Guidelines for reporting zircon Hf isotopic data by LA-MC-ICPMS and potential pitfalls in the interpretation of these data

Over the past decade, the Hf isotope composition of zircon, as determined in situ by laser ablation-multicollector-inductively coupled plasma mass spectrometry (LA-MC-ICPMS), has been applied increasingly to a wide range of geological problems and has proven to be a valuable analytical tool. There has been no uniformity, however, in the reporting of in situ Hf isotopic data and, quite often, reviewers and readers of papers are not provided with sufficient information to assess data quality. The goal of this invited contribution is to provide the non-specialist with a brief outline and explanation of what is required for proper presentation and documentation of in situ Hf isotopic data from zircon, including details of how the challenging large isobaric interference corrections have been made. In addition, we discuss a number of potential pitfalls vis-a-vis the assignment of the incorrect age to the measured Hf isotope composition. Non-specialists should be aware of these important issues when doing their own analyses and evaluating the analyses done by others.