hfIsoR Documentation

Hf isotopes in zircon

Description

Main function that age-corrects the in-situ zircon Hf isotopic data to a given age; calculates initial ε(Hf) values, single-stage CHUR, as well as single- and two-stage depleted-mantle (DM) Nd model ages.

Usage

hfIso(age = NULL, GUI = FALSE)

hfInitial(age, x = WR)

hfEpsilon(age, x = WR, digits = 2)

hfCHURage(x = WR, digits = 3)

hfDMage(x = WR, digits = 3)

hfDM2stgAge(x = WR, age = NULL, RCC = R.crust, digits = 3)

Arguments

age

age in Ma

GUI

logical; is the function called from GUI?

x

numeric matrix with isotopic data to be recalculated

digits

integer; the precision of the result

RCC

numeric; the 176Lu/177Hf ratio of the intermediate crustal reservoir used for calculation of the two-stage Hf model ages

Details

Recalculates the Hf isotopic data and returns the numeric matrix Hfinit with the following columns (DM = Depleted Mantle):

Menu item Explanation
176Hf/177Hfi Initial Hf isotopic ratios
EpsHfi Initial ε(Hf) values
HfTCHUR.1stg Single-stage CHUR Hf model ages
HfTDM.1stg Single-stage DM Hf model ages
HfTDM.2stg Two-stage DM Hf model ages

If the parameter 'age' is provided upon the call to the main function hfIso(), the same value is used for all the samples. On the other hand, if the parameter 'age' is empty, and no column named 'Age' is found in the dataset, the user is prompted to enter a value from a dialogue. For the remaining functions, if the argument 'age' is empty, it is taken from the value assigned upon loading the dataset.

The main parameters for Hf isotopic data recalculations are set from the graphical interface, triggered by the function 'hfOptions'. These include the 176Lu decay constant, 176Lu/177Hf and 176Hf/177Hf ratios of the CHUR and Depleted Mantle reservoirs, and 176Lu/177Hf ratio of the intermediate crustal reservoir used for calculation of the two-stage Hf model ages.

Value

For hfIso:

Hfinit

numeric matrix with the results

For all other functions:

results

numeric matrix, or vector, with the results

Plugin

Hf.r

Author(s)

Vojtěch Janoušek, vojtech.janousek@geology.cz

References

Blichert-Toft J, Albaréde F (1997) The Lu–Hf isotope geochemistry of chondrites and the evolution of the mantle–crust system. Earth Planet Sci Lett 148:243-258. doi: 10.1016/S0012-821X(97)00040-X

Bouvier A, Vervoort JD, Patchett PJ (2008) The Lu–Hf and Sm–Nd isotopic composition of CHUR: constraints from unequilibrated chondrites and implications for the bulk composition of terrestrial planets. Earth Planet Sci Lett 273:48-57. doi: 10.1016/j.epsl.2008.06.010

Chauvel C, Garçon M, Bureau S, Besnault A, Jahn BM, Ding ZL (2014) Constraints from loess on the Hf-Nd isotopic composition of the upper continental crust. Earth Planet Sci Lett 388:48-58. doi: 10.1016/j.epsl.2013.11.045

Fisher CM, Vervoort JD, Hanchar JM (2014) Guidelines for reporting zircon Hf isotopic data by LA-MC-ICPMS and potential pitfalls in the interpretation of these data. Chem Geol 363:125-133. doi: 10.1016/j.chemgeo.2013.10.019

Griffin WL, Wang X, Jackson SE, Pearson NJ, O'Reilly SY, Xu X, Zhou X (2002) Zircon chemistry and magma mixing, SE China: in-situ analysis of Hf isotopes, Tonglu and Pingtan igneous complexes. Lithos 61:237-269. doi: 10.1016/S0024-4937(02)00082-8

Hayakawa T, Shizuma T, Iizuka T (2023) Half-life of the nuclear cosmochronometer 176Lu measured with a windowless 4π solid angle scintillation detector. Communications Physics 6:299. doi: 10.1038/s42005-023-01406-7

Kemp AIS, Hawkesworth CJ (2003) Granitic perspectives on the generation and secular evolution of the continental crust. In: Holland HD, Turekian KK (eds) Treatise on Geochemistry vol. 3, The Crust (ed. R.L. Rudnick). Elsevier-Pergamon, Oxford, pp 349-410. doi: 10.1016/B0-08-043751-6/03027-9

Kemp AIS, Hawkesworth CJ (2014) Growth and differentiation of the continental crust from isotope studies of accessory minerals. In: Holland HD, Turekian KK (eds) Treatise on Geochemistry (Second Edition). Elsevier, Oxford, pp 379-421. doi: 10.1016/B978-0-08-095975-7.00312-0

Lancaster PJ, Storey CD, Hawkesworth CJ, Dhuime B (2011) Understanding the roles of crustal growth and preservation in the detrital zircon record. Earth Planet Sci Lett 305:405-412. doi: 10.1016/j.epsl.2011.03.022

Scherer E, Münker C, Mezger K (2001) Calibration of the lutetium–hafnium clock. Science 293:683-687. doi: 10.1126/science.1061372

Söderlund U, Patchett PJ, Vervoort JD, Isachsen CE (2004) The 176Lu decay constant determined by Lu–Hf and U–Pb isotope systematics of Precambrian mafic intrusions. Earth Planet Sci Lett 219:311-324. doi: 10.1016/S0012-821X(04)00012-3

Spencer CJ, Kirkland CL, Roberts NMW, Evans NJ, Liebmann J (2020) Strategies towards robust interpretations of in situ zircon Lu–Hf isotope analyses. Geosci Front 11:843-853. doi: 10.1016/j.gsf.2019.09.004

Tatsumoto M, Unruh DM, Patchett PJ (1981) U–Pb and Lu–Hf systematics of Antarctic meteorites. Mem Natl Inst Polar Res (Jpn), spec issue 20: 237-249

Vervoort JD, Kemp AIS (2016) Clarifying the zircon Hf isotope record of crust–mantle evolution. Chem Geol 425:65-75. doi: 10.1016/j.chemgeo.2016.01.023

Vervoort JD, Kemp AIS, Fisher CM (2018) Hf isotope constraints on evolution of the depleted mantle and growth of continental crust. AGU Fall Meeting Abstracts.

See Also

hfOptions, hfAgeEps, hfAgeEps2, hfStripplot, hfBoxplot, hfViolinplot, hfAddResults,

hfSaveResults

Examples

sampleDataset("khantaishir_Hf")
    
# Recalculation using the age information from the file; 
# this is done automatically upon loading a new data set;
# column named 'Age' is present in the datafile
hfIso() 
    
# Using the same age for all samples
hfIso(500)
    
hfInitial(346)

out <- cbind(hfEpsilon(0), hfEpsilon(346))
colnames(out) <- c(0, 346)
print(out)
    
# Model ages
hfCHURage()
    
hfDMage()
    
hfDM2stgAge()

# default RCC (crustal 176Lu/177Hf) value is taken from the system (variable 'R.crust')    
hfDM2stgAge(age = 300)   

# basaltic RCC (Lancaster et al. 2011) is assumed here
hfDM2stgAge(RCC = 0.022)