pb_age {ananke} | R Documentation |
Geological Model Age from Lead Isotope Analysis
Description
Compute geological model age (T) and U/Pb (mu) and Th/U (kappa) ratios from lead isotopic measurements.
Usage
pb_age(x, y, z, ...)
## S4 method for signature 'numeric,numeric,numeric'
pb_age(
x,
y,
z,
t0 = 3.8,
x_star = 18.75,
y_star = 15.63,
z_star = 38.86,
mu = 9.66,
kappa = 3.9,
th232 = 0.049475,
u238 = 0.155125,
u235 = 0.98485,
u238_235 = 137.79,
tolerance = sqrt(.Machine$double.eps),
stop = 100
)
## S4 method for signature 'list,missing,missing'
pb_age(
x,
t0 = 3.8,
x_star = 18.75,
y_star = 15.63,
z_star = 38.86,
mu = 9.66,
kappa = 3.9,
th232 = 0.049475,
u238 = 0.155125,
u235 = 0.98485,
u238_235 = 137.79,
tolerance = sqrt(.Machine$double.eps),
stop = 100
)
Arguments
x |
A |
y |
A |
z |
A |
... |
Currently not used. |
t0 |
A |
x_star |
A |
y_star |
A |
z_star |
A |
mu |
A |
kappa |
A |
th232 |
A |
u238 |
A |
u235 |
A |
u238_235 |
A |
tolerance |
A |
stop |
An |
Value
A four columns data.frame
:
age
Geological model age (in Ma).
mu
238U/204Pb ratio.
kappa
232Th/238U ratio.
residual
Newton loop residual.
Note
Reference values from Albarede & Juteau (1984).
Author(s)
N. Frerebeau, F. Albarede (original Matlab code)
References
Albarède, F., Desaulty, A.-M. & Blichert-Toft, J. (2012). A Geological Perspective on the Use of Pb Isotopes in Archaeometry. Archaeometry, 54: 853-867. doi:10.1111/j.1475-4754.2011.00653.x.
Albarède, F. & Juteau, M. (1984). Unscrambling the Lead Model Ages. Geochimica et Cosmochimica Acta, 48(1): 207-12. doi:10.1016/0016-7037(84)90364-8.
Allègre, C. (2005). Géologie isotopique. Belin sup. Paris: Belin.
Examples
Pb <- data.frame(
x = c(18.23247, 18.22936, 18.23102), # Pb206/Pb204
y = c(15.65199, 15.65216, 15.65097), # Pb207/Pb204
z = c(38.5167, 38.51516, 38.51601) # Pb208/Pb204
)
## Default reference values from Albarede & Juteau (1984)
pb_age(
Pb,
t0 = 3.8,
x_star = 18.75, y_star = 15.63, z_star = 38.86,
mu = 9.66, kappa = 3.90, th232 = 0.049475,
u238 = 0.155125, u235 = 0.98485, u238_235 = 137.79
)
## Reference values from Albarede et al. (2012)
pb_age(
Pb,
t0 = 4.43,
x_star = 18.75, y_star = 15.63, z_star = 38.83,
mu = 9.66, kappa = 3.90, th232 = 0.049475,
u238 = 0.155125, u235 = 0.98485, u238_235 = 137.79
)