Calculates U-Pb, Pb-Pb, Ar-Ar, 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.
age(x, ...)# S3 method for default
age(x, method = "U238-Pb206", exterr = TRUE, J = c(NA,
NA), zeta = c(NA, NA), rhoD = c(NA, NA), ...)
# S3 method for UPb
age(x, type = 1, wetherill = TRUE, exterr = TRUE, i = NA,
sigdig = NA, common.Pb = 0, ...)
# S3 method for PbPb
age(x, isochron = TRUE, common.Pb = 1, exterr = TRUE,
i = NA, sigdig = NA, ...)
# S3 method for ArAr
age(x, isochron = FALSE, i2i = TRUE, exterr = TRUE,
i = NA, sigdig = NA, ...)
# S3 method for UThHe
age(x, isochron = FALSE, central = FALSE, i = NA,
sigdig = NA, ...)
# S3 method for fissiontracks
age(x, central = FALSE, i = NA, sigdig = NA,
exterr = TRUE, ...)
# S3 method for ThU
age(x, isochron = FALSE, i2i = TRUE, exterr = TRUE,
i = NA, sigdig = NA, ...)
# S3 method for ReOs
age(x, isochron = TRUE, i2i = TRUE, exterr = TRUE,
i = NA, sigdig = NA, ...)
# S3 method for SmNd
age(x, isochron = TRUE, i2i = TRUE, exterr = TRUE,
i = NA, sigdig = NA, ...)
# S3 method for RbSr
age(x, isochron = TRUE, i2i = TRUE, exterr = TRUE,
i = NA, sigdig = NA, ...)
# S3 method for LuHf
age(x, isochron = TRUE, i2i = TRUE, exterr = TRUE,
i = NA, sigdig = NA, ...)
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 (if method='fissiontracks'),
a four element vector containing Ar40Ar39,
s[Ar40Ar39], J, s[J],
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 six element vector containing Rb, s[Rb],
Sr, s[Sr], Sr87Sr86, and s[Sr87Sr86]
a six element vector containing Re, s[Re],
Os, s[Os], Os187Os188, and s[Os187Os188]
a six element vector containing Sm, s[Sm],
Nd, s[Nd], Nd143Nd144, and s[Nd144Nd143]
a six element vector containing Lu, s[Lu],
Hf, s[Hf], Hf176Hf177, and s[Hf176Hf177]
a five element vector containing 0/8, s[0/8],
4/8, s[4/8] and cov[0/8,4/8]
OR
an object of class UPb, PbPb, ArAr, ThU,
RbSr, SmNd, ReOs, LuHf, UThHe or
fissiontracks.
additional arguments
one of either 'U238-Pb206', 'U235-Pb207',
'Pb207-Pb206', 'Ar-Ar', 'Th-U', 'Re-Os',
'Sm-Nd', 'Rb-Sr', 'Lu-Hf', 'U-Th-He' or
'fissiontracks'
propagate the external (decay constant and calibration factor) uncertainties?
two-element vector with the J-factor and its standard error.
two-element vector with the zeta-factor and its standard error.
two-element vector with the track density of the dosimeter glass and its standard error.
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.
logical flag to indicate whether the data should
be evaluated in Wetherill (TRUE) or Tera-Wasserburg
(FALSE) space. This option is only used when
type=2
(optional) index of a particular aliquot
number of significant digits for the uncertainty
estimate (only used if type=1, isochron=FALSE and
central=FALSE).
apply a common lead correction using one of three methods:
1: use the isochron intercept as the initial Pb-composition
2: use the Stacey-Kramer two-stage model to infer the initial
Pb-composition
3: use the Pb-composition stored in
settings('iratio','Pb206Pb204') and
settings('iratio','Pb207Pb204')
logical flag indicating whether each Ar-Ar analysis
should be considered separately (isochron=FALSE) or an
isochron age should be calculated from all Ar-Ar analyses
together (isochron=TRUE).
`isochron to intercept': calculates the initial (aka
`inherited', `excess', or `common')
\(^{40}\)Ar/\(^{36}\)Ar, \(^{207}\)Pb/\(^{204}\)Pb,
\(^{87}\)Sr/\(^{86}\)Sr, \(^{143}\)Nd/\(^{144}\)Nd,
\(^{187}\)Os/\(^{188}\)Os or \(^{176}\)Hf/\(^{177}\)Hf
ratio from an isochron fit. Setting i2i to FALSE
uses the default values stored in
settings('iratio',...). When applied to data of class
ThU, setting i2i to TRUE applies a
detrital Th-correction.
logical flag indicating whether each analysis should
be considered separately (central=FALSE) or a central
age should be calculated from all analyses together
(central=TRUE).
if x is a scalar or a vector, returns the age using
the geochronometer given by method and its standard error.
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.conc, err[t.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, and the
single grain concordia age and standard error, respectively.
if x has class UPb and type=2, 3, 4 or
5, returns the output of the concordia
function.
if x has class PbPb, ArAr, RbSr,
SmNd, ReOs, LuHf, ThU or UThHe
and isochron=FALSE, returns a table of Pb-Pb, Ar-Ar, Rb-Sr,
Sm-Nd, Re-Os, Lu-Hf, Th-U or U-Th-He ages and their standard
errors.
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.
if x has class PbPb, ArAr, RbSr,
SmNd, ReOs, LuHf, UThHe or ThU
and isochron=TRUE, returns the output of the
isochron function.
if x has class fissiontracks and
central=FALSE, returns a table of fission track ages and
standard errors.
if x has class fissiontracks or UThHe
and central=TRUE, returns the output of the
central function.
# NOT RUN {
data(examples)
tUPb <- age(examples$UPb,type=1)
tconc <- age(examples$UPb,type=2)
tdisc <- age(examples$UPb,type=3)
tArAr <- age(examples$ArAr)
tiso <- age(examples$ArAr,isochron=TRUE,i2i=TRUE)
tcentral <- age(examples$FT1,central=TRUE)
# }
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