Engineering cyber infrastructure for U-Pb geochronology: Tripoli and U-Pb_Redux

Abstract

[1] In the past decade, major advancements in precision and accuracy of U-Pb geochronology, which stem from improved sample pretreatment and refined measurement techniques, have revealed previously unresolvable discrepancies among analyses from different laboratories. One solution to evaluating and resolving many of these discrepancies is the adoption of a common software platform that standardizes data-processing protocols, enabling robust interlaboratory comparisons. We present the results of a collaboration to develop cyber infrastructure for high-precision U-Pb geochronology based on analyzing accessory minerals by isotope dilution-thermal ionization mass spectrometry. This cyber infrastructure implements an architecture specifying the workflows of data acquisition, statistical filtering, analysis and interpretation, publication, community-based archiving, and the compilation and comparison of data from different laboratories. The backbone of the cyber infrastructure consists of two open-source software programs: Tripoli and U-Pb_Redux.

High-precision timeline for Earth’s most severe extinction

“…Isotope ratios of U and Pb were corrected for mass fractionation during analysis using the ET2535 tracer solution. Data acquisition and reduction were done using the Tripoli and U-Pb Redux software packages (24,25).…”

“…We also present a weighted mean 206 Pb/ 238 U date on bed 33, which did not yield a reliable date in the previous study (3). The differences in age and precision reported here reflect adoption of major improvements in the way our U-Pb isotopic data are acquired and reduced, including use of the precisely calibrated EARTHTIME 202 Pb-205 Pb-233 U-235 U tracer solution, changes in the isotopic compositions of standards used to calibrate the tracer, new error propagation algorithms, and improved data acquisition and reduction techniques (23)(24)(25). Application of these improvements, discussed in detail in the SI Text, yields significantly improved accuracy and precision on the weighted mean and interpolated dates (Table S1 and Fig.…”

Pervasive remagnetization of detrital zircon host rocks in the Jack Hills, Western Australia and implications for records of the early geodynamo

“…Isotopic measurements of U and Pb were made on a VG Sector 54 multicollector mass spectrometer equipped with a Daly ion-counting system. Data reduction including date calculation and propagation of uncertainties was carried out using computer applications and algorithms of Bowring et al (2011) andMcLean et al (2011). Complete U-Pb data appear in Table S1.…”

When and how did the terrestrial mid-Permian mass extinction occur? Evidence from the tetrapod record of the Karoo Basin, South Africa

“…All zircons were pre-treated by a chemical abrasion (CA-TIMS) method modified after Mattinson [30] to mitigate the effects of radiation-induced Pb loss, and spiked with the EARTHTIME ET535 mixed 205 Pb -233 U-235 U tracer prior to dissolution and analysis. Uranium and lead isotopic data reduction, date calculation and propagation of uncertainties were carried out using computer applications and algorithms of Bowring et al [31] and McLean et al [32]. Complete U-Pb data appear in the electronic supplementary material, figure S1 and table S3.…”