Input data from the EARTHTIME uranium and lead (U–Pb) isotope tracer calibration experiment

This dataset comprises a series of six .xls workbooks which contain the data auxiliary material for the manuscript "Metrology and Traceability of U–Pb Isotope Dilution Geochronology (EARTHTIME Tracer Calibration Part I)" by Daniel Condon, Blair Schoene, Noah McLean, Samuel Bowring and Randall Parrish, submitted to Geochimica et Cosmochimica Acta (June 2014).

These data comprise the input measurement data for the EARTHTIME U–Pb Tracer Calibration experiment, the results of which are documented in the manuscript mentioned above.

This data set contains isotope ratio data for the manuscript listed above.

ts01.xls Amelin and Davis (2006) Pb reference material isotope ratio data

ts02.xls CRM 115 U isotope ratio data

ts03.xls Gravimetric–Tracer mixture isotope ratio data

ts04.xls GDMS elemental concentration data

ts05.xls Tracer–blank Pb isotope ratio data

ts06.xls U critical mixture isotope ratio data

This data set also contains a series of auxilliary files are MATLAB scripts that perform the algorithms described in a sister manuscript "McLean, N, Condon, D J, Schoene, B, and Bowring, S A, in-review. Evaluating Uncertainties in the Calibration of Isotopic Reference Materials and Multi–Element Isotopic Tracers (EARTHTIME Tracer Calibration Part II). Geochimica et Cosmochimica Acta".

The MATLAB workspaces (.mat files) consisting of parsed data are available from the authors for the EARTHTIME tracer calibration data. The raw data is provided in Condon et al. Metrology and Traceability of U–Pb Isotope Dilution Geochronology (EARTHTIME Tracer Calibration Part I) auxiliary materials (see above).

text01_AmelinTarantola_MLE.m evaluates the Pb standard inter–calibration between NBS 981, NBS 982, and Puratronic Pb, using data from Amelin and Davis (2006).

text02_BlankIC_LinearRegression.m regresses a 4–dimensional line through tracer–blank mixing data using the linear regression algorithm of McLean (2013) and overdispersion calculations of Vermeesch (2011). This script is run iteratively with the next code.

text03_BlankIC_ifyouknowtracer.m evaluates the multivariate overdispersion in the Pb Blank IC dataset, calculating a Pb Blank IC and uncertainty, along with covariance matrices.

text04_TarantolaUIC_Mean.m inverts for the uranium IC (233/235 and 238/235) of the tracer using critical mixtures with U500 and CRM112a and measurements of the tracer uranium alone. This code evaluates the maximum likelihood estimate of the U IC.

text05_TarantolaUIC.m performs Monte Carlo simulations of the U IC calculation in the previous code, with new simulations changing values of parameters with systematic uncertainties (see text).

text06_inverseGravTrac.m populates variables and parameters used for inverting the tracer–gravimetric solution data to calculate the 235U/205Pb and 202Pb/205Pb of the tracers.

text07_inverseGravTrac_Mean.m calculates the maximum likelihood estimates of the model parameters for this inverse problem.

text08_inverseGravTracMC.m calculates the Monte Carlo simulations of the parameters with systematic uncertainties in the gravimetric solution – tracer inversion problem.

text09_inverseGravTrac_MCfiles.m performs inversion of the gravimetric-tracer mixture data for these Monte Carlo simulations, saving the results in a tab-delimited text file for later parsing and interpretation.