Calculates ages and propagates their analytical uncertainties.
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, i2i = TRUE, 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, 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 each U-Pb analysis
should be considered separately (type=1), a
concordia age should be calculated from all U-Pb analyses
together (type=2), or a discordia line should be
fit through all the U-Pb analyses (type=3).
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
or 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',...) or zero (for the Pb-Pb
method). When applied to data of class ThU, setting
i2i to TRUE applies a detrital Th-correction.
logical flag indicating whether each U-Th-He analysis
should be considered separately (central=FALSE) or a
central age should be calculated from all U-Th-He 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
concordia age and standard error, respectively.
if x has class UPb and type=2,
returns a list with the following items:
a named vector with the (weighted mean) U-Pb composition
the covariance matrix of the (mean) U-Pb composition
a 4-element vector with:
t: the concordia age (in Ma)
s[t]: the estimated uncertainty of t
ci[t]: the 95% confidence interval of t for the
appropriate degrees of freedom
disp[t]: the 95% confidence interval for t augmented
by \(\sqrt{MSWD}\) to account for overdispersed datasets.
a vector with three items (equivalence,
concordance and combined) containing the MSWD (Mean
of the Squared Weighted Deviates, a.k.a the reduced Chi-squared
statistic outside of geochronology) of isotopic equivalence, age
concordance and combined goodness of fit, respectively.
a vector with three items (equivalence,
concordance and combined) containing the p-value of
the Chi-square test for isotopic equivalence, age concordance and
combined goodness of fit, respectively.
the number of degrees of freedom used for the
mswd calculation. These values are useful when expanding
the analytical uncertainties when mswd>1.
if x has class UPb and type=3,
returns a list with the following items:
a two element vector with the upper and lower intercept
ages (if wetherill=TRUE) or the lower intercept age and
\(^{207}\)Pb/\(^{206}\)Pb intercept (for Tera-Wasserburg)
the covariance matrix of the elements in x
a 3 x 2 matrix with the following rows:
s: the estimated standard deviation for x
ci: the 95% confidence interval of x for the
appropriate degrees of freedom
disp[t]: the 95% confidence interval for x augmented
by \(\sqrt{MSWD}\) to account for overdispersed datasets.
the degrees of freedom of the concordia fit (concordance + equivalence)
p-value of a Chi-square test for age homogeneity
mean square of the weighted deviates -- a
goodness-of-fit measure. mswd > 1 indicates overdispersion
w.r.t the analytical uncertainties.
if x has class PbPb, ArAr, RbSr,
SmNd, ReOs, LuHf and isochron=FALSE,
returns a table of Pb-Pb, Ar-Ar, Rb-Sr, Sm-Nd, Re-Os or Lu-Hf and
standard errors.
if x has class PbPb, ArAr, RbSr,
SmNd, ReOs or LuHf and isochron=TRUE,
returns a list with the following items:
the intercept of the straight line fit and its standard error.
the slope of the fit and its standard error.
the covariance of the slope and intercept
the mean square of the residuals (a.k.a `reduced Chi-square') statistic
the p-value of a Chi-square test for linearity
a 4-element vector containing:
t: the atmospheric \(^{40}\)Ar/\(^{36}\)Ar or initial
\(^{207}\)Pb/\(^{204}\)Pb, \(^{187}\)Os/\(^{188}\)Os,
\(^{87}\)Sr/\(^{86}\)Sr, \(^{143}\)Nd/\(^{144}\)Nd or
\(^{176}\)Hf/\(^{177}\)Hf ratio.
s[t]: the estimated standard deviation of t
ci[t]: the 95% confidence interval of t for the
appropriate degrees of freedom
disp[t]: the 95% confidence interval for t augmented
by \(\sqrt{MSWD}\) to account for overdispersed datasets.
a 4-element vector containing:
y: the \(^{207}\)Pb/\(^{206}\)Pb,
\(^{40}\)Ar/\(^{39}\)Ar, \(^{187}\)Os/\(^{187}\)Re,
\(^{87}\)Sr/\(^{86}\)Sr, \(^{143}\)Nd/\(^{144}\)Nd or
\(^{176}\)Hf/\(^{177}\)Hf age and its standard error.
s[y]: the estimated standard deviation of y
ci[y]: the 95% confidence interval of y for the
appropriate degrees of freedom
disp[y]: the 95% confidence interval for y augmented
by \(\sqrt{MSWD}\) to account for overdispersed datasets.
the t-value for df degrees of freedom, which
is used for the construction of ci[t] and ci[y]
the degrees of freedom for the isochron fit
copied from the input parameters
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 ThU and isochron=TRUE,
returns the output of an `Osmond Type-II' isochron, i.e.:
the best fitting \(^{234}U/^{238}U\) intercept, \(^{234}U/^{232}Th\) slope, \(^{230}Th/^{238}U\) intercept and \(^{230}Th/^{232}Th\) slope.
the covariance matrix of par.
the \(^{234}U/^{238}U\) intercept (i.e. the detrital Th-corrected value) and its standard error.
the \(^{234}U/^{232}Th\) slope and its standard error.
the covariance of a and b.
the mean square of the residuals (a.k.a `reduced Chi-square') statistic.
the p-value of a Chi-square test for linearity.
a 4-element vector containing:
y: the initial \(^{234}U/^{238}U\)-ratio
s[y]: the estimated standard deviation of y
ci[y]: the 95% confidence interval of y for the
appropriate degrees of freedom
disp[y]: the 95% confidence interval for y augmented
by \(\sqrt{MSWD}\) to account for overdispersed datasets.
a 4-element vector containing:
t: the Th-U isochron age
s[t]: the estimated standard deviation of t
ci[t]: the 95% confidence interval of t for the
appropriate degrees of freedom
disp[t]: the 95% confidence interval for t augmented
by \(\sqrt{MSWD}\) to account for overdispersed datasets.
the degrees of freedom for the isochron fit.
the t-value for df degrees of freedom
if x has class UThHe and central=TRUE,
returns a list with the following items:
a three-element list with the weighted mean log[U/He], log[Th/He] and log[Sm/He] compositions.
a 3 x 3 covariance matrix for uvw
the reduced Chi-square value for the log[U/He]-log[Th/He] compositions.
the p-value of concordance between the log[U/He]-log[Th/He] compositions.
a 4-element vector containing:
t: the central age age, i.e. the U-Th-He age corresponding
to the composition given by uvw
s[t]: the estimated standard deviation of t
ci[t]: the 95% confidence interval of t for the
appropriate degrees of freedom
disp[t]: the 95% confidence interval for t augmented
by \(\sqrt{MSWD}\) to account for overdispersed datasets.
the degrees of freedom for the data fit.
the t-value for df degrees of freedom
if x has class fissiontracks and
central=FALSE, returns a table of fission track ages and
standard errors.
if x has class fissiontracks and
central=TRUE, returns a list with the following items:
the reduced Chi-square value for the fission track ages.
the p-value of concordance between the fission track ages.
a three-element vector with the central age, its standard error and a 95% confidence interval for the appropriate degrees of freedom.
the (over)dispersion of the single grain ages beyond the formal analytical uncertainties.
degrees of freedom for the Chi-square test
# NOT RUN {
data(examples)
print(age(examples$UPb))
print(age(examples$UPb,type=1))
print(age(examples$UPb,type=2))
# }
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