Table of Contents: Mass Spectrometry: Method files Instrumentĭata Reduction/Uncertainty Propagation: SoftwareĮstimate eruption age from mineral age spectrumĬhron. To add to or edit this document, email or open a pull request. This space is meant to be a community-editable compilation of useful codes and software for ID-TIMS U-Pb geochronology, from reducing/interpreting/compiling mass spectrometer data to interpreting ages in geological context. DOI: 10.1016/j.gca.2015.02.040.Repository of software for ID-TIMS U-Pb geochronology (2015) Evaluating Uncertainties in the Calibration of Isotopic Reference Materials and Multi-Element Isotopic Tracers (EARTHTIME Tracer Calibration Part II). Condon, D.J., Schoene, B., and Bowring, S.A. Metrology and Traceability of U-Pb Isotope Dilution Geochronology (EARTHTIME Tracer Calibration Part I). Now we have a common tracer, and a suite of U-Pb reference materials solutions for repeat analyses, we can start to verify the accuracy of data from each laboratory.Ĭondon, D.J., McLean, N., Schoene, B., Bowring, S.A., and Parrish, R.R. Get people to measure ‘age solutions’ and/or ‘standard’ U-bearing minerals (i.e., zircon reference materials). U and Th metals dissolving in nitric acid.Above we suggested that a common tracer could effectively eliminate inter-laboratory bias, well that is the theory but how does it work in practice? Make some ‘age solutions’ to send around to other labs. ![]() The details for these experiments is outlined in two paper listed at the end of this blog. With this new large batch tracer there was an opportunity to undertake a comprehensive tracer calibration exercise – and this is what we did! This experiment involved using gravimetric reference solutions, made by dissolving accurately weighed pieces of high-purity U and Pb metals, with determined isotopic compositions, so we have a solution where the concentration, U/Pb ratio is know through weighing, and the isotopic composition is determined relative to isotopic reference materials. Now we have a large amount of high-quality mixed U-Pb tracer which can be used to effectively minimise inter-laboratory bias (although, see comments below…), the question is – how accurate are U/Pb dates? This question comes from a need to compare U-Pb dates to absolute rocks and minerals ages that are determined using other decay schemes (i.e., K-Ar and the derivative 40Ar/ 39Ar system) or using astrochronology, which is underpinned by our understanding of the physics of planets and other bodies in the solar system.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |