Get and set preferred values for decay constants, isotopic
abundances, molar masses, fission track etch efficiences, and
etchable lengths, and mineral densities, either individually or via
a .json file format.
settings(setting = NA, ..., fname = NA, reset = FALSE)if setting=NA and fname=NA, returns a
.json string
if ... contains only the name of an isotope, isotopic ratio,
element, or mineral and no new value, then settings returns
either a scalar with the existing value, or a two-element vector
with the value and its uncertainty.
unless fname is provided, this should be one
of either:
'lambda': to get and set decay constants
'iratio': isotopic ratios
'imass': isotopic molar masses
'mindens': mineral densities
'etchfact': fission track etch efficiency factors
'tracklength': equivalent isotropic fission track length
'alpha': the significance level of confidence intervals
depends on the value for setting:
For 'lambda': the isotope of interest (one of either
"fission", "U238", "U235", "U234",
"Th232", "Th230", "Pa231", "Ra226",
"Re187", "Sm147", "Rb87", "Lu176", or
"K40") PLUS (optionally) the decay constant value and its
analytical error. Omitting the latter two numbers simply returns
the existing values.
For 'iratio': the isotopic ratio of interest (one of either
"Ar40Ar36", "Ar38Ar36", "Ca40Ca44",
"K39K41", "K40K41", "Rb85Rb87",
"Sr88Sr86", "Sr87Sr86", "Sr84Sr86",
"Re185Re187", "Os184Os188" "Os186Os188",
"Os187Os188", "Os189Os188", "Os190Os188",
"Os192Os188", "Sm144Sm152", "Sm147Sm152",
"Sm148Sm152", "Sm149Sm152", "Sm150Sm152",
"Sm154Sm152", "Nd142Nd144", "Nd143Nd144",
"Nd145Nd144", "Nd146Nd144", "Nd148Nd144",
"Nd150Nd144", "Lu176Lu175", "Hf174Hf177",
"Hf176Hf177", "Hf178Hf177", "Hf179Hf177",
"Hf180Hf177", "U238U235", "Pb207Pb206",
"Pb206Pb204", "Pb207Pb204", "Pb208Pb204",
"Pb206Pb208", "Pb207Pb208") PLUS (optionally) the
isotopic ratio and its analytical error. Omitting the latter two
numbers simply returns the existing values.
For 'imass': the (isotopic) molar mass of interest (one of
either "U", "Th", "Rb", "Rb85",
"Rb87", "Sr84", "Sr86", "Sr87",
"Sr88", "Re", "Re185", "Re187",
"Os", "Os184", "Os186", "Os187",
"Os188", "Os189", "Os190", "Os192",
"Sm", "Nd", "Lu", "Hf") PLUS
(optionally) the molar mass and its analytical error. Omitting the
latter two numbers simply returns the existing values.
For 'mindens': the mineral of interest (one of either
"apatite" or "zircon") PLUS the mineral
density. Omitting the latter number simply returns the existing
value.
For 'etchfact': the mineral of interest (one of either
"apatite" or "zircon") PLUS the etch efficiency
factor. Omitting this number simply returns the existing value.
For 'tracklength': the mineral of interest (one of either
"apatite" or "zircon") PLUS the equivalent isotropic
fission track length. Omitting this number simply returns the
existing value.
the path of a .json file
logical. If TRUE, restores the default values
Decay constants:
\(^{238}\)U, \(^{235}\)U: Jaffey, A. H., et al. "Precision measurement of half-lives and specific activities of U\(^{235}\) and U\(^{238}\)." Physical Review C 4.5 (1971): 1889.
\(^{232}\)Th: Le Roux, L. J., and L. E. Glendenin. "Half-life of \(^{232}\)Th.", Proceedings of the National Meeting on Nuclear Energy, Pretoria, South Africa. 1963.
\(^{234}\)U, \(^{230}\)Th: Cheng, H., Edwards, R.L., Shen, C.C., Polyak, V.J., Asmerom, Y., Woodhead, J., Hellstrom, J., Wang, Y., Kong, X., Spotl, C. and Wang, X., 2013. Improvements in \(^{230}\)Th dating, \(^{230}\)Th and \(^{234}\)U half-life values, and U-Th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry. Earth and Planetary Science Letters, 371, pp.82-91.
\(^{231}\)Pa, \(^{226}\)Ra: Audi, G., Bersillon, O., Blachot, J. and Wapstra, A.H., 2003. The NUBASE evaluation of nuclear and decay properties. Nuclear Physics A, 729(1), pp.3-128.
Sm: Villa, I.M., Holden, N.E., Possolo, A., Ickert, R.B., Hibbert, D.B. and Renne, P.R., 2020. IUPAC-IUGS recommendation on the half-lives of \(^{147}\)Sm and \(^{146}\)Sm. Geochimica et Cosmochimica Acta, 285, pp.70-77.
Nd: Zhao, Motian, et al. "Absolute measurements of neodymium isotopic abundances and atomic weight by MC-ICPMS." International Journal of Mass Spectrometry 245.1 (2005): 36-40.
Re: Smoliar, Michael I., Richard J. Walker, and John W. Morgan. "Re-Os ages of group IIA, IIIA, IVA, and IVB iron meteorites." Science 271.5252 (1996): 1099-1102.
Ar: Renne, Paul R., et al. "Response to the comment by WH Schwarz et al. on "Joint determination of \(^{40}\)K decay constants and \(^{40}\)Ar*/\(^{40}\)K for the Fish Canyon sanidine standard, and improved accuracy for \(^{40}\)Ar/\(^{39}\)Ar geochronology" by PR Renne et al.(2010)." Geochimica et Cosmochimica Acta 75.17 (2011): 5097-5100.
Rb: Villa, I.M., De Bievre, P., Holden, N.E. and Renne, P.R., 2015. "IUPAC-IUGS recommendation on the half life of \(^{87}\)Rb". Geochimica et Cosmochimica Acta, 164, pp.382-385.
Lu: Soederlund, Ulf, et al. "The \(^{176}\)Lu decay constant determined by Lu-Hf and U-Pb isotope systematics of Precambrian mafic intrusions." Earth and Planetary Science Letters 219.3 (2004): 311-324.
Isotopic ratios:
Ar: Lee, Jee-Yon, et al. "A redetermination of the isotopic abundances of atmospheric Ar." Geochimica et Cosmochimica Acta 70.17 (2006): 4507-4512.
K: Garner, E.L., et al. "Absolute isotopic abundance ratios and the atomic weight of a reference sample of potassium". J. Res. Natl. Bur. Stand. A 79.6 (1975): 713-725.
Ca: Moore, L.J. and Machlan, L.A., 1972. High-accuracy determination of calcium in blood serum by isotope dilution mass spectrometry. Analytical chemistry, 44(14), pp.2291-2296.
Rb: Catanzaro, E. J., et al. "Absolute isotopic abundance ratio and atomic weight of terrestrial rubidium." J. Res. Natl. Bur. Stand. A 73 (1969): 511-516.
Sr: Moore, L. J., et al. "Absolute isotopic abundance ratios and atomic weight of a reference sample of strontium." J. Res. Natl. Bur. Stand. 87.1 (1982): 1-8.
and (for \(^{87}\)Sr/\(^{86}\)Sr):
Compston, W., Berry, H., Vernon, M.J., Chappell, B.W. and Kaye, M.J., 1971. Rubidium-strontium chronology and chemistry of lunar material from the Ocean of Storms. In Lunar and Planetary Science Conference Proceedings (Vol. 2, p. 1471).
Sm: Chang, Tsing-Lien, et al. "Absolute isotopic composition and atomic weight of samarium." International Journal of Mass Spectrometry 218.2 (2002): 167-172.
Re: Gramlich, John W., et al. "Absolute isotopic abundance ratio and atomic weight of a reference sample of rhenium." J. Res. Natl. Bur. Stand. A 77 (1973): 691-698.
Os: Voelkening, Joachim, Thomas Walczyk, and Klaus G. Heumann. "Osmium isotope ratio determinations by negative thermal ionization mass spectrometry." Int. J. Mass Spect. Ion Proc. 105.2 (1991): 147-159.
Lu: De Laeter, J. R., and N. Bukilic. "Solar abundance of \(^{176}\)Lu and s-process nucleosynthesis." Physical Review C 73.4 (2006): 045806.
Hf: Patchett, P. Jonathan. "Importance of the Lu-Hf isotopic system in studies of planetary chronology and chemical evolution." Geochimica et Cosmochimica Acta 47.1 (1983): 81-91.
Pb: Stacey, J.T. and Kramers, J. "Approximation of terrestrial lead isotope evolution by a two-stage model." Earth and Planetary Science Letters, 26(2) (1975): 207-221.
U: Hiess, Joe, et al. "\(^{238}\)U/\(^{235}\)U systematics in terrestrial uranium-bearing minerals." Science 335.6076 (2012): 1610-1614.
read.data
# load and show the default constants that come with IsoplotR
json <- system.file("constants.json",package="IsoplotR")
settings(fname=json)
print(settings())
# use the decay constant of Kovarik and Adams (1932)
settings('lambda','U238',0.0001537,0.0000068)
print(settings('lambda','U238'))
# returns the 238U/235U ratio of Hiess et al. (2012):
print(settings('iratio','U238U235'))
# use the 238U/235U ratio of Steiger and Jaeger (1977):
settings('iratio','U238U235',138.88,0)
print(settings('iratio','U238U235'))
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