 8) # diagenetic fluid
text(prime(d18O_ds), D17O_ds, "diagenetic fluid", pos = 4, col = "deeppink")
# Plot the equilibrium curve and points
lines(d18Op, D17O, col = "darkmagenta", lwd = 2)
points(d18Op, D17O, pch = 19, cex = 1.2,
col = shades::gradient(c("blue", "red"), length(temp_sw)))
text(d18Op, D17O, paste(temp_sw, "°C"), pos = 4, cex = 0.8,
col = shades::gradient(c("blue", "red"), length(temp_sw)))
text(30, -0.05, paste("equilibrium calcite \nfrom seawater"),
pos = 3, col = "darkmagenta")
# Plot the mixing model between the equilibrium and diagenetic endmembers
lines(prime(mix[, 1]), mix[, 2], col = "deeppink", lty = 3, lwd = 2)
points(prime(mix[, 1]), mix[, 2], pch = 18, cex = 1.5,
col = shades::gradient(c("#3300CC", "deeppink"), length(mix[, 2])))
text(prime(mix[, 1]), mix[, 2], paste(mix[, 3], "%", sep = ""), pos = 2, cex = 0.8,
col = shades::gradient(c("#3300CC", "deeppink"), length(mix[, 3])))
text(22, -0.09, paste("progressing", "\ndiagenetic alteration", "\n(recrystallisation) at 80°C", sep =""),
pos = 2, col = "deeppink")
Use isogeochem to calculate crystallization temperatures
from carbonate δ18O and ∆47
values.
# Temperature from D47 with or without errors
temp_D47(D47_CDES90 = 0.601, eq = "Petersen19")
#> [1] 24.9
temp_D47(D47_CDES90 = 0.601,
D47_error = 0.008 ,
eq = "Anderson21")
#> temp temp_err
#> 1 22.6 2.7
# Temperature from d18O
temp_d18O(
d18O_c_VSMOW = 30,
d18O_H2O_VSMOW = 0,
min = "calcite",
eq = "Watkins13")
#> [1] 25.9Use isogeochem to calculate
16O/18O fractionation factors at given
temperatures.
if (!require("viridisLite")) install.packages("viridisLite")
plot(0, type = "l", las = 1, yaxt = "n",
xlim = c(10, 30), ylim = c(-30, 50),
xlab = "Temperature (°C)",
ylab = expression("Equilibrium enrichment in "^18*"O relative to H"[2]*"O (‰)"))
axis(2, seq(-30, 50, 10), las = 1)
temps = seq(10, 30, 1)
d18O_H2O_VSMOW = 0
cols = viridisLite::viridis(7, option = "C")
text(10, 45, expression("CO"[2]*" (aq)"), col = cols[1], adj = c(0, 0))
lines(temps, A_from_a(a18_CO2aq_H2O(temps), d18O_H2O_VSMOW),
lwd = 2, lty = 2, col = cols[1])
text(10, 35, expression("HCO"[3]^"–"), col = cols[2], adj = c(0, 0))
lines(temps, A_from_a(a18_HCO3_H2O(temps), d18O_H2O_VSMOW),
lwd = 2, lty = 2, col = cols[2])
text(10, 30, "calcite", col = cols[3], adj = c(0, 0))
lines(temps, A_from_a(a18_c_H2O(temps, "calcite", "Daeron19"), d18O_H2O_VSMOW),
lwd = 2, lty = 1, col = cols[3])
text(10, 21, expression("CO"[3]^"2–"), col = cols[4], adj = c(0, 0))
lines(temps, A_from_a(a18_CO3_H2O(temps), d18O_H2O_VSMOW),
lwd = 2, lty = 2, col = cols[4])
text(10, 1, expression("H"[2]*"O"), col = cols[5], adj = c(0, 0))
lines(temps, rep(d18O_H2O_VSMOW, length(temps)),
lwd = 3, lty = 1, col = cols[5])
text(10, -23, expression("OH"^"–"), col = cols[6], adj = c(0, 0))
lines(temps, B_from_a(a18_H2O_OH(temps, eq = "Z20-X3LYP"), d18O_H2O_VSMOW),
lwd = 2, lty = 1, col = cols[6])
# Convert between the VSMOW and VPDB scales:
to_VPDB(32)
#> [1] 1.05032
to_VSMOW(1)
#> [1] 31.95092
# Convert between classical delta and delta prime values:
prime(10)
#> [1] 9.950331
unprime(9.95)
#> [1] 9.999666
# Calculate isotope fractionation factors:
a_A_B(A = 30.40, B = 0.15)
#> [1] 1.030245
epsilon(a_A_B(A = 30.40, B = 0.15))
#> [1] 30.24546Within isogeochem you have quick access to important
datasets.
| Name | Description | Reference |
|---|---|---|
devilshole |
The original Devils Hole carbonate δ18O time series | Winograd et al. (2006) |
LR04 |
A benthic foraminifera δ18O stack | Lisiecki & Raymo (2005) |
GTS2020 |
An abridged version of the GTS2020 oxygen isotope stack | Grossman & Joachimski (2020) |
meteoric_water |
A compilation of meteoric water δ18O and δ17O values | Barkan & Luz (2010), Aron et al. (2021) |
For more information on the datasets please have a look at the
corresponding documentation, e.g., ?devilshole
There are several other R packages that complement
isogeochem and are worth checking out:
viridisLite
and viridis
produce color-blind and black-and-white printer friendly color
scales.
clumpedr
works with isoreader
to read in raw measurement data and reproducibly process the results to
clumped isotope values.
seasonalclumped
can be used to reconstruct temperature and salinity variations from
seasonal oxygen and clumped isotope records.
deeptime
adds geological timescales to ggplots.
These binaries (installable software) and packages are in development.
They may not be fully stable and should be used with caution. We make no claims about them.