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.
age(x, ...)# S3 method for default
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 UPb
age(
x,
type = 1,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
common.Pb = 0,
discordance = discfilter(),
...
)
# S3 method for PbPb
age(
x,
isochron = TRUE,
common.Pb = 2,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)
# S3 method for ArAr
age(
x,
isochron = FALSE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)
# S3 method for KCa
age(
x,
isochron = FALSE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)
# S3 method for UThHe
age(x, isochron = FALSE, central = FALSE, i = NULL, oerr = 1, sigdig = NA, ...)
# S3 method for fissiontracks
age(x, central = FALSE, i = NULL, oerr = 1, sigdig = NA, exterr = FALSE, ...)
# S3 method for ThU
age(
x,
isochron = FALSE,
Th0i = 0,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
...
)
# S3 method for ThPb
age(
x,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)
# S3 method for ReOs
age(
x,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)
# S3 method for SmNd
age(
x,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)
# S3 method for RbSr
age(
x,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)
# S3 method for LuHf
age(
x,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)
# S3 method for PD
age(
x,
nuclide,
isochron = TRUE,
i2i = TRUE,
exterr = FALSE,
i = NULL,
oerr = 1,
sigdig = NA,
projerr = FALSE,
...
)
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.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.
if x has class UPb and type=2, 3, 4 or
5, returns the output of the concordia
function.
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.
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, ThPb, ArAr,
KCa, 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.
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
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'
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)
number of significant digits for the uncertainty
estimate (only used if type=1, isochron=FALSE and
central=FALSE).
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.
an object of class diseq.
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.
index of a particular aliquot
common lead correction:
0: none
1: use the Pb-composition stored in
settings('iratio','Pb207Pb206') (if x has class
UPb and x$format<4);
settings('iratio','Pb206Pb204') and
settings('iratio','Pb207Pb204') (if x has class
PbPb or x has class UPb and
3<x$format<7); or
settings('iratio','Pb206Pb208') and
settings('iratio','Pb207Pb208') (if x has class
UPb and x$format=7 or 8).
2: use the isochron intercept as the initial Pb-composition
3: use the Stacey-Kramer two-stage model to infer the initial
Pb-composition
discordance calculator. This is an object of
class discfilter, or a two element list
containing:
option: one of
1 or 't' (absolute age filter);
2 or 'r' (relative age filter);
3 or 'sk' (Stacey-Kramers common Pb filter);
4 or 'a' (perpendicular Aitchison distance);
5 or 'c' (concordia distance);
6 or 'p' (p-value of concordance); or
NA (omit the discordance from the output)
before: logical flag indicating whether the discordance
should be calculated before (TRUE) or after (FALSE)
the common-Pb correction.
logical flag indicating whether each analysis
should be considered separately (isochron=FALSE) or an
isochron age should be calculated from all analyses together
(isochron=TRUE).
logical. If TRUE, propagates the uncertainty
of the non-radiogenic isotope correction (the `projection
error') into the age uncertainty. Note that the resulting
single grain age uncertainties may be strongly correlated with
each other, but these error correlations are not reported in
the output.
`isochron to intercept': calculates the initial (aka
`inherited', `excess', or `common')
\(^{40}\)Ar/\(^{36}\)Ar, \(^{40}\)Ca/\(^{44}\)Ca,
\(^{87}\)Sr/\(^{86}\)Sr, \(^{143}\)Nd/\(^{144}\)Nd,
\(^{187}\)Os/\(^{188}\)Os, \(^{176}\)Hf/\(^{177}\)Hf or
\(^{204}\)Pb/\(^{208}\)Pb ratio from an isochron
fit. Setting i2i to FALSE uses the default values
stored in settings('iratio',...).
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).
initial \(^{230}\)Th correction.
0: no correction
1: project the data along an isochron fit
2: if x$format is 1 or 2, correct the
data using the measured present day \(^{230}\)Th/\(^{238}\)U,
\(^{232}\)Th/\(^{238}\)U and \(^{234}\)U/\(^{238}\)U
activity ratios in the detritus. If x$format is 3 or
4, correct the data using the measured
\(^{238}\)U/\(^{232}\)Th activity ratio of the whole rock, as
stored in x by the read.data() function.
3: correct the data using an assumed initial
\(^{230}\)Th/\(^{232}\)Th-ratio for the detritus (only relevant
if x$format is 1 or 2).
a text string corresponding to a valid entry for
settings('lambda',...)
concordia, isochron,
central
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)
Run the code above in your browser using DataLab