age: Calculate isotopic ages In IsoplotR: Statistical Toolbox for Radiometric Geochronology

 age R Documentation

Calculate isotopic ages

Description

Calculates U-Pb, Pb-Pb, Th-Pb, Ar-Ar, K-Ca, Re-Os, Sm-Nd, Rb-Sr, Lu-Hf, U-Th-He, Th-U and fission track ages and propagates their analytical uncertainties. Includes options for single grain, isochron and concordia_ages.

Usage

age(x, ...)

## Default S3 method:
age(
x,
method = "U238-Pb206",
oerr = 1,
sigdig = NA,
exterr = FALSE,
J = c(NA, NA),
zeta = c(NA, NA),
rhoD = c(NA, NA),
d = diseq(),
...
)

## S3 method for class 'UPb'
age(
x,
type = 1,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
common.Pb = 0,
discordance = discfilter(),
...
)

## S3 method for class 'PbPb'
age(
x,
isochron = TRUE,
common.Pb = 2,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)

## S3 method for class 'ArAr'
age(
x,
isochron = FALSE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)

## S3 method for class 'KCa'
age(
x,
isochron = FALSE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)

## S3 method for class 'UThHe'
age(x, isochron = FALSE, central = FALSE, i = NULL, oerr = 1, sigdig = NA, ...)

## S3 method for class 'fissiontracks'
age(x, central = FALSE, i = NULL, oerr = 1, sigdig = NA, exterr = FALSE, ...)

## S3 method for class 'ThU'
age(
x,
isochron = FALSE,
Th0i = 0,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
...
)

## S3 method for class 'ThPb'
age(
x,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)

## S3 method for class 'ReOs'
age(
x,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)

## S3 method for class 'SmNd'
age(
x,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)

## S3 method for class 'RbSr'
age(
x,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)

## S3 method for class 'LuHf'
age(
x,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)

## S3 method for class 'PD'
age(
x,
nuclide,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)


Arguments

 x can be: a scalar containing an isotopic ratio, a two element vector containing an isotopic ratio and its standard error, or the spontaneous and induced track densities Ns and Ni, a two element vector containing Ar40Ar39, s[Ar40Ar39], a two element vector containing K40Ca40 and s[K40Ca40], a six element vector containing U, s[U], Th, s[Th], He and s[He], an eight element vector containing U, s[U], Th, s[Th], He, s[He], Sm and s[Sm] a two element vector containing Sr87Rb87 and s[Sr87Rb87] a two element vector containing Os187Re187 and s[Os187Re187] a two element vector containing Nd143Sm147 and s[Nd144Sm147] a two element vector containing Hf176Lu176 and s[Hf176Lu176] a five element vector containing Th230U238, s[Th230/U238], U234U238, s[U234U238] and cov[Th230U238,U234U238] OR an object of class UPb, PbPb, ThPb, ArAr, KCa, ThU, RbSr, SmNd, ReOs, LuHf, UThHe or fissiontracks. ... additional arguments method one of either 'U238-Pb206', 'U235-Pb207', 'Pb207-Pb206', 'Th232-Pb208', 'Ar-Ar', 'K-Ca', 'Th-U', 'Re-Os', 'Sm-Nd', 'Rb-Sr', 'Lu-Hf', 'U-Th-He' or 'fissiontracks' oerr indicates whether the analytical uncertainties of the output are reported as: 1: 1\sigma absolute uncertainties. 2: 2\sigma absolute uncertainties. 3: absolute (1-\alpha)% confidence intervals, where \alpha equales the value that is stored in settings('alpha'). 4: 1\sigma relative uncertainties (\%). 5: 2\sigma relative uncertainties (\%). 6: relative (1-\alpha)% confidence intervals, where \alpha equales the value that is stored in settings('alpha'). (only used when isochron and central are FALSE) sigdig number of significant digits for the uncertainty estimate (only used if type=1, isochron=FALSE and central=FALSE). exterr propagate the external (decay constant and calibration factor) uncertainties? J two-element vector with the J-factor and its standard error. zeta two-element vector with the zeta-factor and its standard error. rhoD two-element vector with the track density of the dosimeter glass and its standard error. d an object of class diseq. type scalar flag indicating whether 1: each U-Pb analysis should be considered separately, 2: all the measurements should be combined to calculate a concordia_age, 3: a discordia_line should be fitted through all the U-Pb analyses using the maximum likelihood algorithm of Ludwig (1998), which assumes that the scatter of the data is solely due to the analytical uncertainties. 4: a discordia_line should be fitted ignoring the analytical uncertainties. 5: a discordia_line should be fitted using a modified maximum likelihood algorithm that accounts for overdispersion by adding a geological (co)variance term. i index of a particular aliquot common.Pb common lead correction: 0: none 1: use the Pb-composition stored in settings('iratio','Pb207Pb206') (if x has class UPb and x\$format<4); settings('iratio','Pb206Pb204') and settings('iratio','Pb207Pb204') (if x has class PbPb or x has class UPb and 3

Value

1. if x is a scalar or a vector, returns the age using the geochronometer given by method and its standard error.

2. if x has class UPb and type=1, returns a table with the following columns: t.75, err[t.75], t.68, err[t.68], t.76, err[t.76], (t.82, err[t.82],) t.conc, err[t.conc], (disc) or err[p.conc],) containing the ^{207}Pb/^{235}U-age and standard error, the ^{206}Pb/^{238}U-age and standard error, the ^{207}Pb/^{206}Pb-age and standard error, (the ^{208}Pb/^{232}Th-age and standard error,) the single grain concordia_age and standard error, (and the % discordance or p-value for concordance,) respectively.

3. if x has class UPb and type=2, 3, 4 or 5, returns the output of the concordia function.

4. if x has class PbPb, ThPb, ArAr, KCa, RbSr, SmNd, ReOs, LuHf, ThU or UThHe and isochron=FALSE, returns a table of Pb-Pb, Th-Pb, Ar-Ar, K-Ca, Rb-Sr, Sm-Nd, Re-Os, Lu-Hf, Th-U or U-Th-He ages and their standard errors.

5. if x has class ThU and isochron=FALSE, returns a 5-column table with the Th-U ages, their standard errors, the initial ^{234}U/^{238}U-ratios, their standard errors, and the correlation coefficient between the ages and the initial ratios.

6. if x has class PbPb, ThPb, ArAr, KCa, RbSr, SmNd, ReOs, LuHf, UThHe or ThU and isochron=TRUE, returns the output of the isochron function.

7. if x has class fissiontracks and central=FALSE, returns a table of fission track ages and standard errors.

8. if x has class fissiontracks or UThHe and central=TRUE, returns the output of the central function.

concordia, isochron, central

Examples

attach(examples)
tUPb <- age(UPb,type=1)
tconc <- age(UPb,type=2)
tdisc <- age(UPb,type=3)
tArAr <- age(ArAr)
tiso <- age(ArAr,isochron=TRUE,i2i=TRUE)
tcentral <- age(FT1,central=TRUE)
`

IsoplotR documentation built on May 29, 2024, 7:57 a.m.